Never at any moment was I lost in your delivery of information. I’m a newb. My friend Lorne Boyd is my reference for audio. You made this tutorial fun and packed with info. If iI or anyone purchases an R8, we would all want you to perfect it. I’m going to watch this video again…. It’s that flat out great. Thank you
I was really tossing up between the Willsenton or the Muzishare X7, I ended up getting the X7, after two years it’s still going strong. Love your videos 👍
I replaced the outer 6SN7 tubes with identical NOS Sovtek tubes because the Willsenton branded ones supplied were noisy. I would hear crackling sounds on warm up that the NOS tubes removed. I had previously replaced the 6SL7 tubes with NOS JAN Philips 6SL7-GT tubes and those really smoothed out the high frequencies.
I almost bought one of these a few years ago. Ended up with the Muzishare X7 with push-pull KT88 power tubes. One of the power tubes redplated inside of 30 days so I returned it to the manufacturer. Gotta love PayPal! Ended up buying another one a year later, performance was decent but I needed more flexibility than the Muzishare could provide. See you on AK!
I am really surprised to see all those so-called problems you mention. I have had my R8 for almost a year. It sounds great, powerful, beautiful, no "hum" at all, even at almost full power with or without input signal. We would like to hear about several R8 owners to share what they really experience with this amp. For me, I have been 100% satisfied (and I have been in music listening and playing for decades...) and will not change one thing in it, until proven otherwise. Except for some tubes, which I did, for the best. Thank you.
I never said it was going to catch on fire or anything :) Well actually their failure to include a "safety resistor" on the tube bias boards have caused quite a few of these amps to melt down from red plating tubes. Feel free to ignore my advice.
The problem I have with your review is that - while you seem to recommend this amp, the problems you are noting would require quite advanced DIY/electrical know-how to fix - so at the end of the day only the most can-do DIYer is likely to want to take it on. In effect, this is a pretty damning review, even if done indirectly.
I have an R8. It is powering a pair of KEF Q350s. Sounds great, and is dead silent. I have not opened it up to see what is going on inside yet. It is an older unit, it arrived in march of 2020. It may be that I have a dedicated 20amp outlet powering the amp, so nothing like a dimmer or other electronics on the circuit. I also swapped the 3 6SN7 tubes first. This tube swap made a monumental difference to the sound. Harsh glassy high frequencies sounded clean and with less perceived distortion. The entire midrange sounded more precise with more instrument separation. Probably less harmonic distortion, but the tonality seems much more natural and top end is far less fatiguing and harsh. i am lookin g forward to making some cap and resistor swaps. along wit the grounding and choke mod. Thanks for your work!!
Well on spot with the r8 lack of parts and circuitry cheats. It doesn't matter what you buy from uno where. I'm always modifying it. OT quality level are high...like I've been hearing from numerous owners just might as well add the mods quality components. I almost bought one of those after many months on the market. The price soared and availability, lack of, backorder actually keept me from buying two units.
I agree with you regarding Miflex caps - they are way too big to use in these applications the long flying leads needed also act as antennas and cause hum issues and bay also cause instability issues. Excellent comments regarding the design issues, particularly the ground and wire routing though it’s not just Chinese amps that are prone ! I think it’s common for amateur modders to throw expensive components in without addressing the engineering problems inherent in the design.
Thanks for the heads up on the GE 6sl7. I've been spending big dollars trying to tame that upper frequency harshness with my Klipsch. Finally, the GEs did the trick
This is most interesting. I just sold this amp because of the lack of bass response with original tubes. I always thought it was a quality amp but something was missing. Then I had a Fisher 500c receiver restored and when it came back it blew the R8 out of the water. I'm betting with your modifications it will make the R8 a much improved amp.
I can see on the computer the frequency response is bright. The grounding makes zero sense to me and possibly is the root of what I am seeing? Tube amps are very sensitive to grounding!
It’s ALL in the tubes , never used the originals . First they’re not biased as a quad set . Have NOS 6500 and EL34 quads . HUGE difference . I actually disconnect my sub . A very good reasonable ‘newer ‘ quad set I have is electro-harmonic 6500’s ( Russian) sadly not a fan right now . However they are very good and cost effective . Also maybe even as important are the pre-amp tubes.6SL7’s ….try 2 high quality of those even first. The middle tube ( V5) is not that important. Nothing changes the sound of a tube amp like high quality tubes . It’s not about the bass ( it’s there) but the presence of kids ( vocals , acoustic instruments ) it’s life like .
I've been trying to modify this amp myself, I noticed also big hum, hiss and other stuff going on. My speakers are 95db+ and sometimes it can be horrible. I suspect that the frontpanel with all extra curcuitry with crystal etc giving noise because i have extra noise on that same channel. I already rerouted some ground wiring and replaced all resistors and Caps (the orginal caps are not fake but old stock (about 10 yrs old in my amp) and i used Rubycon, Nichicon, Miflex 0,22uf / Mundorf Supreme 0,33uf) and resistors a mix between DALE/ Mills, Kiwame 2W, and 3W (Koa Speer) and Vishay PR03. Orginal blocking caps are made by Clarity Cap btw, cheapest they sell so not horrible chinese caps) Main caps i choose KEMET 330Uf/500V but will be replaced with KEMET MKP C4 filmcaps 210uF and the other ones also with 10uf respec. 30uf film also KEMET. The middle tube to me looks like a voltageregulator. I've seen a schematic on one that was very similar on stereonet forum. I use KT88 from JJ (sounded great compared to orginal..) and all the 6sn7 is JJ also. THe 6SL7 i havent replaced yet. i replaced singalwire with mundorf silver/gold and put a braid over it and run a separate wire to new starground in chassie. I will try to do further improvements with grounding. Got lot of good tips from you so far and will looking forward to next video. I didn't like the main ac wire being unshielded either going to the frontswitch so i installed a new with shield. Almost all wires inside are 13 awg to 14 awg silverplated PTFE. One thing i want to do is to disconnect the relays and drive tubes in triode directly, My idea was to just remove the 39K and 1K and instead add a 100-180R between pin 3-4 on the KT88s and disconnect the yellow wires to OPT (blue ones are highest resistance so this should be the triode winding) - I like triode the best. Please if you have any input on this let me know in video. You seem to have a lot of knowledge. I guess biggest issue i have with this amp that it have always from start been little to forward in uppermid, lower treble. Compared to many other amps like the chinese Yaqin MC100b. I got mine in March/April and it looks to identical inside to mine. others ive seen on the net has slight differences, Ohh yeah one thing i added was 1K gridstoppers but i couldn't detect any difference in sound, And for your info; someone linked your video in Willsentons facebook group =) Best regards Johan from Finland and Happy new year to you. Keep the videos coming! Very nice.
Hey Johan! Amazing list of upgrades you’ve done to your R8. I don’t know how to do any of that stuff but out of curiosity, how much do all those parts that you put in, cost you in the end?
Happy New Year, I have some hum thru my speakers, but can only hear it when I put my ear to the speakers. I switched out the power cord (more for looks than anything else!) to a $30 cord. It cut down the hum by at least half. This is my first tube amp and am definitely not versed on electronics, but just thought I'd offer what happened when I changed the power cord.
It can't convert AC to DC, but yes it's being used as a voltage regulator but I need to sit down and figure out how they wired it in the sample I have.
Good luck finding the source of your hum. My R8 is dead quiet hooked up to a pair of KEF 104/2 floor standers 92 dB & 4-ohm. I use GL KT88s and also have Mullard EL 34s. I run 3 new Electro-Harmonix 6SN7s and 2 NOS Melz 6SL7s (via Jim’s Tube Store). I’ll scope out those GE short bottle tubes you recommended. It would be nice NOT to select the Pre-In each time using the remote as I use a vintage Luxman CL-35 MkIII as a preamp. Great video and look forward to your next R8 adventure!
National tubes are imported by Richardson Electronics from La Fox Illinois also try floating the third wire on the power cord ground with a three wire to two prong adaptor as you may have ground loops thru the power cord. Been building tube amps since I was 14 years old I'm now 77 and have learned a lot of things to get rid of hum I'm presently using a single 211 amp with a homebuilt Cary Audio AE1 preamp and Klipsch Khorn speakers Bonnie Kapischke W9EBO
I found the hum (a bad solder joint on the heater virtual center tap). And NEVER unground a high voltage tube amplifier!!! If there is a ground loop from the power cord, there is either something wrong with the amp or a design issue. An ungrounded amp no longer has protection in case of a parts failure and the chassis could become "hot" with lethal voltage.
Hi Stephe, you obviously know more about this amp than I do, but mine is dead silent. I am using JBL L150s and even with the volume all the way up with my ear in the speaker I cannot hear any hum. I am using the original kt88s (Although I have a quad of KR Audio kt88s on the way!), with PSvane 151 tii in the 6sn7 spots, and Sylvania NOS 1955 tubes in the 6SL7 spots. I tried RCA 5691 red base black plate tubes that were very expensive, but they dulled the mid to upper frequencies too much. The Sylvania's sounded much better to me. I know you said you didn't like the PSvane 151 tubes, and I admit at first they are too bright or harsh, but if you give them time they smooth out tremendously. I have about 150 hours on mine, and I have heard that they require up to 300 hrs. to burn in. Great video thanks for sharing your knowledge!
Mine is silent wide open, I hear a tiny hum at 1/2 volume. I'm not shocked some people hear nothing, I've had other people msg me that theirs does the same as mine. And those JBL's are 88db speakers which might help. :)
Hello there! First, thank you for your videos. Incredibly helpful! I just acquired the Willsenton r800i 845. Had it for about 6 months now. I really like it, but not sure if I'm blown away. Do you have any advice or suggest any modifications similar to this unit? Any info would be greatly appreciated! Lou
Looking forward to that. Really enjoying this amp so far. Great build quality, great sound, but at this price point, I'm sure there is room for improvement/ tweaking like we love to do! Unfortunately I don't have your knowledge but I can solder pretty good. Oh, by the way, this sucker is 94 pounds!!
I have an R8 hooked up to a pair of Heresy IVs and it’s quite as quite gets. I can turn it up to 3/4 volume with no input and it’s silent. Maybe there was more damage to that amp when the tube fried. Or maybe I just got a good one. Who knows. But mine is very quite. (I’m running Golden Lion tubes as well)
Maybe you got lucky? Other folks I read say theirs has some hum. It's not loud but it's there. The ground loop hum issues from weird grounding was loud.
I have this amp driving the new Wharfedale Lintons. DEAD quiet at any setting. Couldn’t be happier with this beauty, even with the stock tubes. Tax return gonna go towards some Gold Lion upgrades.
The R8 is well known for having better bass or too much bass which is relatively subjective to the user’s need of bass. Putting aside the power tubes and preamp tubes, are their parts on the design of the R8 that contributes to the better bass or too much bass (subjective), that is different from other tube amp design.
Well known by whom? Those YT reviewers? When we listened to the R8 vs the X7 the muzishare had at least as good of a bass response but also was less boomy sounding, likely due to having better output transformers. You not only can hear this, you can see it in the frequency response curves. Honestly the R8 design is your basic, bog standard push pull KT88 amp, other than that strange 6SN7 tube they used to power the front end. It's not a bad sounding amp, but it's not anything special either.
@@SkunkieDesignsElectronics, when I said well known for the owners of rhe R8. I dont mean famous, I just dont want to sound ranting on a gadget I dont own. I asked you bcoz of your technical know how on this audio equipments which I trust. Thanks again.
Some people in almost any hobby will defend their purchase decisions to their grave. I will never understand it. there is nothing special about the R8 design that would give it "extra bass". If anything, the values of the coupling caps tend to limit it.
Got one of this. Why are there 3x6SN7s ? Still puzzled by the role played by the one in the middle. I upgraded them to the Psvane CV181 Tii Classic Grey Coated. Just wondered if I could make do with just a pair of the CV181s and leave the Willsenton stock tube in the middle without affecting the performance.
Thank you very much for this review.A lot of nice and precious infos about R8.I own a Willsenton R8 since one year.I have no any issues, no hum, not any kind of noise.At any volume is dead silent. For me, your review is perfect because now I know the 6sl7 tubes influence the quality of output stage sound.I will change it to nos Melz 6sl7. I have a question.I own a tube preamp wich I use with musical fidelity dual monoblock a3cr power amp.The output volume is very high.If I put a variable resistor to every chanel,internally, before the volume pot, will affect the quality of the sound? Thanks again
@@SkunkieDesignsElectronics When I turn up the volume under a quarter it is very loud (supposing 18 o'clock is zero, at 20 begins to be very loud) My speakers are Focal 93 db.
I'm thinking I'm going to create a star ground point with a 3 terminal tag strip near the power transformer at the center and take all the grounds there.
Thank you so much for the videos. Really do enjoy them. Quick question perhaps somebody could help with. I use the R8 as an AMP only so it always stays on the Pre-In selection. In that case , do the 6SN7's and 6SL7's come into play in the circuit at all other than the center 6SN7? No sense rolling those tubes I imagine if they have no effect on the amp circuit when used in Pre-in mode. Thanks for any thoughts.
Not sure of your description but if the output stage is cathode biased maybe they are elevating the heaters and using the cathode resistor voltage as a cheap easy way to get the elevation? It's a noise reduction trick when using old style octal preamp tubes that didn't have a spiral wound heater. No need on the push pull output tubes any hum would cancel. Best would be elevation tapped off the power string using a voltage divider and a cap at about 70V elevating only the stages before the power tubes. Rewiring the heaters with a virtual center tap is a very good idea. If they were so worried about noisy octals they could have fitted in a little DC heater board for the input tubes for little added cost. Anyway, best build it right first, proper grounding, short leads, and proper lead dress, then try elevating the heaters if the octals are hummy. I've found elevation not worth the effort, better to go with DC heaters.
They are grounding the heater on one leg at the transformer end, and using that same leg to ground the cathode of the output tube. So they are using one leg of the AC heater as the signal ground for the cathode. It's a fixed bias amp with a 10ohm shunt for the meter.
@@SkunkieDesignsElectronics I've only seen this in simple tube radios and of course the earliest low end Fenders like the Champ. Very odd choice for fancy modern hifi, penny wise pound foolish, maybe when they prototyped it it worked fine and they went with it. I agree make it right if only for proper design discipline. Wiring up heaters is a boring chore looks like they passed it on to the repair tech!
According to Willsenton R8 manual you should connect speakers from 4ohm (red) and 8ohm (black) terminals. So from 4ohm AND 8ohm. Is that correct? It actually sounds good that way.
you seem very intelligent with tube amplifiers... I was thinking about getting an intigrated Ayon Tube Amp ... but I found someone online that was selling their Ayon and keeping there Naim nait... they said they listen to their Naim more...your thoughts please?
New EH tubes are often as good as NOS, if not better. NOS got so scarce many people are getting pulls, sometimes fakes, besides tubes were not made to stay in stock for 70+ years. The problem we found is grids getting "tired" from tension over so many years. Give them a try because EH are mechanically and chemically far better than most JJ tubes.
@@SkunkieDesignsElectronics I heard about some of their output tubes being good but don't work that much with higher than line signals. EH is certainly the best when it comes to small signal tubes and durable outputs. Have you compared several types of JJ and EH, do you find EH being mechanically and chemically better made?
Yeah maybe there were some different revisions with it and alittle cost cutting too ...very common - mine is also dead quiet. I have noticed with mine and others I've seen was it had a little cheaper clamps for the 2 filter caps and has no cover over the power transformer - been running the 6550's an inbetween from KT88-EL34 On another note the R8 has been my main amp for a couple years UNTIL I built Skunkie's 300B !!! Love the R8 but The 300B is not going anywhere!
It would be very interesting to hear your opinion about the Line Magnetic LM216, it is based on the developments of General Electric and is the same bestseller as the R8.
Never seen one. None of the manufacturers send me products to review. Viewers or friends have sent me the stuff I have reviewed, or it's stuff I have bought or built myself :)
Is it futile to use a separate preamp ? I’ve heard it does not bypass the units preamp section. Love mine but I like to try stuff like preamps and stuff Have mine with Klipsch Heresy IV. Ifi Zen phono and Thorens turntable. Dead quiet and wonderful sound.
I'm not sure how these preamp inputs are wired. Honestly, very few tube amps actually need a pre-amp unless they are specifically designed without a "pre-amp" section.
How About adding Output Tubes?? I want to know or to be Enlightened how it will possible? Please 🙏 Hope that wi be your next Topic Someday in this Channel
Yeah and while it does have >very< minor hum with other amps (1 foot away it's not audible), it's doing CRAZY things with this amp lol. When I heard country music I was like WTF!~
@@SkunkieDesignsElectronics Do you have a radio station transmitter close to you? It would have to be a very strong signal for the phono/amp combo to pick it up. As for country music, i have exactly the same reaction any time I hear it 😁
@@SkunkieDesignsElectronics That's odd. I made one of the phono tube pre amps exactly like yours (chassis is a couple inches shorter -to fit the shelf) and I don't have that issue. Amp is dead quite driving LS50s (85db efficiency). Must have an unique issue? Love the videos! Please post a parts list when you get it sorted out. When I finish the Dynaco ST-70 I can rotate it in and upgrade my R8. Thanks for tackling this one.
I think I did in the other video, triode mode to me sounds dull/dead and likely is from the negative feedback used for UL mode being too much for triode mode. But in other amps, I also prefer the sound of UL.
@@SkunkieDesignsElectronics I have KT88 PP that I have tried both Triode/UL, the triode sounds better with instruments. The distortion level are pretty much the same for both on my amp. Wonder different design would make it's better.
Here is a matched set for $537 on amazon amzn.to/3k4Zgfy You might be able to shop around and find a better deal. I personally don't think all 4 have to be "matched" but I feel each pair per channel should be so 2 matched pairs would also work fine.
I might be able to weigh in on that comparison in the future. I now have all the parts to build a VTA ST-70. I need to finish a Marantz 1060 rebuild first. (Trying to reassemble my first stereo from the mid 70s). When it's done I'll pull my R8 and do some modifications per Skunkie's findings.
@@58markmc Oh super! Im trying to decide on my first proper tube amp for a set of large open baffle speakers and was eying a Dynaco ST70 kit from someone named Bob Latino.
@@SkunkieDesignsElectronics I honestly don't think they would. They are large DIY open baffles with a sensitivity of around 95db at 1w. Im thinking a few clean watts should do but I like to tinker so maybe some extra watts for future proofing if I build some different speakers (just thinking) :)
I've had my R8 for over a year and use the upgrade PSvane KT88s in triode mode all the time. I also got some NOS 6S7Ls and 6SN7s. It's quiet as can be and I can listen for hours with no fatigue. The only other tube amps I have to compare are a Dynakit ST-35 with the Dave Gillespie boards , a DG Magnavox 8600, a DG Maganavox 9300 (with Dynakit OPTs) and some rebuilt Magnavoxes. Those are all low watt amps and drive my Klipsch RP600s or my Dynaco A-25s but the R8 sounds as nice or nicer than any of those. Is there a QC issue with the manufacturing process?
I'm just sharing my subjective opinion, I personally felt the amp just sounds dead in triode mode, clearly you like it. I have no clue what source you are using, many DAC's perform their own equalization curves etc so your system could sound very different from what I am hearing. Even the wide variations is source mastering can change the sound. Also room treatments etc. etc. etc. It's why EVERY review has to be taken with a grain of salt, there are hundreds of variables involved. I can only report what I found on the sample I have, and this one has some MINOR hum at higher volume levels on the knob with no input on both channels. The preamp source also has hum. A few feet from the speaker I can't hear it so this isn't a major deal, but the grounding scheme they are using is far from normal or ideal.
@@SkunkieDesignsElectronics Yes, listening opinions are definitely subjective. Some peeps like triode some like ultralinear. For sources I have a Bluesound Vault and a turntable (Technics SL-Q2 ,Audio Technica VM540ML cartridge and the Ear834 clone) with no hum on either source. Will be interesting to see what the cause turns out to be as some owners have no issues and some do have hum issues.
Never at any moment was I lost in your delivery of information. I’m a newb.
My friend Lorne Boyd is my reference for audio. You made this tutorial fun and packed with info. If iI or anyone purchases an R8, we would all want you to perfect it. I’m going to watch this video again…. It’s that flat out great. Thank you
Nice review Stephe. Looking forward to seeing the differences in the resistor and grounding upgrades.
Most informative video I've seen on the R8. Thanks Skunkie!
Glad it was helpful!
I was really tossing up between the Willsenton or the Muzishare X7, I ended up getting the X7, after two years it’s still going strong. Love your videos 👍
Very informative - Hope you include a list of parts used for the upgrades later on Please.
Thanks for the update Skunkie!!! Very very odd on the heater wiring. The ground scheme too. Looking forward to your fix.
Yeah, I will draw some of this out in a future video, it seriously makes no sense to me. The grounds seem to be all over the place!
Works as EE electronic engineer, find this channel, I must say you are really good , Greetings from Sweden
Thank you very much!
I have NOS Svetlana 6550s in mine - they are amazing. I am blown away by the bass in addition to the midrange and high frequency.
I replaced the outer 6SN7 tubes with identical NOS Sovtek tubes because the Willsenton branded ones supplied were noisy. I would hear crackling sounds on warm up that the NOS tubes removed. I had previously replaced the 6SL7 tubes with NOS JAN Philips 6SL7-GT tubes and those really smoothed out the high frequencies.
Looking forward to seeing you upgrading this amp. Thanks!
I almost bought one of these a few years ago. Ended up with the Muzishare X7 with push-pull KT88 power tubes. One of the power tubes redplated inside of 30 days so I returned it to the manufacturer. Gotta love PayPal! Ended up buying another one a year later, performance was decent but I needed more flexibility than the Muzishare could provide.
See you on AK!
I am really surprised to see all those so-called problems you mention. I have had my R8 for almost a year. It sounds great, powerful, beautiful, no "hum" at all, even at almost full power with or without input signal.
We would like to hear about several R8 owners to share what they really experience with this amp. For me, I have been 100% satisfied (and I have been in music listening and playing for decades...) and will not change one thing in it, until proven otherwise. Except for some tubes, which I did, for the best. Thank you.
I never said it was going to catch on fire or anything :) Well actually their failure to include a "safety resistor" on the tube bias boards have caused quite a few of these amps to melt down from red plating tubes. Feel free to ignore my advice.
@@SkunkieDesignsElectronics I am not ignoring. I am just relating my experience. Thanks.
The problem I have with your review is that - while you seem to recommend this amp, the problems you are noting would require quite advanced DIY/electrical know-how to fix - so at the end of the day only the most can-do DIYer is likely to want to take it on. In effect, this is a pretty damning review, even if done indirectly.
I watched for about 14 minutes and it doesn't sound like a good buy. Thanks for an honest review.
I have an R8. It is powering a pair of KEF Q350s. Sounds great, and is dead silent. I have not opened it up to see what is going on inside yet. It is an older unit, it arrived in march of 2020.
It may be that I have a dedicated 20amp outlet powering the amp, so nothing like a dimmer or other electronics on the circuit. I also swapped the 3 6SN7 tubes first. This tube swap made a monumental difference to the sound. Harsh glassy high frequencies sounded clean and with less perceived distortion. The entire midrange sounded more precise with more instrument separation. Probably less harmonic distortion, but the tonality seems much more natural and top end is far less fatiguing and harsh. i am lookin g forward to making some cap and resistor swaps.
along wit the grounding and choke mod. Thanks for your work!!
Well on spot with the r8 lack of parts and circuitry cheats. It doesn't matter what you buy from uno where. I'm always modifying it. OT quality level are high...like I've been hearing from numerous owners just might as well add the mods quality components. I almost bought one of those after many months on the market. The price soared and availability, lack of, backorder actually keept me from buying two units.
I agree with you regarding Miflex caps - they are way too big to use in these applications the long flying leads needed also act as antennas and cause hum issues and bay also cause instability issues. Excellent comments regarding the design issues, particularly the ground and wire routing though it’s not just Chinese amps that are prone !
I think it’s common for amateur modders to throw expensive components in without addressing the engineering problems inherent in the design.
Thanks for the heads up on the GE 6sl7. I've been spending big dollars trying to tame that upper frequency harshness with my Klipsch. Finally, the GEs did the trick
Awesome!!! Glad it worked for you and I think those little tubes sound great!
Super interesting video - and a much better review than the "how does it sound". I think a lot of people would buy an "upgrade kit"....
Good point!
This is most interesting. I just sold this amp because of the lack of bass response with original tubes. I always thought it was a quality amp but something was missing. Then I had a Fisher 500c receiver restored and when it came back it blew the R8 out of the water.
I'm betting with your modifications it will make the R8 a much improved amp.
I can see on the computer the frequency response is bright. The grounding makes zero sense to me and possibly is the root of what I am seeing? Tube amps are very sensitive to grounding!
It’s ALL in the tubes , never used the originals . First they’re not biased as a quad set . Have NOS 6500 and EL34 quads . HUGE difference . I actually disconnect my sub . A very good reasonable ‘newer ‘ quad set I have is electro-harmonic 6500’s ( Russian) sadly not a fan right now . However they are very good and cost effective . Also maybe even as important are the pre-amp tubes.6SL7’s ….try 2 high quality of those even first. The middle tube ( V5) is not that important. Nothing changes the sound of a tube amp like high quality tubes . It’s not about the bass ( it’s there) but the presence of kids ( vocals , acoustic instruments ) it’s life like .
Thank you Stephe. This is proving very valuable
Another great vid, here's wishing you a Happy New Year..
YOUR lead in song reminds me of the roller rink we went to in the 80;s.
HA! :)
I've been trying to modify this amp myself, I noticed also big hum, hiss and other stuff going on. My speakers are 95db+ and sometimes it can be horrible. I suspect that the frontpanel with all extra curcuitry with crystal etc giving noise because i have extra noise on that same channel. I already rerouted some ground wiring and replaced all resistors and Caps (the orginal caps are not fake but old stock (about 10 yrs old in my amp) and i used Rubycon, Nichicon, Miflex 0,22uf / Mundorf Supreme 0,33uf) and resistors a mix between DALE/ Mills, Kiwame 2W, and 3W (Koa Speer) and Vishay PR03. Orginal blocking caps are made by Clarity Cap btw, cheapest they sell so not horrible chinese caps)
Main caps i choose KEMET 330Uf/500V but will be replaced with KEMET MKP C4 filmcaps 210uF and the other ones also with 10uf respec. 30uf film also KEMET.
The middle tube to me looks like a voltageregulator. I've seen a schematic on one that was very similar on stereonet forum.
I use KT88 from JJ (sounded great compared to orginal..) and all the 6sn7 is JJ also. THe 6SL7 i havent replaced yet.
i replaced singalwire with mundorf silver/gold and put a braid over it and run a separate wire to new starground in chassie. I will try to do further improvements with grounding. Got lot of good tips from you so far and will looking forward to next video. I didn't like the main ac wire being unshielded either going to the frontswitch so i installed a new with shield.
Almost all wires inside are 13 awg to 14 awg silverplated PTFE.
One thing i want to do is to disconnect the relays and drive tubes in triode directly, My idea was to just remove the 39K and 1K and instead add a 100-180R between pin 3-4 on the KT88s and disconnect the yellow wires to OPT (blue ones are highest resistance so this should be the triode winding) - I like triode the best. Please if you have any input on this let me know in video. You seem to have a lot of knowledge.
I guess biggest issue i have with this amp that it have always from start been little to forward in uppermid, lower treble. Compared to many other amps like the chinese Yaqin MC100b.
I got mine in March/April and it looks to identical inside to mine. others ive seen on the net has slight differences,
Ohh yeah one thing i added was 1K gridstoppers but i couldn't detect any difference in sound,
And for your info; someone linked your video in Willsentons facebook group =)
Best regards
Johan from Finland and Happy new year to you. Keep the videos coming! Very nice.
Thanks for all the info!!! I really like those Vishay Pro resistors. My hope is star grounding this amp will resolve a bunch of issues.
Hey Johan! Amazing list of upgrades you’ve done to your R8. I don’t know how to do any of that stuff but out of curiosity, how much do all those parts that you put in, cost you in the end?
@@franknelissen8041 I haven’t thought about it but just caps around 250€? Maybe 300-400€ totally with all wires and so on..
Great stuff. Glad you are tackling this.
Mullard EL34 is what i use, best sounding tube out there
Happy New Year,
I have some hum thru my speakers, but can only hear it when I put my ear to the speakers. I switched out the power cord (more for looks than anything else!) to a $30 cord. It cut down the hum by at least half. This is my first tube amp and am definitely not versed on electronics, but just thought I'd offer what happened when I changed the power cord.
I've read that the center 6SN7 is the voltage regulator, and I've heard that it converts AC to DC.
It can't convert AC to DC, but yes it's being used as a voltage regulator but I need to sit down and figure out how they wired it in the sample I have.
Good luck finding the source of your hum. My R8 is dead quiet hooked up to a pair of KEF 104/2 floor standers 92 dB & 4-ohm. I use GL KT88s and also have Mullard EL 34s. I run 3 new Electro-Harmonix 6SN7s and 2 NOS Melz 6SL7s (via Jim’s Tube Store).
I’ll scope out those GE short bottle tubes you recommended.
It would be nice NOT to select the Pre-In each time using the remote as I use a vintage Luxman CL-35 MkIII as a preamp.
Great video and look forward to your next R8 adventure!
I may explore how to change the default selection later in this series.
@@SkunkieDesignsElectronics - Great! PS - I just ordered two GE short bottle 6SL7 tubes you recommended👍👍
Those GL’s look great too. The British Audiophile likes Psvane.
National tubes are imported by Richardson Electronics from La Fox Illinois also try floating the third wire on the power cord ground with a three wire to two prong adaptor as you may have ground loops thru the power cord. Been building tube amps since I was 14 years old I'm now 77 and have learned a lot of things to get rid of hum I'm presently using a single 211 amp with a homebuilt Cary Audio AE1 preamp and Klipsch Khorn speakers
Bonnie Kapischke W9EBO
I found the hum (a bad solder joint on the heater virtual center tap).
And NEVER unground a high voltage tube amplifier!!! If there is a ground loop from the power cord, there is either something wrong with the amp or a design issue. An ungrounded amp no longer has protection in case of a parts failure and the chassis could become "hot" with lethal voltage.
Hi Stephe, you obviously know more about this amp than I do, but mine is dead silent. I am using JBL L150s and even with the volume all the way up with my ear in the speaker I cannot hear any hum. I am using the original kt88s (Although I have a quad of KR Audio kt88s on the way!), with PSvane 151 tii in the 6sn7 spots, and Sylvania NOS 1955 tubes in the 6SL7 spots. I tried RCA 5691 red base black plate tubes that were very expensive, but they dulled the mid to upper frequencies too much. The Sylvania's sounded much better to me. I know you said you didn't like the PSvane 151 tubes, and I admit at first they are too bright or harsh, but if you give them time they smooth out tremendously. I have about 150 hours on mine, and I have heard that they require up to 300 hrs. to burn in. Great video thanks for sharing your knowledge!
Mine is silent wide open, I hear a tiny hum at 1/2 volume. I'm not shocked some people hear nothing, I've had other people msg me that theirs does the same as mine. And those JBL's are 88db speakers which might help. :)
I meant PSvane 181's I guess I had rum on the brain!😄
I’m glad I swapped out my R8 tubes before the prices went up
Hello there! First, thank you for your videos. Incredibly helpful! I just acquired the Willsenton r800i 845. Had it for about 6 months now. I really like it, but not sure if I'm blown away. Do you have any advice or suggest any modifications similar to this unit? Any info would be greatly appreciated! Lou
I may possibly be working on one of those in the future.
Looking forward to that. Really enjoying this amp so far. Great build quality, great sound, but at this price point, I'm sure there is room for improvement/ tweaking like we love to do! Unfortunately I don't have your knowledge but I can solder pretty good. Oh, by the way, this sucker is 94 pounds!!
And the voltages inside them..... Be careful!!!!
I have an R8 hooked up to a pair of Heresy IVs and it’s quite as quite gets. I can turn it up to 3/4 volume with no input and it’s silent. Maybe there was more damage to that amp when the tube fried. Or maybe I just got a good one. Who knows. But mine is very quite. (I’m running Golden Lion tubes as well)
Maybe you got lucky? Other folks I read say theirs has some hum. It's not loud but it's there. The ground loop hum issues from weird grounding was loud.
I have the same setup, R8 to Heresy IV, and also dead quiet.
@@pnichols6500 I really like my setup. How about you? What DAC are you using? I’ve got a Pontus II, Sounds really good.
I have this amp driving the new Wharfedale Lintons. DEAD quiet at any setting. Couldn’t be happier with this beauty, even with the stock tubes. Tax return gonna go towards some Gold Lion upgrades.
@@jameselliott2975 Go for it James! Golden Lions are worth it. I also have some EL 34’s but they sound thin to me compared to the KT88s.
The R8 is well known for having better bass or too much bass which is relatively subjective to the user’s need of bass. Putting aside the power tubes and preamp tubes, are their parts on the design of the R8 that contributes to the better bass or too much bass (subjective), that is different from other tube amp design.
Well known by whom? Those YT reviewers? When we listened to the R8 vs the X7 the muzishare had at least as good of a bass response but also was less boomy sounding, likely due to having better output transformers. You not only can hear this, you can see it in the frequency response curves. Honestly the R8 design is your basic, bog standard push pull KT88 amp, other than that strange 6SN7 tube they used to power the front end. It's not a bad sounding amp, but it's not anything special either.
@@SkunkieDesignsElectronics, when I said well known for the owners of rhe R8. I dont mean famous, I just dont want to sound ranting on a gadget I dont own. I asked you bcoz of your technical know how on this audio equipments which I trust. Thanks again.
Some people in almost any hobby will defend their purchase decisions to their grave. I will never understand it. there is nothing special about the R8 design that would give it "extra bass". If anything, the values of the coupling caps tend to limit it.
Got one of this. Why are there 3x6SN7s ? Still puzzled by the role played by the one in the middle. I upgraded them to the Psvane CV181 Tii Classic Grey Coated. Just wondered if I could make do with just a pair of the CV181s and leave the Willsenton stock tube in the middle without affecting the performance.
It's a capacitance multiplier/voltage control. It's there to clean up the power going to the front end tubes.
@@SkunkieDesignsElectronics Thanks Stephy. So I guess it would make no difference in sound leaving the stock 6SN7 there to carry out that duty ?
I would experiment, it does seem to impact the sound some
Thank you very much for this review.A lot of nice and precious infos about R8.I own a Willsenton R8 since one year.I have no any issues, no hum, not any kind of noise.At any volume is dead silent. For me, your review is perfect because now I know the 6sl7 tubes influence the quality of output stage sound.I will change it to nos Melz 6sl7.
I have a question.I own a tube preamp wich I use with musical fidelity dual monoblock a3cr power amp.The output volume is very high.If I put a variable resistor to every chanel,internally, before the volume pot, will affect the quality of the sound?
Thanks again
Sounds like the preamp is too hot for the power amp?
@@SkunkieDesignsElectronics When I turn up the volume under a quarter it is very loud (supposing 18 o'clock is zero, at 20 begins to be very loud)
My speakers are Focal 93 db.
If you can adjust the bias manually do you still have to buy matched pairs/quads?
It's a good idea for the tubes on the same channel to be close.
I am sure you will get the grounding issues sorted out.
I'm thinking I'm going to create a star ground point with a 3 terminal tag strip near the power transformer at the center and take all the grounds there.
Thank you so much for the videos. Really do enjoy them. Quick question perhaps somebody could help with. I use the R8 as an AMP only so it always stays on the Pre-In selection. In that case , do the 6SN7's and 6SL7's come into play in the circuit at all other than the center 6SN7? No sense rolling those tubes I imagine if they have no effect on the amp circuit when used in Pre-in mode. Thanks for any thoughts.
The only thing the pre-in bypasses is the volume control.
@@SkunkieDesignsElectronics Thank You! Appreciate the reply.
Not sure of your description but if the output stage is cathode biased maybe they are elevating the heaters and using the cathode resistor voltage as a cheap easy way to get the elevation? It's a noise reduction trick when using old style octal preamp tubes that didn't have a spiral wound heater. No need on the push pull output tubes any hum would cancel. Best would be elevation tapped off the power string using a voltage divider and a cap at about 70V elevating only the stages before the power tubes. Rewiring the heaters with a virtual center tap is a very good idea. If they were so worried about noisy octals they could have fitted in a little DC heater board for the input tubes for little added cost. Anyway, best build it right first, proper grounding, short leads, and proper lead dress, then try elevating the heaters if the octals are hummy. I've found elevation not worth the effort, better to go with DC heaters.
They are grounding the heater on one leg at the transformer end, and using that same leg to ground the cathode of the output tube. So they are using one leg of the AC heater as the signal ground for the cathode. It's a fixed bias amp with a 10ohm shunt for the meter.
@@SkunkieDesignsElectronics I've only seen this in simple tube radios and of course the earliest low end Fenders like the Champ. Very odd choice for fancy modern hifi, penny wise pound foolish, maybe when they prototyped it it worked fine and they went with it. I agree make it right if only for proper design discipline. Wiring up heaters is a boring chore looks like they passed it on to the repair tech!
According to Willsenton R8 manual you should connect speakers from 4ohm (red) and 8ohm (black) terminals. So from 4ohm AND 8ohm. Is that correct? It actually sounds good that way.
I doubt it say to connect across the 4 and 8 ohm terminals. You connect from either of the red to the black, not both.
you seem very intelligent with tube amplifiers... I was thinking about getting an intigrated Ayon Tube Amp ... but I found someone online that was selling their Ayon and keeping there Naim nait... they said they listen to their Naim more...your thoughts please?
No idea on either of those. Never listened to them.
@@SkunkieDesignsElectronics what is your favorite tube amplifier and do you think all tube is better than hybrid tube/ SS ?
New EH tubes are often as good as NOS, if not better. NOS got so scarce many people are getting pulls, sometimes fakes, besides tubes were not made to stay in stock for 70+ years. The problem we found is grids getting "tired" from tension over so many years. Give them a try because EH are mechanically and chemically far better than most JJ tubes.
I agree some of the JJ tubes are not very good, but their EL34L tubes sound really good.
@@SkunkieDesignsElectronics I heard about some of their output tubes being good but don't work that much with higher than line signals. EH is certainly the best when it comes to small signal tubes and durable outputs.
Have you compared several types of JJ and EH, do you find EH being mechanically and chemically better made?
looking forward to your comments on 34s vs 88 sound
I plan to roll in a few different 6CA7 as well as some KT77 too.
The Willsenton R300 seems to be well liked. I wonder if there are ways to upgrade that amplifier aside from tube rolling.
I'd love to look inside one, no one has been willing to send me one to review/update so far.
Yeah maybe there were some different revisions with it and alittle cost cutting too ...very common - mine is also dead quiet. I have noticed with mine and others I've seen was it had a little cheaper clamps for the 2 filter caps and has no cover over the power transformer - been running the 6550's an inbetween from KT88-EL34 On another note the R8 has been my main amp for a couple years UNTIL I built Skunkie's 300B !!! Love the R8 but The 300B is not going anywhere!
Hey. Can I adjust the step increments of the volume control on the remote? Thanks in advance.
No but you could attenuate the signal on the input so that each step didn't change as much.
It would be very interesting to hear your opinion about the Line Magnetic LM216, it is based on the developments of General Electric and is the same bestseller as the R8.
Never seen one. None of the manufacturers send me products to review. Viewers or friends have sent me the stuff I have reviewed, or it's stuff I have bought or built myself :)
What are good tubes that you recommend for a Willsenton R8 I would greatly appreciate your feedback thank you
Check my last R8 video! I go over what tubes I like.
Hi
Would you please do the mod for the popular Wilsenton R300 integrated amp?
Many thanks
I need someone to send me one to upgrade/repair :)
Doraville! Home of the ARS 👍
I live 1/2 mile from where Studio one was, Free Bird was also recorded here.
Is it futile to use a separate preamp ? I’ve heard it does not bypass the units preamp section. Love mine but I like to try stuff like preamps and stuff
Have mine with Klipsch Heresy IV.
Ifi Zen phono and Thorens turntable. Dead quiet and wonderful sound.
I'm not sure how these preamp inputs are wired. Honestly, very few tube amps actually need a pre-amp unless they are specifically designed without a "pre-amp" section.
@@SkunkieDesignsElectronics thanks
How About adding Output Tubes?? I want to know or to be Enlightened how it will possible? Please 🙏 Hope that wi be your next Topic Someday in this Channel
Adding output tubes?
Hi any advice for people who would like to try rolling tubes but can’t hear the difference. I wish I could discern improvements in my setup.
Some amps just don't have audible differences in tubes used.
@@SkunkieDesignsElectronics Thank you for your kind answer. I hadn't thought of that.
@@SkunkieDesignsElectronics Thank you for your quick answer! I find it very reassuring.
The phono pre-amp you speak of that has hum when connected. Is that the tube phono you built on your channel?
Yeah and while it does have >very< minor hum with other amps (1 foot away it's not audible), it's doing CRAZY things with this amp lol. When I heard country music I was like WTF!~
@@SkunkieDesignsElectronics Do you have a radio station transmitter close to you? It would have to be a very strong signal for the phono/amp combo to pick it up. As for country music, i have exactly the same reaction any time I hear it 😁
@@SkunkieDesignsElectronics That's odd. I made one of the phono tube pre amps exactly like yours (chassis is a couple inches shorter -to fit the shelf) and I don't have that issue. Amp is dead quite driving LS50s (85db efficiency). Must have an unique issue? Love the videos! Please post a parts list when you get it sorted out. When I finish the Dynaco ST-70 I can rotate it in and upgrade my R8. Thanks for tackling this one.
dear after i test the amp... how much time i need wait to open it and can touch in parts inside.. need wait a few days or can after 2 hours?
30 minute to an hour should be fine, I would always test the power caps for voltage before touching anyting!
Can you compare between Triode & UL and let us know the sound different between them. Thanks
I think I did in the other video, triode mode to me sounds dull/dead and likely is from the negative feedback used for UL mode being too much for triode mode. But in other amps, I also prefer the sound of UL.
@@SkunkieDesignsElectronics I have KT88 PP that I have tried both Triode/UL, the triode sounds better with instruments. The distortion level are pretty much the same for both on my amp. Wonder different design would make it's better.
Can you post a link to the Golden Lion tubes you used please? Thanks
Here is a matched set for $537 on amazon amzn.to/3k4Zgfy
You might be able to shop around and find a better deal. I personally don't think all 4 have to be "matched" but I feel each pair per channel should be so 2 matched pairs would also work fine.
How would something like this compare with properly built Dynaco ST-70?
I might be able to weigh in on that comparison in the future. I now have all the parts to build a VTA ST-70. I need to finish a Marantz 1060 rebuild first. (Trying to reassemble my first stereo from the mid 70s). When it's done I'll pull my R8 and do some modifications per Skunkie's findings.
@@58markmc Oh super! Im trying to decide on my first proper tube amp for a set of large open baffle speakers and was eying a Dynaco ST70 kit from someone named Bob Latino.
Do those type of speakers really need 45 watts to drive them?
@@SkunkieDesignsElectronics I honestly don't think they would. They are large DIY open baffles with a sensitivity of around 95db at 1w. Im thinking a few clean watts should do but I like to tinker so maybe some extra watts for future proofing if I build some different speakers (just thinking) :)
I want see you do 845 tube amplifier.
Maybe in the future, a 2A3 is probably next.
I've had my R8 for over a year and use the upgrade PSvane KT88s in triode mode all the time. I also got some NOS 6S7Ls and 6SN7s. It's quiet as can be and I can listen for hours with no fatigue. The only other tube amps I have to compare are a Dynakit ST-35 with the Dave Gillespie boards , a DG Magnavox 8600, a DG Maganavox 9300 (with Dynakit OPTs) and some rebuilt Magnavoxes. Those are all low watt amps and drive my Klipsch RP600s or my Dynaco A-25s but the R8 sounds as nice or nicer than any of those. Is there a QC issue with the manufacturing process?
I'm just sharing my subjective opinion, I personally felt the amp just sounds dead in triode mode, clearly you like it. I have no clue what source you are using, many DAC's perform their own equalization curves etc so your system could sound very different from what I am hearing. Even the wide variations is source mastering can change the sound. Also room treatments etc. etc. etc. It's why EVERY review has to be taken with a grain of salt, there are hundreds of variables involved.
I can only report what I found on the sample I have, and this one has some MINOR hum at higher volume levels on the knob with no input on both channels. The preamp source also has hum. A few feet from the speaker I can't hear it so this isn't a major deal, but the grounding scheme they are using is far from normal or ideal.
@@SkunkieDesignsElectronics Yes, listening opinions are definitely subjective. Some peeps like triode some like ultralinear. For sources I have a Bluesound Vault and a turntable (Technics SL-Q2 ,Audio Technica VM540ML cartridge and the Ear834 clone) with no hum on either source. Will be interesting to see what the cause turns out to be as some owners have no issues and some do have hum issues.
👍
Unless it's finance software, no product ever brags about being designed by accountants.
Melz tube are much better than sylvania or ge
So much detail...
Thanks...i heard enough to not want to buy this problematic amp
Hey Skunkie👋 Do you have an instagram account?!
Nope, not right now.