Very informative 👍🏽 And I am from Texas , which would be night and day from England , but music and gear always brings everyone together 😀😀 Thanks mate
Thank you Stuart I own the Origin 20 combo, thanks for the tip on the power output tubes. I normally use JJ's alot so I'm off to buy some Marshall EL34,s relabelled from China source of course. I always check the HT fuse out of habit. And totally agree the older plate meter is easier to read than the LED. I'm glad they have a Bias trim pot loved the way you dived straight in give it a turn and see what happens spoken from a man that knows his valve amps. This was an ezy fix this time and you liked the sound of the amp. For a cheap amp it sounds really good IMO. Cheers
Nice work stewart,some days your the bug some days your the windshield, I'm almost ready to open up my amp repair shop end of may,and I can't wait..i am an ampholic, love your channel,
@@stuartukguitarampguy5830 I'm on the west coast of florida,Clearwater area, I've tried unsuccessfully 3 times to contact you about the schematics you said you could help me out with,for some reason email kept coming back to me, anyways love your work and your humor,I'm looking forward to more of your uploads, thank you for your time and knowledge, cheers from sunny fla
@@johnsalaman503 Hi John. Not sure why. If you go to www.fixguitaramps.co.uk/ and fill in the 'Contact' form, that should get through to me fine. I'd give you my email address but you know what it's like putting something like that on the web! If it fails again please let me know the exact details. Thanks.
@@stuartukguitarampguy5830 Hi. I was thinking about this a bit further and want to ask you about when you took the PI tube out saying that isolates the pre and power stages. Not sure that is right because when you take the PI out there is nothing being passed to the output stage, so you will never hear anything, right? If so then it’s not really testing if noise is coming from the power stage. I’m not an electrical tech so I might be wrong of course. Regards. And thanks again.
@@irf888 Great question! When I said 'isolate' I meant 'eliminate'. So pulling the PI tube, as you say, stops anything from the preamp stage getting through. So ... if the hum is still there it can't be anything on the preamp side, so we've eliminated the preamp side, just leaving the power side. Make sense? If the hum had vanished, we would be fairly sure the fault was in the preamp side of things.
Mr Stuart, I have this exact amp (since mid January 2021) and it has worked fine until our last rehearsal - when we started our first song and solo part came, I switched to the neck pickup and there was this horrible squealing, so I switched back to my bridge pickup (no squealing) and finished the song. We tried to, sort of, figure out what was wrong... At first I thought that maybe wax coating inside my neck pickup fell apart/went bad. But then, my singer handed me his Music Man with humbuckers and I plugged it in and the same squealing occurred, even more so perhaps because I use a Strat with two very low output noiseless pickups (both are HS-3 Dimarzio, neck and bridge). Now, the confusing part is this - I set my amp on the edge of breakup which is Gain on 10, Master on 7. And then I turn on the booster (SD-1, level and drive to max). And that's how I have been using it for the past 10 months and had no issues whatsoever. Also, I use LOW and MID setting without attenuation. So, when I turned off the SD-1, the squealing went away (using Music Man). Then I plugged my Strat back in, switched to the neck pickup and the squealing was not present - without SD-1 engaged (with it ,the squealing came back). So, I put the amp into LOW mode (it was in MID mode all along) and I engaged SD-1 and there was no squealing. Could this be the case of a microphonic preamp tube? this is how it sounded: ruclips.net/video/2c08jNr9XPM/видео.html I would be very grateful to hear your opinion all the best, ST
First time I've seen the inside of the Origin.. As usual, the people doing reviews on these only seem interested in showing you how much distortion you can achieve and never think about looking under the bonnet and discussing the manufacturing quality. Shame Marshall are getting these made in the far East. Thanks for another excellent video Stuart.
It isn't where it's made that is the problem but lousy design choices. I was watching a Lyle Caldwell video in which he had a "boutique" American made amp that was pretty noisy, and the reality is that it was really a clone of something else that has existed for decades. Curiously, he also had an Origin 20 head on his channel recently and wasn't impressed.
Hi Stuart. Gotta love those dreadful JJ's eh! Like you, I just don't think they're pumped out enough. In 100W applications they either run away or blow up in a flash and a pop. It's funny because people are so obsessed with Marshall Amps having leaky boards and the Bias running away. This isn't true of course. Admittedly some early TSL's and even fewer early DSL's may suffer like this, but the first thing I do when I see a 100W amp come in with this problem is remove those blasted JJ's and put anything else in and it's almost always the JJ's with grid emission. Factory setting is 70mV at Con32 on the Origin 50. (Con32 isn't fitted so it's easy to stick your probes in there and tweak it up) 😉
A loud, buzzy hum like that can also be the result of a dead filament center-tap circuit (dead balancing resistors, or the transformer's centertap wire went dead), which I've seen a number of times, and can be caused by a shorted tube. Also, if you can't turn the hum down with the volume controls, and pulling the phase inverter tube has no effect, then the problem is likely either the output tubes *OR* in the power supply, since the power-supply is common to every circuit in the amp. Swapping the output tubes was of course the quickest way to determine that the problem *wasn't* the power supply.
@GOD&GUNS , If the hum goes down when you turn the volume down then obviously it has to be mixing with or modulating the audio signal from somewhere in the circuitry *before the volume control". Without further information and knowing what type of amplifier, how old, whether it's handwired or uses a printed circuit board, and how many stages of gain it has prior to the volume control, it's pretty tough to narrow it down further over the Internet. Swapping out the preamp tubes would be the first thing to try (you've probably already tried that); you should also check to see if any unused input jacks are shorting themselves to ground as they are supposed to when there's no cable plug inserted into them, otherwise they'll act like an antenna (the simplest way to check this, without opening up the amp and using an ohmeter, would be to make a 1/4" plug with a short wire inside of it to short the hot to ground, and plug that into any unused jacks). Make sure all the jacks and control pots are bolted tightly to the chassis. You could have a bad filter cap or a bad ground in the preamp stages before the volume control. Perhaps there is an unshielded signal-carrying wire that runs too close to higher voltage parts of the circuit. I have no idea how good your technical skills are with high voltage circuits in tube amps, so proceed cautiously, and if you're unsure of yourself, consult a good Tech.
To be honest, given the rather bad production methods of the origin amps it's probably as well to use an mg 50 GFX, not too keen on PCB mounted valves or controls soldered to the board, as the mg marshalls are but the mg amps will probably out last the origin amps by a long way if you can put up with the solid state sound of course.
Another home run! How are you liking the newest Eurotubes Pro One? Not as good as the old one you say? Been close to ordering one for a couple months now.
Always wanted to know; Like a light bulb, does finger/body oil affect the life of the tube. Should you wipe tubes off after installing to remove any finger oil?
My view is that although you may as well clean off the valve, it doesn;t make any difference if you leave fingerprints etc on it. Btw that tip is only used for high wattage halogen bulbs (e.g. porjector bulbs) it doesn;t apply to ordinary room light bulbs.
I think sometimes people run these amps constantly at the lower power setting, which causes problems. had that problem with a Mesa Express 5/50 Plus head. It was expensive to just change out 1 tube. Since that hapened, I always run them a the full 50 watt setting and keep the volume low. When I have to. Naturally I do not get the real Amps tone unless driven at least to 1/2 volume. There is usually a price to pay with these lower watt settings. I have a Carvin V3M, lunch box 50 watt head. I think the rear switch says 15, 25 or 50 watt. I have had better luck keeping at the full 50 watts.
Hi Stuart, these videos are so informative for a casual and very much novice amp tech such as myself! Watching your fault diagnosis process is great! I have quite a noticeable hum on my Diezel VH-2 (100 watt, 2 channel tube amp) on the overdrive channel, I noticed I have one tube glowing brighter than the others and slightly red plating, could this be the cause? I've swapped it's position in the amp and the glow remains with that one tube so a bad tube seems the likely culprit. I wondered if it was essential to buy a new matched quad for the sake of one tube, or if I could just buy a pair and swap out the bad one and it's partner, then perhaps adjusting the overall bias against whichever tube shows the highest mA reading?
Hi Graham If the fault moves with the tube it's definitely the tube. Are you able to check bias? It may be they're both running way too hot but only one shows signs of it. Yes if you are tight for money you can buy a paid and do as you say.
@@stuartukguitarampguy5830 Thanks for the reply Stuart, much appreciated! Just taken some bias readings and have to admit I am somewhat shocked/baffled! From L-R looking at the front of the amp I have the following reading using a bias probe that measures cathode current at pin 8 (according to the eBay listing), they are KT77s; 1: -06.0mV 2: 07.3mV 3: -12.0mV 4: 03.3mV The reading seem to be fluctuating wildly though I'm not really sure what's going on? Could this all be down to the bad tube?
@@stuartukguitarampguy5830 Yes that's what the meter was showing at the time but it never really seemed to stabilise. I have used this same probe and meter to bias amps before and it worked as expected but these readings are making me doubt that I know what I'm doing! As mentioned they fluctuated a great deal in the half an hour or so I was checking the bias so at the moment it feels that I'm either doing something wrong, or the faulty tube is throwing everything out?
@@graybronze Something is screwy there - you can;t get a NEGATIVE reading across the cathode resistor (unless of course you swap the meter leads). So I'm at a bit of a loss I'm afraid.
Hello! I have the 50 Watt head model of this amp and it's making the EXACT same buzz after a few minutes of playing (sometimes instantaneously). It's been doing this for close to 2 months now and I have absolutely no clue what's causing it. Important things to note are: the valves don't look like they're redplating and it IS affected by the Master volume knob (I.e. it gets louder). Does anyone have any ideas how I could sort this out, or what the cause might be? Thanks! Edit: those strange hissing and crackling noises also happen on mine, though not near as prominent. It usually happens the second I plug in my guitar (but not the sound of the jack hitting the input or anything like that), or when touching the Master volume.
Hi Bryson The caps should be rated to at least the highest voltage they are ever expected to experience. It doesn't matter if they are over rated (e.g. it's fine to have a 600V cap in a circuit which only ever gets to say 350V) but not under rated. Yes, in some amps the voltage on switch on can be higher than the 'warmed up' voltage. Incidentally, this is why the standby switch was invented - to protect the caps until the amp warmed up. These days you don;t need a standby switch but guitarists get funny if you try and remove it!
Hi there Stuart. Just watched your video and it was very interesting and informative. I have the exact same amp and it has just stopped working although it's only 2 months old. The power light is on but the sound cut out while I was playing on the mid (20 watt) level. My leads and guitar are all working normally. Any ideas?
Hi Phil. Hard to diagnose these things over the internet of course. I can;t recall if this amp has an HT fuse. If so, that would be the first thing to check.
@@stuartukguitarampguy5830 Great thanks Stuart. I have just read the same advice on another forum so I’m going to check the fuse first up. Many thanks!
Well the fuses LOOK ok but without checking them with a multimeter I couldn’t know for sure. I’ve decided to take the amp back to the shop as it’s still under warranty. Cheers
@@stuartukguitarampguy5830 Well they gave me a NEW amp! Problem solved. I might keep watching and learning though. Got to keep the old grey matter active. Cheers.
I have the origin 20 combo, mine is quiet as a mouse, no hum when even cranked on full, wouldn't even know it was on until you strum a note and get blown away. That was still noisy after you changed all the valves imo, no where near as bad, but still noisy.
My understanding is the Marshall valves are EL34B which can take a higher plate voltage than the standard EL34. In my view it's a bit of a myth the balanced phase splitter. Yes of course it is better to have it balanced as then both power valves are driven equally. If there is an imbalance however, this will manifest as a little bit of distortion on the signal - and we wouldn't want distortion in a valve guitar amplifier now, would we???
I own the origin 50 and *knock on wood* it doesn't have this problem. On 99.99999% of my gear. Just on the bridge pickup of my SRV strat. Gives a hell of a hum. So I'm guessing it's that one particular texas special that's wonky and not the amp.
I am glad I have not bought one. I have been looking at these on Reverb. The cheapest is around 560.00 plus tax say 600.00. 750 new. The sellers I have contacted do not have the footswitches. That is around 50.00. The good thing -it appears that there is a boost (N big deal, and an FX loop button-This isa make or break situation, as I have been spoiled by my Mesa TC 50 watt head. It has the 3 channel and the FX loop on the footswitch. This is a must for me. The sellers on Reverb state they do not come with a footswitch. When I look at Sweetwater there are pitcures that show these amps come with one. This tells me something went wrong for them, or not the origional owners. No one I emailed back and fourth are telling me to go buy a ffotswitch now before buying the amp they want to sell for 2-250.00 less. Naturally no warranty. Sweetwater has a 2 year built in protection plan, no cost.
@@stuartukguitarampguy5830 They do, I believe the red print tubes are JJs and white print tubes are Chinese Shuguangs, who have been closed since 2019. Only major tube factories left are JJ in Slovakia, New Sensor in Russia and Psvane in China, who are geared more towards the hifi market and pretty expensive, although I think TADs new Redbase line are made there. Not a lot of choice left for valve aficionados.
@@alecboyyes Hi Yes the valve situation is dire. For a number of reasons there seems little chance of the Shuguang factory reopening any time soon, if ever.
The factory tubes on this amp are horrible. They must be Chinese with the Marshall logo and they break in just over two months. It's a good amp, it sounds great, but it's obvious where they've cut back on quality in order to bring it to the market at an affordable price. It is necessary to replace them with very hard valves because they work at very high voltages. The last one I repaired came from the factory with a 45 mAh bias setting, and according to Weber's chart it is absolutely disproportionate.
Hi Andrea. I'm not totally sure that's right is it? Are the Marshalls rebranded JJ? Anyway, I mean the 'normal' EL34 JJ. The EL34 II is better and I believe they made this specifically to overcome the problem I was mentioning. Btw I do like JJ except in one situation - this situiation. Normal JJ EL34 in 100W Marshall. They pften fail.
@@stuartukguitarampguy5830 yes, Marshall el34 are jj rebranded, in my origin there are Marshall el34 which are, according to the code , rebranded el34 ii jj
@@andrp692 Hi Andrea Yes I've now confirmed this too. Anyway, so it's basically the original EL34 (JJ) that are no good in Marshall 100W amps. The JJ EL34II is fine and I use them. Also the Marshall EL34 of course which I now know is the same thing.
You always speak about origin Marshall tubes - there are no existing Original Marshall Tubes, their are always build by Mullard, Valvo, Siemens, Tungsol, Tesla, JJ , or unknown Chinese Brands !
![NoCap - Maliboo [Official Music Video]](http://i.ytimg.com/vi/FUV7E0QyniU/mqdefault.jpg)
Very informative 👍🏽 And I am from Texas , which would be night and day from England , but music and gear always brings everyone together 😀😀 Thanks mate
Best damn state in the USA!
Thank you Stuart I own the Origin 20 combo, thanks for the tip on the power output tubes. I normally use JJ's alot so I'm off to buy some Marshall EL34,s relabelled from China source of course. I always check the HT fuse out of habit. And totally agree the older plate meter is easier to read than the LED. I'm glad they have a Bias trim pot loved the way you dived straight in give it a turn and see what happens spoken from a man that knows his valve amps. This was an ezy fix this time and you liked the sound of the amp. For a cheap amp it sounds really good IMO. Cheers
Glad you enjoyed it!
Thanks for the content Stuart, loving your videos. Cheers
Thanks!
Hey, very informative as usual..Love the videos..Top work..Ed..Herts..UK..😁
Nice work stewart,some days your the bug some days your the windshield, I'm almost ready to open up my amp repair shop end of may,and I can't wait..i am an ampholic, love your channel,
Great! We need more amp techs. Whereabouts are you based?
@@stuartukguitarampguy5830 I'm on the west coast of florida,Clearwater area, I've tried unsuccessfully 3 times to contact you about the schematics you said you could help me out with,for some reason email kept coming back to me, anyways love your work and your humor,I'm looking forward to more of your uploads, thank you for your time and knowledge, cheers from sunny fla
@@johnsalaman503 Hi John. Not sure why. If you go to www.fixguitaramps.co.uk/ and fill in the 'Contact' form, that should get through to me fine. I'd give you my email address but you know what it's like putting something like that on the web! If it fails again please let me know the exact details. Thanks.
Good job. I really enjoy your videos.
Thanks Zack!
Hi. Great video. I don’t even own this amp but several other valve amps and still found this really interesting. Thank you for doing it. Regards.
Thanks for the feedback!
@@stuartukguitarampguy5830 Hi. I was thinking about this a bit further and want to ask you about when you took the PI tube out saying that isolates the pre and power stages. Not sure that is right because when you take the PI out there is nothing being passed to the output stage, so you will never hear anything, right? If so then it’s not really testing if noise is coming from the power stage. I’m not an electrical tech so I might be wrong of course. Regards. And thanks again.
@@irf888 Great question! When I said 'isolate' I meant 'eliminate'. So pulling the PI tube, as you say, stops anything from the preamp stage getting through. So ... if the hum is still there it can't be anything on the preamp side, so we've eliminated the preamp side, just leaving the power side. Make sense? If the hum had vanished, we would be fairly sure the fault was in the preamp side of things.
@@stuartukguitarampguy5830 Hi. Yes I understand now, thanks!
Mr Stuart, I have this exact amp (since mid January 2021) and it has worked fine until our last rehearsal - when we started our first song and solo part came, I switched to the neck pickup and there was this horrible squealing, so I switched back to my bridge pickup (no squealing) and finished the song.
We tried to, sort of, figure out what was wrong... At first I thought that maybe wax coating inside my neck pickup fell apart/went bad. But then, my singer handed me his Music Man with humbuckers and I plugged it in and the same squealing occurred, even more so perhaps because I use a Strat with two very low output noiseless pickups (both are HS-3 Dimarzio, neck and bridge).
Now, the confusing part is this - I set my amp on the edge of breakup which is Gain on 10, Master on 7. And then I turn on the booster (SD-1, level and drive to max). And that's how I have been using it for the past 10 months and had no issues whatsoever. Also, I use LOW and MID setting without attenuation.
So, when I turned off the SD-1, the squealing went away (using Music Man). Then I plugged my Strat back in, switched to the neck pickup and the squealing was not present - without SD-1 engaged (with it ,the squealing came back). So, I put the amp into LOW mode (it was in MID mode all along) and I engaged SD-1 and there was no squealing.
Could this be the case of a microphonic preamp tube?
this is how it sounded:
ruclips.net/video/2c08jNr9XPM/видео.html
I would be very grateful to hear your opinion
all the best, ST
Great video!
Thanks Don!
Great content!
Thanks cal!
great video
Thanks Jamie
First time I've seen the inside of the Origin.. As usual, the people doing reviews on these only seem interested in showing you how much distortion you can achieve and never think about looking under the bonnet and discussing the manufacturing quality. Shame Marshall are getting these made in the far East. Thanks for another excellent video Stuart.
Glad you enjoyed it Pete.
It isn't where it's made that is the problem but lousy design choices.
I was watching a Lyle Caldwell video in which he had a "boutique" American made amp that was pretty noisy, and the reality is that it was really a clone of something else that has existed for decades.
Curiously, he also had an Origin 20 head on his channel recently and wasn't impressed.
Hi Stuart.
Gotta love those dreadful JJ's eh!
Like you, I just don't think they're pumped out enough. In 100W applications they either run away or blow up in a flash and a pop. It's funny because people are so obsessed with Marshall Amps having leaky boards and the Bias running away. This isn't true of course. Admittedly some early TSL's and even fewer early DSL's may suffer like this, but the first thing I do when I see a 100W amp come in with this problem is remove those blasted JJ's and put anything else in and it's almost always the JJ's with grid emission.
Factory setting is 70mV at Con32 on the Origin 50.
(Con32 isn't fitted so it's easy to stick your probes in there and tweak it up) 😉
YEs I do the same. I put in Marshall EL34s which seem quite good.
I had heard that Marshall doesn’t actually manufacture tubes, they outsource JJs and print their logo on them. Is that not correct?
A loud, buzzy hum like that can also be the result of a dead filament center-tap circuit (dead balancing resistors, or the transformer's centertap wire went dead), which I've seen a number of times, and can be caused by a shorted tube. Also, if you can't turn the hum down with the volume controls, and pulling the phase inverter tube has no effect, then the problem is likely either the output tubes *OR* in the power supply, since the power-supply is common to every circuit in the amp. Swapping the output tubes was of course the quickest way to determine that the problem *wasn't* the power supply.
@GOD&GUNS , If the hum goes down when you turn the volume down then obviously it has to be mixing with or modulating the audio signal from somewhere in the circuitry *before the volume control". Without further information and knowing what type of amplifier, how old, whether it's handwired or uses a printed circuit board, and how many stages of gain it has prior to the volume control, it's pretty tough to narrow it down further over the Internet. Swapping out the preamp tubes would be the first thing to try (you've probably already tried that); you should also check to see if any unused input jacks are shorting themselves to ground as they are supposed to when there's no cable plug inserted into them, otherwise they'll act like an antenna (the simplest way to check this, without opening up the amp and using an ohmeter, would be to make a 1/4" plug with a short wire inside of it to short the hot to ground, and plug that into any unused jacks). Make sure all the jacks and control pots are bolted tightly to the chassis. You could have a bad filter cap or a bad ground in the preamp stages before the volume control. Perhaps there is an unshielded signal-carrying wire that runs too close to higher voltage parts of the circuit. I have no idea how good your technical skills are with high voltage circuits in tube amps, so proceed cautiously, and if you're unsure of yourself, consult a good Tech.
@GOD&GUNS What model of amplifier is it anyway?
To be honest, given the rather bad production methods of the origin amps it's probably as well to use an mg 50 GFX, not too keen on PCB mounted valves or controls soldered to the board, as the mg marshalls are but the mg amps will probably out last the origin amps by a long way if you can put up with the solid state sound of course.
Another home run! How are you liking the newest Eurotubes Pro One? Not as good as the old one you say? Been close to ordering one for a couple months now.
Yes its good but no better than the original in my opinion. Plus it doesn't show up on camera so I have to use the old LCD pones for my filiming!
Always wanted to know; Like a light bulb, does finger/body oil affect the life of the tube. Should you wipe tubes off after installing to remove any finger oil?
My view is that although you may as well clean off the valve, it doesn;t make any difference if you leave fingerprints etc on it. Btw that tip is only used for high wattage halogen bulbs (e.g. porjector bulbs) it doesn;t apply to ordinary room light bulbs.
I think sometimes people run these amps constantly at the lower power setting, which causes problems. had that problem with a Mesa Express 5/50 Plus head. It was expensive to just change out 1 tube. Since that hapened, I always run them a the full 50 watt setting and keep the volume low. When I have to. Naturally I do not get the real Amps tone unless driven at least to 1/2 volume. There is usually a price to pay with these lower watt settings. I have a Carvin V3M, lunch box 50 watt head. I think the rear switch says 15, 25 or 50 watt. I have had better luck keeping at the full 50 watts.
Ok interesting, thanks for the advice Shawn
Hi Stuart, these videos are so informative for a casual and very much novice amp tech such as myself! Watching your fault diagnosis process is great! I have quite a noticeable hum on my Diezel VH-2 (100 watt, 2 channel tube amp) on the overdrive channel, I noticed I have one tube glowing brighter than the others and slightly red plating, could this be the cause? I've swapped it's position in the amp and the glow remains with that one tube so a bad tube seems the likely culprit. I wondered if it was essential to buy a new matched quad for the sake of one tube, or if I could just buy a pair and swap out the bad one and it's partner, then perhaps adjusting the overall bias against whichever tube shows the highest mA reading?
Hi Graham If the fault moves with the tube it's definitely the tube. Are you able to check bias? It may be they're both running way too hot but only one shows signs of it. Yes if you are tight for money you can buy a paid and do as you say.
@@stuartukguitarampguy5830 Thanks for the reply Stuart, much appreciated! Just taken some bias readings and have to admit I am somewhat shocked/baffled! From L-R looking at the front of the amp I have the following reading using a bias probe that measures cathode current at pin 8 (according to the eBay listing), they are KT77s;
1: -06.0mV
2: 07.3mV
3: -12.0mV
4: 03.3mV
The reading seem to be fluctuating wildly though I'm not really sure what's going on? Could this all be down to the bad tube?
@@graybronze Graham, just checking you mean MINUS 6.0mV and MINUS 12.0mV??
@@stuartukguitarampguy5830 Yes that's what the meter was showing at the time but it never really seemed to stabilise. I have used this same probe and meter to bias amps before and it worked as expected but these readings are making me doubt that I know what I'm doing! As mentioned they fluctuated a great deal in the half an hour or so I was checking the bias so at the moment it feels that I'm either doing something wrong, or the faulty tube is throwing everything out?
@@graybronze Something is screwy there - you can;t get a NEGATIVE reading across the cathode resistor (unless of course you swap the meter leads). So I'm at a bit of a loss I'm afraid.
Hello! I have the 50 Watt head model of this amp and it's making the EXACT same buzz after a few minutes of playing (sometimes instantaneously). It's been doing this for close to 2 months now and I have absolutely no clue what's causing it. Important things to note are: the valves don't look like they're redplating and it IS affected by the Master volume knob (I.e. it gets louder). Does anyone have any ideas how I could sort this out, or what the cause might be? Thanks!
Edit: those strange hissing and crackling noises also happen on mine, though not near as prominent. It usually happens the second I plug in my guitar (but not the sound of the jack hitting the input or anything like that), or when touching the Master volume.
Hi. Sorry but it's SO hard to try to diagnose your problem over the net, it could be a lot of different things. I hope you manage to get it sorted.
Are those smoothing caps rated to handle the 500v start up before tubes draw current? I wonder their voltage rating.
Hi Bryson The caps should be rated to at least the highest voltage they are ever expected to experience. It doesn't matter if they are over rated (e.g. it's fine to have a 600V cap in a circuit which only ever gets to say 350V) but not under rated. Yes, in some amps the voltage on switch on can be higher than the 'warmed up' voltage. Incidentally, this is why the standby switch was invented - to protect the caps until the amp warmed up. These days you don;t need a standby switch but guitarists get funny if you try and remove it!
Hi there Stuart. Just watched your video and it was very interesting and informative. I have the exact same amp and it has just stopped working although it's only 2 months old. The power light is on but the sound cut out while I was playing on the mid (20 watt) level. My leads and guitar are all working normally. Any ideas?
Hi Phil. Hard to diagnose these things over the internet of course. I can;t recall if this amp has an HT fuse. If so, that would be the first thing to check.
@@stuartukguitarampguy5830 Great thanks Stuart. I have just read the same advice on another forum so I’m going to check the fuse first up. Many thanks!
Well the fuses LOOK ok but without checking them with a multimeter I couldn’t know for sure. I’ve decided to take the amp back to the shop as it’s still under warranty. Cheers
@@007SpencerForHire Ok thats probably the best plan.
@@stuartukguitarampguy5830 Well they gave me a NEW amp! Problem solved. I might keep watching and learning though. Got to keep the old grey matter active. Cheers.
I have the origin 20 combo, mine is quiet as a mouse, no hum when even cranked on full, wouldn't even know it was on until you strum a note and get blown away. That was still noisy after you changed all the valves imo, no where near as bad, but still noisy.
Interesting. I wonder why they are so different?
So Marshall-branded EL34s instead of JJs or similar then?
Does the V3 preamp tube NEED to be a balanced 12AX7?
My understanding is the Marshall valves are EL34B which can take a higher plate voltage than the standard EL34. In my view it's a bit of a myth the balanced phase splitter. Yes of course it is better to have it balanced as then both power valves are driven equally. If there is an imbalance however, this will manifest as a little bit of distortion on the signal - and we wouldn't want distortion in a valve guitar amplifier now, would we???
@@stuartukguitarampguy5830 oh no, NOBODY buys a Marshall amp for their distorted tones 😂 excellent, thanks for your input Stuart, much appreciated
Hi Stuart. Im thinking of buying a small amp. Did you like this amp sound compaired to the real Marshalls.
hi Monty. Unfortunately I'm not a guitarist and so I refrain from commenting on the sound of any particular amp.
Stuart cracks me up! He’s like a sober Dudley Moore in Arthur.
Ha ha! Nice one!
Reading you say? Might be heading your way someday then.
Can you share with Bias Calculator?
If you go to tedweber dot com you will see it there.
@@stuartukguitarampguy5830 thank you so much!
I own the origin 50 and *knock on wood* it doesn't have this problem. On 99.99999% of my gear. Just on the bridge pickup of my SRV strat. Gives a hell of a hum. So I'm guessing it's that one particular texas special that's wonky and not the amp.
Yes it sounds like your amp is basically ok.
I agree about the jj tubes. Not at all good tubes
I am glad I have not bought one. I have been looking at these on Reverb. The cheapest is around 560.00 plus tax say 600.00. 750 new. The sellers I have contacted do not have the footswitches. That is around 50.00. The good thing -it appears that there is a boost (N big deal, and an FX loop button-This isa make or break situation, as I have been spoiled by my Mesa TC 50 watt head. It has the 3 channel and the FX loop on the footswitch. This is a must for me. The sellers on Reverb state they do not come with a footswitch. When I look at Sweetwater there are pitcures that show these amps come with one. This tells me something went wrong for them, or not the origional owners. No one I emailed back and fourth are telling me to go buy a ffotswitch now before buying the amp they want to sell for 2-250.00 less. Naturally no warranty. Sweetwater has a 2 year built in protection plan, no cost.
The original output valves looked like JJs, albeit labelled Marshall.
Hi Steve I'm 99% certain Marshall do not use JJ valves.
@@stuartukguitarampguy5830 They do, I believe the red print tubes are JJs and white print tubes are Chinese Shuguangs, who have been closed since 2019.
Only major tube factories left are JJ in Slovakia, New Sensor in Russia and Psvane in China, who are geared more towards the hifi market and pretty expensive, although I think TADs new Redbase line are made there.
Not a lot of choice left for valve aficionados.
@@alecboyyes Hi Yes the valve situation is dire. For a number of reasons there seems little chance of the Shuguang factory reopening any time soon, if ever.
Didn't really sound like a typical valve failure to me, but there you go.. Rule #1: Check the easiest thing first!
Yes I totally agree, you probably heard I was a bit surprised.
Hovering over the live board to mess with/look at the knobs... be careful with that... super dangerous. 400 constant voltage.
Woah, really? Thanks for the heads up!! :)
My origin 20 power trans filament supply had a partial short to ht internally ' bad hum had to change it'
when in doubt change the tubes...
Exactly!
The factory tubes on this amp are horrible. They must be Chinese with the Marshall logo and they break in just over two months. It's a good amp, it sounds great, but it's obvious where they've cut back on quality in order to bring it to the market at an affordable price. It is necessary to replace them with very hard valves because they work at very high voltages. The last one I repaired came from the factory with a 45 mAh bias setting, and according to Weber's chart it is absolutely disproportionate.
I am sure that neither Marshall or even Mesa makes their own valves. The question is, who does? Its either China or Russia.
"I don't like JJs" and then put marshalls which are rebranded JJs (EL34, E34L or EL34II whatever model it is)... Ooooook
Hi Andrea. I'm not totally sure that's right is it? Are the Marshalls rebranded JJ? Anyway, I mean the 'normal' EL34 JJ. The EL34 II is better and I believe they made this specifically to overcome the problem I was mentioning.
Btw I do like JJ except in one situation - this situiation. Normal JJ EL34 in 100W Marshall. They pften fail.
@@stuartukguitarampguy5830 yes, Marshall el34 are jj rebranded, in my origin there are Marshall el34 which are, according to the code , rebranded el34 ii jj
@@andrp692 Hi Andrea Yes I've now confirmed this too. Anyway, so it's basically the original EL34 (JJ) that are no good in Marshall 100W amps. The JJ EL34II is fine and I use them. Also the Marshall EL34 of course which I now know is the same thing.
You always speak about origin Marshall tubes - there are no existing Original Marshall Tubes, their are always build by Mullard, Valvo, Siemens, Tungsol, Tesla, JJ , or unknown Chinese Brands !
Hi Rudolf, yes I know it's just a shorthand.