Stephe, you have uncovered the reason for my first version having floating ground, Two fried transformers later the problem was solved but seeing that ground hole being isolated from ground is a true eye-opener! It looks like future builders should look carefully for this - it is easy to miss
Haha, this is me, I found out the hard way by doing exactly what Stephe is talking about here. I'd just like to say a MASSIVE thank you to Stephe for personally walking me through the problems that I've been having over the last few weeks. VERY MUCH APPRECIATED !!!!!
Great advice Stephe! This is good for everyone! Inexperienced builders may miss minor, but important details. This video will save you a lot of time & brainstrain too, trying to help people. GOLDEN information!
I built one of these following your design except for a couple of things. I had to use a case just a little bit shorter to fit on the shelf. I put a sheet of copper between the two boards which I split per the first build. Turned out fine with no noise. Your new revisions look good. Thanks for sharing.
What a great timing. I was just about to put the soldered board into the chassis. Now I could do all checks following your advices. Indeed, I had some bad solder joints and such a clone of clone board, with bad grounding. Thanks for this great video! Love your channel.
I just took mine apart to make some minor tweaks, and bam…super loud hum again. Fought with it for a couple of hours. Finally fixed it with a new star washer! The solder lug had a built in star washer, but can only be used once. Added a star washer to the grind lug and back to normal.
Quick tip for taking the corners off the standoffs; chuck up the standoff in a drill and spin it against your spinning grinder wheel at the desired angle.
I got one of the "clone" EAR834's from China. The one that comes with the power supply separate from the the preamp board. It wasn't overly expensive, but I found it to be virtually silent even at idle. So much so that I have forgotten to turn it off a couple of times.... About the only thing I found with it that I needed to change was just some of the capacitors in the audio chain. Like a lot of clones, the components chosen were not the best quality
I've had a build using the same Douk board for a little while now and it's amazing just how much refinement you can do to it. There are a bunch of mods suggested on Lenco Heaven drawn together from a lot of different members and they're definitely worth having a look at, imo. Even then though, I still had some light audible hum on headphones and the solution for me ended up being to beef up the original kit supplied components for the DC heaters. The corner frequency on the RC filters comes out a bit too high for comfort so I paralleled some spare 20000 uF nichicons with the original caps included and now the noise floor of the first triode stage is the only interference :) as long as your parts can handle the ripple current and the heater voltage under load is still where it needs to be, I really dont think there's any downside to giving it a go :)
Hi Stephe. Beware Rega turntables, as they do not have a separate ground/earth wire. They connect their ground to the left channel's negative. I had a problem with my Rega and so I cut the ground wire to the left channel and connected a ground wire to one of the tonearm's mounting screws and ran the wire to my tube phono preamp's earth lug. This solved the problem, so maybe you should ask whether they are using the EAR834 with a Rega turntable. PS - My phono preamp was also a kit, but from Mellow Tone Kits. Refer to their RUclips channel by the same name.
Yayy, so help me Morgan Jones :) Whoa, nice board!! Like to think I've gort a ROUGH idea how to Do it - but I KNOW I try and cram things in a bit too close ;)
The high voltage on mine was running at just over 300 volts dc. I removed the two 75 volt zeners and ran all 68volt zeners. Now it regulates to 286 volts. I think that got rid of my mid frequency distortion.
Mariusz! Hey, brother. Great to see ya here. This is one of my absolute favorite channels. Stephe is a brilliant amp builder and her trouble shooting skills are top notch. This is the phono pre I’ve built in the past. I’m building my 4th right now. It’s a fantastic sounding phono stage.
Please let me know how to connect correctly for this phono preamp the ground of mains earth socket, gnd binding post for tonearm cable, gnd of transformer and gnd of board to reduce hum saving the electrical safety of the appliance. Greetings from Italy. Marco
I'm one of those who seperated the boards and changes the layout since I didn't know better. Also, I hade a short early on in the build. If a short fries the choke, what is the symptom of that? Could that result in hum?
There’s no substitute for experience. Your a great teacher. Lord I love this Channel 🌹
Stephe, you have uncovered the reason for my first version having floating ground, Two fried transformers later the problem was solved but seeing that ground hole being isolated from ground is a true eye-opener! It looks like future builders should look carefully for this - it is easy to miss
RF Electrical Engineer and Audiophile here, Great explanation of design/build philosophy. One of best builder channels on RUclips.. Thanks for vids.
Haha, this is me, I found out the hard way by doing exactly what Stephe is talking about here.
I'd just like to say a MASSIVE thank you to Stephe for personally walking me through the problems that I've been having over the last few weeks. VERY MUCH APPRECIATED !!!!!
Man tell me She’s not the best.
What a great Lady
Thank You :)
Great advice Stephe! This is good for everyone! Inexperienced builders may miss minor, but important details. This video will save you a lot of time & brainstrain too, trying to help people. GOLDEN information!
Morgan Jones is an excellent reference. It’s one of the first books I read when I started building amplifiers 20 years ago,
And IMHO it's easy to understand language without pages of math to sort through.
Great video, learned a lot. In RF circuits it's exactly the same. Solid ground plane and quality components like capacitors. Excellent video Stephe
I built one of these following your design except for a couple of things. I had to use a case just a little bit shorter to fit on the shelf. I put a sheet of copper between the two boards which I split per the first build. Turned out fine with no noise. Your new revisions look good. Thanks for sharing.
What a great timing. I was just about to put the soldered board into the chassis. Now I could do all checks following your advices. Indeed, I had some bad solder joints and such a clone of clone board, with bad grounding. Thanks for this great video! Love your channel.
Glad I could help
I just took mine apart to make some minor tweaks, and bam…super loud hum again. Fought with it for a couple of hours. Finally fixed it with a new star washer! The solder lug had a built in star washer, but can only be used once. Added a star washer to the grind lug and back to normal.
Great tip!!!
I just fear you will stop making videos. I get so much enjoyment from them.
Not in my plans, I enjoy making them too!
Quick tip for taking the corners off the standoffs; chuck up the standoff in a drill and spin it against your spinning grinder wheel at the desired angle.
I got one of the "clone" EAR834's from China. The one that comes with the power supply separate from the the preamp board. It wasn't overly expensive, but I found it to be virtually silent even at idle. So much so that I have forgotten to turn it off a couple of times.... About the only thing I found with it that I needed to change was just some of the capacitors in the audio chain. Like a lot of clones, the components chosen were not the best quality
Great info! I'm hoping 2024 will be the year I can finally build one, but until then I'm still rockin' with my Little Bear T11!
The little bear upgraded is a nice little pre-amp!
I've had a build using the same Douk board for a little while now and it's amazing just how much refinement you can do to it. There are a bunch of mods suggested on Lenco Heaven drawn together from a lot of different members and they're definitely worth having a look at, imo. Even then though, I still had some light audible hum on headphones and the solution for me ended up being to beef up the original kit supplied components for the DC heaters. The corner frequency on the RC filters comes out a bit too high for comfort so I paralleled some spare 20000 uF nichicons with the original caps included and now the noise floor of the first triode stage is the only interference :) as long as your parts can handle the ripple current and the heater voltage under load is still where it needs to be, I really dont think there's any downside to giving it a go :)
Hi Stephe. Beware Rega turntables, as they do not have a separate ground/earth wire. They connect their ground to the left channel's negative. I had a problem with my Rega and so I cut the ground wire to the left channel and connected a ground wire to one of the tonearm's mounting screws and ran the wire to my tube phono preamp's earth lug. This solved the problem, so maybe you should ask whether they are using the EAR834 with a Rega turntable. PS - My phono preamp was also a kit, but from Mellow Tone Kits. Refer to their RUclips channel by the same name.
Yayy, so help me Morgan Jones :)
Whoa, nice board!!
Like to think I've gort a ROUGH idea how to Do it - but I KNOW I try and cram things in a bit too close ;)
The high voltage on mine was running at just over 300 volts dc. I removed the two 75 volt zeners and ran all 68volt zeners. Now it regulates to 286 volts. I think that got rid of my mid frequency distortion.
I ❤ this channel.
Great explanation.
Glad it was helpful!
To keep the stand off from connecting to ground, would it make sense to use a nylon washer, or a nylon standoff & screw?
That's an option.
Very informative! 🙂
Glad it was helpful!
Me like it. Me follow this build series. 👍🏻
Mariusz! Hey, brother. Great to see ya here. This is one of my absolute favorite channels. Stephe is a brilliant amp builder and her trouble shooting skills are top notch. This is the phono pre I’ve built in the past. I’m building my 4th right now. It’s a fantastic sounding phono stage.
@@NickP333Hey Nick. Yeah, subed on ur recommendation. And like it. Good stuff and yeah, this phono sure looks familiar. 😂
Have you tried 12AY7 / 6072A tubes
Please let me know how to connect correctly for this phono preamp the ground of mains earth socket, gnd binding post for tonearm cable, gnd of transformer and gnd of board to reduce hum saving the electrical safety of the appliance. Greetings from Italy. Marco
Probably better to send me an email from the contact page of my website.
Genius!
Hi Stephe, Where can you purchase these EAR845 Clone preamp kits from?
I get mine off ebay
could this be modified to suit guitar preamp application🎸🎶 if not, could you reccomend something
No, these have EQ correction for vinyl i.e. RIAA EQ.
For guitar amps , build and repair or modifications..........have a look at D LAB.......( on yt )
I'm one of those who seperated the boards and changes the layout since I didn't know better. Also, I hade a short early on in the build. If a short fries the choke, what is the symptom of that? Could that result in hum?
That's not likely the cause.
@@SkunkieDesignsElectronics Ok, thanks! I will look at that ground point in the front and see wich board I have. Thanks for your great content!