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FlaCharlie
Super Member
I haven't, but I would have two concerns. First, and most importantly, the few I looked at did not have a schematic. I think I'd want to know what circuit was being used and do some research on it. Second, I've always been a little concerned that tube sockets that are mounted on a circuit board might put pressure on the board and cause it to flex when tubes are removed and installed. And I don't recall if the ones I looked at gave any info on how thick the board is. Maybe that's not a major issue? Still, I'd be concerned about possible breakage of the board or how it might affect solder joints.
When I DIY something I prefer to use a solid chassis and point to point wiring. That way you can easily alter the circuit and try a different design if you want, try a different layout, or have more flexibility in your choice of parts. My most recent DIY project, a SE amp, has been through a few incarnations and configurations over the past several years - 6V6 in triode, 6V6 in pentode, 6P3S-E in pentode and now a true SET using a 6A5G. I've run cathode battery bias on both drivers (27s) and the 6V6 outputs, cathode battery bias on drivers only, and now grid battery bias on the 27s. Changes like that would be difficult, or maybe impossible, with a PCB. You are pretty much stuck with the original design.
Of course there are always kits that are known to perform well because a lot of people have built them and reported good results. There are tradeoffs involved in each approach.
Was there a particular PCB you were interested in? How bout a link?
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primosounds
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If it is a single ended circuit building point to point is definitely the way to go.
FlaCharlie
Super Member
True, SE is much simpler. But even for PP the advantages I mentioned still apply. I also have a DIY PP 6B4G amp that I plan to convert to 6A5G and make a couple of other changes to. Having used point to point, it will be relatively simple.
primosounds
Powered with pure tube sounds.
I am just saying that with a SE amp being such a straight forward arrangement of driver to power tube. point to point is relatively easy and a good beginners project.
KKnight
Active Member
Go to fleabay. Enter EL34 pcb in the search.
"..there are always kits that are known to perform well because a lot of people have built them and reported good results..".
Great! Can you link 3~4 of them?
You guys get off topic so quick lol.. Isnt a discussion about the advantages of point-to-point wiring.
There are a great deal of seemingly decent quality bare PCB's on fleabay for EL34 amps.
Who has built one from scratch?
FlaCharlie
Super Member
As I said, I did look at a few of them before I posted. My comments were based on what I saw (or didn't see, actually, which was schematics of the circuit) as well as what I perceive as the possible limitations imposed by using a PCB. Perhaps there are other listings that do have schematics. And perhaps the limitations which are inherent in using PCBs aren't important to you. The point was to make sure you're aware of the difficulties involved IF you should want to alter the circuit and experiment. Better to be aware of the limitations ahead of time, that's all. I don't consider those considerations to be off topic.
Since you have apparently spent some time investigating these, why don't you post some links to some of the ones that you find most interesting? You seem to have thought about which output tube you want to use. But are you interested in SE or PP? Tube rectification or solid state? Typically, those factors are primary considerations, along with the choice of a particular circuit.
When I mentioned kits the ones that came to mind were the ones sold by Bob Latino, which I've seen discussed here and on other boards. I think they are based on the Dynaco design but, perhaps, updated a bit. They seem to have quite a few avid fans. I'm sure, if you asked, their owners would be happy to share their experiences. Here's a link: http://www.tubes4hifi.com/bob.htm
I've also heard of this company before: http://www.ankaudiokits.com/l4el34pp.html
And here's another that popped up in a quick search: http://www.audion.co.uk/Kits/kits.html
Yeah, some of these kits are pretty pricey. I'm sure there are many more including much cheaper ones available from China. Seems I read a post of yours saying that you've owned quite a few Chinese amps so I'm sure you know a lot more about the Chinese offerings than I do. I would think that would be another reason why you would want to see the schematics. You may not want to build a circuit that you've used already, whether you found it lacking or thought it sounded great. Why would you want to build something you already have? Well, maybe you would just to build something yourself.
I only have three EL34 amps so my experience is somewhat limited . . . a Dynaco ST-70, which I have yet to rebuild so no real experience with it. I also have an Eico HF-87 and a Pilot SA-260, both of which sound great and are very well regarded. I've never heard a Marantz 8B but I've read comments that the Pilot is in the same league. I've also read high praise for the Bell 6060. I've seen PCBs that are supposedly based on the Marantz 7C preamp so perhaps someone makes one based on the 8B. Of course all these schematics, and many others, are available. But you'd have to build point to point. Or maybe you can find someone to custom make a PCB for you. Sorry if that's off topic.
Since you have apparently spent some time investigating these, why don't you post some links to some of the ones that you find most interesting? You seem to have thought about which output tube you want to use. But are you interested in SE or PP? Tube rectification or solid state? Typically, those factors are primary considerations, along with the choice of a particular circuit.
When I mentioned kits the ones that came to mind were the ones sold by Bob Latino, which I've seen discussed here and on other boards. I think they are based on the Dynaco design but, perhaps, updated a bit. They seem to have quite a few avid fans. I'm sure, if you asked, their owners would be happy to share their experiences. Here's a link: http://www.tubes4hifi.com/bob.htm
I've also heard of this company before: http://www.ankaudiokits.com/l4el34pp.html
And here's another that popped up in a quick search: http://www.audion.co.uk/Kits/kits.html
Yeah, some of these kits are pretty pricey. I'm sure there are many more including much cheaper ones available from China. Seems I read a post of yours saying that you've owned quite a few Chinese amps so I'm sure you know a lot more about the Chinese offerings than I do. I would think that would be another reason why you would want to see the schematics. You may not want to build a circuit that you've used already, whether you found it lacking or thought it sounded great. Why would you want to build something you already have? Well, maybe you would just to build something yourself.
I only have three EL34 amps so my experience is somewhat limited . . . a Dynaco ST-70, which I have yet to rebuild so no real experience with it. I also have an Eico HF-87 and a Pilot SA-260, both of which sound great and are very well regarded. I've never heard a Marantz 8B but I've read comments that the Pilot is in the same league. I've also read high praise for the Bell 6060. I've seen PCBs that are supposedly based on the Marantz 7C preamp so perhaps someone makes one based on the 8B. Of course all these schematics, and many others, are available. But you'd have to build point to point. Or maybe you can find someone to custom make a PCB for you. Sorry if that's off topic.
Shadowdog
Super Member
If you want proven very affordable SE & SET PCB's George Anderson's a tube amp enthusiast whom is recently retired from Motorola.
See his site at tubelab.com and his forum on diyaudio with schematics for his PP EL84 amp.
Another site to check out is diytube.com with simpler designs for SE & SET etc as well as Eico PP PCB'S for EL34 etc.
See his site at tubelab.com and his forum on diyaudio with schematics for his PP EL84 amp.
Another site to check out is diytube.com with simpler designs for SE & SET etc as well as Eico PP PCB'S for EL34 etc.
FlaCharlie
Super Member
What's this talk of EL84s? Clearly off topic - he's interested in EL34s not wimpy EL84s. Sheesh!
I forgot about the Tubelab designs. I've never looked at his offerings closely but I seemed to recall that he had some boards that allowed the use of a variety of output tubes. So I took a look at his site. Here's a link to his board that can be built with, yes, EL34s.
http://tubelab.com/pc-boards/tubelab-sse/
I'd suggest going this route and forgetting about the Chinese PCBs. Lots of people have built these and there is lots of documentation and help available - from the engineer who designed them - if you have questions.
Shadowdog
Super Member
I just mentioned what he was selling as for the EL84's (but you could run 7591 tubes in that circuit for the same power as EL34 with a bigger power supply and sky wired output tube sockets) , and he is supposed to have a PP driver board out
for a number of big tubes out soon. I should mention Pete Millet also has PP driver PCB's for sweep tubes
that could be used with regular big tubes, but it would be too complicated for a beginner to change things.
As for SE or PP it just depends on the speakers one has with SE 10-12 W/CH is the most your going to get
affordably because of output transformer cost's etc.
for a number of big tubes out soon. I should mention Pete Millet also has PP driver PCB's for sweep tubes
that could be used with regular big tubes, but it would be too complicated for a beginner to change things.
As for SE or PP it just depends on the speakers one has with SE 10-12 W/CH is the most your going to get
affordably because of output transformer cost's etc.
OneyedK
Active Member
This one seems ok to me:
http://www.ebay.com/itm/EL34-PP-pow...485094?hash=item338f002b66:g:SnMAAOxyP4dTd4eA
Plain simple 12AX7 driving a 12AU7 long tail, can be taylored to your taste.
You'll have to build a decent power supply yourself, and I wouldn't recommend the sellers suggestion.
(gimme a SS rectifier, large caps and a small -or no- choke)
Did a few of scratch build EL34PP's, but like the others here, point to point.
http://www.ebay.com/itm/EL34-PP-pow...485094?hash=item338f002b66:g:SnMAAOxyP4dTd4eA
Plain simple 12AX7 driving a 12AU7 long tail, can be taylored to your taste.
You'll have to build a decent power supply yourself, and I wouldn't recommend the sellers suggestion.
(gimme a SS rectifier, large caps and a small -or no- choke)
Did a few of scratch build EL34PP's, but like the others here, point to point.
KKnight
Active Member
Man..
No one has built one.
The Tubelab IS a pcb from China. Get it cheaper directly thru fleabay.
If I or anyone wanted a EL84 kit the waaaaaay overpriced Oddwatt Poddwatt kit is out there.
Ya... I know. The link you posted is one of the ones on fleabay and what I originally asked in the first post. But you or no one has actually built one.
No one has built one.
The Tubelab IS a pcb from China. Get it cheaper directly thru fleabay.
If I or anyone wanted a EL84 kit the waaaaaay overpriced Oddwatt Poddwatt kit is out there.
Ya... I know. The link you posted is one of the ones on fleabay and what I originally asked in the first post. But you or no one has actually built one.
FlaCharlie
Super Member
Tubelab apparently does sell things on eBay but don't seem to have anything on there now. Here's their seller listings: http://www.ebay.com/sch/tubelab*com/m.html?_nkw=&_armrs=1&_from=&_ipg=
I wouldn't be surprised if someone is selling knockoffs. I'd be concerned that the quality may not be as good, though. And, frankly, a PCB is such a small part of the overall cost of a DIY build that - to me - saving literally a few bucks by buying a knockoff wouldn't make sense.
If being able to tap into the experience of others is as important to you as it seems to be, I would think that Tubelab would be the best option. There are obviously lots of people who have built them - a whole forum full of builders who have shared and continue to share their experiences daily. Plus extensive documentation and advice directly from the designer.
I'm not sure if it's OK to link another forum on here so I won't but there's a link on their website. It looks like there are 64 pages of threads on there - that's almost 1300 threads!
So it seems to meet your interests - PCB from China, usable with EL34s, sold on eBay, lots of people have built them and can tell you all about it.
FlaCharlie
Super Member
Just curious . . . did you decide to build an amp with one of the Chinese eBay boards you mentioned (or maybe the Tubelab) or have you abandoned the idea of this project?
Some of them might not be much different from completed Chinese amps offered on eBay - hard to say since the schematics aren't always easy to find - but at least you have the option of choosing the parts you want. I certainly wouldn't shy away from trying one just because nobody on this board has built one. Where's your pioneering spirit??
Some of them might not be much different from completed Chinese amps offered on eBay - hard to say since the schematics aren't always easy to find - but at least you have the option of choosing the parts you want. I certainly wouldn't shy away from trying one just because nobody on this board has built one. Where's your pioneering spirit??
