EL34 PP - again !!!

[Klaatu]

Hello all,

this is my first post - so be gentle.

I'm looking to take the plunge and build a decent but easy amp, so I searched the net for a PCB design to get me started.

I found this one :-



I looked at it and I find the voltages on the driver stages to be very low, but this could just be ignorance on my side.

Could you guys offer your opinion on this design and the voltages being used ?

Thanks in advance

[Klaatu]

I see that the schematic is not available on my initial post but I am not able to edit it,
so I have placed a copy of the schematic here -> EL34 PP Amp

Klaatu

[boywonder]

Originally Posted by Klaatu

I'm looking to take the plunge and build a decent but easy amp, so I searched the net for a PCB design to get me started.

IMHO a fixed bias PPP amp isn't exactly an easy amp, but a PCB would make the build easier. 4 matched pairs of output tubes and the related iron won't be cheap, either.

What's your $$ budget?

How much power do you need?

What is the sensitivity of your speakers?

How large is your listening room?

What genre of music do you listen to?

If you are not afraid of point-to-point wiring (it's quite easy), there are handfuls of great PP projects on the forum here, such as the Eli D's El Cheapo, Gingertubes baby huey, Poindexter's Music Machine, etc. etc.

If single ended power is enough (5W-12W or so), Tubelab's Simple SE is a great first amp and he sells the PCB's for about $35 or so. Very flexible, cathode bias, tube or SS rectification, triode or UL, EL34, KT88, 6L6 output tubes, etc. Lot's of support here for that project, check out Tubelab George's thread.

Or if kits suit your fancy check out the various dynaclones which are updated classic Mullard PP designs.

Here is one vendor, but there are many more.

Triode Electronics Inc. Tube Amp Kits Transformers Tubes Dynaco Upgrades and Parts

Keep in mind that fixed bias requires a slightly more complex power supply (a negative rail) than cathode bias and fixed bias also requires periodic adjustments (no big deal....)

I realize that I haven't answered your questions, but I thought I'd give you my .02.

[Klaatu]

Okay, let me have a go at your questions.

1. No specific budget, I just want something to build.
2. Looking for a high power amp - no reason, just want one :-)
3. No speakers yet, will have to buy some to match.
4. 15' * 20'
5. Everything, except country and rap.

I suppose I phrased my initial question badly. I found this schematic on the web and it appealed to me somehow, however as I said the figures look low to me and wondered if anyone had actually built one of these and could advise me on its sound quality etc.

I have no problem actually building this, but I would not be able to fix it if it sounded awful when finished, that was my main concern.

Thanks

Klaatu

[alex mm]

...... from same german site , my amplifier with only two NOS tubes 6P3S per channel

Regards Alex

[tinitus]

Triode Dick's Page

mono Bill

[tinitus]

different

Acrosound 6-50 Class A PP Monobloecke, von Jochen Wankmiller

http://www.jogis-roehrenbude.de/Lese...rion34MKII.htm

[kentarhos]

If you want a very good el34 pp amp , is the ''straight''
by Elektor magazine, fully documented , easy to build ,pcb .
Me and a lot of friends have built it .
Excellent sound !
If you are interested , i can give the links.

[mashaffer]

Clever way of balancing the PI. Simple.

[boywonder]

Originally Posted by tinitus

Triode Dick's Page

mono Bill

Has anyone around here built this? I'm halfway through breadboarding the mono Bill II but have not found any comments/suggestions about this amp......

Klaatu:

Here are a couple of additional links to 60W (or so) Mullard 5-20 based amp projects. Both are PP UL KT88 amps, with the Opus using mosfets and ccs's for additional fun NO PCBs for these, though.

"Mullard 5-20 KT88 PP blocks!

OPUS 5.0 A Modern Mullard