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Old 1st October 2006, 08:33 PM   #1
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Default need advice selecting a 2a3

I have decided to build my first DIY 2a3 tube amp to drive my Fostex 206E speakers mounted in BHL (I only need few watts). I have chosen four rather similar projects but because of my lack of knowledge on this matter, I don't know which of them could be the best. The schematics are:

1. JE Labs Stereo Single Ended 2A3 Amplifier 2001 Edition, at

2. JE Labs Simple 2A3 at

3. JE Labs SRPP 2A3 at

4. Arnold Cruz's 2A3 at

Can you help me selecting one ?

Sorry for my bad English
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Old 1st October 2006, 10:15 PM   #2
phn is offline phn  Sweden
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A very nice-looking 2A3 here (Angelo):
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Old 1st October 2006, 11:57 PM   #3
arnoldc is offline arnoldc  Philippines
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Default Re: need advice selecting a 2a3

Originally posted by lquintas
4. Arnold Cruz's 2A3 at
Yikes! That's me

And it's based on JE Labs SRPP 2A3

If you want higher gain (no need for active linestage), you can also try the Sun Audio 2A3 that uses 6SN7 instead as drivers. I have built this too, but stuck to the above.

If you have access to 76/56 tubes, I would suggest you give JE Labs 2A3 DX a try. I have built this briefly, but changed it to a 300B instead.
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Old 2nd October 2006, 11:45 PM   #4
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you might also want to look into this design:

Best regards
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Old 3rd October 2006, 07:17 AM   #5
EC8010 is offline EC8010  United Kingdom
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Hello lquintas, I've edited the title of this thread - you might get more responses...
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
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Old 3rd October 2006, 12:29 PM   #6
Cassiel is offline Cassiel  Libya
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The Sun audio circuit sounds very good but it all depends on your needs and tastes. How much gain do you need? With a CD player as a source the SRPP will have enough gain but if you have less than 2 volts input do the Sun audio amp. I think it sounds more on the romantic side, SRPP has more nerve.

Anyway the 2a3 always sounds good so don't worry much about what circuit you choose.
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Old 3rd October 2006, 06:00 PM   #7
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Thank you all for your advices. The JE Labs 2A3 DX is for me the dreamed amp, but it is rather expensive (about 1200 euros) and therefore risky for me and my skills: my only experience is a first amp with ECC83 and EL84 tubes (I needed help to make it sound) that hums too much in my horn speakers, and a gainclone (this one works very well). But I want to do a new step, and the 2a3 amps I am considering cost the half. I don't need too much gain, I use a CD player. My principal concern is hum... and a simple schematic. Perhaps the JE LABS 2A3 or 300B (Derek Walton's site is wonderful) is not more difficult than the JE Labs SRPP 2A3 amp, is it?
Concerning Angelo's amp and the very interesting EL84/2A3 amp of Torsten Eisenberg, I think that it will be more difficult for me to identify and to get the parts than those of JE Labs (mainly Angela Instruments).
Arnold: Does the difference between your 2A3 and the 300B worth it ?
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Old 1st April 2014, 11:50 AM   #8
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very interesting EL84/2A3 amp of Torsten Eisenberg
Does anyone know what happened to Torsten's site...and more specifically the page he had on his amp.

Did he take the design of the net because of some problems with it or perhaps he just took it off his site because it is not his primary main interest?
If you can see the speaker cone's not hifi.
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Old 2nd April 2014, 08:50 PM   #9
tomchr is offline tomchr  Canada
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My Damn Good 300B design can be modified to drive the 2A3 by changing a couple of resistors.

Modulus-86: 40W/8Ω @ 0.000061% THD. HP-1: 3W/20Ω, 450mW/300Ω @ 0.000032% THD. DG300B and Other Tube Circuits.
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Old 2nd April 2014, 09:38 PM   #10
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Recommend a direct coupled design using 12ax7 driver. Very simple design. My everyday amp and I've tried Other designs. Go to audio asylum and search for info.

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