ACA illustrated build guide

[6L6]

They are an amazing PSU - because they are able to accept exoteric interference.

That's a useful specification.

 

[vdi_nenna]

I absolutely love the "warnings" listed on the PSU (see Post 17, first photo).

Nice warning, that the PSU will not cause harmful interference, I guess.

The second warning, I can't even begin to decipher......!

The unit will not interfere with other electronic components, but other compononents can interfere with it. In other words, it can pickup interference.

I think this is just a case of word choice by someone with English as a second language.

 

[6L6]

Yes, we were just making fun of the Chinglish...

 

[bcmbob]

......It's the best Headphone Amp / Preamp, can drive anything, is completely silent, and is just a truly amazing project. On top of that it's utterly fantastic value for the money.

Wholeheartedly recommended to anybody who needs any of the following -

Attenuation
Gain
The ability to drive anything
Headphone amp
Impedance matching
A new, fun, useful project.

+1

I got the new Subbu DAC, the 02 as pre and a BA-3 all together today - and the combo is really top shelf. The ACAs are next to hear with the 02 and I'm sure that will provide the same performance level bump.

 

[rubofdagreen]

I ordered the kit to power my tweeters. The build guide was excellent. Thank you! Very Very simple build, dive in the water is great. I recommend this for everyone. Even if you have zero knowledge. I found the 2.1K resistors finally in the bag with the LCD holders. I now believe the heat sinks I am using for other Pass amps are over sized. This thing gets pretty warm. I am a fan of, if you can't cuddle with it it is too hot.

 

[Zen Mod]

Big ACA Shade ......... just for fun

look Ma!

no hands!

......... I mean - no feedback (at least - not overall one)

 

[WalterW]

Nice! Would love to listen to your no feedback mod, but 70 Watts is way over the top....

 

[Zen Mod]

no use to change it in smaller iteration , 19V is way too sissy for Shaded mosfet

result is 20db more THD , comparing to original ACA

 

[johngalt47]

I just finished mine, adjusted the bias and now am listening to them through my fairly inefficient speakers. I was surprised how much I had to crank up my preamp compared to my Aragon 4004 Mk II since I don't listen to them loudly. The tonal balance is a little different but they sound ok.

 

[bcmbob]

Now, is that really fair ????

 

[johngalt47]

I didn't mean it as a criticism, because the ACA sounds good. I probably only use the first watt or two of any amp since I don't listen to loud music.

 

[bcmbob]

My reply was just a weak attampt at humor. Understood what you were saying

 

[johngalt47]

Ok, I discovered that these amps don't have enough power for watching movies. Still good for music though.

 

[Flyin_V]

Can someone tell me which transistors are Q3 and which are Q4?

Thanks.

 

[Zen Mod]

in which schematic ?

 

[Flyin_V]

The Amp Camp #1, as is post #1 of this thread.

Thanks

 

[Zen Mod]

Q4 is JFet , Q3 is bjt

 

[Flyin_V]

Thanks for the reply, but I have no idea what you're talking about. One bag says it contains "transistors" (LSK170F) and another bag has the ZTX transistors but nothing more about which is Q3 and Q4. Could you be more specific?

Thanks

 

[Flyin_V]

Never mind, a local guy had the answer.

Thanks again

 

[Zen Mod]

well - you have these on schematic , too