Amp Camp Amp - ACA

Yes its Block trafo from reichelt.

I take the 50VA 24V version. This gives me ca. 30V unregulated Rails.
Because i want to regulate the voltage like in zen var. 3 --> this is the next step
In the moment i burn the voltage down with resistors to desired level.
Works really well but resitors run a little bit hot.

If you would do it without active regulation, probably 15V secondary should be ok.

correct me if i`m wrong ---but this should give ca. 19V at the supply

greets alex
 
Question for you more technical types:

My vanilla ACA will be driving 109dB/W/m horns and I'll be using Lpads on the speaker level to bring them in line with the the bass output. I also need a vol pot for gain matching. What pot value should I use 50k/100k etc etc?

tnx chaps

James
 
Oh, okay.

Pano's reasoning was this - "Horns are very efficient. That means all the hiss, hum, buzz, rizz, etc. that you don't notice on normal speakers will be plenty obvious on the horns. Dropping the horn's level 6-12dB will get the amp's output up out of the dirt. Yes, you'll need more power, but that's rarely a problem in domestic settings."
 
Amp Camp Amp as BA-2 driver

I recently built a pair of Amp Camp amps point to point on perf board. The components were as Nelson specified. I was very impressed with how these little amps perform in my living room system. When I let a friend listen to them, he also was impressed, but wanted to know how the output power could be increased. I described the ways that Nelson mentioned in the Amp Camp article, and the various methods that others on this thread have proposed, but he challenged me to think of a way that perhaps no one else had tried. I had built BA-2 a while back that, prior to the ACA's, was my system amp. The idea occurred to me to use the ACA's as a front-end to the BA-2 output stage (Nelson mentions his modular design of the BA series circuits), to increase the output capability while hopefully not losing too much of the character of the ACA. We cobbled this together and listened to some CD's. I have to say the result was quite nice, and didn't lose all the quality of the original Amp Camp design. Bass response seemed a lot stronger for some reason. For anyone interested in trying this experiment, we loaded the ACA output with five-Watt, eight-ohm resistors and connected the ACA output to the BA-2's output stage at the circuit's coupling cap. If anyone else tries this, I'd like to know your thoughts of the result.
 
Actually I drive a pair of 8 Ohm two way speakers with an efficiency of 87dB and the aca goes loud enough for me.
Can I use it on 4 Ohm speakers and 92dB efficiency?
I read in the Zen Amplifier article that a single ended amp won't deliver enough current into a 4 ohm load.
 
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