Amp Camp Amp - ACA

[jrebman]

Can somebody verbally describe where this new resistor goes? Can't see the pic.

Thanks,

Jim

 

[Zen Mod]

solder 2K2 from B to E of small bjt - Q3 , ZTX450

 

[jrebman]

Thanks ZM -- simple enough.

-- Jim

 

[Variac]

and the women?

that's easy .......

I live where amps are hot

 

[Variac]

Seems wise to check the 10volt spec as explained in the original article...

Just did the tweak, it pulls instead of 0.98 A now 1.40 A, and on the AC side it pulls 34 Watt instead of 21 Watt.
Adjusted the drain of Q1 to 10 Volts.
My little red ACA chassis from the DIYAudio store can handle this extra heat very easily.

Walter

 

[jacco vermeulen]

and the women?

As ZM already told you, he lives where amps are hot.

 

[WalterW]

 

[ma_coule]

I live where (l)amps are hot

 

[mc297]

The scheme reports 2K21: the resistor should be 2K21 (1%) or is it the same using 2K2, normal 5% tol.?

solder 2K2 from B to E of small bjt - Q3 , ZTX450

 

[Zen Mod]

2K2

2K21 is just Papa's usual trick to confuse us

(and wakoo Yank way of making costlier resistors)

 

[Zen Mod]

at least use IRF510 or similar small mosfet - at lowish PSU it will work better

 

[kiven chen]

How about K1058?

 

[kiven chen]

I have some IRF610 540
No 510

 

[Zen Mod]

I have some IRF610 540
No 510

good enough - they're similar

 

[kiven chen]

Thank you, I will try to use IRF610.
I 1:30 A.M. here, I'm going to bed,
Good night. Bye!

 

[sippy]

Hi,
am considering (still) building ACA.
A while back a friend gave me a dead amp and it has a pair of heat sinks with the following dimensions:
H: 120mm
W: 110mm
D: 40mm
Base: 5mm
14 fins per sink.

Base thickness isn't much, but could be increased with a 10mm or so plate lapped / bolted to the sink.

 

[sippy]

Forgot to ask:
Are these sinks too small?

 

[6L6]

They are likely just big enough.

 

[kiven chen]

If it gets too hot, increase 4 high power resistance（0.47 and 0.68） would be able to reduce operating current

 

[sippy]

They are likely just big enough.

Is this with an increase in base thickness?

Thanks for the tip Kivin, the lay-out of the case allows for the fitting of fans if needs be.