Aleph J Schematic

Now that my F5T will soon replace my F5 ,I intend to reuse my F5 chassis, heatsink & psu for Aleph J. So a few questions

--If I omit C1 will I have to jumper the C1 cap pads?
--I have 2 Silmics ,so better to use them @ C3 . Can someone tell me the voltage rating @C2, I have some 220uF 16v,25V
--If I use BC550/560 do any of the resistor values need change. Also will my bias current go down?

That's all I can think of now :)

Thanks
 
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Now that my F5T will soon replace my F5 ,I intend to reuse my F5 chassis, heatsink & psu for Aleph J. So a few questions

--If I omit C1 will I have to jumper the C1 cap pads?
--I have 2 Silmics ,so better to use them @ C3 . Can someone tell me the voltage rating @C2, I have some 220uF 16v,25V
--If I use BC550/560 do any of the resistor values need change. Also will my bias current go down?

That's all I can think of now :)

Thanks

-- yes

--for C3 16V is plenty enough , for C2 35V is tight , 50V means peaceful sleep

--just use them and do not worry
 
I do not totally agree.
Several of us, including me, found a bias current as high as 1.2 to 1.3 amps per leg using stock values.
1 amp per leg (2 amps total) is enough though. (think about dissipation)
By curiosity, you should measure the bias current on your amp.
Anyway, your amp is running a little too warm IMO.(You tell 33 above ambient)
 
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I don't know how to measure the bias (is probably mentioned somewhere in this long, long thread) but I don't have any trimpots anyway. Any adjustment would have to be by taking out (or adding) resistors. I think I will leave it as is for now:xfingers:

I finally got the feet on today. Metalwork is not easy for someone in an electric wheelchair :wchair:, I can tell you.

The amp is sitting on the bench and has been cooking for a bit under an hour with the top plate in place. DC offset is at 39mV (and still slowly decreasing) at speaker outputs (input shorted) and temperature is 59 Celsius (ambient + 33) at the hottest point I can find on the heatsinks. Seems OK to me :)

I will leave it for another hour and check again. If it is still OK I hope to be able to test the sound tomorrow.

Thanks again everyone for all your help, and of course a big thank you to Nelson :worship: for your generosity. It makes it possible to build and own such beautiful amps!

Albert

PS It is quite possible that I will be asking simple questions in other threads in the future, as I think I may have been infected by a diy-amp virus that is prevalent on this forum!:cheers: