100W Ultimate Fidelity Amplifier

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Joined 2006
Gerbers on P30 preamp.
 

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  • P30 ZF GERBERS.zip
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Member
Joined 2023
Any idea which transistor this is
 

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Member
Joined 2013
I finished my P30ZF yesterday in the late evening. Not heard yet.
Dont know if a delay with relais is necessary, i built it in. The supply i an old one, which was build for an headphone amp in the past. The regulators are adjustet to +-24 Volt. The R-core delivers 2x18 Volt, 1 A.
I first had a little trouble with the BD140 on one channel. After 5 minutes the heatsink became very hot. I tried to find out some mistake, found none. The values are all ok, the transistors are soldered in on their right place. Changed the BD140 and one BC560 on the negative rail...the mistake was remaining.
I soldered a new board and all seems fine , only a little heat now.
 

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Joined 2013
Do you mean the problem with the heating BD140 wents away connecting the P30Zf to an amp ?
Too late..made a new soldering on a PCB :)
You must test preamp with amp connect to output, amp input impedance load preamp with 22k... P30ZF DC offset is very good for circuit without global negative feedback.
 
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Member
Joined 2013
Testing....👍
What a very nice preamp. Sound ist very good. The only thing i dont know...what is the pot for ? Apex wrote for THD, but an other member answered there is no effect...
Can i make a measurement to get an effect ? In the moment i have adjusted the pot for 500 ohm each...

Peter
 

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Joined 2010
...and my board options are there (on PCBWAY).
The measurements of the Apex AX20 are on my boards, if anyone is curious. 1W, 25W, 64W
4ohm _1W.png

4ohm_25W.png
4ohm_64W .png
 
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Joined 2018
Hi,not sure how to navigate on here ? But can someone help me try and find PCBs for

FH9HVX apex amplifier as a relative nieve builder of amps thanks to anyone who can help​

 
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