Hello everyone!
I've finished and tested sound wise Apex AX9 and PSU100 together. My Ax9 it's modified from input to the VAS like A9. Drivers and outputs are like in the schematic. With the schematic ax9 values, gain was to much for me. With input shorted it was still hum in the speaker when my hand was next to the amplifier..... With values of the A9 schematic looks better and no more hum in the speakers with input shorted. The gain is lower than the original. Is it OK if I do this modification? Is there any other way to get it done properly. I use it with +/-38,5Vcc.
I've finished and tested sound wise Apex AX9 and PSU100 together. My Ax9 it's modified from input to the VAS like A9. Drivers and outputs are like in the schematic. With the schematic ax9 values, gain was to much for me. With input shorted it was still hum in the speaker when my hand was next to the amplifier..... With values of the A9 schematic looks better and no more hum in the speakers with input shorted. The gain is lower than the original. Is it OK if I do this modification? Is there any other way to get it done properly. I use it with +/-38,5Vcc.
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A pair of bridged amplifiers gives double the power into double the load impedance compared to the two single amplifiers. This is stated dozens of time in this Forum. Do some reading.
For a +-50Vdc supply you can expect a good amplifier to give around 200W into 4r, i.e. the two amplifiers give 200W+200W into 4r+4r
The bridged pair will give 400W into 8r.
Note, no extra power is magically created !
It really is that simple.
My fh
Congratulations on the design sounds great, very compact and powerful ...
My montage.
Congratulations on the design sounds great, very compact and powerful ...
My montage.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
FH9 (HV)/FH11 PCB's for free
Hello!
In the late summer of last year I modified the existing PCB designs of these 2 great sounding amplifiers in a way that you need only 1 PCB to build FH9 OR FH11. You can read details here. I ordered PCB's to test them, but unfortunately, for some personal reasons, I could not continue. So I would the 10 PCB's itself give away for free and would charge only my shipping costs: when I got them ($12) and those I have, when I send them ($5). So if someone is interested, please PM me! The PCB's, you can see here. The links to the BoMs are here and here.
I hope that soon my personal situation will change. Then I will start another try.
Hello!
In the late summer of last year I modified the existing PCB designs of these 2 great sounding amplifiers in a way that you need only 1 PCB to build FH9 OR FH11. You can read details here. I ordered PCB's to test them, but unfortunately, for some personal reasons, I could not continue. So I would the 10 PCB's itself give away for free and would charge only my shipping costs: when I got them ($12) and those I have, when I send them ($5). So if someone is interested, please PM me! The PCB's, you can see here. The links to the BoMs are here and here.
I hope that soon my personal situation will change. Then I will start another try.
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Here is my build of Apex A40 but need help to increase the input gain any suggestions ??
https://youtu.be/wChAKhl-kAI
https://youtu.be/wChAKhl-kAI
There are 3x1k resisters in series with 100 ohm resister to ground
here is the schematic.
Nice job, Sir. From what I've read in this thread the A40 amplifier works great with p30 preamp, which has quite high gain.
This thread has many excellent designs. Look in the "directory": http://www.diyaudio.com/forums/solid-state/292226-directory-apex-audio-amplifiers.html and http://www.diyaudio.com/forums/solid-state/295475-directory-apex-audio-amplifiers-chapter-2-a.html
Hi all can i use 2SC5198 as output in this amplifier? Thanks in advance!
An externally hosted image should be here but it was not working when we last tested it.
yes sir but the A40 has advance input staging. I think it can have high input gain but, dont have perfect idea about the mods require and due the ckt is hell complex i need some advice to increase the gain of a40.
It not final schematic .
this is final schematic, You can try it.
An externally hosted image should be here but it was not working when we last tested it.
You can lower the value of 100 Ohm resistor (one that is connecting to gnd after three 1k feedback resistors) to increase gain.