Aleph J Schematic

Try repeating the test on your preamp, both connected to your amp and alone. How much can you get out of it to driving the amp? Is the output voltage lower with the amp connected?

I'm guessing that although amp gain is correct, your feedback network resistors may be an order of magnitude lower than expected (1K input instead of 10K), presenting a low impedance load that your preamp cannot handle.
 
A B1 ought to be able to handle the amp and not load the source significantly. Measure the source's output into your B1. You should be able to find some full scale signals to burn to CD to test with.

You may need a little gain in the system now. One easy way would be to increase the gain of your AJ a bit, but of course that would impact its sound.
 
And yes, 10x voltage gain is 20 dB, so the amp is working correctly.

Have you tried with the exact same music with the new amp (too bad you can't do a side by side comparison)? Apparent loudness of individual tracks can vary widely. It's a bit surprising to me how soft so many of my older songs sound compared to modern recordings and 30 years of loudness wars. I find myself riding the volume control as I shuffle through my ripped music collection.
 
And yes, 10x voltage gain is 20 dB, so the amp is working correctly.

Have you tried with the exact same music with the new amp (too bad you can't do a side by side comparison)? Apparent loudness of individual tracks can vary widely. It's a bit surprising to me how soft so many of my older songs sound compared to modern recordings and 30 years of loudness wars. I find myself riding the volume control as I shuffle through my ripped music collection.

Well song was Floyd Us & Them & yup I have heard it on both setup..

If the AJ is setup ok,I can build Jumas preamp (meant for F5)
 
And yes, 10x voltage gain is 20 dB, so the amp is working correctly.

Have you tried with the exact same music with the new amp (too bad you can't do a side by side comparison)? Apparent loudness of individual tracks can vary widely. It's a bit surprising to me how soft so many of my older songs sound compared to modern recordings and 30 years of loudness wars. I find myself riding the volume control as I shuffle through my ripped music collection.

Well song was Floyd Us & Them & yup I have heard it on both setup..

If the AJ is setup ok,I can build Jumas preamp (meant for F5)
 
Since there is nothing to debug :) pic of the crows nest.don't flame me for the long input output wires, I driiled the holes wrong (short circuit in between two God given headphones :) )
 

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I hope someone can explain some things for me.

I have been looking at the manuals (user and service) of the A3, A30 and AJ and have made some notes of the differences. I then tried to relate the differences by comparing the amps schematics, but there are too many variables for a newcomer like me to explain the specifications. I hope you guys can give me a hand.

Rails are about the same:
A3 and A30: 25V
AJ 24V

Gain:
A3 20dB
A30 20dB (balanced) 26dB (single ended; manual explains that A30 has 6dB greater dynamic range than A3)
AJ 19.6dB (does not specify a difference between balanced and single ended)

I understand the higher gain of the A30 is due to the input stage. Is this correct?

Power used:
A3 and A30: Each channel draws about 100W
but:
A3 250W consumption
A30 and AJ 200W consumption

Question:
If A3 and A30 both have each channel drawing 100W, should total consumption not be similar?

Active output stage biased by current source at
A3 slightly greater than 2 amps
A30 slightly less than 2 amps
AJ not given

Max. output:
A3 30W/8R, 60W/4R, 60W/2R
A30 30W/8R, 40W/4R
AJ 25W/8R, 13W/4R (Firstwatt product table)

Question:
What causes the difference between 4 Ohm output of A3 and A30? I assume it is the "slightly greater" and "slightly less" than 2A bias that is the cause. Is this assumption correct?

Question:
How come the AJ has so much lower power into 4 Ohm? I assumed that, since total power consumption is similar, bias must be similar.

Max output
A3 23V 8A
A30 25V 5A
AJ 21V 2.5A

Questions:
What causes the relative large difference between A3 and A30?
Are the numbers for the AJ correct? If so, why so different from A3 and A30?

Thanks,

Albert