Low volume on one Ambika

During this lockdown, I have built a second Ambika…
I have compared this new one to the one I built last summer…they both work 100%, but with great surprise I noticed that the new one sounds much louder and crispier than the “old” one, which in contrast sounds a bit softer an “dullier”…
Builder is the same of course, components are mostly the same, ordered on Mouser and other suppliers, different batches of course…
Same Power Supply, same Mixer Channel, same everything…

What should I check on my “old” Ambika to get the same crispy and loud sound that I have on the second one? What could be the reason of this audible difference?

mmmm…
i have checked the individual outputs and they are loud and crisp as well…so the problem should be in the Output Mixer section…

Resistor Network is orientated OK, 470R resistors are the same. 100K R12 and R13 are a bit different, on the “old” one I have 100K 5% tolerance, new one has 2% tolerance…could it be that?

A quick check of the components in the Mixer revealed that…I am an IDIOT ! :wink:

I had put a 100nf (104) capacitor instead of a 100pF (101).
Of course replacing it solved the problem.
Damn eyes. I need a new and better head magnifier to work on my circuits