[Emu amp simulator] Not enough drive/gain (compare to normal results)

Fr4nck

New member
Hi all,

I built an Emu amp simulator, I really like the sound. But I'm not sure I built it perfectly because the "Hi gain" or "Hot rod" mod does not deliver any overdrive or crunch even if the drive is full.

Have I missed something? which part of the pcb should i look in? Otherwise all the switches apply sound modifications ... it gives the impression that the drive does not send enough to reach saturation.

Hoping someone can help me figure out what's going on.

IMG_9734.jpg IMG_9735.jpg
 
I'm back,

I verified all resistances and one was wrong. I changed it but it's the same.
I measured Ic Voltages (dc 8,5)
If you have any ideas to help me...

IC1
  1. 4,1v
  2. 4.1v
  3. 2v
  4. 0v
  5. 2.7v
  6. 4.5v
  7. 4.1v
  8. 8.2v
IC2
  1. 4.1v
  2. 4.5v
  3. 3.6v
  4. 0v
  5. 4.1v
  6. 4.5v
  7. 4.1v
  8. 8.2v
IC3
  1. 4.1v
  2. 4.1v
  3. 3.9v
  4. 0v
  5. 3.8v
  6. 4.1v
  7. 4.1v
  8. 8.2v
IC4
  1. 4.1v
  2. 4.1v
  3. 4.1v
  4. 0v
  5. 4.1v
  6. 4.1v
  7. 4.1v
  8. 8,2v
transistor 2n5088
  1. 3.5v
  2. 4.1v
  3. 8.2v
 
I have one in progress right now that doesn’t seem quite right as well. I’m not near a schematic at the moment but just from your voltages IC1 pins 3 and 5 don’t seem right. I remember the voltages on my first IC being more in line with the other 3.
 
Hi,

thanks dlazzarini, i found my mistakes... look at c10 & c11, i soldered 2 220nf instead of 220pf!
Now i have fun with it :)

do you know what function have each ic? I would like to test with others opamp for clean sound etc...

see you!
 
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