Surfybear Spring Reverb Reverb Path Volume

[lars-musik]

Hi folks,
I just finished a Surfybear Spring Reverb clone and am not really content with the volume/gain of the reverberation path. There’s a huge volume drop when I turn the mix knob slightly up. It’s the third build on the same PCB/schematic but the first time this happens.

The JFETS are mmbf5457 measured according to specifications given in a former build documentation from the surfybear forum with a Peak Atlas DC75 (Vgs(off) <-1.2V; gfs >3,5 <5 mA/V).

Here’s the schematic with the voltages. Do you happen to find anything suspicious?

Thanks!

[Kipper4]

Hey Lars.
What does it sound like at C8?
Might be a cap in the tone stack?
TC my friend.
Rich

[lars-musik]

Hey Rich,

I will check this out!

And I again realise how "impedance-thick" I am.  The original reverb tank has an imput impedance of 8 Ohm and an output-Z of 2250 Ohm. My new unit has 10 Ohm in,  2575 Ohm out. The off-precentage seemed to be absolutely OK to me. But could this make such a difference?

[Kipper4]

I’d have gone with the specs near enough.
Hope you find the issue.