one more Wurlitzer 200 question...

[PRR]

Stopping a trem oscillator is tricky.... they can be VERY slow to start.

The pop may be hard to fix. Here's something to try, won't take long, can't hurt.

 

[PRR]

> VERY slow to start

Sorry, was thinking something else.

Try breaking R12, the positive feedback loop. The function generator should stall at its average DC level, making the LED bias and no-trem signal attenuation similar to the with-trem average signal attenuation.

 

[wmtunate]

I tried your first suggestion, PRR, as it was pretty easy to swap a couple wires around.  It was better, but still there.  So I tried grounding out pins 5 or 6 on the IC, which disabled the trem.  However, I'm using a SPST switching pot for the depth control, so I need it to do the opposite function and actually enable trem when I turn up the depth.

So I went the easy way and ran pin 4 of the IC (V-) through the switch to basically turn the IC on when I want trem.  I don't know if it's totally kosher, but it works.

 

[geoff004]

I built this pre for my 206 a good while back.
The trem section in the schematic wasn't really the right thing for my taste - it popped and did some funny things, and ultimately it just didn't sound like what a tremolo in a wurlitzer should sound like.
So after trying some other circuits I just lifted the original out of the 200a circuit.  Sounds and works just like it should.
here it is:

just to be clear the other side of the nsl32 goes to ground and the tremolo pot for the front of the wurly is the 100k pot between the circuit and the LDR.  The pots P1 and P2 are onboard the main amp. If you can find cheaper parts for NTE289a please let me know.
Like I said this is right off the 200a schematic.

 

[wmtunate]

I think the problem is the NSL32.  I tried it in the original schematic and it just didn't sound right.  I swapped it for a VTL5C9 and it really helped.