Transformer alternative for Wolftone Chaos?

[Sesh]

Hi all

I'm making a Wolftone Chaos - super cool, unique wavefolder fuzz in vero.



The circuit calls for a 42tm117. Neither Banzai or Musikding that I shop at stock it. Mouser doesnt either.

It's a 50k:1k transformer. Are there any alternative? Would other transformers work?

[Marcos - Munky]

I think the 42TL002 will work. It's a 10K:2K transformer, but what really matters is the ratio is the same (5:1). The 42TM022 (ratio 2.5:1) also should work, maybe with not the same result but probably very close.

[PRR]

> ratio is the same

Check your math on that.

[anotherjim]

I drew a blank looking for a schematic for this one. Anybody got a link?

[Sesh]

I drew a blank looking for a schematic for this one. Anybody got a link?

[anotherjim]

Well, it looks like only half of the "secondary" winding is used, so the turns ratio is even higher and 50k:500R.
I think the purpose is to drive a much higher voltage. The feedback diodes on the first opamp will limit the output to about 3v peak to peak, so the transformer ratio steps it up and maintains the following clipping and crossover distortion stages for longer during the decay of the instrument. It's a good ploy.
Really, any audio transformer with a high turns ratio will be worth trying since any voltage step-up will help. There is a 42TL003 with 1k2:8R. This is a much higher ratio, but it can be cut back with a series resistor from the opamp output and you may use the whole 8R secondary.

[PRR]

As drawn, the "S" winding shorts itself?

If I read the intent right, it makes maybe +/-13V swings to overwhelm diode network. You could skip the odd transformer with a +/-15V supply and another opamp.

[Marcos - Munky]

> ratio is the same
Check your math on that.

Ouch. I checked the numbers in a hurry, and missed a zero. I saw 5K:1K instead of 50K:1K. My bad.

[digi2t]

I drew a blank looking for a schematic for this one. Anybody got a link?

Here, on the last page. This is the Malekko version, not the original Studio Electronics. I think there were some minor differences between the two;

https://drive.google.com/file/d/1bUjtxL2mKXU_XNpaBd_l0bTrgiR6Kis6/view

As for the 42TM117 xfo, TEDSS has it in stock, but you have to buy two. I bought mine off Ebay from a UK vendor, along with some other xfos that I needed.