New SLO 100 clone

[sluckey]

The LDR in the Vactrol VTL5C1 has a response time that works well in a tremolo circuit even though it is illuminated by a LED. I replaced the dead incandescent lamp optocoupler in my Sunn Sceptre with a Vactrol VTL5C1. Had to change a couple resistors to adapt to the LED. The results is a very smooth tremolo effect. The schematic in on my Sunn Sceptre page.

The Vactrol VTL5C1 is still available in many stores even though it is listed as obsolete.

[dcribbs1412]

FYI
https://www.cedist.com/products/optocou ... -switching

D

[M Fowler]

Funny how Mike Soldano stated in his Tonetalk interview that he redesigned the SLO because of unavailability of the Vactrol.

I think it was because guys like Dave Friedman teased him about an old circuit design.

Mark

[sluckey]

Newark, Allied, Mouser, and Amazon all list the VTL5C1 as discontinued. I suspect distributors such as CE will not be able to replenish stock.

There are a lot of high quality amps out there that depend on the VTL5C1 and variants for channel switching. Probably fairly easy to find a compatible optocoupler for switching applications, but might be a lot harder to find one suitable for tremolo circuits.

[roberto]

Can I ask you why you don't consider the VTL compatible for tremolos?

[caps8419]

Ordered transformer set from Heyboer $340 shipped:

PT 100w Heyboer HTS-9741
OT 100w Heyboer HTS-9740
Choke 10h Heyboer HTS-9743


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How do they Heyboers compare to O'Netics? I know Bud is not really making them anymore. Thanks!

[M Fowler]

I do not know the answer to your question and still waiting on delivery of mine.

Mark

[roberto]

caps8419, what do you want to know exactly? Soundwise? On the construction?

[caps8419]

caps8419, what do you want to know exactly? Soundwise? On the construction?

Soundwise mainly. It's about a $100 price difference between the two. I've used and know Heyboer is great in general but everyone says O'netics is the end all for this type of amp.

[roberto]

I've not found the thread I remember was on sloclone, but IIRC there was not such a difference between the two.
Nobody unwinded both, AFAIK, but soundwise there was not a big difference.
Just consider if you want to use it or sell it later: O'netics trafos could give you that "commercial plus".

[caps8419]

Thanks roberto. Nah, this would be for personal use.

[M Fowler]

Still waiting on Heyboer transformers and finally got a chance to work on the SLOclone.

Mark

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[dcribbs1412]

Looking good Mark
Its a great circuit
Like to hear what you think of it compared to other high gain amps you've built.
BTW Missing some vactrols on pre board?

D

[M Fowler]

Yeah it was a late night and didn't install the other two vactrols yet.

Will be fun to try out, never played or heard one except U-tube.

Mark

[roberto]

Well done Mark!
Keep us updated!