defendyachtrock wrote: Sat Mar 22, 2025 9:14 pm it’s voiced very bright and the Tone knob feels more like a presence control) but so far I’m really liking it.

I keep the tone knob on mine between 8 and 9 o'clock. It just has more treble on tap than anyone could want. Otherwise it's awesome. Definitely better and more versatile than your standard Tube Screamer.

losthighway wrote:

defendyachtrock wrote: Sat Mar 22, 2025 9:14 pm it’s voiced very bright and the Tone knob feels more like a presence control) but so far I’m really liking it.

I keep the tone knob on mine between 8 and 9 o'clock. It just has more treble on tap than anyone could want. Otherwise it's awesome. Definitely better and more versatile than your standard Tube Screamer.

I have a feeling I’m gonna be asked to turn the Tone knob down at next practice. I have it at 2:00 right now just playing at bedroom levels. I’m assuming that at gig or practice volume it’ll end up going lower.

Dr Tony Balls wrote: Thu Mar 20, 2025 9:43 am

Nate Dort wrote: Thu Mar 20, 2025 9:05 am I might sit down with it one day if I get bored and draw it out.

I'll happily help disseminate it out into the various DIY forums if you do.

I spent a few hours this weekend drawing it up: Supro S6497 Combo Tremolo Schematic PDF

that's seriously impressive how fast you did that. Did components actually have value indications?!

TylerDeadPine wrote: Sun Mar 23, 2025 9:51 pm that's seriously impressive how fast you did that. Did components actually have value indications?!

Pretty much everything was marked in some way, except for the output transformer. I've drawn hundreds of schematics in my career, but this was my first time using KiCad and it was surprisingly intuitive. Found some good user-created vacuum tube libraries out there.





Working on tracing out my Hiwatt Custom 20 right now. It's quite a bit simpler (one channel, no trem). Same number of tubes though.

Nate Dort wrote: Mon Mar 24, 2025 7:06 am Working on tracing out my Hiwatt Custom 20 right now. It's quite a bit simpler (one channel, no trem). Same number of tubes though.

Do you have reason to believe its different from this one that's floating around online?

Dr Tony Balls wrote: Mon Mar 24, 2025 8:41 am

Nate Dort wrote: Mon Mar 24, 2025 7:06 am Working on tracing out my Hiwatt Custom 20 right now. It's quite a bit simpler (one channel, no trem). Same number of tubes though.

Do you have reason to believe its different from this one that's floating around online?

The "Custom 20 Tube" (US made?) is a different beast than the more recent UK-made Hiwatt Custom 20 (also called the SA210 or SA20).

Here's the Custom 20 (SA20 / SA210) schematic I just finished drawing: Hiwatt SA20 SA210 Custom 20 Schematic.pdf

A few interesting things off the bat:
1) Not the typical fixed-bias LTP PI that you would see in the bigger DR-series Hiwatts. Looks more like a Fender-esque LTP.
2) DC-biased heaters.
3) Despite the relatively low plate voltage on the EL84s (~290V), I'm calculating about 43 mA of plate dissipation, or 12W per output tube. That's the maximum that an EL84 is technically rated for.

Mine has a Mercury Magnetics replacement PT that the previous owner swapped in (incorrectly, which is why I got it so cheap). I believe the voltages are comparable to what the original transformer would have produced though, based on some other info I've seen.

Nate Dort wrote: Mon Mar 24, 2025 7:06 am

TylerDeadPine wrote: Sun Mar 23, 2025 9:51 pm that's seriously impressive how fast you did that. Did components actually have value indications?!

Pretty much everything was marked in some way, except for the output transformer. I've drawn hundreds of schematics in my career, but this was my first time using KiCad and it was surprisingly intuitive. Found some good user-created vacuum tube libraries out there.

That's beautifully lucky - I seem to have the opposite luck where every vintage item I open up has no marked indicators or very strange old capacitor markings that I can't decypher.

I love KiCad for that reason - I used it at home enough that I use it at work now too (Was just plain faster than in NI and my stuff is very simple). It's mostly everything I like about LT Spice and it looks nice. I still don't have simulation set up well though. Libraries are extensive.
The board layout CAD is terrible though, that part is tough but I just make sure to do everything in a real CAD system and import the layers I need.

I mostly have fun when I use it and that's the hallmark of great software

Went to pick up a 6 knob Laney AOR100 (the Sleep amp) and the dude happened to have the 8 knob beside it (his garage was like an Aladdin's cave of stoner heads and cabs). I tried them both and I have to say, the 6 knob was a bit underwhelming. Maybe it needs a pedal. I switched to the 8 knob and my jaw dropped. Fucking low -end grind for days. Instant Sleep.

I walked away with the latter.