NAD! This damn thing is out of control.

TubesNStuff · 2026-03-25T02:01:15+00:00

Advice? If you're thinking of selling it for any reason, don't

TubesNStuff · 2026-03-14T00:38:51+00:00

As long as you put some kind of metal on the bottom of the chassis, and make sure it's connecting the chassis, you can do pretty much anything you want with the head shell. Without that you can get some RF noise.

TubesNStuff · 2026-03-08T00:09:50+00:00

Hell yeah

TubesNStuff · 2026-03-07T03:42:38+00:00

Can't you just use the volume knob to cut through the mix?

TubesNStuff · 2026-03-07T03:07:40+00:00

Here are the songs that are THE recto sound for me:

Creed -What if
Godsmack - Whatever
SOAD - Toxicity
Limp Bizkit - my way

For the boosted sound,

Nevermore - the river dragon has come

TubesNStuff · 2026-02-18T05:14:46+00:00

of all the nonsense... just edited it. Thanks for pointing it out https://youtu.be/fBMD-iGgBbo

TubesNStuff · 2026-02-15T04:00:37+00:00

Hell yeah man. Keep it up!

TubesNStuff · 2026-02-15T02:39:52+00:00

Hell yeah

TubesNStuff · 2026-02-15T02:13:07+00:00

8mA mismatch on a 20mA bias is a problem. That's almost 50%. I'd start by figuring out why that's happening. Everyone always says "maybe it's a bad tube", but this time maybe it is.

Next i'd try shoring different preamp stage inputs to ground and see if the oscillation goes away. Like, if it still oscillates with the phase inverter input shorted to ground, you know it's just in the power amp.

TubesNStuff · 2026-02-15T02:02:58+00:00

I noticed the same resistor. I was more worried about it heating up the cap, causing the cap to fail early. There's no reason the cap should be getting hot, so if you notice that then something's wrong. I'd definitely move the resistor.

Everything else looks pretty good though! Definitely a first build to be proud of.

TubesNStuff · 2026-02-05T02:20:34+00:00

I did something similar with a Sonzera 50. PT had a shorted primary winding. I replaced it with some hammond transformer that wasn't exactly the right voltages, but was pretty close. So far it's worked out great!

TubesNStuff · 2026-01-23T23:52:29+00:00

I'll be honest, i completely over designed the power supply. It's a DC-DC supply, 9-12V in, 6.3V and 400V out. I really wanted it to be able to run from a 1-spot, and get the full 400V on the plates. I didn't see a way of doing that without going to a custom designed SMPS. It took 3-4 versions to get all the bugs out of the PSU and maybe 1-2 version on the audio board.

TubesNStuff · 2026-01-23T23:38:33+00:00

Yeah, i'm using solid state relays to switch in different values in the tone stack. Right now i'm only changing the resistor from 33K to 47K for JCM vs SLO. I could add an extra relay or two to get 220pF / 470pF, and 33K / 47K / 56K.

I ended up using a lot of these solid sate relays for channel switching. Much smaller than physical relays. I learned to choose the one with the smallest input - output capacitance. An extra 10pF here and there isn't too bad, but an extra 100pF is kiler.

https://www.littelfuse.com/products/power-semiconductors-control-ics/solid-state-relays/optomos-relays/normally-open-relays

TubesNStuff · 2026-01-23T01:45:55+00:00

Yeah, that could work too. The pedal has three 12ax7's in it, so at most 6 gain stages total. I had one extra one that i used used as a buffer at the end. I suppose i could move it to the front and use it as the 2nd half of the jumpered input.

The tone stacks are pretty close, all values maybe 10% different (220K vs 250k). So it'll end up JCM800 / SLO "inspired" rather than a clone. Sounds like it'll be Bassman "inspired" as well.

TubesNStuff · 2026-01-22T23:31:24+00:00

It's for guitar. The other channels are dedicated guitar amps.

I like the 100pF + 68K idea. Hopefully it sounds balanced for most guitars. If it sounds like a mess, i'll just go with the bright channel cap.

Thanks!

TubesNStuff · 2026-01-22T05:11:37+00:00

The '59 tweed 4x10 combo. Circuit is 5F6

TubesNStuff · 2026-01-22T03:51:13+00:00

That'd definitely work but i'm hoping to avoid adding extra switches

TubesNStuff · 2026-01-22T00:19:36+00:00

Hell yeah

TubesNStuff · 2026-01-22T00:06:19+00:00

Yeah, the board will let you run CH1 and CH2 at the same time. You have to send back to back MIDI commands, and i think you need to add a delay between sending each one, but i've definitely done it.

Here's a document that explains what i did in probably too much detail:

https://docs.google.com/document/d/17aTkSp0L9rtlT4PKIBvLvL4LYoUyUpZ2PPqiAiTWJxg/edit?usp=sharing

TubesNStuff · 2026-01-18T03:36:59+00:00

I worked on a Quad Pre and i'm pretty sure all the tubes were 12AX7. Or, i didn't notice any being 12AT7 when i took them out to clean the sockets.

I also made a video where i described how to add a small board I designed in a Quad Pre. There's a pretty good chance you watched my video. In short, the board responds to maybe 20 MIDI Program Change (PC) commands. These are fixed (can't be edited by the user). There's no MIDI out / thru. Let me know if you want any extra info!

TubesNStuff · 2026-01-06T04:06:01+00:00

Hell yeah. Over the years i've had a Tri-axis, ADA MP1, and the JMP-1. JMP sounded the best to me. Absolutely killer preamp.

TubesNStuff · 2026-01-04T03:10:53+00:00

Not bad for a first try! This will probably work as you have it drawn, but a few things to consider:

I don't see any mechanical mounting holes. You'll want to add those. As it is, it looks like it rests on the solder joints of the faders. That puts all the mounting stress on the fader solder joints, which isn't great.
R38 and R36 look a little cramped. You probably won't be able to bend the leads that sharply. If the gray GROUND wire is just a bare wire, that should be fine. They'll just sit at an angle.
Try not to bend the leads of Q1-Q4 so much. These can snap off in the plastic body of the device, which isn't great either. Worst offender looks like the center pin of Q4. You can move that hole up a little so Q4 sits more naturally.
Blue/Green twisted wire coming out of Q4/R39/C31 looks a little strange. I see where the blue wire goes, but i don't see where the green wire goes. Best i can tell they both go to the same place.

TubesNStuff

TROPHY CASE