The Amp Garage

martin manning wrote: ↑Thu Jan 20, 2022 10:50 am Which circuit do you have and what are the component values around the OD stages?

Here’s the layout.

Thx guys for jumping in. I’ll snap some pics later, and see if I can locate the schematic I used.

I agree it sounds like a tube being hit too hard. I did adjust the OD input trim, no change. Now the bypass cap might make sense. I have a 5uF now, I’ll try a 1uF and see what happens. Looking at the waveforms on the scope, it appears to be overdriving as expected, no hard clipping. Here’s a pic of ...

Hi folks, I’ve been away for a few years. Retired from my day job, playing a ton using amps I’ve build, restoring a 1948 Ford truck, and mostly enjoying time with my granddaughter. A few years ago I build a hi-plate non HRM ODS in a Princeton Reverb chassis. The clean side is really great but the OD...

Agreed Tony. I noticed that another amp I built has that punchy low mid drive where this amp didn’t. I compared the schems and saw the difference in the gain pot.

It all comes down to these amps being a complete system, no one thing makes it great.

Ok folks, tell me my ears are playing tricks on me. I took the amp out into the family room, connected to a 1x12 ET-65 and recorded some. One clip is clean and OD, the other is showing the range of the TS with the 22nF and 3k3 tail. Sounds pretty good to me. Nice range of clean and distorted sounds...

Ok folks, tell me my ears are playing tricks on me. I took the amp out into the family room, connected to a 1x12 ET-65 and recorded some.

One clip is clean and OD, the other is showing the range of the TS with the 22nF and 3k3 tail.

Bob, if you want to increase the range on the Skyliner stack, decrease the tail resistor on the bass pot to 3k9 (more attenuation of bass and mid), and increase the 10n feeding the mid pot to 22n (more mid scoop). That will give you something closer to Fender BF range. Don't worry a bit about the r...

talbany wrote: ↑Wed May 01, 2019 9:05 pm Yeah those look OK Great.

Try this real quick. Try putting a 100 Pf cap across the PI plates (ala Marshall/Blues master)
If it's still there then try the 6L's and see what you get then

Curious to see what this does

Tony

The 100pF did nothing, which tells me everything's fine.

I pulled out the scope, I can't see any PO. Every stage looks correct to me. I captured the speaker out with a sine wave on both clean and OD. Looked at the scope with signal and no signal, ran it up to max gain and frequency and looked for any anomalies, nuffin wrong. Here are the captures, it look...

Bob, if you want to increase the range on the Skyliner stack, decrease the tail resistor on the bass pot to 3k9 (more attenuation of bass and mid), and increase the 10n feeding the mid pot to 22n (more mid scoop). That will give you something closer to Fender BF range. Don't worry a bit about the r...

Bob So here are a few things that come to mind looking at the shots. 1st.. I don't think I would necessarily correlate a thin sounding/harsh or sterile amp directly to the tone stack or a problem with the stack unless something was either not wired correctly or I have a poor or fractured solder con...

I've found that the amps are so well balanced you don't actually need to mess with the tone stack that much. Only thing I ever seem to do is remove some bass depending on the situation, or flip on the bright/mid or Jazz switch to taste. If you look at Robben Ford or Larry carlton's amps they almost...

BTW. A picture of the amp with what component types/brands you used might contribute to the sterile sound. Do you have a gut shot handy? :wink: Tony I agree with that 100%, however I'm using components from the same stash as several other builds. I know the MPP caps are not highly thought of, but I...

Just a thought... Put a smaller value, like 33k, in series with a 100-250k pot wired as a variable resistor. Install that in place of the slope resistor. You might want to block the DC from the plate... use a 0.1µf for that. You can dial in your slope value by ear or drill a hole for it on a panel ...