Also, a while ago I built a solid state Bassman-like preamp in pedal form for a guy in the UK. His plan was to match it with a pedal sized power amp and have an all-in-one pedalboard/amp so he could take the bus to shows if needed and just plug into a cab. If I remember correctly after he got the preamp he then realized there werent that many small format power amps around. Everything was a pedalboard amp with it own pre. I'm sure its different with rack gear but that was a frustrating one.

Dr Tony Balls wrote: Thu Apr 27, 2023 9:19 am Also, a while ago I built a solid state Bassman-like preamp in pedal form for a guy in the UK. His plan was to match it with a pedal sized power amp and have an all-in-one pedalboard/amp so he could take the bus to shows if needed and just plug into a cab. If I remember correctly after he got the preamp he then realized there werent that many small format power amps around. Everything was a pedalboard amp with it own pre. I'm sure its different with rack gear but that was a frustrating one.

This is related to something I wanted to bring up in relation to the original question. What goes into considering a ss preamp and separate ss power amp set up instead of going with some modern ss all-in-one deal like a a Quilter.

I’ve been wondering this as I’ve been considering a flexible ss rig but one where I could tinker with swapping various pre amp or pre amp pedals (like a rusty box,Beta Lead clone, a Sansamp, or whatever). So that would favor using separate units, but I’ve heard that a ss amp with a flat enough eq could take some preamp boxes (like a sansamp) well enough and act like a power amp. Anyone with that experience?

(My high school set up was a SansAmp into a ss peavey combo, which was definitely an improvement over the default peavey sound, but that’s about all I knew for comparison back then.)

VaticanShotglass wrote: Sun Apr 30, 2023 12:42 pmI’ve been wondering this as I’ve been considering a flexible ss rig but one where I could tinker with swapping various pre amp or pre amp pedals (like a rusty box,Beta Lead clone, a Sansamp, or whatever). So that would favor using separate units, but I’ve heard that a ss amp with a flat enough eq could take some preamp boxes (like a sansamp) well enough and act like a power amp. Anyone with that experience?

I'd stick with amps that have an effect loop / "power amp in" so you can bypass the pre and go directly to the power stage. "Flat" is somewhat subjective, and unless the manual is specific about that the flat setting is, you'd really have to run a test tone to confirm it, and then you still have an interaction with the input gain stage, so you won't know the true character of the preamp. That said, if you get a good direct sound (off the preamp) you like first, then you can use the amp's EQ to compensate for different speakers. My main bass recording rig goes through some rack stuff with one output going to tape and another going to the front end of a 1000w bass head that powers a 1000w 18", and I use the amp's EQ to get the most out of that speaker. Side note: 18" speakers fuckin' rule

This all sort of begs the question....what is a simple *good sounding* solid state power amp that could be made in small package. Thinking along the lines of Traynor, Sunn, Peavey...the good sounding 70's stuff.

I tried out a Mooer Baby Bomb, and thought it sounded pretty bad. I'm not sold on the class D pedal amps.

Dr Tony Balls wrote: Mon May 01, 2023 9:20 am This all sort of begs the question....what is a simple *good sounding* solid state power amp that could be made in small package. Thinking along the lines of Traynor, Sunn, Peavey...the good sounding 70's stuff.

Depends on how close to original you want to get.

The majority of the weight in those old power amps would be in the power supply, so going to a switching supply would be the first step.

TO-3 transistors are big and bulky and hard to mount and expensive. You're better off reworking the design to support TO-220 or TO-247 packages.

Heat-sink requirements would also dictate the form factor. When you're sitting at 60 % efficiency for a Class AB output stage, you're dissipating multiple watts at idle. Heat sinks are heavy and bulky.

Krev wrote: Mon May 01, 2023 9:40 am I tried out a Mooer Baby Bomb, and thought it sounded pretty bad. I'm not sold on the class D pedal amps.

I like the Quilter Interblock 45. I was playing a 2x12 DeVille in a practice space and experiencing some (likely) power strip related issues, so I plugged the Interblock into the combo's speakers and both the drummer and I were pretty impressed. Yeah, I was surprised it could keep up with drums too. Granted I've been playing pretty clean in recent years, or using amps for soundwash type stuff, but it's the "amp" I play most at home now.

(I wish there was an on/off switch, but if this is what keeps it small so be it)

Krev wrote: Mon May 01, 2023 9:40 am I tried out a Mooer Baby Bomb, and thought it sounded pretty bad. I'm not sold on the class D pedal amps.

I have a Quilter amp-in-a-pedal I use for troubleshooting blown speakers and it works great for that. I don’t think I’ve ever used it for anything else

llllllllllllllllllll wrote: Mon May 01, 2023 11:37 am

Krev wrote: Mon May 01, 2023 9:40 am I tried out a Mooer Baby Bomb, and thought it sounded pretty bad. I'm not sold on the class D pedal amps.

I have a Quilter amp-in-a-pedal I use for troubleshooting blown speakers and it works great for that. I don’t think I’ve ever used it for anything else

I don't have any digital stuff, i.e., AxeFX, but they probably work better for that. I plugged a guitar preamp into it, and was really flat sounding.

Dismissing all Class D amps because one sounded bad is just like dismissing all tube amps for the same reason. There are some dogshit tube amps out there, just like there are dogshit Class D amps.

A lot of our favorite old solid state designs are anything but flat, even in the power amp section. I think what a lot of these class D amp-in-a-pedal designs get wrong is that they're basing their power-stage voicing on Infineon or Texas Instruments application notes that are shooting for the lowest distortion and flattest bandwidth. Lots of negative feedback and low-distortion components, like a HiFi system. That's not necessarily what you want in a guitar amp.