VaticanShotglass wrote: Thu Jul 03, 2025 4:35 pm So I've noticed that a lot of the solid state amps (seriously almost typed solid snake amps) and preamps that I like, such as my little Vox Pathfinder and the Rusty Box Traynor family, have boost circuits. Do you know or have you designed any tube amps that have use an inbuilt boost like that.

Do I know of: Sure, it's been done before. You mention some examples. Dumble also commonly did it where a lot of amps had a FET input which was slightly boosted by a JFET gain stage. The Royal Super Bunny I worked on for someone from this forum also had something similar. I think the weird Vox Brian May AC30 (the one with just one knob) had a built in treble booster as well.

Have I designed: Yep. Neal mentioned the Ross Fame Series rebuild I did with a Rangemaster circuit installed for the "Tube Blaster" function. I've also done the same thing on one of my BF-15 amps. I've also done a tube version on a rebuild of a Pro Jr I did where I added a switchable EF86 pentode boost circuit up front.

Those look cool. I remember the Fame project now. How did you like the tube boost on the Pro Jr? I only ask about a tube based pre-drive like that because it doesn't seem like a common implementation, which is curious. More tubes are more parts and all, but it does seem like a relatively simple way to add more gain.

This question got me looking at videos of old Garnet Herzog units. My impression is it is more like an entire damned amp implemented as an overdrive. Crazy shit. I've seen you guys talk about Garnet amps before, but never really looked into them much. Wild stuff.

BRUH. Trashman Spring Reverb. Using the little tiny Accutronics tank I was able to squeeze an actual spring reverb into a not so crazy sized enclosure (5.75" x 4.75"). The circuit is 6G15 inspired so everything kinda operates in the same capacity. Sounds GREAT to me, super lush and spacey and most importantly does the actual spring thing, not just simulate it. If you kick it, it will clang. In fact there's a *tiny* amount of noise when you engage the switch without playing, but I didnt wanna further isolate the tank and eliminate the clang.

Now fit a trem in there too.....lol.

Frankie99 wrote: Mon Jul 07, 2025 3:57 pm Now fit a trem in there too.....lol.

In a bigger enclosure, maybe.

Also, wrapped and shipped all the PRFBBQ charity fuzzes. Thanks to everyone that participted!

Dr Tony Balls wrote: Mon Jul 07, 2025 3:36 pm BRUH. Trashman Spring Reverb. Using the little tiny Accutronics tank I was able to squeeze an actual spring reverb into a not so crazy sized enclosure (5.75" x 4.75"). The circuit is 6G15 inspired so everything kinda operates in the same capacity. Sounds GREAT to me, super lush and spacey and most importantly does the actual spring thing, not just simulate it. If you kick it, it will clang. In fact there's a *tiny* amount of noise when you engage the switch without playing, but I didnt wanna further isolate the tank and eliminate the clang.

Dang! How much will they be, doc?

Dudley wrote: Tue Jul 08, 2025 9:55 am Dang! How much will they be, doc?

$235 ppd in the US, $245 elsewhere. I have a few right now.

VaticanShotglass wrote: Thu Jul 03, 2025 4:35 pm So I've noticed that a lot of the solid state amps (seriously almost typed solid snake amps) and preamps that I like, such as my little Vox Pathfinder and the Rusty Box Traynor family, have boost circuits. Do you know or have you designed any tube amps that have use an inbuilt boost like that.

This is kinda pedestrian, but the Fender Blues Jr has the Fat switch. This brings in a cathode bypass cap on a tube stage to increase the gain (and probably low frequency) of that stage. This is not an uncommon gain boost mod, and I've seen them in many amps. Only issue is that it is difficult to make it adjustable via potentiometer.

I agree that adding an extra tube stage to a clean amp like a fender is kind of a bad wat to make a boost circuit. It almost always comes out sounding somewhat liek a mesa boogie Mark I.

Dr Tony Balls wrote: Tue Jul 08, 2025 9:58 am

Dudley wrote: Tue Jul 08, 2025 9:55 am Dang! How much will they be, doc?

$235 ppd in the US, $245 elsewhere. I have a few right now.

Awesome stuff. Do you have any Dummys left?

jirbling rake wrote: Tue Jul 08, 2025 10:36 pm

Dr Tony Balls wrote: Tue Jul 08, 2025 9:58 am

Dudley wrote: Tue Jul 08, 2025 9:55 am Dang! How much will they be, doc?

$235 ppd in the US, $245 elsewhere. I have a few right now.

Awesome stuff. Do you have any Dummys left?

No, but I have a soft wait list of people to be contacted the next time I make some. I'll be making more probably more towards the end of summer. DM me if you want on the contact list.