Hoffman Amplifiers Tube Amplifier Forum

Other Stuff => Video Clips => Topic started by: Johntb on August 24, 2017, 06:53:35 pm

Title: Latest build
Post by: Johntb on August 24, 2017, 06:53:35 pm

Based on Bancika's Mark IIC+, with modded Mark IIB tone stack with boost. I also modded to add a "crunch" channel.
This was before some more mods.
It's now as single ended KT88/EL34/6V6 (but can use any combo and a 6L6) sounds much better to me.

I can't play worth a crap I know. I just learn riffs. I have more fun making this stuff anyway.

https://m.youtube.com/watch?v=8XT8XqU63aE

Title: Re: Latest build
Post by: pompeiisneaks on August 25, 2017, 03:52:03 pm

Sounds good, well done!  What did you use as your schematic and layout? 

~Phil

Title: Re: Latest build
Post by: Johntb on August 25, 2017, 06:41:35 pm

Thanks!

Used this for the most part.
http://diy-fever.com/amps/mesa-mark-iic-pcb/ (http://diy-fever.com/amps/mesa-mark-iic-pcb/)
I modded it though. The "crunch" is just a 1M resistor with a 5nf ceramic and 510pf poly on a switch/relay parallel with the 10pf/3.3M resistor between V1B & V3A

Then used the Mark IIB tone stack and modded with 820p (ceramic treb),  47nf (pio bass) and 15nf (pio mid) and boost was 5nf ceramic with resistor.

As far as power amp goes I just came up with a simple 1/2 12ax7 circuit after looking and studying some of the others out there.

My own layout on a tag board.

It's very touchy and has some sweet spots. The crunch is cool but really needs the deep switch on.

John