AC15 C1 modifications?

[leonc]

Anyone here every do any modifications to their Vox AC15 C1?


I just bypassed the 330k resistor (R1) in series with the volume pot in the normal channel. That opens things up a bit!


I also changed the speaker (upgrade to a Cele Blue Alnico) and built a new speaker cable such that it has a female 1/4" jack from the amp and a 1/4" plug from the speaker. This way, I can get my Power Station in between  (I like using the loop in the PS for wet effects).


I'm contemplating modding the main board to change the routing of B+ so that the preamp stages get their B+ from the screen grid node, like in the earlier JMI models, rather than from the node that supplies the phase inverter. Seems like this will require drilling out a via, which I'm somewhat reluctant to do. Anyone tried this?

[sluckey]

I've never messed with an AC15-C1 but I did build a 1960 VAC15 and made several mods. You may want to look at some of my mods to see if they are of interest to you.

     https://sluckeyamps.com/VAC15/Vox_AC15.pdf

[leonc]

I've never messed with an AC15-C1 but I did build a 1960 VAC15 and made several mods. You may want to look at some of my mods to see if they are of interest to you.

     https://sluckeyamps.com/VAC15/Vox_AC15.pdf

I was toying with the idea of replacing the big 1K dropper in the AC15 C1 with a choke, but I think I'd want one with higher DC resistance to keep the B+ closer to 315VDC...but I take it your happy with the Hammond you used?

[sluckey]

I'm very pleased with the Hammond. And I do use a Celestion Blue. There have been several of these built using my layout which looks nothing like the original. My layout looks more like a Marshall.

Look closely at the Vib/Trem switch mod. If it's of interest, you could probably easily put it in a pcb amp.

Here's some more info on my AC15 project...

     https://sluckeyamps.com/VAC15/ac15.htm