ValveKing "JCM" mode using Volume Boost switch

This forum is for talking about all kinds of Peavey guitar amplifiers.
Jltcet
New Member
Posts: 1
Joined: Sun Sep 17, 2017 9:17 pm

Re: ValveKing "JCM" mode using Volume Boost switch

Post by Jltcet » Sun Sep 17, 2017 9:25 pm

I know this thread :? is quite old, but I opened up my amp, and my board has different numbers. But it looks the same. Is it ok to continue. :?

johnc
New Member
Posts: 1
Joined: Mon Feb 12, 2018 5:31 pm

Re: ValveKing "JCM" mode using Volume Boost switch

Post by johnc » Mon Feb 12, 2018 6:58 pm

Just finished doing these mod's on my VK 112 and it is absolutely awesome, Peavey should put you on the payroll.
I did read a post about how hard it is to get the thing apart, my one had a strip of double sided tape along the
top and bottom front edges of the chassis . You have to unscrew the logo plate and loosen the rest of the screws
then get a thin bladed knife (Not a craft knife,nothing to sharp) and use it to break the seal top and bottom.
There wasn't any chance of just pushing it out it was stuck fast. Haven't seen this mentioned anywhere so
perhaps its just us lucky people here in the UK who get them glued together.

macsguitar
New Member
Posts: 2
Joined: Wed May 09, 2018 10:02 pm

Re: ValveKing "JCM" mode using Volume Boost switch

Post by macsguitar » Thu May 10, 2018 7:45 am

Well I just recently did this mod to my VK 100 head and I'm experiencing the same issues that Sebwhite had with the "dying battery in the pedal" "Noise gate" type of sounds from the new jcm channel! It is a little better with the gain boost engaged but still bad enough that its really not usable! I have triple checked all solder connections, with no change. Mine is also the second version of the PCB so that may be the problem, unfortunately I don't have the skills to figure it so any help at all would be greatly appreciated! BTW the original VK channel works fine, but the boost button on the footswitch basically either turns on the channel or off either with the gain boost engaged or not and does not function like 65 Sg originally described. Thanks

Lflores
New Member
Posts: 2
Joined: Thu Oct 15, 2020 12:49 pm

Re: ValveKing "JCM" mode using Volume Boost switch

Post by Lflores » Thu Oct 15, 2020 12:56 pm

Sorry to bring this post back to live, i recently bought a used vk 112 which i loved but the first channel doesn't sound so i opened it and noticed this mod and the 1st channel input was broken so changed the input and turned it un but a horrible dc sound came up and burnout the r126 (af 47 ohms resistor at the right of the switch 2), checked the amp, changed the cutout components and reversed the mod. Also connected 2 cables to rejoin the switch as it should be but when i turned it on the amp makes an incredibly high amount of noise in both channels, both channels sounds but it makes a lot of noise in the clean channel for both inputs, i don't know why is this happening, thanks

Lflores
New Member
Posts: 2
Joined: Thu Oct 15, 2020 12:49 pm

Re: ValveKing "JCM" mode using Volume Boost switch

Post by Lflores » Thu Oct 15, 2020 2:35 pm

Sorry for awaking this post, i bought a peavey vk112 which input1 doesn't sound so i decided to open it and search for what it could be and notice some bad connections, also noticed this mod but didn't changed it so i turned on the amp and a really loud DC noise come out and burned r126 in the amp, so decided to turn back that mod and change the resistor that was burnt, also jumped the switch but it makes a horrible amount of hum even in the clean channel, can anyone help me? Thanks

Post Reply