Guitar Gear Forum

I recently got a Jet City 100w head and there is a small issue with it.

There is some cross-over of the Overdrive and Normal channels. When i have it on the Normal channel, set up for clean, you can still here the OD channel kinda underneath the clean sound. Its fairly quite but it's hindering me getting a perfect clean sound with no break up.

What would be the cause of this and can i fix it?

From the schematic looks like 2 gain stages are dropped out the circuit by the LDRs that change the chanels. If those stages aren't correcly sent to ground then some signal would still pass through the OD circuit?

I assume this isn't a commen problem as google didnt help and hopefully they would've de-bugged that kinda thing when they designed the PCB.

What do you reckon?

Thats normal in the JCs and SLOs, Liam. You can only stop that by adding another VTL or a relay and put the lead's channel earlier in the circuit to ground. Problem with VTLs in the JCs is, that the supply voltage is taken off the heaters - so you need to adjust the resistor's values for all VTLs when adding another one of them.
You could follow the SLO scheme with 4 VTLs as posted in the SLo clone forums but keep in mind that the supply is different.

Olaf

Thanks Olaf.

I think i'll leave it as it is for the minute. The changes you mention are bit above my head for the minute. I need to do furhter reading on switching, LDRs and relays...

Just wanted to ask if that was a problem with the amp or not.