Channels 1 and 2 Just don't work on my Roadster

[Indigo]

I thought it might have been because i reconfigured my g system.. but when i just go straight into the amp. channels 3 and 4 will work. 1 and 2.. nadda. ive checked settings.. cables.. switches. just totally blank here.

 

[hellaboogie]

Check your preamp tubes if you have a back up or a tube that you know to be good try swapping out the preamp tubes one at a time start with v1 then v2 work your way through all of them or untill you find the bad preamp tube if it is in fact a bad preamp tube, also try cleaning your effects loop

 

[DaveCarter]

Were you using the G System relays to switch channels on the Roadster? Ive read you're not supposed to do that as it can damage the amp...probably not the cause of the problem but still worth mentioning

 

[Indigo]

Check your preamp tubes if you have a back up or a tube that you know to be good try swapping out the preamp tubes one at a time start with v1 then v2 work your way through all of them or untill you find the bad preamp tube if it is in fact a bad preamp tube, also try cleaning your effects loop

can a bad preamp tube be the cause of only the distorted channels working? i dont know if some preamp tubes are for some channels.. some for another.

also, whatdo you mean clean my effects loop?

 

[7slinger]

Were you using the G System relays to switch channels on the Roadster? Ive read you're not supposed to do that as it can damage the amp...probably not the cause of the problem but still worth mentioning

this

for starters, take you g system out of the signal path and just plug straight into your amp, cycle through your channels, see what works and what doesn't. if they all work, obviously it is a routing problem with how you have things hooked up with your channel switching. if the channels still don't work when you are plugged straight into the amp, then your amp is the problem. tubes is always a good place to start when diagnosing problems with tube amps.

fwiw I used a midi switcher from axess electronics (cfx4) to do the channel switching when I ran a recto/g system setup

edit: should have read the op more closely. if the gsystem is already out of the picture, proceed with checking your tubes. contact spray cleaner for electronics can be used to clean the contacts of your effects loop. it's about 10 bucks a can at radio shack. spray some on the end of a 1/4" cable and then make sweet love to your effects loop send and return for about 10 seconds.

 

[Indigo]

now how exactly do i check my tubes? just see which ones are lighting up? and take the covers off of all of them? or do i need to dig up some of my older tubes and see if they work (they should all be good) ill try the effects loop cleaning thing first

 

[hellaboogie]

Yes a bad tube can do funny things, as far as what I mean about cleaning your effects loop there's a product that called Deoxit that works pretty well.
All you need in a guitar cable spray some on the end of it place it in the effects loop and work it back and forth say 10 times see if it takes care of the problem.
A dirty effects loop can also reek havoc on your amp, something as simple as a little dust or dirt in your effects loop can cause your amp to not operate properly it's not a big deal easy fix.

To check your preamp tubes take the tube protectors off start with the tube closes to you input jack
I suggest pulling one out at a time and replacing it with one that you know is good, check to see if your channels are back, if it's not move to the next tube. If you replace a tube and it takes care of your problem your all good just check one at a time as it makes it much easier diagnose.

 

[Indigo]

i didnt mention that when i crank the amp. like master volume to 10. the clean channel will work very quietly. still mean anything?

 

[hellaboogie]

Did you already try changing out the preamp tubes did you clean the effects loop?

 

[Leuchty]

i didnt mention that when i crank the amp. like master volume to 10. the clean channel will work very quietly. still mean anything?

sounds like a bad tube.

 

[Indigo]

was a bad preamp tube!
i replaced it with a really old mesa one full of fingerprints. hope its okay =\

 

[Meldville]

was a bad preamp tube!
i replaced it with a really old mesa one full of fingerprints. hope its okay =\

Clean it off before you crank 'er up! That grease can kill a tube, same way it can kill a bulb in a headlight

 

[budda]

also, make sure you have your channel selector set to the right setting, if you've tweaked it.