HT 20H head: distortion not working on OD channel?

[Volkum]

I just got my Studio HT 20H and I rushed home from work today all excited...only to find out that I don't get any distortion/overdrive on the OD channel. Both channels are clean regardless of the gain/volume/any and all settings, though I still get the high gain "hum". Is it possible I'm missing something obvious here? I'd really hate to have to RMA this thing (and it would probably cost me a small fortune based on size and weight). Obligatory pic below:



Cab is DIY with a single Celestion classic lead 80 (8 ohm).

[Superchampable]

I know if you have the footswitch pluged in you may need to press it or press overdrive in on the amp.. just mess around with those two buttons and youll probaly get it to work after a few try.. same thing happed to me but not faulty.

Oh and dont bother contacting blackstar.. heard they dont respond from numerous reviews.. jerks. You need great costomer service if you want your amp to make it!

[Icarus]

Its a long shot because i have no experience with these amps so i dont know a thing about them but try removing the back, making sure the valves are all seated correctly. You could also try patching a cable from your fx loop send --> return and see what that does. Another cause could be a bad preamp valve.

[gt_jumper]

dude, does the light work on the amp and foot switch?

But the gain hiss makes me think its a bad preamp valve!

[Volkum]

I know if you have the footswitch pluged in you may need to press it or press overdrive in on the amp.. just mess around with those two buttons and youll probaly get it to work after a few try.. same thing happed to me but not faulty.

Oh and dont bother contacting blackstar.. heard they dont respond from numerous reviews.. jerks. You need great costomer service if you want your amp to make it!

I haven't had any luck. The behavior is consistent with or without the footswitch.

Its a long shot because i have no experience with these amps so i dont know a thing about them but try removing the back, making sure the valves are all seated correctly. You could also try patching a cable from your fx loop send --> return and see what that does. Another cause could be a bad preamp valve.

Valves seated -- check (also tried reseating them)
FX loop -- no change
Bad valve -- don't have a spare :-/

dude, does the light work on the amp and foot switch?

But the gain hiss makes me think its a bad preamp valve!

Yes, the pilot light and the OD channel light on the amp as well as the light on the footswitch all function.

I appreciate all the replies, but it's not looking like this amp is gonna "make" my weekend like I had intended.

[gt_jumper]

Pull me up if i am sounding pushy but i hate it when something you have waited on for so long is broken.....

You dont have another amp to pull the 12ax7 outta?

most DIY electric shops have them for cheap, even better if you can get a tung sol, coz it will end up staying in!!!

[Volkum]

Pull me up if i am sounding pushy but i hate it when something you have waited on for so long is broken.....

You dont have another amp to pull the 12ax7 outta?

most DIY electric shops have them for cheap, even better if you can get a tung sol, coz it will end up staying in!!!

This is my first tube amp. I've built solid state hifi headphone amps and my old guitar amp was a solid state fender, so no, I do not have any extra tubes lying around, unfortunately. I guess I'll have to call up some local guitar shops and see if I can go buy a spare 12AX7WA or 2 (while crossing my fingers that it fixes the issue).

[Volkum]

Side question, would any ECC83/12AX7 be compatible?

[gt_jumper]

Side question, would any ECC83/12AX7 be compatible?

same thing, different name!

[Volkum]

I just replaced the preamp tubes with a pair of 12AX7EHs and that didn't fix the problem.

Music123 sent me a return label. I'm shipping this hunk of junk back.