marshall atv100 have no distortion?

[code]

Hi everybody! I bought this amps 3 months ago , this is second hand , but now i cant use its distortion channel,is there anyone knows what's happen with my amps and how to repair?

THANKS ALL!

[code]

anybody can help me?

[Jazz P Bass]

Marshall AVT100

How are you accessing the distortion channel.
Footswitch?
Front panel switches?
Do the LED indicators change at all when you switch channels?

[Enzo]

Are you telling us that when you switch to the OD channels, no sound comes out? Or are you telling us that sound comes out but it is not distorting like it should?

[code]

How are you accessing the distortion channel.
Footswitch?
Front panel switches?
Do the LED indicators change at all when you switch channels?

I use the front panel switches, the LED indicators change too , but no sound , now I just use the clean channel

[code]

Are you telling us that when you switch to the OD channels, no sound comes out? Or are you telling us that sound comes out but it is not distorting like it should?

Yes , when I switch to the OD channel, it is no sound comes out , I dont know where is the problem, and how to repair it

[Steve Conner]

This amp has a tube in it, doesn't it? Have you tried changing the tube?

[code]

This amp has a tube in it, doesn't it? Have you tried changing the tube?

yes , i've think about it so , but here , in beijing I dont know where sell this tube ... , I hope this can be repaired ... thanks a lot , and I want to know it may be have another problem , isn't it?

[code]

and if I want to change the tube , what kind of tube should I going to buy? I just know it is 12AX7 tube

[Steve Conner]

Any 12AX7 or ECC83 will do.

China is one of the main producers of vacuum tubes now, so don't tell me you can't find any. Try Chinese Ebay or your local electronics street market.

[code]

Any 12AX7 or ECC83 will do.

China is one of the main producers of vacuum tubes now, so don't tell me you can't find any. Try Chinese Ebay or your local electronics street market.

I really dont like some made in china things ... I searched , they have a lot of 12AX7 tube and I dont know marshall use what kind of tube , brand?

[Jazz P Bass]

Marshall tubes

As far as I know, Marshall uses russian tubes.
At this point we are trying to repair a fault.
Put aside your bias & try another tube.
The tube is the easiest thing to change at this point in time.

[code]

As far as I know, Marshall uses russian tubes.
At this point we are trying to repair a fault.
Put aside your bias & try another tube.
The tube is the easiest thing to change at this point in time.

Yes , I'll do it first , I hope it can work... and if not work , I want to learn how to fix too , haha

[code]

I changed the tube but it's still have no sound at OD channel , what can I do now?

[J M Fahey]

!) First of all, get the schematic.
2) apply some sound to its input and, schematic in hand, follow the signal path until you find a point where it dissapears.
3)Just for starters, check whether audio *reaches* that tube, that's splitting the problem in half.
4) If all I say confuses you, well, that's not a sin, but get somebody with troubleshooting experience, say, somebody who regularly repairs TVs, VCRs, Home Theaters, hopefully PA equipment.
Even if he's not into "Rock", he has the skills and equipment.
Good luck.
PS: sheer curiosity: how much does a 12AX7 cost to you? Can you post some vendor links? (even if in Chinese)
How much does an amp like yours cost, new (if available) or used?
Any music shop links, some that cater to Chinese internal Market (Not AliBaba and the like)?
Believe or not, we know nothing about it.
Thanks in advance.