Help with 1000S.

[IKOH2OH]

I'll try to be brief and descriptive to the best of my limited ability.

The amp works until I go past 3 on the volume, then an ungodly cracking/crunching sound and it appears to go dead(no sound.) But if you listen closely you can hear The guitar/ effects faintly(and Clean), like running the 2.5 watts(using 412SP Cab.)

Then the same ungodly sound, as it seems to wish to function at indicated levels, But that crackle/crunch sound drowneds it out.  Turn the volume all the way down it stops, turn it up again and the process repetes itself. 

That last action was one of desparation/wishfull thinking.

When the sound goes faint, it does respond to the volume control.

I checked the Cab and connecting cables out using my 100% Sound City 120R and they are no longer suspect.

I have some ideas.

But I'd like to get some input from others, esp the many on this site with greater knowledge.

Thanks in advance.

IKO

[JoeArthur]

Sounds like the volume pot would be a likely suspect.

I'd first give it a good cleaning. If that doesn't help then I would replace it.

It would also help to know if you just got this amp and this is the condition you received it, Or if you've had the amp for a period of time and it just "out of the blue" just started acting this way... or if there was a recent repair... or the last time the tubes were changed.

If you have the head on the speaker cab, move the head to the floor and see if you can duplicate the problem - if you can, this would eliminate the possibility of it being vibration related.

[IKOH2OH]

Thanks;  More detail following.

I've had it for about a year and a half.

This problem did occur out of the blue, as before that it sounded great.

Since I've owned it there has been no work done, or tube replacement.  But, it is not used that frequently.

I have moved it to the floor with the same result.


I should add it appears to be input related as well.

Using a Ernie Ball MM subone(humbucker), amp can run 10 if guitar volume is kept below 3.
Go to 6 or above and she'll go the same noise then cut out route, after 3-4 on amp volume.

Will start with the volume pot though.

Thanks for the advice.