SVT-6 PRO static and volume intermittent issue

[chandman1004]

I have a SVT 6 Pro that every few minutes has an issue with static and at the same time, lower volume. Sound does not completely stop, but drops much lower with static introduced. this is intermittent for a few minutes, then goes away only to return shortly. Cabinet is a SVT-410HLF classic that works fine with a Markbass LM3 using the same speaker and instrument cables. Volume is not high, as this is in my practice area at home. Maybe at most 2 or three. Would a preamp tube going bad cause an issue like this? Or a pot needing cleaning?

 

[JimmyM]

Those could be causes as well as the effects loop needing cleaning.

 

[chandman1004]

Thanks for the quick answer Jimmy. Is inserting / removing a cable multiple times from the socket enough to clean and test the effect loop theory? Not knowing exactly how the switching works, if a cable is run from effects out directly to effect in , and the issue goes away , would that be the answer?

 

[JimmyM]

Thanks for the quick answer Jimmy. Is inserting / removing a cable multiple times from the socket enough to clean and test the effect loop theory? Not knowing exactly how the switching works, if a cable is run from effects out directly to effect in , and the issue goes away , would that be the answer?

Usually it'll clean it up doing that. And yes, inserting a cable from send to return will let you know if that's the problem.

 

[chandman1004]

Thanks!

 

[BogeyBass]

Effect loop cleaning possible. Or the board has intermittent connections that need touching up. Like 6 tubes in that thing could be tube going out. Intermittent cathode / heater short. Or all the above. Good trace the signal path tap around with chopstick and look for glitches. Likewise scope the heater voltage and look for glitches

 

[chandman1004]

Thanks Bogey. Going to have to hope that it is the effects loop, no scope. If that doesn't get it I'll have to find a tech near me.

 

[chandman1004]

Seems to have gone away with a vigorous effect loop cleaning. Now to do something about those loud fans....

 

[MC1970]

I have an SVT 6 Pro that every few minutes has an issue with static and at the same time, lower volume. Sound does not completely stop, but drops much lower with static introduced. this is intermittent for a few minutes, then goes away only to return shortly. Cabinet is a SVT-410HLF classic that works fine with a Markbass LM3 using the same speaker and instrument cables. Volume is not high, as this is in my practice area at home. Maybe at most 2 or three. Would a preamp tube going bad cause an issue like this? Or a pot needing cleaning?

Hi Chandman, I had the very same problem with mine, and it was caused by the soldering of the 4 big black and white capacitors gone cracked/loose

they have silicone filled gaps between them to absorb vibrations that has proven not effettive enough to prevent the problem.

It was solved by unsoldering them from the board, soldering them back again and then a good amount of carefully placed silicone between them


Hope it works for you as well as it did for me

 

[Raw N Low]

Hi Chandman, I had the very same problem with mine, and it was caused by the soldering of the 4 big black and white capacitors gone cracked/loose

they have silicone filled gaps between them to absorb vibrations that has proven not effettive enough to prevent the problem.

It was solved by unsoldering them from the board, soldering them back again and then a good amount of carefully placed silicone between them


Hope it works for you as well as it did for me

Thanks MC - this is good knowledge as mine had the same issue and has been sitting since. I wonder if the techs I took it to may have missed this? I may crack it open this weekend and give it a look.

 

[MC1970]

Thanks MC - this is good knowledge as mine had the same issue and has been sitting since. I wonder if the techs I took it to may have missed this? I may crack it open this weekend and give it a look.

I sincerely hope it helps solving your issue; it’s a great sounding amp

greetings from italy

 

[Raw N Low]

I sincerely hope it helps solving your issue; it’s a great sounding amp

greetings from italy

For reference - I opened up the amp and took a few photos. Hoping to get this information to my tech to re-evaluate and hopefully fix. I really love this amp.

 

[chandman1004]

Oh man.. This amp has been sitting at the repair shop for 6 months. Already cost me a crazy amount of money. Thanks for your posts. If it still happens if I ever get it back I will take this under advisement.

 

[agedhorse]

6 MONTHS???

You need to find a better repair shop.

 

[chandman1004]

Yes, this whole thing is incredibly stupid. Gives me a sick feeling. I tried to find someone to work on this here where I live, but it was like trying to pull teeth to get the amp to them. So I opted to send it away to someone in St Louis who says he help design the amp at the factory. That was in June. Now I even have doubts i will get it back fixed, even if I get it back at all.

 

[BassmanPaul]

Yes, this whole thing is incredibly stupid. Gives me a sick feeling. I tried to find someone to work on this here where I live, but it was like trying to pull teeth to get the amp to them. So I opted to send it away to someone in St Louis who says he help design the amp at the factory. That was in June. Now I even have doubts i will get it back fixed, even if I get it back at all.

Demand the amp back and don’t take no for an answer!!

Perhaps a letter from a law firm would grease the wheels a bit!