Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: bluesfuze1 on July 08, 2020, 04:58:01 pm

Title: Output changes on EC tremolux while playing
Post by: bluesfuze1 on July 08, 2020, 04:58:01 pm: Anyone know if a power tubes 6V6 can all of a sudden change output volume
When I play ec tremolux on low or high output setting volume can be loud and then drop and be clipping slightly
When output is strong and I dig in on guitar it seems like it sags and doesnt come back but if i just pick normally it stays at strong output
Could this be bad tubes or something else?
Title: Re: Output changes on EC tremolux while playing
Post by: vampwizzard on July 08, 2020, 05:10:38 pm: Could be. Did you make other modifications after removing that resistor from the other thread?
Title: Re: Output changes on EC tremolux while playing
Post by: bluesfuze1 on July 08, 2020, 07:39:41 pm: Quote from: vampwizzard on July 08, 2020, 05:10:38 pm
Could be. Did you make other modifications after removing that resistor from the other thread?

no I did not
Title: Re: Output changes on EC tremolux while playing
Post by: tubeswell on July 08, 2020, 10:14:33 pm: What is happening with the bias and power rail voltages when it sags?
Title: Re: Output changes on EC tremolux while playing
Post by: vampwizzard on July 08, 2020, 10:53:06 pm: Ok, thanks for that clarification.

What brand tubes are they?
Title: Re: Output changes on EC tremolux while playing
Post by: bluesfuze1 on July 09, 2020, 08:17:52 am: Quote from: vampwizzard on July 08, 2020, 10:53:06 pm
Ok, thanks for that clarification.

What brand tubes are they?

JJ 6V6 s
Title: Re: Output changes on EC tremolux while playing
Post by: bluesfuze1 on July 09, 2020, 08:21:41 am: Quote from: tubeswell on July 08, 2020, 10:14:33 pm
What is happening with the bias and power rail voltages when it sags?

I dont know how measure any of that...like I said I am a newbee
I do notice some blue sparks in one of the power tubes when it sags
Title: Re: Output changes on EC tremolux while playing
Post by: vampwizzard on July 09, 2020, 08:41:46 am: Quote from: bluesfuze1 on July 09, 2020, 08:21:41 am
Quote from: tubeswell on July 08, 2020, 10:14:33 pm
What is happening with the bias and power rail voltages when it sags?

I dont know how measure any of that...like I said I am a newbee
I do notice some blue sparks in one of the power tubes when it sags

You'll need to know how to bias amps as a bare minimum for figuring out whats going on. It sounds like you may be biased too high, but without the bias info we wont know
Title: Re: Output changes on EC tremolux while playing
Post by: bluesfuze1 on July 09, 2020, 10:12:26 am: Quote from: vampwizzard on July 09, 2020, 08:41:46 am
Quote from: bluesfuze1 on July 09, 2020, 08:21:41 am
Quote from: tubeswell on July 08, 2020, 10:14:33 pm
What is happening with the bias and power rail voltages when it sags?

I dont know how measure any of that...like I said I am a newbee
I do notice some blue sparks in one of the power tubes when it sags

You'll need to know how to bias amps as a bare minimum for figuring out whats going on. It sounds like you may be biased too high, but without the bias info we wont know

The amp is stock from Fender never changed anything except Tubes so dont know how bias would change
Do you have any ideas?
Title: Re: Output changes on EC tremolux while playing
Post by: shooter on July 09, 2020, 10:19:44 am: Quote
never changed anything except Tubes
ANY time I change tubes, I verify bias

ever go to start your car and it don't start? everything breaks, drifts, goes bad.....
find a Tech in your area
Title: Re: Output changes on EC tremolux while playing
Post by: bluesfuze1 on July 09, 2020, 10:59:38 am: Quote from: shooter on July 09, 2020, 10:19:44 am
Quote
never changed anything except Tubes
ANY time I change tubes, I verify bias

ever go to start your car and it don't start? everything breaks, drifts, goes bad.....
find a Tech in your area

No one in Florida keys I trust...I will try a new set of sovteks
Out of curiosity what tool do I need to check bias?
Thanks for your input
Title: Re: Output changes on EC tremolux while playing
Post by: shooter on July 09, 2020, 11:31:59 am: what if your voltages are off for the PS, what if the bias circuit is bad, can you verify those? otherwise I wouldn't buy tubes, I'd buy a book on basic tube amp understanding and read.

somewhere southwest FL there's a great store, nothing but tube amps, Naples area I think.
Title: Re: Output changes on EC tremolux while playing
Post by: bluesfuze1 on July 09, 2020, 12:46:04 pm: Quote from: shooter on July 09, 2020, 11:31:59 am
what if your voltages are off for the PS, what if the bias circuit is bad, can you verify those? otherwise I wouldn't buy tubes, I'd buy a book on basic tube amp understanding and read.

somewhere southwest FL there's a great store, nothing but tube amps, Naples area I think.

Way west of me...I am just gonna try new tubes if it fixes problem I am good
I would love a good newbie book on basic tube amps can you recommend one?
Thanks for your input
Title: Re: Output changes on EC tremolux while playing
Post by: drew on July 09, 2020, 05:56:29 pm: Quote from: bluesfuze1 on July 09, 2020, 12:46:04 pm
Quote from: shooter on July 09, 2020, 11:31:59 am
what if your voltages are off for the PS, what if the bias circuit is bad, can you verify those? otherwise I wouldn't buy tubes, I'd buy a book on basic tube amp understanding and read.

somewhere southwest FL there's a great store, nothing but tube amps, Naples area I think.

Way west of me...I am just gonna try new tubes if it fixes problem I am good
I would love a good newbie book on basic tube amps can you recommend one?
Thanks for your input
Look at the All-Time Great Information thread, at the very top of the listing for this sub-forum.

There have to be some people in the Keys who can do simple tube amp trouble-shooting and repairs. It's not rocket surgery.
Title: Re: Output changes on EC tremolux while playing
Post by: tubeswell on July 09, 2020, 05:58:43 pm: Jack Darr book might still be free on-line somewhere.

Google is your friend
Title: Re: Output changes on EC tremolux while playing
Post by: shooter on July 09, 2020, 06:24:45 pm: Quote
It's not rocket surgery
:laugh:
I was a guided missile tech in the Navy, the math was harder, but the gremlins were way nicer than guitar tube ones :icon_biggrin:
Title: Re: Output changes on EC tremolux while playing
Post by: bluesfuze1 on July 09, 2020, 06:33:23 pm: Quote from: tubeswell on July 09, 2020, 05:58:43 pm
Jack Darr book might still be free on-line somewhere.

Google is your friend

Thank you