The Boogie Board

Discussion Forum for Mesa Boogie Products
It is currently Mon Sep 25, 2017 12:05 pm

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 6 posts ] 
Author Message
PostPosted: Sat Jan 10, 2015 11:43 am 
Offline
Mark II

Joined: Mon Aug 17, 2009 9:28 am
Posts: 99
A few weeks ago my Dyne head started doing something very odd at a gig. It is most obvious when playing a chord, as the volume starts to die down the amp (for lack of better description) almost sounds like it has a tremolo on it, the volume sputters about.

At first I thought I was a perhaps an issue with the voltage in the venue because it didn't do it when I was at home. But last night, different venue, same thing. Our sound tech plugged the amp into a filtered power supply and that did not help.

It does not do it everytime, but will say of a 3 set show, it was prevalent in the first and second sets, but not at all noticable in the 3rd set.

I am guessing a tube problem - just curious if all think I should look to power tubes or pre-amp first?

Thanks very much

_________________
Mike Keller

Mini Rectifier Head
Electra-Dyne Head
Royal Atlantic 27" 1x12 Cabinet

EBMM Guitars


http://www.theseguyslive.com


Top
 Profile  
 
PostPosted: Sat Jan 10, 2015 5:30 pm 
Offline
Mark III

Joined: Wed Jan 04, 2012 9:32 pm
Posts: 217
Probably your power tubes. I bet there's one that's shorting. Run the amp in 45 watt mode. Does it do it? If it does, swap the inner 2 power tubes with the outer 2 power tubes. Did that fix it? If so, buy new tubes. If not, take it to a good amp tech.

_________________
Electra Dyne 1x12 combo
Deluxe Reverb Reissue
American Deluxe strat
PRS Custom 22

Image


Top
 Profile  
 
PostPosted: Sun Jan 11, 2015 12:42 am 
Offline
Donating Member
User avatar

Joined: Thu Oct 15, 2009 1:30 pm
Posts: 2533
Location: San Francisco Bay Area, CA
I'd bet PI tube. I had a similar experience. It went completely bad in short order.

_________________
Electra Dyne Head
JP-2C WICKER, Baby!
Mini Rectifier blue LED
Recto 2x12 Horizontal
2x Recto 2x12 Vertical


Top
 Profile  
 
PostPosted: Sun Jan 11, 2015 10:28 am 
Offline
Mark II

Joined: Mon Aug 17, 2009 9:28 am
Posts: 99
Thanks for the suggestions !!

Elvis: which one is the Phase Inverter? I can't tell by looking at tube layout chart in the manual?

_________________
Mike Keller

Mini Rectifier Head
Electra-Dyne Head
Royal Atlantic 27" 1x12 Cabinet

EBMM Guitars


http://www.theseguyslive.com


Top
 Profile  
 
PostPosted: Sun Jan 11, 2015 2:05 pm 
Offline
Donating Member
User avatar

Joined: Thu Oct 15, 2009 1:30 pm
Posts: 2533
Location: San Francisco Bay Area, CA
The PI is pretty much always the last (highest number) preamp tube, and may also be called a driver.

_________________
Electra Dyne Head
JP-2C WICKER, Baby!
Mini Rectifier blue LED
Recto 2x12 Horizontal
2x Recto 2x12 Vertical


Top
 Profile  
 
PostPosted: Sun Jan 11, 2015 4:02 pm 
Offline
Mark II

Joined: Mon Aug 17, 2009 9:28 am
Posts: 99
Thank you - I thought so, appreciate the verification.

_________________
Mike Keller

Mini Rectifier Head
Electra-Dyne Head
Royal Atlantic 27" 1x12 Cabinet

EBMM Guitars


http://www.theseguyslive.com


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group