Hey guys - My DRRI reverb sort of quit, and then just wasn't working right at all last week.
I can't recall, is there a tube in the RI, or only original?
What should I look at first?
I wasn't using it when it happened, but was on stage. It sounded mostly like it just quit working, but the amp also began to resonate, and howl - like a hollowbody getting away from you volume-wise.
what do you think?
Kenny Belmont
>:^{I)>
The reverb circuit contains two tubes -- V3 is the driver, V4 handles the recovery duties. Start your troubleshooting there.
"When injustice becomes law then rebellion becomes duty."
I just had V4 start to die on me and the reverb would come and go. I actually mis-diagnosed it myself because the solder points on mine, inside the tank, are pretty iffy. I had to reconnect/re-solder one of the wires a few years back.
When I saw there wasn't a problem in the tank this time and I realized it tended to work more often when starting the amp cold and then die out, I figured it had to be a tube. Swapped V3 and no difference, swapped V4 and voila, plenty o'verb.
"......I realized it tended to work more often when starting the amp cold and then die out......"Originally Posted by pc
I'd suspect a fractured solder joint, given this revelation. It might not be a bad idea to reflow the joints on the pins of each tube socket, especially if the amp dates to 2006 or later when RoHS-compliant solder became the norm.
"When injustice becomes law then rebellion becomes duty."
I cannot see the tube diagram - is that a 12ax7/at7....?
EDIT -
Disregard - got it
V1 12ax7 = Preamp normal channel
V2 12ax7 = Preamp vibrato channel
V3 12at7 = Reverb send
V4 12ax7 = 1/2 Reverb recovery and 1/2 gain stage for vibrato channel
V5 12ax7 = Vibrato
V6 12at7 = Phase inverter
V7 6V6 = Power tube #1
V8 6V6 = Power tube #2
V9 GZ34 = Rectifier tube
Last edited by FrankJohnson; 10-15-2014 at 11:56 AM.
Kenny Belmont
>:^{I)>
Ken, shake the tank. If you can hear it, the problem is tied to V3. If you can't, it's V4.
Several guitars in different colors
Things to make them fuzzy
Things to make them louder
orange picks
Hey, Kap'n......good to see you back!
"When injustice becomes law then rebellion becomes duty."
COOL!!! Welcome back Kap'n too!!!!
I will be out there tomorrow to check it out
THANKS GUYS!!!!
Kenny Belmont
>:^{I)>
Good advice!
Welcome back Kap'n
Mark
Welcome back Kap...
Re reverb issues with DRs... I don't know why - but they (DRs) seem to be really tough on the 12AT7 (driver side)...
Last edited by yankeerob; 10-16-2014 at 02:03 PM.
If I could find a road to get away it wouldn't be too soon....... Shipwreck Moon.......
Kap'n, welcome back. My world is round again.
You've been missed.
SCOTS still rule. You changed my musical journey with a random act of kindness and I often think of you when I play because of it.
Hoping you'll stay around.
"No harmonic knowledge, no sense of time, a ghastly tone, unskilled vibrato, and so on. Chuck is one of the worst guitar players I know" -Gravity Jim
Guys - thanks much!! V4 tube replaced - had some on hand and it immediately fixed it! We had our international blues challenge play-offs yesterday and this was one of the backline amps - so we didn't have to use a backup.
Thanks again!! great having you guys back!!!! AND.......Being Back!!!
Kenny Belmont
>:^{I)>
Smooth.
Rawk on, Kenny!
"When injustice becomes law then rebellion becomes duty."
Roger - I seriously didn't know what to do! I am SO glad we are back up and runningSmooth.
Rawk on, Kenny!
BTW - I have read an AU7 will tame or make the reverb more controllable - your thoughts? or is this a YMMV thing?
Kenny Belmont
>:^{I)>
I've heard that as well. My concern would be that the 12AU7's relatively low mu factor would result in significantly lower gain for some applications. I would try a 12AY7 first and see how that performs. In either case, no harm is likely to result -- give them both a try and see how they sound.
"When injustice becomes law then rebellion becomes duty."
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