# Deluxe Reverb Reissue help



## paddleguy (Dec 11, 2009)

I recently bought a used DRRI that has a vibration that happens when the volume is at 4 or over, and only when playing lower tones (I tune down the guitar to DGCFAD). The low D to about G are the worst. I'm not sure how old the amp and the tubes are, but the guy I bought it from says he played it for about an hour once 4 years ago. The amp is in excellent physical shape, leading me to believe it hasn't been abused or gigged heavily (or at all). I checked the tubes visually and they appear to be ok, and they are seated properly. The amp sounds good, starts to break up around four, everything seems to work well except for that vibration. Any suggestions? Deeper diagnostics would have to be done by someone other than me (anybody recommend a tech in the Winnipeg area?). Any help would be appreciated.

Thanks.


----------



## hollowbody (Jan 15, 2008)

First thing I'd do is check to see how tight all the screws are.


----------



## Wild Bill (May 3, 2006)

paddleguy said:


> I recently bought a used DRRI that has a vibration that happens when the volume is at 4 or over, and only when playing lower tones (I tune down the guitar to DGCFAD). The low D to about G are the worst. I'm not sure how old the amp and the tubes are, but the guy I bought it from says he played it for about an hour once 4 years ago. The amp is in excellent physical shape, leading me to believe it hasn't been abused or gigged heavily (or at all). I checked the tubes visually and they appear to be ok, and they are seated properly. The amp sounds good, starts to break up around four, everything seems to work well except for that vibration. Any suggestions? Deeper diagnostics would have to be done by someone other than me (anybody recommend a tech in the Winnipeg area?). Any help would be appreciated.
> 
> Thanks.


First off, when you play in that lower tuning, you are going below the range of a standard guitar amp and into bass amp territory. There are a few differences between a regular guitar amp and a bass amp. The main one is the output transformer. It has to be about a third larger and heavier to handle the energy of those longer wanvelength bass notes. 

The OT in your DRRI is likely simply too small to do a good job on those low bass notes, at higher volumes!

Another possibility is that one or more of the preamp tubes may have gotten sensitive to vibration, or microphonic. This means the tube acts like a microphone and will pick up the note from the speaker and amplify it, just like a mike held directly in front of a PA speaker!

This is easy to check! Take a pencil or a plastic pen and gently tap each preamp tube. If one is microphonic you will hear it "chime" as you tap it! You may not have to replace it. Sometimes you can swap it with another one in a different position and it will work ok there. If not, then you will have to replace it.

WB


----------



## paddleguy (Dec 11, 2009)

Thanks for your suggestions. I made sure all the screws were tight, and did the microphonics test (negative). Wild Bill, I hear what you are saying about the OT, but I've played a Vox Night Train, Blackheart Little Giant, Egnater Rebel 30, Fender Twin, and a Roland JC120 in my tuning and haven't had the same problem. Are the other things I might try? If not, I guess I'll try to find a tech if any one can recommend one.

Cheers...


----------



## washburned (Oct 13, 2006)

Have you tried running it through another speaker? Could be a problem with the stock speaker, especially if it has been sitting for a long time. I once had a piece of paper get into a speaker, between the cone and frame, and it would vibrate like crazy at low frequency.


----------



## Wild Bill (May 3, 2006)

paddleguy said:


> Thanks for your suggestions. I made sure all the screws were tight, and did the microphonics test (negative). Wild Bill, I hear what you are saying about the OT, but I've played a Vox Night Train, Blackheart Little Giant, Egnater Rebel 30, Fender Twin, and a Roland JC120 in my tuning and haven't had the same problem. Are the other things I might try? If not, I guess I'll try to find a tech if any one can recommend one.
> 
> Cheers...


Washburned had a good idea about trying another speaker! Why not try plugging in a larger extension cab and see if that sounds any better?

WB


----------



## paddleguy (Dec 11, 2009)

That is an excellent idea. I'll do that at my next jam, later this week...

pg


----------



## paddleguy (Dec 11, 2009)

It turns out that it was the speaker(torn cone in a couple of places). Dropped in a Cannabis Rex and all is good. Another question though, the amp seems to break up between 3 and 4, and gets fairly crunchy at 5. Do other DRRI users find this as well? 

Thanks.


----------



## nonreverb (Sep 19, 2006)

Have you had the bias on the output tubes checked? Probably a good place to start


----------



## paddleguy (Dec 11, 2009)

I had thought of that, but I was interested in hearing how others amps behaved. As soon as I get a bias probe I'll check the heck out of that bias and maybe put in some new tubes while I'm at it...


----------



## keto (May 23, 2006)

Ya, yours us behaving exactly as it should. With humbuckers I had to turn down guitar vol to stay clean by '4' on the amp, had to keep it to 3ish if I wanted clean and even then couldn't hit it hard with my right hand. With weak (Strat) single coils and standard tuning, headroom closer to 5ish.


----------



## nonreverb (Sep 19, 2006)

Some people run 6L6's in those amps which will give you tighter bass. However, the bias circuit has to be modded to get more negative bias for them. I have not seen any problem with the power transformers in the old ones although I don't know how the new ones would handle the extra filament current.


----------



## paddleguy (Dec 11, 2009)

I play a Strat with lace sensors and it seems to break up a little earlier than you are describing (not necessarily a bad thing, tone wise, for me!). I'll check the bias and do some tube swapping and see what happens...


----------

