2002? DRRI Newly Acquired.. Look inside and tell me what I got myself into.. Pic Heavy

[giogolf]

Hey TDPRI'ers!,

The conquest continues.. This months haul: 2002? DRRI Amp; that I think I paid a fair price for. So I saw this listed a week ago in my area and had I nice convo with the gent. Unfortunately couldn't meetup to check it out at the time as I was headed out of town. Lucky for me (maybe), it was available when I got back, checked it out, played it and came home with it.

So after playing it for about an hour after I got home, I took it apart, cleaned it up and snapped a bunch of pictures for those of you who know what you are looking at, internally.. So if you could be so kind as to let me know what I should know, what I should do, fix, replace, etc..

Things I already know: The amp was gigged for a good while (has battle wounds on the tolex), the speaker was swapped out with a WGS British Lead 80w and jewel glass was swapped to purple, I dig it .

So take a peak and tell me what the deal is here... Please

 

[giogolf]

More Pics

 

[giogolf]

And more...

 

[Sea Devil]

Normally it's very hard to tell anything from photos, but when there's a burnt spot on the board, something is very wrong. Even if no components are damaged (yet!), you absolutely must scrape the black carbonized portion of the board clean. Carbon is conductive.

 

[giogolf]

Well shoot, didn’t even see that.. What do you recommend here?

 

[Sea Devil]

First of all, that's a high-voltage point in power portion of the circuit, hence the P in P13. The schematic says 396 Volts DC, which can kill you. If you don't have a multimeter, take it to a tech.

If you do have a multimeter, you could take the huge risk of turning it on until it produces a sound (since you've apparently already done that), and if it doesn't explode or catch fire, power the amp off, leaving the standby on. Unplug it. Wait a few minutes. Check to make sure the electrolytic capacitors are drained. (If you don't know how, take it to a tech! If you do, read on.) Pull the black wire off; it should wiggle off without too much trouble. Scrape the area clean of ALL of the black stuff that's touching anything metal. A Dremel helps, but patience and an X-Acto with a curved blade will get the job done. I had a similar issue when some unevaporated solvent I was using to clean off water damage caught fire in mine! It was fine in the end.
You should probably just take it to a tech anyway; that may be an indicator that there are other problems farther downstream in your circuit, and that could cause much more expensive problems very quickly. I'm surprised it works at all.

The picture below is mine before scraping. It was a simple arc that didn't send the juice anywhere it wasn't supposed to go, which is why it didn't do any secondary damage.

 

[giogolf]

If you don't have a multimeter, take it to a tech. If you do, you could take the risk of turning it on until it produces a sound (since you've apparently already done that), then power the amp off, leaving the standby on. Unplug it. Wait a few minutes. Check to make sure the electrolytic capacitors are drained. (If you don't know how, take it to a tech! If you do, read on.) Scrape the area clean of all the black stuff that's touching anything metal. A Dremel helps, but patience and an X-Acto with a curved blade will get the job done. I had a similar issue when some unevaporated solvent I was using to clean off water damage caught fire in mine! It was fine in the end.
You should probably just take it to a tech anyway; that may be an indicator that there are other problems farther downstream in your circuit, and that could cause much more expensive problems very quickly. I'm surprised it works at all.

Thank you; yes, the amp works very well actually.. Sounds incredible, no noise, hiss, pops or weirdness.. Also, no burning smell when on or after playing

 

[sax4blues]

Thank you; yes, the amp works very well actually.. Sounds incredible, no noise, hiss, pops or weirdness.. Also, no burning smell when on or after playing

This is why I may not really be a forum type guy. It has never occurred to me to open my gear and look for problems, especially when first impression is, looks good/sounds good/smells good.

 

[Sea Devil]

I may be exaggerating the danger here, but you'll get some more informed opinions soon, I'm sure.

If it's playing ok, I'd still scrape that spot. It's super-easy to check the capacitors with even a crappy ten-dollar meter. If you're feeling adventurous, you can just make sure they're discharged by touching a rubber-handled screwdriver simultaneously to the positive terminal of each cap and the chassis, preferably while wearing runner-soled shoes with one hand in your pocket.

That's after the rectifier, so just turning off the power is absolutely not enough. If you don't know amps, it never is.

I edited my previous post to include more details and more warnings, btw. I recommend going over it again.

 

[giogolf]

This is why I may not really be a forum type guy. It has never occurred to me to open my gear and look for problems, especially when first impression is, looks good/sounds good/smells good.

Normally, I don’t go blabbing about on here about things, hence my low post count.. But times like these, it’s really nice to have ya’ll take a look and provide an opinion..

And I thank you and Sea Devil for that. I just glanced over that and didn’t notice it.. So a few more set of eyes in this situation may prevent more $$ spent down the road

 

[Sea Devil]

It might be very superficial. Shot of tequila or grape juice or beer that dripped in and got fried, fixed with a replacement fuse once dried. It still should be addressed. But one of the resistors has some discoloration too, so who knows?

At least now if you take it to a tech, you know what to say: check the bias and filter caps, scrape the burnt crud. It probably won't cost much, and it's always a good idea to have an old amp looked at anyway. If the filter caps have never been changed, it's time.

You should always factor at least a bench fee into the cost of an amp that hasn't been serviced for a while.

 

[Milspec]

One thing to add, it has casters and it was gigged with quite a bit by the speaker label wear and battle scars. I never found the Deluxe to be overly heavy, but the previous owner must have so he added the casters. The problem is, rolling an amp across concrete (sidewalks, driveways, etc.) will transfer a lot of vibration straight to the internals of the amp. Such usage can cause a lot of things to go wrong (failed solder joints, loosened components, etc.).

I was screamed at by my amp tech when he witnessed me rolling my boat anchor Twin from my car up the sidewalk to his shop. The dude is very laid back, but he came flying out of his shop when he saw it out his window.

Rolling is fine on smooth surfaces like carpet, wood or tile floors, etc., but NEVER across cement. If you must roll it to save your back, place the amp on a furniture dolly or something so it absorbs the vibrations instead of the amp.

Could rolling it over cement cause that burn mark? Maybe, just something to keep in mind.

 

[giogolf]

It might be very superficial. Shot of tequila or grape juice or beer that dripped in and got fried, fixed with a replacement fuse once dried. It still should be addressed.

It’s funny you say that, because prior to cleaning you can clearly see lots of ring marks on the top of the amp. Nearly all the metal on the outside is patinaed or rusted, this sucker was definitely used and gigged hard. But surprisingly everything is very tight sounds great and looks good minus that one part of the PCB that you noticed. I wouldn’t doubt this sucker had its fair share of beer and tequila spilled all over it.

 

[Sea Devil]

I've played my share of bar gigs, believe me. Once a guy who was leaning against a long table right next to my amp stood up suddenly while someone was sitting on the other end, and about twenty half-filled bottles, mugs, and glasses went airborne, some landing right on my Blues Jr, which has plenty of points of entry for liquids. I was on that power switch in nothing flat!

When the other guitarist wanted to put his beer on my Vibrolux, I told him I'd need a $1400 deposit before I'd let him do that. He laughed and put the beer somewhere more sensible. He'd just killed his DeVille in mid-gig a week or two before doing the same thing.

 

[giogolf]

I've played my share of bar gigs, believe me. Once a guy who was leaning against a long table right next to my amp stood up suddenly while someone was sitting on the other end, and about twenty half-filled bottles, mugs, and glasses went airborne, some landing right on my Blues Jr, which has plenty of points of entry for liquids. I was on that power switch in nothing flat!

When the other guitarist wanted to put his beer on my Vibrolux, I told him I'd need a $1400 deposit before I'd let him do that. He laughed and put the beer somewhere more sensible. He'd just killed his DeVille in mid-gig a week or two before doing the same thing.

Those days are definitely behind me as I am now just playing in my house.. But boy did my 68’ Twin see its fair share of bad behavior when I was gigging musician.. How that thing survived is beyond me..

 

[guitar_paul1]

I've been watching DRRI videos on youtube.
Psionic Audio has a ton of good videos on this amp, showing innards and telling you what to look for.

If you're not already a tube tech I wouldn't start learning on this amp. There are some gotchas in the PCB design, but easier to work on than a lot of them.

Great amp, though. And easier to work on than a lot of them.

 

[giogolf]

One thing to add, it has casters and it was gigged with quite a bit by the speaker label wear and battle scars. I never found the Deluxe to be overly heavy, but the previous owner must have so he added the casters. The problem is, rolling an amp across concrete (sidewalks, driveways, etc.) will transfer a lot of vibration straight to the internals of the amp. Such usage can cause a lot of things to go wrong (failed solder joints, loosened components, etc.).

I was screamed at by my amp tech when he witnessed me rolling my boat anchor Twin from my car up the sidewalk to his shop. The dude is very laid back, but he came flying out of his shop when he saw it out his window.

Rolling is fine on smooth surfaces like carpet, wood or tile floors, etc., but NEVER across cement. If you must roll it to save your back, place the amp on a furniture dolly or something so it absorbs the vibrations instead of the amp.

Could rolling it over cement cause that burn mark? Maybe, just something to keep in mind.

Well during one drunken night after a gig back in the day.. My singer and I, road our Twins down a street in NJ.. Lets say, I didn’t tell my tech why I was bringing my ampnin for service

Gladly those days of no common sense are long gone

I have since pulled the casters of this DRRI, it will live the reat of its life in a shelf while I play it in the comfort of my home

 

[giogolf]

It thought the honey moon was over this morning before I even got really into this amp. Plugged it in this morning and immediately Hum city without anything plugged in.. Turned the reverb knob and the Hum got louder and started feedbacking (still no guitar plugged in). I thought well, here we go, time to dump some money in to this thing!

Then I figured I fiddled with something after I took it apart yesterday for the photo shoot.. Put it on the bench, tried a known well grounded receptacle and still Hum city.. Unscrewed the back, wiggled the tubes, nothing unusual, all looks well, the Recti Tube glows more than the 6v6 (can’t remember if this is normal or not).. But then I remembered I had this thing sideway, upside down and such.. So I powered down, tilted it sideways, shook the reverb tank, and bam, reverb spring noise and everything is back to where it was..

So, I guess while I had this thing upside down and sideways both ways the reverb springs got stuck or jammed or something..

But all is well, back in the Honeymoon phase for now

 

[Sea Devil]

Since no one else has chimed in here with words of warning: I still think you should buy a cheap multimeter to make sure your filter caps are drained and scrape that spot. While you have the "doghouse" under the chassis where the caps live open, look for signs of leakage. Take it in for servicing ASAP if you see any. Otherwise, just plan to get it serviced some time relatively soon, or learn how to do it yourself.

 

[Sea Devil]

The hum was probably from the reverb cables.