So many problems with my DRRI !

[soundguruman]

I tried to measure with the power tubes removed... big flash and fuse blown... badly burnt !

Enough is enough. Stop playing around before you kill yourself.
Give that thing to a tech and get it fixed correctly.

I mean replace the fuse or plug in a tube, OK. But step away from the amp, sir. For yer own safety please.

[Wil]

Haha no, no! I did not get burnt, I was talking about the fuse! Sorry haha english is not my mothertongue!
I think the rectifier blows the fuses. I found that R59 measured approx. 23k and was supposed to be 10k. It's the resistor that goes from lug 3 (or 1 I don't remember) of the bias pot to ground. I changed it.
I'll buy a new rectifier tube and some fuses tomorow and I hope it will be fixed ! It it still isn't, I'll check the PT voltages.

[Cygnus X1]

My head hurts.
I quit this thread long ago...the best advice has already been given.
Get it to someone who knows what they are doing.

[Cygnus X1]

Diablo El Double strikes again...

[Wil]

Or I could have someone to explain me a little more.

Give a man a fish and you feed him for a day, teach a man to fish and you feed him for a lifetime. So help me god, haha

[Cygnus X1]

OK then.
Here is my advice.
Build a 5F1 Fender Champ.
Sell it when you're done.
Then build a 5E3 Deluxe.
Sell it if you dare, if you do it right you will keep it forever.

When you have completed those tasks, come back.

[Gibsonman63]

Once you decide to go point to point, it is much more than just following the schematic and soldering. A few things to consider:

Lead dress (routing and layout of the wiring) is critical. Decide what wire works best for you. Personally, I like the cloth covered pushback wire for blackface Fender projects. It is easy to work with, it stays where you put it and it is period correct.

You will need new pots and jacks. Use high quality parts.

I don't know if the tube sockets are PCB mounted or not on the DRRI. If so, you will need to replace them. If not, you may consider upgrading them.

You will still not have a solid pine finger-jointed cabinet. Some say that also contributes the the tone. If you replace this as well, you end up just using the original chassis and faceplates and not much else by the time you are done. If you get to that point, you might as well build from scratch and save the labor of disassembly. You could sell your amp for about half the cost of a decent kit and save yourself a lot of time.

If you are really serious about doing this, download the AB763 schematic and layout from Schematic Heaven or other such site and lurk on eBay and download as many gutshots from blackface DRs as you can find. This is a serious undertaking and to really do it correctly will take some hours.

Once you have done all of this your troubles may not be over. You will have a whole new amp to troubleshoot. For just a few dollars, you can build a light-bulb current limiter and a signal tracer.

If you have never done this before, I would recommend building a Champ or something similar to get some practice in.

[Wil]

Thank you for the answer. It appears that my problem was R59, I replaced it and now I can get normal bias reading! It made my day! But after that I replaced the rectifier and put some old output tubes (I didn't want to blow my brand new tung sol's). I played a bit, then I cranked the amp and bang, smoke coming out of the chassis. I immediately looked at the output tubes and V7 seemed to have some trouble. I turned the amp off. And replaced them with good JJ's. But when I sniff my amp like a dog, the smell is more pronounciate on the PCB. The amp now, with the JJ's, still works but I think I have a little little volume loss. (All tubes where correctly biased when played).
Everything I can say now is that I have a little headache (it feels like my head is a balloon haha) because I sniffed the smoke to track down the problem, but it appears to be the tube (I guess...). It came from the left part of the PCB, near the PT.
The first suspect is V7...
I used Gerald Weber's tip to control the output of the amp and the result is approx. 20W

[JoeM]

Wil, respectfully, you are still just guessing at where the problem(s) are in this amp. It's apparent to anyone with experience that you are over your head and just doing more damage to the amp. Now your saying the amp smokes and it didn't do this before you worked on it. Stop doing more damage and take it in.

[soundguruman]

Thank you for the answer. It appears that my problem was R59, I replaced it and now I can get normal bias reading! It made my day! But after that I replaced the rectifier and put some old output tubes (I didn't want to blow my brand new tung sol's). I played a bit, then I cranked the amp and bang, smoke coming out of the chassis. I immediately looked at the output tubes and V7 seemed to have some trouble. I turned the amp off. And replaced them with good JJ's. But when I sniff my amp like a dog, the smell is more pronounciate on the PCB. The amp now, with the JJ's, still works but I think I have a little little volume loss. (All tubes where correctly biased when played).
Everything I can say now is that I have a little headache (it feels like my head is a balloon haha) because I sniffed the smoke to track down the problem, but it appears to be the tube (I guess...). It came from the left part of the PCB, near the PT.
The first suspect is V7...
I used Gerald Weber's tip to control the output of the amp and the result is approx. 20W

This thread has more explosions than a James Bond Movie.

[Wil]

The amp now sounds fine. it's obvious techs know billions more things on amps than I do but I want to learn. If this amp has to play the guinea pig then no problem. Experience is mother of sciences. And I prefer experience over money.
But according to me, as long as it play and sounds great, I don't think I'm wrecking it.

That's the first time for weeks that the amp shows signs of improvements. I know I'm a newbie at amps, I only heavily modified a Blues junior before the DRRI (I also made about 12 effects that work great), I know the danger, I always discharge the amp before touching anything potentially dangerous.
But the thing is there are no techs in my area. (Today I bought a GZ34 rectifier at my local shop, first they told I had to command it, then I told them "Come on it's a standard in Fender amps, you have to have it... And they had 1... only one) So you're my only source of informations about Fender amps. (My uncle is a engineer in electornics, he warned me a lot about all the dangers that messing around with high voltages implies...)

[soundguruman]

"I always discharge the amp before touching anything potentially dangerous."
but, do you unplug the amp from power? before doing that?

[überfuzz]

do you unplug the amp from power? before doing that?

Doesn't seems to me that he's one on the zapped tinkerers.

[Wil]

Plate voltage is now 410V when I set the bias at 0.024A.
It sounds find on the bench, (a little noisy, like a turntable), I'll reassemble everything and tell you what, thank you for your help.

[JoeM]

Try biasing your tubes a little cooler. My DRRI loses some higher end definition when it's biased much over about 18ma. Could just be the particular 6V6s I have - Tung-Sol RI.