First time working on an amp - recapping a Deluxe plus some tweaks.

JamieJ

JamieJ

Well-known member
I’ve been wanting to build my own amp for ages after seeing so many amazing builds here but I can’t justify the spend at the moment. So I thought I’d have go at doing some work on my DRRI 65. I’ve done a fair bit of reading over the last couple of months (rob robinettes website is an absolute goldmine). I’ve also been watching lots of psionic audios YT channel which served as a big inspiration to give this a go.

I hate desoldering with a passion (as I’m no good at it). So I did some practice runs from
my graveyard collection of pedals.

It was good to get used to how to properly discharge filter caps. I used a 150ohm 10W resistor with an alligator clip to ground.

This DRRI is 15 years old and surprisingly the filter caps were in fairly good condition. One had the faintest hint of a bulge forming but no leaks. I wanted to recap the amp as a proactive step.

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I sprang for a set F&Ts and the amp is definitely a touch louder after replacing them. After being spoilt by PedalPCB boards it was a shock to see how crappy these fender boards are - they are reasonably translucent. So I was super nervous about ruining the amp. I managed to not damage a pad which was a relief.

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I then went onto desolder remove one leg of the bright cap. I did I this way so if I changed my mind it can be easily corrected. I tend to play the amp at 2 or 3 and the bright cap makes the amp incredibly bright ( even though it’s pretty bright to begin with) and not play so nice with OD pedals.

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I had come across a psionic video that showed how the RI amps have some issues with the wiring with V3 as part of the reverb circuit so I corrected this.


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I then decided to call it a day and put the amp back together (feeling good that I didn’t kill my self through electrocution and that the work went well) but in testing it there was a loud hum in both channels and no sound at all. This made me shit myself a little bit as I thought I might have wrecked the amp. I went back in, discharged the caps again and started looking for the issue.

Me being an idiot - I didn’t connect the pot board to the main circuit board! Take two of putting it back together went well and its sounding great.

For the amp experts - I’ve read lots online about the design flaws fender put in place on these amps by mounting the heater balance and screen resistors to the board (rather than on the sockets). Is it worth removing these in case of heat related failure?
 
I would move the screens to the tube sockets and at least install the heater resistors with some distance off the board from the body of the resistor. Or just follow what Lyle/Psionic does. It’s a good “while you’re at it” mod to prevent it from hurting itself lol.
 
Very nice and good call on the F&T's. I like socket mounting stuff whenever possible. Just keep a bit of stand off so that they get some air. By the time you roast them you'll likely be looking at recapping again anyway, which will likely be never.

I see a lot of IL caps and currently have a really nice Divided by 13 amp on the bench and he used all Sprague's but then put a single IL cap on the board. I've seen photos of other instances of this so doesn't seem to be a one off. It was such a weird choice I just assumed that somebody hacked the amp but think it's virgin.
 
Gordo said:
Very nice and good call on the F&T's. I like socket mounting stuff whenever possible. Just keep a bit of stand off so that they get some air. By the time you roast them you'll likely be looking at recapping again anyway, which will likely be never.

I see a lot of IL caps and currently have a really nice Divided by 13 amp on the bench and he used all Sprague's but then put a single IL cap on the board. I've seen photos of other instances of this so doesn't seem to be a one off. It was such a weird choice I just assumed that somebody hacked the amp but think it's virgin.
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Illinois does offer good, reliable capacitors; but Fender chose to use their cheapest options for the reissue series. They also skimped on the voltage ratings in some areas, leading to premature failure.

Peavey also used IC caps since the early 80s but they opted for their higher quality offerings. It’s not uncommon to see 5150, Butchers, and VTMs working just fine with the original electrolytics and I have not heard of reliability issues with the Classic series.
 
I let done. I opted to remove the bright cap from the top like he demonstrates in one video. I’m not confident enough to take this one apart past putting in the WGS ET65. I over hauled my horrid deluxe, but this one, this one is special. It’s got the western hand tooled looking Rolex.
 

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Nice work! I have a Reverend Hellhound that needs a recap and a Blues Junior III that needs some mods. I'm hesitant to get started out of fear of lifting pads when I desolder the old caps. Can you share a little more about your desoldering process?
 
keevohn said:
Nice work! I have a Reverend Hellhound that needs a recap and a Blues Junior III that needs some mods. I'm hesitant to get started out of fear of lifting pads when I desolder the old caps. Can you share a little more about your desoldering process?
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Solder braid and a solder sucker. Just work quick, those boards don’t normally need a a lot of heat.
 
So I followed some advice from the psionic channel. I’ll see if I can find it later on.

I clipped the caps so that a straight cap leg is left. I made sure it would be able to move straight through hole when removed so not to stress the pad. I then added some new leaded solder to the joint quickly then heated the joint whilst pushing to leg through from the other side using a metal tool. They tend to stick to soldering iron which helps remove them. The thing is that the legs are bent at the joint so if you try and move it through the capacitor side you will damage the board. I then used solder wick to clean the pad and pushed a small needle through the hole to make sure it was clear before removing the old caps and soldering in the new.
 
Thanks! Appreciate the rundown on your process. My Hellhound has radial caps, so I'll have to research best practice for removing these bad boys...

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I have discovered that not all desoldering braids are equal. I could never understand how Mr Psionic could get solder off with braid so well. Turns out the braid I had was crap. It just won't lift solder. Bought a different brand and the solder comes of so easily. The good stuff I found is called Gootwick, made in Japan by Taiyo Electric.

I would definitely get the filaments off the PCB. It's very simple and will prevent possible (probable?) issues further down the road. It seems Fender only put them onto the board so that they could use quick connects. It's a simple matter of removing the quick connects from the board, snipping off the plugs and soldering the wires to a power tube socket.

While the Fender PCBs are crappy single sided things I have yet to damage one. They seem to take desoldering and resoldering ok. Just be quick and use a very clean iron.

A friend asked me to gut a Princeton Reverb RI for him and rebuild it like an original. I was a little sceptical but it actually did sound better and one hell of a lot less noisy. I've done this to a Deluxe Reverb RI and a Super Reverb RI too - not at all cost effective! And not a night-and-day difference but the longer you play them the more you appreciate the difference.
 
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