filter cap question

[bob p]

I'm with Pedro and Chuck. The idea of buying a DRRI and gutting it to put an eyelet board in place of the PCB makes no sense whatsoever. the PCB amps are markedly more consistent in their layout, which results in higher overall quality than an eyelet board layout with flying leads. I'd have no problems putting one of the PCB pulls into my own amp if I could get one for $20, but short of getting a good price on a used board I'm content to put together an AB763 circuit on a pre-fab eyelet board if that's the easy way out.

So why is there this silly mojo-lust for eyelet board amps? To be honest, I think that there's a large contingent in the DIY crowd that wants to avoid PCB because their soldering skills are so poor that they can't work on a PCB without lifting traces. Those are the kinds of people who think that axial caps sound better than little square box caps by WIMA.

[Leo_Gnardo]

I'm with Pedro and Chuck. The idea of buying a DRRI and gutting it to put an eyelet board in place of the PCB makes no sense whatsoever. the PCB amps are markedly more consistent in their layout, which results in higher overall quality than an eyelet board layout with flying leads. I'd have no problems putting one of the PCB pulls into my own amp if I could get one for $20, but short of getting a good price on a used board I'm content to put together an AB763 circuit on a pre-fab eyelet board if that's the easy way out.

So why is there this silly mojo-lust for eyelet board amps? To be honest, I think that there's a large contingent in the DIY crowd that wants to avoid PCB because their soldering skills are so poor that they can't work on a PCB without lifting traces. Those are the kinds of people who think that axial caps sound better than little square box caps by WIMA.

As long as your eyelet board isn't made of that leaky black cardboard crap all should be well. And WIMA caps are perfectly good, I'm just too lazy to stick extra bits of wire onto the leads when I can get axial caps that reach from here to there without unnecessary fiddling around.

And yes, if the PC board is working OK why make the change. In another case one of my regular crustomers got a hankerin' for an Alessandro "mod" on his perfectly well working Super Reverb. $550 plus shipping later, it came back with all Alessandro branded caps. Didn't sound any better. Crustomer must be thrilled to have his pockets picked, go figure.

[bob p]

I've seen the same anti-PCB sentiment toward amps extend over to anti-SMD sentiment in stompboxes. Just like there are people who insist that all PCB amps must suck because they use PCB, and that only eyelet amps are any good, there are people who insist that SMD stompboxes inherently suck, and that a good boutique stompbox has to use hand-assembled through-hole components. I bet that it's the same people making both sets of complaints.

[Randall]

In my experience, my DRRI was a bit thin sounding, a little ice-picky. When I rebuilt it, not only did it sound sweeter, it was actually quieter. I thought it didn't work when I first turned it on because of a lower noise floor. For those that don't know, I built it on Mojotone fiber the first time and had to tear it out because it was conductive with the moist weather, then I did it a second time on a glass turret board. I also put in a big copper Mashall style ground buss. I built mine mainly because I wanted to. Say what you will, it sounded better than it did. And it no longer had Illinois caps, push-on connectors and ribbon cables, little thin wires, and was easier to service.

[Chuck H]

In my experience, my DRRI was a bit thin sounding, a little ice-picky. When I rebuilt it, not only did it sound sweeter, it was actually quieter. I thought it didn't work when I first turned it on because of a lower noise floor. For those that don't know, I built it on Mojotone fiber the first time and had to tear it out because it was conductive with the moist weather, then I did it a second time on a glass turret board. I also put in a big copper Mashall style ground buss. I built mine mainly because I wanted to. Say what you will, it sounded better than it did. And it no longer had Illinois caps, push-on connectors and ribbon cables, little thin wires, and was easier to service.

Ok, I was a little harsh above. I'll stand by what I said about reissue vs. vintage in general, but it's true also that we who build these things are paying more attention to specific aspects of the hand wired build than a manufacturer would. So some details (like grounding and eliminating those crappy Illinois caps) ARE actually improved in these rebuilds. The main advantage to a good handwired rebuild would probably be reliability and serviceability. Once it's working and any bugs are out you have an amp that's eminently more durable and less prone to anything like heat buggered traces, oxidized ribbon cable connections or compromised tube socket to board connections. And I won't argue that there is better iron than the stock stuff. I just don't think it makes enough difference to merit tearing down a new amp. Still, if there's a few percent improvement that's the grail in our efforts here. I guess it's also relevant that most of us aren't using +/- 10% carbon comp resistors and the caps we use are also tighter in tolerance. So, done right I suppose you can at least hope for some improvement in tone and you can certainly expect an improvement in reliability and serviceability. There. That's my concession.

I hate Illinois caps.

[The Dude]

I haven't run the numbers, but it seems like an expensive building platform. Why not just sell the amp and build something from scratch? It seems counterproductive to gut a working tube amp that still sells for good money only to build another one in the same chassis.

Oh, and I also hate Illinois caps.

[bob p]

I think the numbers make sense for Randall, because he's got a customer paying him to do the work.

There are a lot of guys out there who can't afford an old DR, and don't want a new PCB amp because it doesn't have that "point to point mojo" that "sounds better." So they split the difference by having someone convert a new DRRI to look like an old BFDR.

It's definitely expensive. $1100 for a new DRRI, throw away perfectly good parts, pay someone to re-wire it.

People do this because they want to look at that Fender BF faceplate with the script logo and pretend. If they weren't obsessed with the vintage replica I suppose they'd just build the Mojo kit. It costs $1006 list. The problem is that the Mojo kit lacks the Fender branding, and that's part of the mojo lust. So they pay more to have a reworked DRRI, just for the cosmetics.

That's the most sense that I can make of it.

What really makes no sense to me is the Alessandro rebuilds that cost twice as much.

http://alessandro-products.com/rewiring-services/

[Randall]

I have a customer who picked up a 2015 RI for $700. He wanted Mercury trannys put in it, but was open when I explained they were not made of gold, despite being priced as such. But Mercury is the only game in town for PTs for these. Until that is, I contacted Hammond and asked what they had. They said they don't have that covered, but if they could borrow the original I have, they would prototype one for me to check out and if it works I can have it for free, and they will add it to the line. I told them I am looking for their upgrade model, and I think they will agree. SO, this customer is likely going to get his rebuild for~$1500 total. That's really not a big deal to guys with a big boat and a pool behind their house, ya know?

[The Dude]

FWIW: My comment above was just a general observation on the subject- directed at no one in particular. If someone wants to pay you to do the job, and you're willing, great! Go for it- however silly the request might seem.

[bob p]

If you shop for a used DRRI they can be had for $650-$700 though GC prices are typically $100 over that. At $650 they move fast, at $800 not so much. What strikes me as odd about the DRRI is that Fender charges an extra $100 list price for the version with a BF faceplate. What a screw job.

back in the 90s I used the MM BFDR transformers in my own build. Since then I have been using generic iron from suppliers like Marvel and Hammond and Mojo as well as the Fender parts iron. Another option would be Heyboer. IMO the industry already has this transformer need fully covered and the MM iron is NOT worth the extra cost.

I don't understand why Hammond would tell you they don't have that amp covered.
Everyone in the industry has that amp covered.

[bob p]

If you want Hammond then look at the 1620 / 1750H / 1760H.

http://www.hammfg.com/files/parts/pdf/1620.pdf
http://www.hammfg.com/files/parts/pdf/1750H.pdf
http://www.hammfg.com/files/parts/pdf/1760H.pdf

[mikepukmel]

I was really surprised how big the effect on bass response moving from 2 x 16uf to 2 x 22uf on my frankenstein deluxe. With 2 x 16's, it rattled the shelves and windows with bass set at 6 or 8. I was worried (probably waaaay too much as I am about every damn little thing) that when the standby was "on", the voltage across the first two caps creeps over 475 (it does, I measured it). So I swapped out for 2 x 22uf 500v, and now the bass on 10 or 5 not a huge difference in sound. It is "tighter" as the articles say, but the bass control doesn't have a lot of adjustment from 1 to 10 now. Since then, Ive been looking for 500v caps closer to 16uf, or 1 x <something> that totaled closer to 32 uf. F&T has a huge catalogue, if you look on their German site, but its mega tough to get at the values you want. Retailers just don't stock them.

[mikepukmel]

Ive seen a single 30uf 500v at Tube Depot. Its only another 8 bucks, try your bigger 47, then try the 30 and see the effect it has on tone, if you're up for an experiment.

[mikepukmel]

If you want Hammond then look at the 1620 / 1750H / 1760H.

http://www.hammfg.com/files/parts/pdf/1620.pdf
http://www.hammfg.com/files/parts/pdf/1750H.pdf
http://www.hammfg.com/files/parts/pdf/1760H.pdf

That's what I used in my deluxe build. Pretty good transformers.

[mikepukmel]

If you shop for a used DRRI they can be had for $650-$700 though GC prices are typically $100 over that. At $650 they move fast, at $800 not so much. What strikes me as odd about the DRRI is that Fender charges an extra $100 list price for the version with a BF faceplate. What a screw job.

back in the 90s I used the MM BFDR transformers in my own build. Since then I have been using generic iron from suppliers like Marvel and Hammond and Mojo as well as the Fender parts iron. Another option would be Heyboer. IMO the industry already has this transformer need fully covered and the MM iron is NOT worth the extra cost.

I don't understand why Hammond would tell you they don't have that amp covered.
Everyone in the industry has that amp covered.

Yeah, doesn't the reissue still have 2 x 6V6 output tubes? The PT and OT should be about the same as it was since they made those amps with stone knives and bearskins.