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Vintage threads from the first ten years

Hoffman board for Fender RI Reverb

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3/6/2000 12:43 AM

Hoffman board for Fender RI Reverb

I just finished the installation. The materials and workmanship on the board are first rate. It was fairly easy to install, just gut the thing and drill (gulp) four mounting holes for the new board, mount it, then wire everything up. The instructions included are NOT for beginners. They presume competence and knowledge in electronics, the ability to read schematics and layout drawings, as well as good soldering and lead dress skills. No problem for most Ampagers, but as I said, NOT for beginners. The instructions included a sheet on the board itself, showing what hooks to where, as well as a couple pages of generic instructions (written around an amp board) on how to go about installing the board in the chassis and the order in which things should be done. If you're excpecting step-by-step instructions and handholding, it isn't there. You must know what you're doing. The board came with a kit of hookup wire, about 3x more than was needed (thanks Doug for the extra wire). It sounds great, BTW. Should servicing be required at some time in the future, it sure will be a helluva lot easier than with that cheezy stock PC board. Doug gets my vote.

3/6/2000 2:19 AM
jason	Congrats John. Doug is on helluva guy. Just wondering, are using a 6K6 in yours or the 6V6 they now come with. jason

3/6/2000 5:11 PM
John Stokes	Jason, the stock RI reverb comes with a Sovtek 6V6. I yanked that out as soon as I bought the thing. Ever since then I've been running a NOS RCA 6K6 in there.

3/6/2000 6:56 PM

quote:
"It was fairly easy to install, just gut the thing and drill (gulp) four mounting holes for the new board, mount it, then wire everything up."

I always knew you were a true Ampager at heart Trem . Next you will be gutting Bassmans like the rest of us!

Welcome to the dark side.

..Joe L

3/6/2000 7:55 PM
John Stokes	Well, uhhh, Joe, I might gut a reissue Bassman for the installation of a Hoffman board, but I'd never even dream of doing a Torres job to an original.

3/8/2000 7:21 AM

John:

    Just a thought: it seems like Hoffman makes boards to install in the reissue amps so that they will sound more like the originals. And Torres makes boards to install in the originals so that they will sound more like the reissues (and the "no-issues" like the Peavey Classic 30). Not completely accurate but I figured that it might make a good sound bite for the news shows... < grin >

    Perhaps in 2020 we will be talking about the RI amps in the same way that we talk about the BF amps today, but at this time I really don't think that the reissues are "vintage treasures".

Steve Ahola

P.S. In the Hoffman drawings I've seen, he tends to follow the original designs very closely, while Dan seems to revise everything a little bit so that he can claim that it is "original". I think that explains the poor results that many people report (if he'd just stick to the tried and true designs his mods would sound better- like his improved BF Clean channel and reverb circuits- how can you improve upon perfection?)

    With the Hoffman boards, you start out with a fairly stock circuit and if you want to fine-tune it you certainly can. But with the Torres boards they are already fine-tuned to *his* tastes so you first have to "un-Dan" them before you can try out your own tweaks. I think I'd vote for the Hoffman approach, although Doug can't claim that they are his own designs "better than the originals"... Just the same, practically everybody says that the Hoffman boards sound great (and you certainly don't hear that about the Torres boards).

3/8/2000 8:02 PM

Steve, basically I agree with what you said. My biggest question is why do people keep buying stuff from that hack?

Speaking of "fine-tuning" the circuit, I did a bit of that when installing the board. One of the main complaints I've heard about the reissue is that it can sound a bit brittle and not as warm as an original. This can be remedied a bit by the familiar cap mod where that 250 pf cap from the tone control to the mix control is bumped up in value. I used 500 pf. Another variation is in wet reverb return from the pan to the recovery amp. Stock with the board, Doug has you install a 220k resistor across the jack then run a straight wire from the jack to the 12AX7 grid. My variation on this took inspiration from the recovery circuit in an old Ampeg Reverberocket. I reduced the input load resistor to 68k. Instead of a straight wire to the tube, I use a 10k resistor. Additionally, I connect a small value cap (forgot the value, sorry, .0022 I think) across the tube socket between grid and cathode. This forms a low pass filter that gets rid of the extreme high end and a lot of noise and crap. Not brittle any more!!

Another thing I've been thinking about (but not tried), is to use the 6K6 in triode mode. That would reduce the total gain on the signal going to the pan, but there's more than enough anyway unless you're Dick Dale. Right now I run the Dwell control on about 3, so there's plenty of gain to spare. Any thoughts on this? I've also thought about putting in a better quality drive transformer, but there's not a lot of room to spare.

Anybody notice ground loop problems when using a RI reverb? The RI uses a 3-prong power cord and if the amp does as well, then I get hum. Using a ground-lift adapter kills the hum.

Comments?

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