I really like the layout and components on these boards. I might get one of these myself.

Here's a diagram:
http://www.el34world.com/Hoffman/images/fendrev.gif

The beauty and magic mystery of well done work.

xxx

Gosh time does fly. When I gave up trying to be a surf band I lost interest in this project for a few years.

Presently at the stage of wiring, it would be of great interest to see how other Hoffman 6G15 builders accomplished their task. If you have a completed Hoffman stand alone reverb unit with this specification turret board please upload photos to this thread. Thank you.

Currently the only decent Hoffman 6G15 photos I can find with Google are the ones I posted at the beginning of this thread.

Greatly Appreciated.

BJB wrote:

I've installed Hoffman boards for other people and I have to say I am not a fan. I have issues with this board but the #1 concern is the power supply capacitor that is located directly over the hot reverb driver tube. This is a huge no-no because exposing electrolytic capacitors to heat reduces their life! The originals had the caps on the other side of the chassis, away from the heat. But who knows, some people seem to be able to get away with breaking the rules. Good luck!

This is my third chassis. The second one I had made a 1/2" inch deeper to allow for more component space, the wood plank I used to build the box was an inch wider than standard so there was plenty of room behind for the output transformer. Due to the high price of nickel plating the steel chassis + face plate hassles I finally opt for a factory built chrome job.
I agree that the capacitor is a bit too close for comfort.

You pays your money and takes your pick, as they say!

Last edited: Sep 06, 2013 17:41:13

Perhaps modern day capacitors are more hardy. I've read Japanese caps found in high end pc motherboards and PSU's (85C or 105C) should last many times that of a standard cap. What's the life span of a 1960s spec cap - 10 years max? Hopefully the greater part of the heat stays outside the chassis.

I wouldn't be too concerned over temps inside the chassis. Yes, Fender mounted the filters outboard in a doghouse cover similar to a BF amp however after a long period of use, a hour or two, the whole chassis will heat soak inside those small cabs. I'd expect at least 10-15 years out of the caps pictured. I don't think the tube temps are any more or less an issue no matter where the caps are located.

I prefer F & T caps at present. High quality and their smaller physical size puts them in places only lesser brands would fit in the past.

Keep it Drippy Brothers and Sisters!

That's one of the reasons I needed a photo of a completed Hoffman 6G15 project!

This is the only photo of the board on the Hoffman site(s). You'd think this is the way to install it but looking at the potentiometer layout it is upside down, plus some writing at the top is upside down also.

If you look to the bottom right of the board there is a BR310 bridge rectifier unit, mine doesn't have that and it's confusing the hell out of me.

Last edited: Sep 10, 2013 17:11:48

crumble, I know what you're going through. Schematics are hieroglyphics to me too. I'd post the Triode diagram (for dummies like me) but components are in diff places and wouldn't be much help. Anyway, sounds like you're getting it sorted out!

BJB, good eye!

I'm sure this is frustrating for you but you should be proud of the progress you are making!

Instead of the bridge rectifier, your version of the board has two diodes that are connected (more or less) in series as a half-wave rectifier. The two red wires from the power transformer are meant to be attached to those two red turrets near the corner of the board, next to the two big blue capacitors. The original Fender reverb unit also used a half-wave rectifier but the reissues and everyone else uses a full-wave bridge. The advantage of the full-wave is that there is less power supply ripple, which makes life easier on the power supply capacitors:

In the old days, diodes were expensive and it was cheaper to go with a half-wave rectifier and use bigger power supply capacitors than add the extra diodes required for full-wave.

I also used a full-wave rectifier but I did mine using four individual diodes. That tiny brown board next to the cap board is dedicated entirely to these four diodes! It would have been possible to add two diodes to your board and convert it to full-wave, but diodes cost nearly 10 cents each and that seems to be more cost than the company was willing to put into building this board.

If it ain't broke, fix it until it is.

Last edited: Sep 10, 2013 17:14:20

Haha! I don't think this will be up to your standards BJB. I shouldn't laugh because all the mount holes are out of alignment and I can only get two screws in!

Oh well, assume lotus position, breathe..