Eyett fiberboard vs turret boards - BYO vs. Weber

[Smokebreak]

Smokebreak, that looks nice.

You using orange drops... 715s?

6PS series

[Structo]

I have bought from Hoffman many times.

He usually ships the same day of the order.

I used to get shipments from him in two to three days in Oregon.

[Prairie Dawg]

You got me thinking so I went down to the laboratory and got a piece of Mojotone vulcanized fiberboard about 24 inches long and hooked up my insulation tester. It was not able to measure resistance because it was far above 2000 megohms. That's close enough to infinite for me, until I finish building a hipot tester.

The process by which it is made is pretty interesting.

http://en.wikipedia.org/wiki/Vulcanized_fibre
http://www.toyofibre.com/fibre.html

Some of the other stuff I've seen in older Vox amps I am not very impressed with-the trade name is Tufnol but it is merely paper impregnated with phenolic resin.

By far the best material for circuit boards would be the micarta we used in the aerospace industry, which is phenolic impregnated nomex or kevlar, sometimes linen. Resin impregnated glass fiber would be a close second.

Of course, with any material once you've had a short and the substrate has a carbon track, all bets are off.

[chuckulaa]

Well, Tube Depot got my bid. 5$ shipping, great prices, and they take paypal.

I'm sure Hoffman and Turretboards.com sell top notch stuff, but they need to bring their prices down before I can give them my business.

[AmpegSVT]

G10 from mcmaster, a small tile/wetsaw (home depot $50) and a drill press.

[rogb]

G10 from mcmaster, a small tile/wetsaw (home depot $50) and a drill press.

I've got a tile diamond wetsaw. I never thought of cutting G10 with it!

Great tip, thanks!

[chuckulaa]

That's good advise. I would have just used a band saw on the G10. I think my shop has a tile saw.

Well I ordered some eyelets from mouser, and got the natural G10 from tubedepot with some turrets and some simple press fitting tools with rubber pad.

I'm going to make a swage tool. The shop has a stainless steel grinder. I'm going to basically use the Hoffman layout, but modified so that I can fit bigger coupling capacitors. (Those black beauty .1uf caps are huge.) Any suggestions for the split cathode capacitor values for the 12AY7? (Bright and normal values?)

I am going to use eyelets around the input jacks. I hope this works out well. I'm going to post some pictures and such.

[Structo]

Yeah, you don't want to breathe any of that G-10 dust.

Nasty stuff and will do a number on your lungs.

Wet saw keeps the dust down.

[ampgeek]

I use 0.68 or 1 uf on the normal side and 10 to 25uf on the bright side in my 5F6A builds. But....I always do a final check/tweaking once I know what speaker type/arrangement and guitar is going to be used.

Have fun!
Dave O.

[chuckulaa]

I use 0.68 or 1 uf on the normal side and 10 to 25uf on the bright side in my 5F6A builds. But....I always do a final check/tweaking once I know what speaker type/arrangement and guitar is going to be used.

wait, so let me get this straight... you put the more bass heavy capacitor on the bright channel and the less bass heavy capacitor on the normal channel?

I assumed you would put the less bass heavy cathode cap on the bright channel, and the more bass heavy cathode cap on the normal channel.

[drew]

I'm going to basically use the Hoffman layout, but modified so that I can fit bigger coupling capacitors. (Those black beauty .1uf caps are huge.)

I guess I'm a little late on this, but for future reference of anyone who may be reading this, Hoffman has a program that allows customers to custom-design a board, then have it drilled on his CNC machine. So you could have started with his existing 5E3 layout, modified it to suit you, ordered the board, turrets, and staking tool from him, only paid shipping from one supplier, and saved yourself the trouble of cutting/drilling the fiberglass board.

[ampgeek]

Yes! But I also jumper the two channels at the tube socket for permanent parallel operation. The "mis-matched" cathode caps allows you to open up the two volume controls wider without dominating the mix with either the normal or bright componants. To my tin ear, the wider open the volumes, the fatter tone. YMMV of course.
Cheers,
Dave O.