The Amp Garage

He died today at 74. Another one gone; he did have serious medical problems apparently.

Too bad, the band he put together for Joe Cocker aeons ago was really great.

Like this?

Dorrisant, I didn't know that. Can you elaborate? I would assume the counterfeit ones look different in some way, otherwise how would you know? Lettering, dimensions, seals??

Tom, fight hard and it will come back. The will to live is capable of more than we would think possible.

I had major surgery go south on me four years ago but I did survive it and have largely recovered.

It takes a lot of time and patience but we are all awaiting your return.

+1 on that! I had that problem more than once a few years ago with Switchcraft send & return jacks. I changed to the Mil-Spec Switchcraft jacks, cost twice as much but have solid silverplated contacts on the shorting pin--no more problems. Also I think the steel is stiffer too. I now use them exclus...

Mine is a Fluke 187, long discontinued but probably available used in the usual places.
The only way it could be better for what we do would be if it had an inductance range, so I would not have had to buy an LCR meter, which are not cheap.

Just use the YKK 3 way make before break impedance switch. Built like a tank, silver plated contacts, 6A rated.
I have used one Lorlin, only because it was for a TW Express build, cheaper than YKK but does not compare in any way!

Hoffman has the YKK, so does Mouser.

It overdrives nastily without feedback. I've built amps without global NFB that work fine. It could probably be fixed with a large-ish gridstopper on V2A. Sort of thing that Dumble did to control gain architecture. Or a voltage divider to ground, like an Express. But the NFB seems to work and it sou...

Thanx Steve! One thing I forgot to mention, I'm wondering whether I should change the NFB resistor to reflect the change from two to four power tubes. I recall in Dumbles going from four to two one is supposed to reduce the NFB resistor by dividing its four tube value by sq. rt 2 ie 1.4, assuming th...

This one took longer than I thought it would and was more complex to build than I anticipated. Attached is the schematic, pasted up from the original 2x6BM8 of Geezer's from the EL34 forum, plus an as built gutshot and upper chassis/tube count pic. Iron is Edcor from RJ Guitars, as noted on the sche...

HRM was not designed for the 2nd gen circuit and may not work the way you might think it would. I would try the simpler mods first. I had not thought of a 5751 but that would be worth a try, as xtian shows. Doesn't have to be a gold pin triple mica blackplate Sylvania! They don't all cost huge $$$ e...

Looks good Andre! Hard to say what the OD problem(s) might need to fix. What tube is in the OD position? IME the most common problem is fizzy and/or harsh distortion. Parasitics often the cause. Fizzy can be as simple as lead dress in the OD area, maybe higher value snubbers, although IIRC yours is ...

I have generally drilled my own bias pin holes on the back apron of the CE chassis as they are more easily accessible. I have always used the .080" pin type because then I don't have to change the pins on my DMM. Most of these jacks have plastic bodies, but the best ones I have used were made by Pom...

That is a hi-fi rip-off imho. I know a bit about elastomers and viton is relatively expensive compared to most elastomers, but it's not gold!

Please note my addition in my post above-your response beat me to it! That page explains Garnet's reasoning, but doesn't answer the ? about gain/power, and also muddies things up by showing a connection of the screen to the suppressor thru pin 1, so he can use 6L6GC tubes too with proper bias, using...