JCM800 2204 Build In Process

[NickC]

Started this one a couple weeks ago; building in my spare time.

Compared (more like contrast) to other build pictures hereabouts, I confess my work isn't pretty.

The main circuit board is built, but not installed yet.

I only used the 120V primary, the 220V and 240V wires are insulated and securely tucked against the side-wall (for future implementation if necessary).

I installed a couple of stand-off's for hooking up the under-board can cap (without having to lift the board). I hope the amp out-lasts me and someone years from now will appreciate the serviceability.

I did not install 1 ohm bias sense resistors. There isn't much real estate near the big bottles (will be EL34) since I mounted the PEC bias pot between them, and I use a socket mounted bias meter tool anyway.

I'm waiting on a 100pF 1 watt cap for V1, and 500mA slo blo fuse (because I ordered slo-blo and rec'd fast-blo).

The board will get dropped in next ...... unless ya'll spot some idiotic thing I've done so far ...... in which case I'd be grateful for pointing out the error of my ways. Thanks!

[cbass]

Looking good.

[M Fowler]

I think it is looking good too.

[Bob S]

Nice Nick. Very nice.
Do you have a plan for switches to alter the gain/freq. response? Tons of options - too many - some good & some not so.
Great job so far - getting the deck work done properly is key. I would hate to have to undo a completed amp because of an error in the deck work. Not that it's ever happened to me... No.
Keep us updated - looks like it's a winner.

[beasleybodyshop]

Very Nice Nick!

[NickC]

Thanks for the kind words of encouragement. Some progress to report:

Pictures of the chassis with main board mounted attached. Soldered the last wires into place a few minutes ago.

I wish there were more real-estate around the power tubes. Wiring gets real congested in that area (in part because I located the thru-chassis bias pot between the octal sockets).


Now I must mow the lawn before tracing all my work, double checking, then triple checking, and then I'll fire it up for the first time on the variac (with light bulb current limiter in-line) and hope the smoke stays inside.

[Reeltarded]

Good deal! Good luck! Looks like a runner from here!

[Smokebreak]

Good work, man! I used to really stress about congested wiring around the outputs too, but that seems to be an area where it's OK. Good luck with the fire up and happy tweaking.

[NickC]

All finished!

I hit a couple of snags since I last posted in this build thread; not the least of which was coming this about close -----><------- to getting electrocuted. Lesson learned; I will not work on high-voltage circuits late at night when I am tired any more.

Anyway, I installed the chassis in an old, beat-up head cabinet that is structurally sound, if not a little unsightly. I have a name plate on the way, which will cover the ugly face to replace where I scavenged a plate for another build.

She sounds good. I can't wait to use it on a gig where I can turn it up and let it breath.

Thanks for all the help ya'll! You are fantastic, and I am deeply grateful!

[Reeltarded]

Unsightly is beautiful, Nick!