Groovy Guitar Amp

[gain-wire]

Ohh, you didn't drill the holes in the panel yet?

[MJL21193]

Originally Posted by gain-wire

Very nice corners! It almost looks like a modern "fleur-de-lys" don't it? I am starting to see a theme here: Blue amplifier, Fluer-de-Lys inspired corners...

Are you a Quebecer?

Si oui, c'est ben correct!

If not, then it's still a great looking amplifier!

Sorry, not from Quebec but been there a time or two. Je ne parle pas francais...just a leetle beet.

The corner was meant to look like a stiletto - a dagger Oh well, I still like it.
Thanks for the fine compliments. I have not done anything with the case since, I'm still working on the preamp section and I've taken an ambitious turn: I am reproducing the preamp and chorus from the Ampeg VH140C. See the schematics HERE.
So far I have the preamp section boards laid out. I had to split them in two to get a size small enough to print and etch here:

118.PNG

The other half:

1116.PNG

[gain-wire]

aha, I see...

That's really an impressive project you got going there... Quite the project, m'yes. But there's one thing: You did not include the chorus section on your pcb, or did you not finish that layout yet?

huh... two reverb channels, pretty neat. Or two return level controls, rather, which are bridged together in some kind of way. I don't understand...

[gain-wire]

Originally Posted by MJL21193

...
So far I have the preamp section boards laid out.

I forgot to read carefully. So, does DigiKey still carry the bucket brigade MN3001 chip? That's the only place I know that has it(had it?).

You must like the POLICE or Pink Floyd to want to incorporate a chorus unit in your amplifier!

[MJL21193]

Originally Posted by gain-wire

I forgot to read carefully. So, does DigiKey still carry the bucket brigade MN3001 chip? That's the only place I know that has it(had it?).

You must like the POLICE or Pink Floyd to want to incorporate a chorus unit in your amplifier!

Not at Digikey, I found them on ebay (of course) HERE. That gives me a few extra to play with (or break).

I have the parts coming for the preamp tomorrow from Digikey and I want to get that up and running before I start in on the chorus board. This is meant to be a looooong term project. My fingers are crossed against the real likelihood that I messed something up in that layout. Wish me luck...

I chose the Ampeg as a challenge and it is highly regarded. I wanted a project to sink my teeth into, completely opposite to how this started (with the ESP preamp). I'm not a player yet so I only have advice and instinct to work on.

[bishopdante]

but why on earth would you spoil it all with *eminence* drivers?! LOL.

ElectroVoice, or one of the late 80s british makes. Waaaay nicer sounding.

[MJL21193]

I assumed Eminence drivers were acceptable - they are available locally and reasonably cheap.
The first project in any hobby will have compromises. If there is a second, I will further explore the options.
In the meantime, which EV 12" would you recommend?

BTW, still stalled (or, more appropriately, stalling) on the preamp. I have the parts, I have the boards etched (no camera for any pics - my ex have borrowed it) but I can't bring myself to stuff them, for fear that I made a mistake in the layout. I'm such a coward...

[gain-wire]

what?! Come on man, you'Re so close! If you made a mistake you'll be able to track it down, and if you're not able to we'll help you out!

and bishopdante,
although Electro-voice is highly regarded since the late fifties, Eminence did not garner its fine reputation by manufacturing mediocre products... Plus if he's not happy with them, he can sell them (they'll sell in no time in the local classified ads) and buy whatever. I'd go with some Celestions though...

I have a vintage 65 in my Traynor DG-30D and it sounds really good.

cheers all!

[MJL21193]

Close??
Ok, I started stuffing board 1, I have the jumpers and most of the resistors in and it only took 2 hours! Just to refresh your memory, here's board one (half of the preamp section only):

118.PNG

I feel helpless without my camera unable to take any pics of the actual boards (pics are motivational). I'm extremely paranoid about the component values that are printed on the board. I have checked and re-checked them but I still feel like something is wrong...I need therapy.
After this board is assembled I need to figure how to test it for mistakes. Besides the input jacks, I have 6 traces that go to board 2, three of these are GND, +15 and -15. The other three I'll have to trace on the schematic to see their impact on the circuit.
For luck, I'm crossing my fingers and my eyes on this one!

[MJL21193]

Board one is assembled. I can't really check for circuit operation without board #2 (too much of #1 relies on #2), so I'm stuffing that now. Both of these connect to the chorus board which I haven't even started the layout on yet. I'll need to make sure that the preamp section is working properly before I start the chorus, just to give me some encouragement to press on.
I missed a few parts when I made my order, significant is the 330 ohm, 10 watt resistor in the reverb section and a few miscellaneous caps and resistors, both of which I have, but not in the size or quality I want.