Copper Spitfire Clone!

[ampdork]

Yeah to 98087? eBay auction?

[Cygnus X1]

Yeah to 98087? eBay auction?

Not sure of his ID...he is a friend that picked it up with me in mind, as a gift.
You say this sat out in the rain?

Doesn't look like it...it is very clean and I was overjoyed to see the transformers had zero corrosion on them!
The chassis is actually copper plated aluminum, but still very nice.

Thank you for saving this...I had a lot of fun brainstorming (OK, I had help)
and building it. It will go into a 1x12 cabinet...yet to be built for it.

[ampdork]

The amp was in an organ that was headed to the dump when a friend picked it up with me in mind. So the organ was out in the elements but I imagine the amp itself was nestled somewhere inside safe. Anyway crazy how many times it has flipped hands. Good to see it again. I knew it would make an excellent little amp. Any clips!?

[Cygnus X1]

Well, just a couple of flips...and the best of all:

A friend thinking of a friend...and another friend thinking of me!
What goes around comes around.

So,
What sort of speaker do you want in this amp?

[ampdork]

What sort of speaker do you want in this amp?

Well if I could choose I'd keep with the theme and it would be some cool old field coil also saved from a fate at the dump. Since we're dreaming it up too the cab would be some awesome woods salvaged from an organ as well. Sometimes that wood is finer than you can find and buy today.
gotta love organ donors...

[CaseyJones]

What sort of speaker do you want in this amp?

Well if I could choose I'd keep with the theme and it would be some cool old field coil also saved from a fate at the dump. Since we're dreaming it up too the cab would be some awesome woods salvaged from an organ as well. Sometimes that wood is finer than you can find and buy today.
gotta love organ donors...

I hate to break your bubble but most of the wood old organs were made of is useless.

Hammond used poplar with a veneer overlay on early units. It's hard to find enough wood that hasn't had cleats torn off it or screws driven in everywhere to get anything out of it. The later stuff is even worse, veneered chipboard. Yuck!

All hope is not lost. If you can find an old Kinsman (good luck!) the back panel is a beautiful slab of void free U.S. made hardwood plywood. You can't get that stuff anymore.

Speakers: Cletron (Cleveland) 12" alnicos from an old Thomas. Or two Hammond "L"s worth of ribbed cone Heppners.

There is no such thing as a "cool old field coil". Those old cones might as well be made out of the same material as Pringles potato chips, that's how fragile they are.

[Cygnus X1]

Right now it sounds best through a Celestion G12M70.
Gummed if I can figure it out...I have had that speaker for over twenty years, and it sounds best on the Fender Deluxe Reverb, and now the Tweed Deluxe.

It sounds muddy on my uber high gain amps.

So I ran it to the Spitfire, and sure enough...good tone.

[ampdork]

Beg to differ. While perhaps most organs came with crappy woods I have picked up plenty that have awesome woods. I have some oak boards wider than I have ever seen before....from an organ.
Same with field coils. I have two here that are not crumbling and have been tested as working dandy.

I dunno man maybe I have had a better run of luck at it but I have lots of good materials from organ donors. I did not even mention tubes!!!

[Cygnus X1]

It seems most of the damage that occurs to donor organ parts happens after the parts are pulled. This aluminum/copper chassis is mint.

As for real wood...I had the misfortune of helping a band that hauled around a Hammond B3 or something. That thing weighed a ton! I strongly suspect it had furniture grade hardwood on it.
It had "casters", but of course those were torn up from the truck bed it sat on.

[s2]

The phase cancellation MV is wonky unless you use 1 or 2% resistors throughout the PI. At least that's been my experience with it.

[Cygnus X1]

The phase cancellation MV is wonky unless you use 1 or 2% resistors throughout the PI. At least that's been my experience with it.

Hmmm.
Thanks for that info, s2.
I might just look into that.

[mcrracer]

Super cool chassis! Did you build it with a choke? If so what value did you use? I see #9565 as the choke but no values.
Thanks...crank er up!

[Cygnus X1]

Super cool chassis! Did you build it with a choke? If so what value did you use? I see #9565 as the choke but no values.
Thanks...crank er up!

Sorry, I didn't see this.

No, I didn't use a choke. I ended up with a 4.7K ohm 5 watt power resistor.

[Cygnus X1]

Bump.
I have a problem with this.
I eliminated the MV altogether.
It lacks volume, but the biggest issue is when I turn the volume down on the guitar there is a corresponding hum as the volume decreases to a level point.

Grounding issue?

The input is isolated, with the negative lead going to a common star type ground point.

[Cygnus X1]

I'm bumping this thread back up because I'm building another Spitfire, this time on a board like MFowler did.

I did get that amp sounding very good, and found out what that hum was...it was coming from the EZ81 rectifier filaments.
She is sweet.
But now I'm wondering about something.

Anyone notice how many errors...total...that Ceriatone layout had?
(And why they wouldn't fix them)?
Not only the MV issue but pin 3 to the PI was not shown to be connected to anything except tied to pin 8.

I wound up taking out the MV and using the hole for a bright switch...a much better choice.

Building this one with a 75ma 9H choke.
Not sure what that will do, as this amp was a little loose in the first place...we shall see.