Copper Spitfire Clone!

[Cygnus X1]

Happy Birthday, new amp day!
And a Christmas present to myself.

My first swing at a point to point...it looks a mess, but it came out great sounding, and quiet! It was a Gulbransen APS-4 organ amp.
I ended up gutting it and building an 18 watt Matchless Spitfire into it.

I connected it to the speaker in the cab that holds my 5E3.
Very nice cleans, but I haven't cranked it much yet.
(Mom in law is visiting).


[img:570:550]http://img122.imageshack.us/img122/6719 ... idefi4.jpg[/img]

[drhulsey]

...it looks a mess...

Doesn't point-to-point always look a mess
Very nice

[Cygnus X1]

There is one problem, though...

The MV doesn't work right.
It has just about zero range and works only a bit for signal attenuation between the 1 and 2 position. After that it is full on.

I desoldered it and double checked the pot...no problem when it is disconnected.

It is a 1 meg using lugs 2 and 3, connected between the plates of the pi.
Lug 1 is not used, and none of the lugs is grounded.

[austinb]

sounds like you used the wrong taper pot.

[M Fowler]

Nice build,

That chassis came out of an organ, never seen a copper chassis.

I built a Matchless Spitfire using Ken Watts layout and the master volume doesn't work on mine either. Tried ground pin 3 and next I will wire it to the wiper (mid) then to pin 3 instead of pin 1 and wiper.

Mark

[Cygnus X1]

sounds like you used the wrong taper pot.

It is audio taper, as called for on the schem...it breaks out really fast
when in circuit, but tests normally when out of circuit.

[mlp-mx6]

Have you tried using the other 2 tabs?

[Cygnus X1]

Have you tried using the other 2 tabs?

Yes.

[CaseyJones]

That phase cancellation MV that Matchless uses is functionally pretty wonky IMHO. Maybe if you drive the crap outta the PI it will cancel "properly" but I haven't grown any love for it.

Go with a PPIMV. Or rip the master out entirely and CRANK 'ER UP!!!

[Cygnus X1]

That phase cancellation MV that Matchless uses is functionally pretty wonky IMHO. Maybe if you drive the crap outta the PI it will cancel "properly" but I haven't grown any love for it.

Go with a PPIMV. Or rip the master out entirely and CRANK 'ER UP!!!

I'm quite happy without the MV.
But now I have an extra knob (or hole) to deal with.

Suppose I can make a presence control?

[CaseyJones]

That phase cancellation MV that Matchless uses is functionally pretty wonky IMHO. Maybe if you drive the crap outta the PI it will cancel "properly" but I haven't grown any love for it.

Go with a PPIMV. Or rip the master out entirely and CRANK 'ER UP!!!

I'm quite happy without the MV.
But now I have an extra knob (or hole) to deal with.

Suppose I can make a presence control?

Presence control is a good idea. More useful than a master volume IMHO.

Look up a "cut " control. I think the phase cancellation MV stinks but I like a cut control. I wouldn't drill an extra hole to accomodate but it's cool.

[Cygnus X1]

Not lazy...I got involved in rewirng a 4x12 cab.

But what's the best way to wire a presence on this amp?
(It is the same schematic as the third posted above).

[ampdork]

Nice to see her again. Unless mistaken this was a chassis i had collecting dust for awhile on a shelf. very cool to see her have a new life as a guitar amp. The whole thing screamed to be a rocking little amp.
The copper too is pure coolness. Nice recycling job for sure. And to think she was sitting out in the rain waiting to go to some landfill...
Great job cygnus!!

[Cygnus X1]

Nice to see her again. Unless mistaken this was a chassis i had collecting dust for awhile on a shelf. very cool to see her have a new life as a guitar amp. The whole thing screamed to be a rocking little amp.
The copper too is pure coolness. Nice recycling job for sure. And to think she was sitting out in the rain waiting to go to some landfill...
Great job cygnus!!

What?

Did you happen to sell this to a guy in Washington state by any chance?

[M Fowler]

Since the master volume in mine is working I don't miss it either so will try the PPIMV or cut control as suggested.

Mark