anyone built the matchless hotbox?

[Thebrain]

anyone here built it?

if yes please share your experiences

i need help with finding a compact transformer for the project that will fit a stomp box.
it also needs to have 220V primary.

there is a layout file in general guitar gadgets but it's in low quality
if someone has a layout in good quality it will be of much help!

other than that any tips on the build for a toobnoob will be much appreciated.

[Doz]

How about a 1:1 220V 220V transformer from a "Shaver" socket? You'll still need to find 6/12 volts for the heaters, or alternatively two small 220V > 6V mains transformers back to back... you've got the heater volts then too from the middle

[Trout]

Here is a good build article on a yahoo blog

Original version


Translated version

Depending on how compact you wish the unit to be, several guys have used the 269EX Hammond on USA versions, and 369EX for multiple voltage needs.
Most certainly there are other options.

[Thebrain]

hey trout that link is very helpful! thx.

doz i rather buy a designated transformer...
else the sound engineer will always complain about my strat buzzing

i'll go for the hammond 369EX.

will this hammond enclosure fit the project (with the 369EX)?
http://www.hammondmfg.com/pdf/1456KH3.pdf

[MrCurwen]

One option would be to have the PSU a bit farther away in a separate box, thus alleviating the space dilemma.

[darryl_h]

Originally Posted by Doz

How about a 1:1 220V 220V transformer from a "Shaver" socket? You'll still need to find 6/12 volts for the heaters, or alternatively two small 220V > 6V mains transformers back to back... you've got the heater volts then too from the middle

You could use an external 12VAC plugpack for the stepdown. A 220V to 12V transformer could then be used "backwards" inside the main box as a stepup for the B+ supply. The 12VAC would also power the 12AX7 heaters.

[Thebrain]

Originally Posted by darryl_h

You could use an external 12VAC plugpack for the stepdown. A 220V to 12V transformer could then be used "backwards" inside the main box as a stepup for the B+ supply. The 12VAC would also power the 12AX7 heaters.

sorry for this question i'm a bit of a noob in this
won't this combination make more hum or noise than a designated transformer?

[Doz]

Originally Posted by Thebrain

hey trout that link is very helpful! thx.

doz i rather buy a designated transformer...
else the sound engineer will always complain about my strat buzzing

i'll go for the hammond 369EX.

will this hammond enclosure fit the project (with the 369EX)?
http://www.hammondmfg.com/pdf/1456KH3.pdf

There is no reason 2 transformers will create any more hum than one, in fact you will end up with more noise filtering.

[Trout]

Originally Posted by Doz

There is no reason 2 transformers will create any more hum than one, in fact you will end up with more noise filtering.

Very true,

In fact, it is common to use 2 transformers for tube driven pedals. That way you can plug the wall wart needed into a standard pedal board strip.
Bonus, it cuts down on chassis space as well.

In all honesty I was surprised to see that pedal set up with a conventional PT.

The Hughes Kettner Tubeman uses a small internal transformer (12V to 250V) and a walwart 120V - 12V.
They run the 12AX7 filament on 12V rectified rather than 6.3V.

It just depends on how accurate you want to clone the pedal.

[Thebrain]

according to the schematic the B+ for V1 is supposed to be 242V

so if I use a 220V to 12V backwards won't i get only 220V?