transformer O.D /saturation box

[Paul Maybury]

Hi does anyone have any ideas for building a line level transformer saturation box?
I assume it would just be an input buffer/ gain trim and an output buffer/gain trim with a cheapo transformer in between. Maybe hi and lo pass filters somewhere.
Is there more to it that that? Anyone tried something like this?

[Hookemeister]

Hi Paul

1> Try feeding some DC thru a pot into the primary.

2> Get a very small and cheap mic transformer ( I'm talking about the type you find inside a dynamic mic) and drive the primary via a pot with a hot signal then add some gain make up to the secondary.

Saturation in transformers is most noticeable in the low frequency range.

Have fun,

[rob]

somewhere on the proharmonic experimental shelf is exactly one of these. Balanced line level in and out with a "drive" control that determines saturation of a transformer while keeping the overall gain close to unity. It has been out on "tour" a few times and apparently sat across bass for The Necks for a year or so.

[Paul Maybury]

Hi Rob, that's cool, does yours bias the transformer with D.C?
I've read a few ideas about this and most recommend D.C on the primary.
I've got some little mic input traffos (Altronics 1:4's and some scavenged from an Altec 1220 desk) that should break up nicely at line level.
I guess I should start experimenting!
Thanks to Hookmeister for the tips.
Cheers,
Paul

[rob]

yes, there is a switch which puts dc bias on the transformer to increase the saturation. There is also lots more to it in the drive circuitry

[The Tasmanian]

When are you going to make one Rob?
I'd really like a box that has a pair of inductor EQ's involved to shape the distortion characteristics - and a wet/dry blend
(My Neve Tele Distorts are rockin by the way)
You know how much I like distortion - great blending/parallel tool.....
We may have to soon join forces and make a "Frankendistortion"

[rob]

well the prototype mk I is done and sitting on the shelf, for the cost of to and fro postage I could send it down for you to play with.
Yes, one with EQ might be MkII

[The Tasmanian]

Got a pic Rob?
what functions does it have - a blend/wet dry?

[rob]

hmmm can't find a photo.
It is just a small extruded box, runs off a plug pack with a drive control, bypass and mode switch. Mode changes the type of saturation.
I'm about to go away for a week but when I get back i'll dig something up. I'm also supposed to be testing the hydraphone out in the shed for you

.... remind me

[The Tasmanian]

I'm going to use bug mic's glued to the skins for underwater drums - its simple/easy and cheap.
So dont worry about the shed...

[rob]

I never worry about the shed ...