Transformers in a patchbay?

[Slaytex]

Hey guys, I was talking to a mastering engineer the other day and we were discussing transformers and gear that adds saturation and harmonics to the signal. He mentioned that he had a box with multiple pairs of transformers that he can essentially patch into to alter the signal. Has anyone here heard of this and if so how is this done? I'm very interested in making something like this.
Thanks.

[Doc Mixwell]

Yea,

We're going to implement a transformer patch bay for our Little Labs LMNO Pre, which can use external microphone input transformers attached to the box via 5-pin XLR. Since we have all kinds of vintage IRON hanging around here, I thought it would be pretty suave and de-boner, if we racked up an XLR panel leading to a transformer housing where there might be 5-10 different transformers that you can freely patch when you want to change the tone of the microphone preamp.

Could be pretty amazing, but we have yet to pull it off.......

[Slaytex]

Adam, is this something that would be pretty hard to wire up?
I can solder good, but I'm far from a tech. It's good to hear that someone else is going to try out this route.
Thanks.

[David Kulka]

Basically it's an ok idea, but you run into a couple of little snags. The first thing is that this shouldn't really be attempted with input transformers, because the secondary connections from them should be kept very short (inches), and because the way the input transformer behaves will be quite random (and in some cases, crummy) depending on the the impedance of the gear and capacitance of the cable that follows it.

Output transformers are better suited to this, but now the problem is that most of them have little or no shielding, and are very sensitive to hum. If you wire outboard transformers to a bay, take care to mount them inside a shielded enclosure, well away from power transformers, power cords, fans, computers, etc.

[Slaytex]

Thanks David, that's good to know.

[myoshida]

Hi,

We used to have a panel with two 111C repeat coils wired for 600 ohm in and out. But we used to use them for buffering since we were using a mix of balanced and unbalanced gear.

M Yoshida
KPFA

[Doc Mixwell]

Originally Posted by Slaytex

Adam, is this something that would be pretty hard to wire up?
I can solder good, but I'm far from a tech. It's good to hear that someone else is going to try out this route.
Thanks.

Yes......and maybe no.......we've yet to figure it out......its just an idea at the moment....

[Fredrik]

I have had some thoughts to do this aswell but for making splits 1-2 or 1-3 etc instead of using a Y connection on the back.

[nosebleedaudio]

All you need is a enclosure or a rack mount chassis and install transformers in box and wire ins/outs to bay.
Works like any other outboard gear..
Have done this many times and it can be a problem solver or adding warmth, depending on trans. used.

[Slaytex]

Mike, do you have any diagrams of how I can do this? Even a picture of the insides would be great.
Thanks.

[Kronos147]

I have a little box a friend built me. It is kind of like a pair of API 312's with power supply in a 2 space rack. So you have a discrete amplifier feeding a sweet output transformer. Times two.

I usually leave it on the 2 bus. I call it the "Magic Bus."

[Max_Power]

Wondering:
1. Isn't it better to use 1:1 transformers as effect transformers to avoid unnecessary level and impedance changes?
2. Do step-up and step-down transformers add more flavor to the signal than unity transformers?
3. Is there a greater range of interesting step-up and step-down transformers for this fx-purpose than unity transformers?