concept: saturator unit - transformer

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concept: saturator unit - transformer

Post by plantylife »

Hello all,

This is my first post on the forum. Wanted to say i've read a lot of interesting stuff so far here and
the atmosphere is quite nice, most of the time very objective.

I mailed Wayne about building a transformer saturator unit, since I think some other people maybe have benefit from it as well.
His response was nice and oppert the idea of a "color extractor"
the idea of nulling the transformer "attenuate / amplify" it and mixing it back in the original signal.

Further points:
1) Also it would be nice to "drive" the transformer(s) to saturate harder (or softer.)

2) Perhaps a 2ch unit for L/R or M/S stereo imaging.

3) lpf / hpf stage at the input stage for parallel use.

4) tilt or low shelf & high shelf after the nulling.

5) phase invert.

6) order offset.

7) bypass functions.

8) a couple of different transformers in one box.

What is already there we're we can take inspiration from:

1) Ian stated on groupdiy: "Rupert Neve's 'Silk' circuit I believe adds a little dc current to the output transformer. This shifts the magnetic bias so the transformer clips unevenly which tend to create odd harmonics" ... ain.77975/

2) Foote's MTB-1 ... l-box.html

3) couple of diy transformer box projects on the internet.

Maybe Im forgetting some obvious things but I think it's nice to be open for suggestion of course.

I think the "coloration" of transformers is a subtle but beautiful sounding thing on it's own and im not
sure if I find something similar in the digital realm this naturally non-linear smooth sounding.

I heard a HDE-250A with transformer mode on/offed (wow!) what gave the latest push to go ask Wayne if I could publish the concept idea here! :)

Last edited by plantylife on Tue Nov 07, 2023 2:42 pm, edited 1 time in total.
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Re: concept: saturator unit - transformer

Post by mediatechnology »

Thanks for joining us!

I've thought of injecting DC as well to bias the core into its non-linear region.

I had clients that demagnetized their mic input transformers with high-level LF tone because they would become magnetized in use from phantom shorted to ground on one leg.
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Re: concept: saturator unit - transformer

Post by emrr »

As an owner of a zillion varieties of transformers, I find entropy has a way of destroying this concept - too many people with too many disparate aesthetic interpretations! To make something universal, you'd need to decide on a median level handling range, provide both attenuation and gain before and after, provide variable drive and load Z, probably have options for high nickel and steel core turns into a bazillion dollar box fast, and people are always gonna have opinions about the type of amplifiers wrapped around it. I talk to people regularly who've bought this that and the other type of transformer color box, and most are just confused, many return them if they can, as it's very hard to make a product to match the wide variety of expectations, realistic and not.

The popular route a decade or so back was to DIY a panel with a bunch of transformer options, connectors for each, patch them until you hit the one you like......old transformers were cheaper then......

Honestly, the high operating levels people work at are gonna produce an effect with all but the highest headroom transformers these days. The transition, for most people, from 'hardly' to 'subtle' to 'crunchy' is a pretty small window, so vastly affected by overall system gain staging; that's probably all over the place depending on who you ask. It depends on the lowest frequency required as to where the headroom sits, and what it takes to distort it.

For the cost of an all-in-one box covering many bases, one could build a number of dedicated transformer coupled channels of something, preamps, compressors, etc and start gaining the subtle effect on the capture side. Strikes me as possibly more rewarding in the long run. In my experience I've not ever heard the sorts of pleasing effects I get with transformer coupled preamps in a later line level device. I have Western Electric 111-C's on my master analog bus which add another layer of subtle coloration that feels classy and familiar, though I think you could bypass them and unless pointed out, many people wouldn't hear any difference at all since they're high level transformers, you'd have to push full range +27dB into them probably to really start noticing them, and then you've got to attenuate after to work with most converters. Switch to something like a UTC 'A' series transformer, you might have to turn down the input to be happy and turn up the output.

I don't really know what happens sonically with bias effects, if it's really the same thing, or another type of effect unlike the usual variable level/frequency based effect.

Keep going! As you were....

Doug Williams
Electromagnetic Radiation Recorders
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Re: concept: saturator unit - transformer

Post by plantylife »

Hi Doug,

Thanks for your feedback and well thought text. You've made some good pointers I think.

I understand the point of a lot of different options of the transformer choice.
Since I don't have a zillion transformers i was thinking about OEP or edcor since I read they are
less "pro". Getting some and experiment and let the ear decide if its worth it to go deeper on this.

Wayne also showed me the waveulator he started. Im studying that at the moment.

Think are gonna be slow since I have limited time for this project. But any feedback is welcome.
If I got more I get back posting some here.
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