"Standalone" transformer?

[Schnert]

Hello there,

I've been told that much of the "color" that comes with older/retro/reissued equipment is in the transformers. I have a very clean path, and was advised to get a transformer in there if I wanted some color.
I know very little of these things....I just turn those knobs without knowing what's inside . So, could I just put a transformer of my choice after the preamp? Or would I have to build this thing into the preamp? Does it need power? Are there "standalone" transformers made for this purpose?

Ahem......don't laugh if these are hilarious questions...

[Marshall Simmons]

i was wondering the same thing.. i was thinking about using an input transformer connected to an output transformer... but i don't know the logistics of it

Marsh

[Geoff_T]

Originally posted by Schnert
Hello there,

I've been told that much of the "color" that comes with older/retro/reissued equipment is in the transformers. I have a very clean path, and was advised to get a transformer in there if I wanted some color.
I know very little of these things....I just turn those knobs without knowing what's inside . So, could I just put a transformer of my choice after the preamp? Or would I have to build this thing into the preamp? Does it need power? Are there "standalone" transformers made for this purpose?

Ahem......don't laugh if these are hilarious questions...

Hi

I don't think that it's quite as easy as that but there's no harm in experimenting!

If you just took the vintage Neve example, like 1073 and 1272, that output transformer has a fairly substantial dc current flowing through the primary and this will very much affect the way the transformer sounds... compared to just dumping it across the output of a third party preamp and expecting a Neve sound to materialise.

Transformers are also affected by the damping factor driving them and the impedance (especially capacitance related) on the secondary. These can dramatically affect the sound the transformer produces.

You could try wiring a 1:1 ratio output transformer across the output of your pre (which I assume doesn't have a transformer). It will provide a balanced and floating output and may improve the signal... just don't expect anything earth shaking!

[Marshall Simmons]

thank you for your reply...

would a standalone transformer still offer the same bass distortion and harmonic enhancement that it would in a full circuit?
(atleast thats what i'm hearing with older transformer premap designs)

Marsh

[Bernd G]

Hello Marshall,

try a mic splitter designed with a transformer and A/B the direct and transformer coupled signal. Depending on the transformer, you will hear a change. I tried this once many years ago with a Whirlwind mic splitter (1X2, I think), and all of my colleagues agreed that the transformer signal subjectively added "bass" to the original signal. This is a very "unscientific" approach - but convincing for your purposes. For a detailed technical discussion see: Glenn Ballou's Handbook for Sound Engineers, particularly Bill Whitlock's chapter on Audio Transformers and Steve Dove's paragraph on Microphone Transformers. Also see one of the threads that I started a while ago which deals with Audio Transformers ("Audio Transformers - The Last Word (s)".

Cheers

[Marshall Simmons]

thanks a bunch!


i'll check that thread out again.

i have some old RCA ba33 and ba34's that have old UTC input and output transformers. I'm going to try to wire them together to some xlr tails and see what it sounds like

marsh

[gyraf]

..Do some experiments with the relatively cheap "ground isolation" transformers made for car audio (the ones with two flying leads and four phono connectors). They're usually rated 10k:10k - but don't let that disturb you. Most transformers has most sound when operated close to - or even outside - their specs.

If you run them at the right levels and output loads, you can acheive very fine results. Think about loading output with a potentiometer, e.g. a 10K log.

If you're balanced, you'll need to crack open the little box with the transformers, and rewire for balanced connectors. It's quite simple.

Jakob E.

[cymatics]

Originally posted by gyraf
(snip) Most transformers has most sound when operated close to - or even outside - their specs.

If you run them at the right levels and output loads, you can acheive very fine results. Think about loading output with a potentiometer, e.g. a 10K log.

You're saying to hit the x-former with a really hot level, then attenuate after the output with a 10k pot?


- jon

[gyraf]

..not attenuate (well, that may be needed also..) but load.

It's the current through the transformer that pushes it towards it's limits. Think of it as a dummy-load, shorting the current on the secondary side of the transformer...

Jakob E.

[cymatics]

Got it.

Thanks for the clarification.


- jon

[silverdisk]

Originally posted by gyraf
..Do some experiments with the relatively cheap "ground isolation" transformers made for car audio (the ones with two flying leads and four phono connectors). They're usually rated 10k:10k - but don't let that disturb you. Most transformers has most sound when operated close to - or even outside - their specs.

If you run them at the right levels and output loads, you can acheive very fine results. Think about loading output with a potentiometer, e.g. a 10K log.

If you're balanced, you'll need to crack open the little box with the transformers, and rewire for balanced connectors. It's quite simple.

Jakob E.

I want to try this for fun, but being an electronics newb, i dont understand where to connect the potentiometer. I am guessing it would have to soldered on somewhere, but where?
ins, outs? to one side or the other.... sorry, thanks for tolerating this hobbyist question.......

[Marty Shields.]

Mucking around with tranny's changes the dynamic range of the signal,get yourself a crow, so you can see the difference as well as hear it .It's great fun,put the pot any where,but try to keep every thing balanced tho.
Marts.

[David Kulka]

A mic or mic splitter transformer should not be used with line level signals.

A line input transformer should be used within a few inches of the stage it is driving and its impedance should be matched to the circuit. If it is connected externally, you wind up with an input transformer that's being used as an output transformer, perhaps connected to a random, unknown impedance. It probably won't perform properly.

The best bet would be an output transformer with XLR in and out (as suggested above), or perhaps wired to a patchbay. It could be thought of as a passive piece of outboard gear. The sonic change with say a high quality Jensen transformer might be undetectable. As you go down the line towards smaller, more primitive transformers, low and high frequency rolloff will come into play. Loading will affect high frequencies.

Also, high level low frequency material will oversaturate the transformer, causing distortion, especially with smaller transformers.