The No.1 Website for Pro Audio
Transformer Color Box
Old 27th March 2018
  #1
Gear Addict
 
MYN's Avatar
 
1 Review written
🎧 5 years
Transformer Color Box

Was reading the preview of that old Tape Op article about adding a transformer into the chain to induce more color/mojo. Using Transformers: to Transform Audio | Tape Op Magazine | Longform candid interviews with music producers and audio engineers covering mixing, mastering, recording and music production.

Sounds easy enough, right? And it got me thinking about experimenting with something like this, so I'm asking for your best informed opinions.

My singular use is VO and I record completely ITB with an Apollo Twin so would a switchable transformer color box work in between the mic and the Apollo?

And if so, what specific transformer(s) would you suggest for this purpose? I'm particularly interested in CineMag and Jensen traffos for this purpose, but very curious to hear what others suggest.

Note: I get it that phantom can't be passed through the transformer, but in my particular setup, the mics in my booth first go into a Radial Gold Digger mic switcher where they get phantom before going into the Apollo.
Old 27th March 2018
  #2
Lives for gear
 
🎧 15 years
A Jensen is unlikely to give any colour as they are designed to be as transparent as possible.
Cinemags may also be quite 'clean' too.
Matt S
Old 28th March 2018
  #3
Lives for gear
 
zvukofor's Avatar
 
🎧 10 years
IME, there's not so much color from transformers alone, but from a complex combination of a transformer and a circuit driving it.
Old 28th March 2018 | Show parent
  #4
Gear Addict
 
MYN's Avatar
 
1 Review written
🎧 5 years
Quote:
Originally Posted by Matt Syson ➑️
A Jensen is unlikely to give any colour as they are designed to be as transparent as possible.
Cinemags may also be quite 'clean' too.
Matt S
I think you're right. I was kinda thinking along the lines of how deep those Jensen lows go in the John Hardy preamp, but that may not be completely because of the transformer. Some of those Jensen Output traffos are not that expensive so I may just get one to try, while keeping my expectations on the low end... pun intended.
Old 28th March 2018 | Show parent
  #5
Gear Addict
 
MYN's Avatar
 
1 Review written
🎧 5 years
Quote:
Originally Posted by zvukofor ➑️
IME, there's not so much color from transformers alone, but from a complex combination of a transformer and a circuit driving it.
Given that my thoughts along this line in terms of my personal use involve putting that transformer between the mic and pre, I think I have to check my expectations of "color" inducement and instead think of it as a way to experiment with some of the definition, width and depth of the sound. For my stuff, I'd love to get just a touch of that transformer squish when using my transformerless Sennheiser 416 shotgun on louder VO's like car spots or animation/character voices (as opposed to using compression) to get some of the hair off it.

I was intrigued by this guy's use of a transformer in between his mic and pre. It's subtle, but there's some nice stuff going on sonically with those transformers switched in.

YouTube

This whole thing could really just be a waste of time, but I just finished building a bunch of u87's and I'm bored and in need another DIY project. This seems like a simple and easy palette cleanser before I decide on a more complicated electronic project.
Old 28th March 2018
  #6
Lives for gear
 
🎧 15 years
Jensen make a big song and dance about how wide the frequency range is and how low the distortion is which ordinarily is what is wanted, galvanic isolation with minimal loss of quality. If you want colour, they are certainly not ones to go for.
Lesser 'quality' transformers would give more colour but as pointed out by Zvukofor it is often the interaction between transformer and the amplifier driving it which gives that particular sound.
As frequency reduces and level increases at some point the transformer core starts to saturate. Depending on the amplifier driving it this may enter current limiting adding horrible distortion to the signal so simply having a 'transformer in a box' will produce different sound when used with equipment with different output stages.

Matt S
Old 28th March 2018
  #7
Lives for gear
 
🎧 15 years
Hi
Mic signals are way below saturation of all but the smallest transformers so I would not expect much if anything.
If the mic has a transformer inside, and the preamp has one, then you add a third I would expect some phase and frequency anomalies going on but not much 'saturation'.
Matt S
Old 28th March 2018 | Show parent
  #8
Gear Addict
 
MYN's Avatar
 
1 Review written
🎧 5 years
Quote:
Originally Posted by Matt Syson ➑️
Hi
Mic signals are way below saturation of all but the smallest transformers so I would not expect much if anything.
If the mic has a transformer inside, and the preamp has one, then you add a third I would expect some phase and frequency anomalies going on but not much 'saturation'.
Matt S
I get ya, man. In my case, for this use, the mic is transformerless and the Apollo Twin is as well. I'm intrigued by that guy in the video I posted above because he says he's using a 57 direct into the UTC transformers. Like I said, it's just something I'm curiously poking around and will probably try just for the heck of it. With what I do, the deliverables are all naked voice tracks so even very subtle changes are a lot more obvious than if it were just a vocal in a big mix which is why this seems worth trying, if even only just to hear on my own how it doesn't work.
Old 28th March 2018
  #9
Lives for gear
 
🎧 15 years
Hi
In that case 'go for it'!
I would anticipate the transformers with the lowest signal handling capacity would have most effect.
Let us know what you find.
Matt S
Old 28th March 2018
  #10
Lives for gear
 
zvukofor's Avatar
 
🎧 10 years
Once i tried a very small trafo on mic preamp input, really small Bourns, designed for analog telecommunications... it was long time ago, and i can't remember what it did to the sound, as this was for communication purposes only...

As for removing that 416 "signature"...nothing will help, unless you change it for more nicely sounding shotgun... been there, worked on movie sets for more than 10 years.
Old 28th March 2018 | Show parent
  #11
Gear Addict
 
MYN's Avatar
 
1 Review written
🎧 5 years
Quote:
Originally Posted by Matt Syson ➑️
Hi
In that case 'go for it'!
I would anticipate the transformers with the lowest signal handling capacity would have most effect.
Let us know what you find.
Matt S
I will. For sure. David Guerin at Cinemag told me to hit him up next week. They just moved into a new factory here in So. Cal a few days ago so he said to give him a few days. I'll probably just go over there and pick his brain for ideas.
Old 28th March 2018 | Show parent
  #12
Gear Addict
 
MYN's Avatar
 
1 Review written
🎧 5 years
Quote:
Originally Posted by zvukofor ➑️
Once i tried a very small trafo on mic preamp input, really small Bourns, designed for analog telecommunications... it was long time ago, and i can't remember what it did to the sound, as this was for communication purposes only...

As for removing that 416 "signature"...nothing will help, unless you change it for more nicely sounding shotgun... been there, worked on movie sets for more than 10 years.
Hah! Unfortunately, or fortunately, the 416 is such a signature VO mic, especially here in L.A. so I'm stuck with it. Most of the time I love it, but really for non-commercial and highly dynamic stuff, I'd like to see what a transformer before the pre may or may not do since, as you have probably experienced, it really doesn't like being shouted into from 6 inches away.
Old 28th March 2018
  #13
Deleted User
Guest
This topic has come up before. so I'll repeat the same ideas I did in the other threads:

(1) Steel laminations tend to sound more colored and raw. Nickel more hi-fi.

(2) Higher impedance transformation ratios sound more colored. Unity transformation ratios sound more hi-fi.

(3) Pay attention to the published Total Harmonic Distortion (THD) metrics for transformers from various vendors. Higher THD usually means more color.

There are exceptions, but these three bullet points will help you get started in the right direction.

To my ears, Jensen transformers sound very clean as others have said, though they still impart a transformer quality to the sound. Cinemag can wind you colorful steel lamination transformers or highly transparent hi-Ni transformers as they call them. They can do it all, whatever you want.
Old 28th March 2018 | Show parent
  #14
Gear Addict
 
MYN's Avatar
 
1 Review written
🎧 5 years
Quote:
Originally Posted by Frank_Case ➑️
This topic has come up before. so I'll repeat the same ideas I did in the other threads:

(1) Steel laminations tend to sound more colored and raw. Nickel more hi-fi.

(2) Higher impedance transformation ratios sound more colored. Unity transformation ratios sound more hi-fi.

(3) Pay attention to the published Total Harmonic Distortion (THD) metrics for transformers from various vendors. Higher THD usually means more color.

There are exceptions, but these three bullet points will help you get started in the right direction.

To my ears, Jensen transformers sound very clean as others have said, though they still impart a transformer quality to the sound. Cinemag can wind you colorful steel lamination transformers or highly transparent hi-Ni transformers as they call them. They can do it all, whatever you want.
Thank you, Frank! This info will definitely help me with my research on this flight of fancy. Dave at Cinemag is such a super nice guy and so helpful, I have a good feeling that a few minutes with him next week will either convince me to do this or abandon this. After reading your post, I'm thinking I should pick his brain on doing both one of those hi-Ni and one colorful steel transformers and make them switchable (and maybe blendable?) inside a project box just as a starting point.
Old 28th March 2018
  #15
Gear Addict
 
MYN's Avatar
 
1 Review written
🎧 5 years
As I sit here and daydream about this idea as it pertains to my personal use, if it works, ultimately what would be cool is a box like my Radial Gold Digger with phantom power and 3-4 switchable XLR inputs, but then feeds into a transformer that can be switched in and out of the circuit before hitting the output. Or maybe two different transformers... So Phantom power on the front end, transformer color on the back end and then output right to the pre.
Old 29th March 2018
  #16
Deleted User
Guest
A common way of doing this is to put two high impedance ratio transformers of the same kind back to back, the first jacking up the impedance, the second jacking it back down to unity, with the overall effect being no change in impedance from source to output. Changing the impedance along the way would make your color device less flexible, so shoot for 1:1 impedance unity overall.
Old 2nd April 2018
  #17
Lives for gear
 
🎧 10 years
You can find all kinds of 600 ohm 1:1 coupling transformers on line. EBay is loaded with them as are all the parts outlets. The ones typically used for vintage audio tend to have flatter/extended frequency responses. Prices range from a few dollars to maybe $100 depending on what you buy. It surely wouldn't take much to throw a couple of different pairs in a box with switches and connectors.

Once you test the actual audio responses using some white/pink noise and a frequency analyzer you can wire them in some kind of a pecking order from beat to worst audio response and label the settings by the roll off frequencies. This way you have a useful tool you can choose to incorporate in your signal path or choose to bypass. It could be something you use on single track or mastering just like you would with any form of EQ.

I'm not sure it would provide more magic then some fill LRC EQ's I've used. Many EQ's only use caps and resistors to create their frequency cuts. You add coils and the whole ball game changes.

Back in my repair days I used to repair allot of vintage audio gear for a living and came across some excellent designs which I've never seen copied. One was a vintage EQ, probably from an old German design. Instead of using pots to adjust the tones it used mechanical sliders which moved cables to withdraw iron cores from coils thereby changing the number of Henry's and the frequencies bands being cut. Never saw anything like it prior or after in the 50 years as a technician but always thought that was one of the niftiest designs. No pots to wear out.

Changes were fairly mild but the quality was very transparent and it didn't produce the mud tones most RC circuits produce. I always thought someone would take that design and do something cool with it. With the new Mu Metals available now you could use much smaller slugs for the coils and easily come up with some kind of draw bar design which would be efficient and economic. I suppose engineers rarely think outside of the box any more when it comes to audio and stick copying popular designs for profit. Really cant blame them. It costs allot to design and pro audio is an extremely small income in the big scheme of things. Even for consumer audi, kids would rather have a cell phone then a decent stereo so most of what we do to record music is targeting crap audio systems.
Old 3rd April 2018 | Show parent
  #18
Gear Addict
 
MYN's Avatar
 
1 Review written
🎧 5 years
Quote:
Originally Posted by wrgkmc ➑️
Back in my repair days I used to repair allot of vintage audio gear for a living and came across some excellent designs which I've never seen copied. One was a vintage EQ, probably from an old German design. Instead of using pots to adjust the tones it used mechanical sliders which moved cables to withdraw iron cores from coils thereby changing the number of Henry's and the frequencies bands being cut. Never saw anything like it prior or after in the 50 years as a technician but always thought that was one of the niftiest designs. No pots to wear out.

Changes were fairly mild but the quality was very transparent and it didn't produce the mud tones most RC circuits produce. I always thought someone would take that design and do something cool with it. With the new Mu Metals available now you could use much smaller slugs for the coils and easily come up with some kind of draw bar design which would be efficient and economic. I suppose engineers rarely think outside of the box any more when it comes to audio and stick copying popular designs for profit. Really cant blame them. It costs allot to design and pro audio is an extremely small income in the big scheme of things. Even for consumer audi, kids would rather have a cell phone then a decent stereo so most of what we do to record music is targeting crap audio systems.
Mind blown.
Old 3rd April 2018
  #19
Gear Addict
 
MYN's Avatar
 
1 Review written
🎧 5 years


Let me throw this out there. I saw this photo of someone's transformer color box online using UTC's. I see he's tied the ground to Pin 4 on the Secondary with a resistor. Can't make it out myself, but any ideas what size this resistor could be?

Also, and probably more importantly, can someone explain why those resistors are there... and preferably, explain it to me like I was five years old?
Old 3rd April 2018
  #20
Lives for gear
 
🎧 15 years
Hi
As Wkrgkmc says things can be done with hardware. Some of the old Studer gear gets heavily into 'precision mechanical engineering', thinking of a fader unit I have seen which uses an ordinary rotary pot but a helically grooved aluminium bar with sprung 'carriage' to turn it. This alone would now cost more than a whole 'mixer' in terms of parts and labour to assemble them.
The tone wheel assembly for a Leslie (or was it hammond) organ is a precision engineers dream.
Variable inductance EQ is of course possible but would be so specialised that you would literally be 'on your own'.
Matt S
Old 3rd April 2018
  #21
Lives for gear
 
zvukofor's Avatar
 
🎧 10 years
Old Sennheiser 421 used that type of low cut filter - changing the inductance mechanically. You can build your own simply using a small steel-core inductance and a magnet. You move magnet closer - get less lows (and more distortion on them, if using this trick on a transformer).
Old 5th April 2018 | Show parent
  #22
Lives for gear
 
Cozmik Prod.'s Avatar
 
🎧 5 years
Quote:
Originally Posted by MYN ➑️


Let me throw this out there. I saw this photo of someone's transformer color box online using UTC's. I see he's tied the ground to Pin 4 on the Secondary with a resistor. Can't make it out myself, but any ideas what size this resistor could be?

Also, and probably more importantly, can someone explain why those resistors are there... and preferably, explain it to me like I was five years old?
I'm no expert on this....

Pin 4 is chassis (metal casing)
Pin 1 is signal ground.
Usually they meet somewhere.
But you'd want the path with least resistance go to signal ground and not the chassis.
A low value resistor 1 to 10 Ohms to chassis keeps the path of least resistance going to signal ground.

Please correct me if I'm wrong.
Old 11th June 2018
  #23
Lives for gear
 
Jesse Skeens's Avatar
 
🎧 15 years
Is it ok to just leave both sides floating or does something need to tie to ground? I'm looking at using some Carnhills and have seen them wired to just pins 2/3.
Old 11th June 2018
  #24
Lives for gear
 
🎧 15 years
Hi
The windings can be floating but one side or the other should have pin 1 (ground) taken to any metalwork.
Matt S
Old 11th June 2018 | Show parent
  #25
Lives for gear
 
Jesse Skeens's Avatar
 
🎧 15 years
Quote:
Originally Posted by Matt Syson ➑️
Hi
The windings can be floating but one side or the other should have pin 1 (ground) taken to any metalwork.
Matt S
Thanks Matt. So if I put it in a little metal box does that count? In other words XLR in, pin 1 to the box the trannies are in and pins 2/3 to the Carnhill primary. Then out of the secondary to pin 2/3 with pin 1 floating on XLR out?

cheers
Old 11th June 2018
  #26
Lives for gear
 
🎧 15 years
Hi
Yep!
You could add a switch so that you take the pin 1 of the outgoing XLR to ground too just in case you need it in a different setup.
Matt S
Old 12th June 2018
  #27
Gear Addict
 
MYN's Avatar
 
1 Review written
🎧 5 years
Super cool idea with the Carnhills. If you get a chance, I'd love to hear a sample of how that sounds on whatever you're going to put it on.
Old 12th June 2018
  #28
Lives for gear
 
🎧 15 years
Hi
As an observation, Carnhill make hundreds of different transformers each with their own 'recipe' so although a particular 'range' may have similar characteristics but having different ratios for example, how any will react to YOUR circumstances is anyone's guess.
Sending impedance, receiving impedance and signal level all play a massive part in the overall 'effect'.
Similarly any other transformer manufacturer and situation.
Matt S
Old 12th June 2018 | Show parent
  #29
Lives for gear
 
Jesse Skeens's Avatar
 
🎧 15 years
Quote:
Originally Posted by Matt Syson ➑️
Hi
Yep!
You could add a switch so that you take the pin 1 of the outgoing XLR to ground too just in case you need it in a different setup.
Matt S
Thanks will keep that in mind too.
Old 12th June 2018 | Show parent
  #30
Lives for gear
 
Jesse Skeens's Avatar
 
🎧 15 years
Quote:
Originally Posted by Matt Syson ➑️
Hi
As an observation, Carnhill make hundreds of different transformers each with their own 'recipe' so although a particular 'range' may have similar characteristics but having different ratios for example, how any will react to YOUR circumstances is anyone's guess.
Sending impedance, receiving impedance and signal level all play a massive part in the overall 'effect'.
Similarly any other transformer manufacturer and situation.
Matt S
I had my eye on the 2281's, seen them referenced a few times for this application. Will probably hang the box behind a Gyraf SSL. Have also seen those modded with the Carnhills direct on the out so should work the same.

I did watch a vid of the Dangerous 2buss+ which has a drive for the transformer. Is there a simple way to accomplish that? I'm planning on running the 2281's 600/600 but from what I understand adding a variable resistance to one leg might change the impedance ratio to drive it more? That's a little beyond my basic understanding at the moment though.

Cheers
πŸ“ Reply
Topic:
Post Reply

Welcome to the Gearspace Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…

Forum Jump
Forum Jump