Anyone know of an equivalent Neumann U67 mic transformer?

[TLRT]

There is another thread where we spoke about BV12 recreations, AMI has the T67 - cheap,but only similar(too hifi), BV12 Classic - very close,but expensive(370EUR) Max/Ioaudio - too dark,you need to play with tubes and feedback caps, but he is unavailable anyway. Chris from FAB Microphones(UK) is also working on a BV12 clone.

 

[Avgatzeblouz]

I ordered one of FAB transformers for U67. I will make a mic with this and an original Neumann capsule. Will report in a few months.

 

[emrr]

Seems the FAB are not direct retrofit, so unsuitable for restorations or clones following original dimensions.  Curious how they sound. 

 

[micaddict]

There is another thread where we spoke about BV12 recreations, AMI has the T67 - cheap,but only similar(too hifi), BV12 Classic - very close,but expensive(370EUR) Max/Ioaudio - too dark,you need to play with tubes and feedback caps, but he is unavailable anyway. Chris from FAB Microphones(UK) is also working on a BV12 clone.

Here's the thread I started earlier this year:
https://groupdiy.com/index.php?topic=64945.0

 

[TLRT]

Seems the FAB are not direct retrofit, so unsuitable for restorations or clones following original dimensions.  Curious how they sound.

Yes the first one was bigger than the original.(I tested the prototype) Now he is working to make it similar size as the original. Soundwise it was between the AMI T67 and the BV12 Classic but he will try different alloy combinations so I hope he will nail the right sound. I using his other trannies too which are excellent.

 

[emrr]

One that nails the sound AND fits original and repro mics would be great. 

 

[TLRT]

One that nails the sound AND fits original and repro mics would be great.

At this time I think AMI BV12 Classic is the closest recreation. I have clones with AMI and original Neumann capsules and vintage u67's too.

 

[Avgatzeblouz]

At this time I think AMI BV12 Classic is the closest recreation. I have clones with AMI and original Neumann capsules and vintage u67's too.

How far would you describe FAB version, compared to AMI ? And could the tube choice help to get closer to the original sound, considering an original K67 in the mic ?
Thanks.

 

[emrr]

The differences in transformers I've heard will not be mitigated by any tube swap.  The transformer itself is ALWAYS the larger contributor in any tube circuit. 

 

[TLRT]

How far would you describe FAB version, compared to AMI ? And could the tube choice help to get closer to the original sound, considering an original K67 in the mic ?
Thanks.

As I said earlier, it was in between of the cheap and expensive AMI's, but he is redesigning it now.
The BV12 is really important in the mic's character,
About the tubes I think this topic is still valid about the EF86's:
http://prorecordingworkshop.lefora.com/topic/3849602/EF86-manufacturer-recommendations#.WTQifdy8rIU

E80F is also good option but it is a bigger tube and it has 50% more heater consumption which is not so good for the original PSU,so a mod/new PSU is needed.

 

[Moby]

Just to warm u up a little.... Here is my first piece of BV.12 replacement TX. After this I did approx 100 pieces for one German repairman. (sorry can't name the guy The final pieces were done with exact bobbin replica and with the same isolation tape as  vintage originals. Unfortunatelly complete lams batch went there, so I have no leftovers. Of course, it's possible to make it again but nothing under 10kg of lams. Few years ago I spoke with one member here to make it available for forum people but nothing happened.  :-\ cheers

 

[Delta Sigma]

The differences in transformers I've heard will not be mitigated by any tube swap.  The transformer itself is ALWAYS the larger contributor in any tube circuit.

I agree with this. I ended up chasing solutions to the "dark" sound of my Max K U67. I definitely tricked my ears into thinking I'd found a solution only to relisten the next day and be disappointed.

 

[Khron]

Double-blind testing, anyone? Or perhaps measurements? As in, comparing to a calibrated measurement mic?

I agree with this. I ended up chasing solutions to the "dark" sound of my Max K U67. I definitely tricked my ears into thinking I'd found a solution only to relisten the next day and be disappointed.

 

[TLRT]

I agree with this. I ended up chasing solutions to the "dark" sound of my Max K U67. I definitely tricked my ears into thinking I'd found a solution only to relisten the next day and be disappointed.

You can use a brighter tube(NOS Philips EF86) and lower the feedback caps below 80pf  - or leave it out completely This will help.