Bogen line transformers

[Quayhog]

I've acquired over time enough octal sized 9 pin Bogen transformers and I'm curious if there is a description of their intended use.  Part numbers include
T-155,  T-156, T-161 and an output T-165,

I also have a similar amount of Newcomb line/mic transformers with part numbers T-91 and T-100.  I have enough to dedicate to a large and ambitious project.

I'm looking for any literature and opinions of quality.
Thanks
Quahog

 

[mjrippe]

I've only got a little info but I'll post it here for you and future googlers.

Bogen T-155:
Rated for 150-200 ohm microphones to single grid.
Checks out as about 200 ohms to 50K ohms.
Input primary pins 5, 6(ct), and 8
Secondary pins 2 and 9
Pin 1 internal shield.

Newcomb TR-91 is similar, see attached photo for pinout.

Can't offer an opinion on quality.

 

[gridcurrent]

Part numbers include
T-155,  T-156, T-161 and an output T-165

from Presto 800 series tape machine manual
T-155: input, 150-250 ohms
T-157: input, 50 ohms
T-156: input, 500 ohms

pertaining to A908 electronics, part of the model 800.  expected those metal can transformers to be Bogen quality (not in a good way). 
pleasantly surprised.  preliminary tests reveal excellent peformance,
wide frequency response, low harmonic distortion., mic transformers had minimal loading.

 

[PRR]

I've felt the Bogen Octal mike transformers were better than expected.

However when I went from a simple preamp using them to a good transformerless commercial preamp, the no-transfo was more transparent on rich live orchestra. Not a wow difference, but when integrating the new preamps I went back and forth many times (between preamps and between monitors and the concert hall) and felt the no-transfo was more "literal".

The Bogens certainly have a place when you can select a brush for the sound you want. They don't suck, and no big color, but not the same as the universal $10-$1000 preamps.

 

[fum]

I've got a stash of the T-155 transformers, as they were used as input transformers in an old RCA tube mixer I worked on.  I only needed one, and wound up with 9 =)

ju

 

[Quayhog]

The T-165 is the line output transformer.  I'm looking through my stash of stuff for output transformers and hoping it would work well in a Pultec MEQ-5 circuit.  The operative words are work well.  All I know is it has a 600 ohm secondary.  I have some Altec 15095 and  the McGohan equivalent (sort of) I could use. The  triad HS-50 is unobtainable.

For the MEG-5 600:600 input I'll probably use some OpAmp Labs T-25.
20-20khz and 24dbm. No center taps.

 

[johannpolzer]

Looking for Bogen T-155s can someone help me out?

 

[C12VR]

Looking for Bogen T-155s can someone help me out?

They are available often on ebay for about 50 bucks nominal, 35-40 if you ask. Make sure you get the ones with the shield. Sellers don't tend to put any stock in that but I'm pretty sure the base can is just an aluminum extruded thing.

 

[CJ]

Du Kane octals are also nice,