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I read with interest the introduction of the BC-2B mic preamp kit. It turns out that I have a pair of these original (two-channel) RCA preamplifiers, and a handful of extra transformers. The transformers are definitely made by UTC, but they're also definitely not LS-10s and LS-27s, in spite of what it says on Larry Seyer's website. I was curious, Kevin, if you've done any research on the actual transformers in these preamps. I don't remember if I asked this once before, but I've been trying to decide if they're worth anything for a hi-fi project.
Anyone know any further tidbits on this unit? There seems very little info on it available, other than it was a good pre. Like how did a Radio mixer become a sought after Studio pre? When were they made? How do they differ or resemble up to say a Telefunken V72?
Thanks,
RM
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Hi Henry!I haven't. I briefly had a BC-2B module in my possession a couple of years ago, but I didn't have the presence of mind to test the transformers. They could easily have been "plain wrapper" versions of the LS-10 and LS-27. I've never seen the actual transformers contained within those palatial cast enclosures that the LS series came in, so I don't know how big they are. I would guess that they are very good transformers, based on my experience with the UTC HA-100X. In any case, they are worth real money to vintage mic pre afficionados, even if they turn out not to work out for you!
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Thanks for the information, Kevin.FYI, Scott Dorsey of rec.audio.pro fame has stated (IIRC) that the Lundahl transformers are much better than the OEM UTC units.
I would think the line out transformers could be useful. It's less clear what good the input transformers are for hi-fi. If I had an MC cartridge, it would be interesting to see how they work as step-ups.
I use Altec mic-mixer input transformers, # 15095 (the red ones), for my MC step-ups (Denon DL103D) and they sound quite good (but not as good as Dake Ackley's Lundahl step-ups, which I had here for a little while.)
I suspect that the input transformer could be used for an MC transformer. The output transformer would be useful for a higher mu lower Rp tube (like the 12AY7 that was used in the preamp), if operated at relatively little standing current.
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