The elusive RCA BC-3C vacuum tube consolette

Here we see depicted the two units in essentially the same condition as they were when I got them. These were deemed actual radio transmitters at the music shop where I picked them up, effectively concealing their hidden potential in the doubly convoluted misunderstanding of vacuum tube & radio technologies. I picked them up because they looked cool, and was happy to discover that they were nothing more than tube mixing consoles.

 

 

Select an image below for larger version, then select the image again to return.

Front panel opens for ease of tube replacement.

Service entry through rear.

A glimpse of the business side of the controls.

Input transformer posts peeking from beneath the 'pre-amp bridge'.

The single most intimidating point at first...

A bit of exposure for the pair.

 

1 October, 2002

While indeed it seemed at first a profound benefit to have at hand a ‘parts unit’, I decided that to part out the already wrecked device would be a mistake. I’ve found nothing in the way of in depth information on these; they are scarce, and it would be stupid to needlessly destroy one, especially due to the fact that both units are essentially intact and to the best of my knowledge not in need of anything major. I have decided that minor dissections to further understand the circuit will be performed on the wreck. After having a go through on the clean unit, I will set about reconstructing the wreck with the parts I have on hand. This will allow me the option of using them in conjunction with stereophonic program material without butchering the interior signal path of either unit (something I was seriously considering for some time).

Each unit is comprised of a number of PCB modules hardwired to one another. This modular layout is quite attractive in regards to experimentation with modified signal path & component upgrades, but as stated, it is my wish to keep these units relatively close to original. A few modifications I am considering are:

  • Point to point wired preamplifier cards. Rather self explanatory, and simple to revert if things don’t work out as planned.
  • Reverb. This seems a neat use of the onboard monitor amplifier, to drive a set of springs.
  • Outboard power supplies. The power supply is the first stage that will be addressed, as any progress done elsewhere in this unit will rely on it’s health. The physical removal of the power supply may make future experimentation with voltage regulation, DC filament current, etc. far simpler & reduce potential proximity affect from the AC windings.
  • Additional channels. Okay, this is swaying pretty hard from the straight and narrow, but there are two (count 'em, two) empty slots sized up for the preamplifier PCB's. Another application for this space could be a reverb return amplifier, 'pre' pre-amplifiers or maybe a tone shaping stage. I think it safe to say that I will not stand for such potential remaining untapped.

The layout at a glance (this is nothing more than speculation on my part):

The five printed circuits handle microphone/line pre-amplification duties, and the final mixing of audio signal to mono being performed by a transformer. Front panel controls are limited to attenuation and signal routing, no tone ‘correction’ for the radio boys! Also on deck is what appears to be another signal amplifier (perhaps the main feed output), near a low power monitor amplifier (push-pull 6V6). The wiring buss implies an open ended structure, able to route several separate signal paths simultaneously, independant of one another.

Progress, in the form of confirmation of signal routing, drawn schematics, and actual results will be posted as events warrant. I also intend on replacing many of the pics with clearer shots; my apologies on image quality as this was my first time out with that particular camera, and the brief photo session took place whilst I was preparing for a move!

11 November, 2004.
It has been some time in terms of update, but I sourced a well rendered copy of the original user/service manual for this unit over a year ago. I intend on posting the contents in whole when I get the chance.

25 September, 2006.
I move like molasses in January...

BC3C table of contents
It is at the moment a bunch of links to .jpg files, it will likely be this way for some time yet.

I would love to hear from any one of you who has information or lore attached to this elusive piece of audio history. Please feel free to email me by pressing the creepy little cartoon character, there are no numeric characters in my email address, so I would recommend removing the numbers in order to facilitate mail delivery.

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