The BE-100 is a plug-in equalizer module that was made for use with the RCA BC-100 mixing console. I have never seen a BC-100 in the flesh, nor am i aware of any albums that were recorded with a BC-100. Since it was a product aimed at the broadcast market, and fairly rare, it’s possible that no albums ever were made on one. From what i can gather from the forums, the BC-100 was apparently a custom-built product, and the pre-amps in these consoles were apparently built by API for RCA (no word on RCA’s involvement with the BE100). A few years ago i was at a local flea market and some guys had a box truck with the contents of a storage-unit forfeiture sale. I bought about 25 lbs of electronic parts, mic parts, etc., for a few bucks. I also got some very interesting AES journals (interesting insofar as who had owned them) which i’ll post soon. Anyhow, one of the parts i got was this BE-100. just the raw module. I bought a copy of the BC-100 manual from a dude who had been selling other parts from these RCA consoles on eBay. He was not in the business of selling manuals, but agreed to sell me one for $25. a very fair price. he even spiral-bound it! Here’s the schematic for the BE-100:
I added an old NOS BUD case, +/- 15v powersupply, a NOS UTC line-to-transistor input transformer from the local electronics warehouse, and an output transformer i pulled from an RCA broadcast phono pre of the same period.
I was too lazy to look up the specs on the transistors used in the BE100 to confirm that i was using transformers with the correct impedances, but my ‘good guess’ must have been close enough: it works just fine.
The unit sounds… grungy. Aggressive. not subtle, and not hi-fi. It is quiet (IE no hum, white noise, etc). I have not measured the freq response, but it sounds like it’s pretty much full-range… i think the transformers i used are pretty decent. The most interesting feature is the 40hz low boost. it sounds awesome. this will definitely find some use in the studio.
Has anyone else used one of these? any tips or suggestions?
Does anyone know any records/studios that used these?
2 replies on “TECH: RCA BE-100”
The RCA BC-100 was a special-order-only item available to broadcasters in the early 1970s. It was a radio board; at most, a broadcasting production board. It was never intended for a recording studio! The insides of the thing were loaded with uA709 op-amps. 709s are very close relatives of the infamous 741 op-amp. Stories vary wildly about this board. Some liked it, others hated it. It gained a bad reputation for being vulnerable to RFI. (ummm… *not* a good thing for a radio station console!) Remember that this was the early days of op-amps and “the book” was still being written on them. (heck, we were only into the first few chapters!)
I had the chance to fool with one, and never forgot the experience. The overall construction was solid, but it had that op-amp sound that went right through you. The example I had my hands on had no issues and no complaints from anyone that used it. Having said that, it isn’t a studio recording board like folks here are looking for. Worse yet, the configurations are all completely different and were made on a one-off basis for whomever the finish product was intended. Stations going this route went here when #1 they had an oddball config requirement, and #2 they had a big budget. (RCA didn’t give anyone a break!) Don’t expect to make too much use of one in a recording studio, unless you want to completely redesign it from top to bottom.
Remember that a radio station needs something reliable above all; high-fidelity is a secondary consideration.
I won a pair of these raw BE100 channels on ebay about 2 years ago and finally got the chance to hear them … not fully racked yet, just prepped by my tech. I was skeptical going in, but the sound of these EQ channels is quite good. I ran a Coles 4038 on a Fender amp / Gibson SG through my RCA BA31 preamp into the BE100 EQ channel. On guitar, this EQ is blasting with character. The high end (6khz?) is smooth. Low end is big (seems around 80hz). The painton fader had a positive sonic effect on the low end, at least I though. The Mid boost is excellent at 800, which is right at the bottom of the mid boost’s range, unfortunately. We were both convinced that this was a winner.