RS1b Bass Servo
 

Anyone got any thoughts about using a alternative bass crossover to the RS1b servo/crossover unit. My unit is still going fine but I'm conscious of how old it now is. Of course a replacement would not have the back emf servo function - would its absence be a deal breaker?

I ran my Betas using the crossover function of the MEN220 with good results for a few months. But I have put my servo eq back in line mainly because I felt it could give me more control over a nasty low end room bump and it didn't feel right not using the servo.

It can be done with good results depending on whether you need that lowest octave.

Ah, thanks. I guessed the loss of the servo function might be quite important especially on those lower bass frequencies where the Infinities really do move the air.
I'll hope the servo keeps on going, however if it fails I've got the schematic and its fairly straightforward circuitry.
The schematic isn't wholly accurate but its sufficient to fault find with.

Mike.......I would not give up the servo control function on the Infinities. That is a major part of the design of the bass function and controlling the woofers for low distortion.

jdandy. I kinda thought that'd be the case.
Looking at the circuit the servo system used is a lot more basic than that used on the Reference with an additional 'voice coil' on one woofer providing motional feedback.
It good to know that sampling via 0.1ohm resistors obviously does work well after all then :)

Assume you have this but here it is for the AA record. From the "infinity-classics.de" site.

Just to add my two cents, Dan is right on. I had a set of NOS RS1b's with a new servo so I tried several crossovers including a simple one by NHT, I believe it was the X2. The factory servo is matched to it. Like you say, it is easy to fix and there are several guys that are really great with the servos so let us know if yours has a problem and we can point you to them. The factory servo is designed for them and does work the best. That is true with the RS1b's, IRS Beta's, and other similar systems. The IRS V's have the servo controls built into the amplifier so it is possible to bypass that crossover a bit more easily.

I would ask Gary Koh of Genesis Technologies (took over for Arnie Nudell who designed your speakers)...he is incredibly knowledgeable and helpful. You can find him on various forums, or just email him from his website email address. He is also extremely responsive...i have never had to wait more than 1 day for him to ping back an email. Good luck.

Thanks guys, its really great to get so many responses. Just knowing there's such a wealth of expertise sharing from Audio Afficionado members is a huge plus especially for those of us who are running vintage equipment.
A big AA family :-)

Mike

Hello. New to AA and would appreciate a lead to repairs on my Beta servo. I am unable to PM now as a newbee. Thanks.