Aleph L Muting Relay Rating

[PaulyG]

First, let me introduce myself. I am Paul and this is my first foray into building audio equipment in over 20 years. I am happy to have found this forum.

In the past I built a 60W Mosfet amp, a op amp based preamp, (both designs from Audio Amateur) and a set of transmission line speakers with Dynaudio drivers. After two decades, it seems like a good time to upgrade some of my equipment!

My first project is to upgrade the preamp. I am planning on building the Pearl phono section and the Aleph L preamp. Panos, who has built the "L" has been very kind to give me some information on resistor wattages and heatsink info. As I have been looking at the schematic, I realized that it was unclear (at least to me) what the voltage rating and the internal resistance of the normally closed muting relay is. It looks like a 24V relay but I am not sure. Does anyone know the specs for this part?

Thanks in advance,

Paul

 

[Nelson Pass]

It's probably 24 volt, but has been known to vary. If so,
we adjust the series resistance (measure it with an
ohm-meter) to suit. They usually kick on at 1/2 rating
or so, and most of them can take a lot of abuse being
run over their rated voltage.

 

[Joe Berry]

Something else to watch out for is that some of these relays are polarized and will only work with the DC applied in one direction. If I remember correctly, Nelson & Co. use Aromat parts, which are polarized, so you'll want to strictly observe the polarity shown in the Aleph L schematic. If you still manage to get it wrong in your PCB layout, you can spend a few cents more and get the equivalent Omron part, which will work with the DC applied in either direction. Both parts are available from Digi-Key. Ask me how I know.

 

[PaulyG]

Wow, an answer right from "the one and only"! Thank you for your help.

Paul