With the intention of rebuilding an SCA35 into an integrated amp for my TV, I needed a remote volume control. After much consternation (yes, price is a big factor!) I bought a Chinese GA-5 off of an eBay seller. $44 & $12 shipping from Hong Kong.
http://www.ebay.com/itm/121288717326?ss ... 1497.l2648I haven't yet passed music through it, however, a couple of observations to guide anyone interested (and, no, I'd not expect this to be in the same league as P&G pots, Goldpoint/naked Vishay stepped attenuators, LDR attenuators, Slagle autoformers, etc.) in a solution where remote control volume is desired at a cheap price.
The important item, the pot is an Alps 4-gang 100k motorized pot. It is four gang because the unit supports one balanced input. Since I have no intention of using the balanced function, it is a simple task to parallel two wipers per channel, giving a 50k pot and minimize those rectification issues associated with wipers on tracks. Gold plated (flashed?) contacts for signal wire connections and a separate control board, IR module and pot. Takes up a lot of space but not unworkable.
The remote control is included.
The mute function simply rotates the pot to the zero position, albeit slowly.
The unit supports 5 inputs, at least it is supposed to. In the one I have, input 4 is engaged whenever input 5 (balanced) is engaged. There is no miswiring or evidence of shorted PC traces, so I assume the problem is in the IC controlling the relays. In any event, mine is just a 4 input setup, which suits me just fine, so the flaw is NBD for me. Who knows, other units may not have this problem.
Also included is a rotary enocder, used to cycle between the inputs. It mounts in a 1/4" (6mm) hole, so you can also have front panel chassis control of the inputs. LED drivers are built-in, and a cable included, so your indicator LEDs can be very simply connected to the unit. Standoffs are included for the main board.
9-12VAC is required. Bridge rectifier and LM7805 are on board. I suppose, you may be able to sneak by with a 6.3VAC supply IF you swap out the 7805 for a low-dropout unit and the bridge for Schottkys, but it will be close.
I'd submit more pics, but had to reduce size and resolution of this one to post it. If you want more pics or info, please let me know.
Stuart