Passive pre recommendations & advice on pots, etc

[Arkless Electronics]

Never heard of that before but I guess it's not something common?

It's commonly available yes. L & R out from passive to centre contacts and then just take one set of L & R outs from say the left side of the switch to one pair of phono sockets and repeat from the other side of the switch to other output sockets. You''l obviously have to drill a hole for the switch.

[DSJR]

I regularly use two power amps off my workroom passive preamp and I genuinely cannot hear the difference having one or both connected together. I appreciate the electrics may suggest otherwise, but I suggest it's at inaudible frequencies in practise. The Crowns offer 13k input impedance with the gain pots set around three quarters up.

I've used the dinky attenuators as used in the Tisbury and although in isolation they're ok and with superb channel matching obviously, I really do prefer a little plastic film pot I know rather well now. From around ten degrees from minimum on the control, channel matching is fine right round to maximum.

Valve amps are different, or at least older ones may be. This may be due to insensitivity on their inputs, or very high output impedance on the active preamps and this is where careful matching comes in I believe.


For me at any rate, I've been able to compare a modern source straight into a power amp and then insert a few preamps, match the volume as carefully as possible and see if the sound changes by their insertion. In *my* situation and with power amps offering input impedances of 12k to 25k +, a passive preamp has the least to zero effect sonically, even the shunt-attenuator version which really does play havoc with any theoretical 'impedance matching.' Maybe an Albarry amp with input of 1.5k may show an effect, but I'll never be able to find out now.