[andyn]

Slage AVC versus Sowter 9335

I have what is essentially a balanced Izzy-Wizzy (http://www.izzy-wizzy.com/audio/preampnew.html) preamp which uses a Lundahl LL1660AM/PP wired as a 2.25+2.25:1 to drive a Sowter 9335 TCV. I have always been happy with it but the idea of trying a Dave Slagle AVC was too tempting to miss.

I managed to create a situation where, by use of relays, I could switch between the two types of volume control whilst still playing music. In this way we would not be dependant upon memories of minutes or days ago when making comparisons.

The hardware was “run in” over a period of a couple of weeks and some additional 48 hours of a CD on repeat driving the AVC.

Two separate sessions were arranged to audition the differences. During the first session Ian Foxon and I listed to a variety of music. It had to be said that the differences were relatively small – certainly smaller than changing the power cord of my Teres Audio, Verus Motor controller. Overall Ian preferred the Slage iron which he found to be more forward in its presentation and more relaxing – without being rolled off in any way.

The second session was myself and Andrew Ivimey. Once again the differences were small, it was clear that there were differences but getting a handle on them was difficult. Playing “A Kind of Blue” or “Ah Um” only revealed that there was a difference but not one we could reliably get a handle on. We then moved onto Shostakovich Symphony 11 (Melodiya). If you don’t know it, this is a work of great scale and pace which when combined with being a very good recording makes quite a good reference record. I was struck by the difference in presentation of the Tympani. The Slagle iron revealed more character of the instruments, in addition the presentation was once again more forward and the top less aggressive.

Overall the Slagle iron was preferred but not by a large amount. I would not be able to walk into the room and know which device I was listening to. To be honest one would likely find a bigger difference swapping capacitor types – even of good grade capacitors or power cords.

Clearly YMMV.

Hope this may assist someone.

Andy