Ah!! wait a minute!! This is all about some turntables that we supplied to ILR stations in the 70s. They were either ‘Presto’ or ‘Technics’ turntables and I suppose we supplied them with a local pre-amp. I must own up that I have forgotten what we supplied there; I would expect that, because of the timescales at the time we would have ‘bought in’ a commercial preamp. I’m embarrassed that I can’t remember. so I’m really sorry, I can’t help here.
I’m actually working on a new disk pre-amp right now but it’s not scheduled for production any time soon.