They are data cables that control the relays of the VTL 7.5 amplifier. In order to avoid noise and interference the IR remote receiver and preamplifier controller are located at the power supply box. It connects to the tube/FET amplifying box by a the DC power supply cables and two wide connector Centronics cables transmitting just DC signals to control the volume and switching relay coils. All this information is sent in parallel, avoiding any noise due to decoders or digital circuits. In this aspect, the 7.5 is textbook!
I am a new TL 7.5 Series III owner and I am bowled over by the technology and the all around excellence of this preamp.
Of course the sonics are the end goal, but they're here, in my opinion. I am glad, it's the best I've had in my system.
I expected excellence, and I haven't been disappointed. Music simply snapped into focus. My old pre immediately got switched out.
It's more fun to listen!
I had purchased a used TL-6.5 signature a week or so before, which absolutely bowled me over with its build quality. Components, board, casework... Plus, the size is convenient, it fits in a normal sized billy bags rack slot.
I was impressed enough that, without even plugging it in or listening to it, I purchased the TL-7.5 Series III. I am so glad I did.
The TL 6.5 Signature is really great for a single box preamp, it gets toes tapping, and that's one measure of excellence. Lots of trickle down technology from the TL 7.5 Series I. I do believe it is quite deserving of the label "Overachieving". And, there's a Series II that I am sure is better.
The TL 7.5 Series III is even more amazing.
I have to admit, I was a little bored with listening, and I wasn't listening much at all. But the new preamps changed all that, I am listening a lot more now and combing the local thrift stores for Compact Discs, as my winter desert house has only a CD player. But the joy of music is running more strongly than ever.
To clarify a bit of prior information, there are three versions of the TL 7.5- the series I, series II, and series III. I don't believe there are any other rolling updates of any kind. A series III is a series III, I believe, with no variation between them. The series III will say on the power board that it's a series III. These boards are beautiful, a wonder.
If anyone has a Manual for the TL-7.5 Series III, I could use a copy...