TVC Promethius versus Bent

Unfortunately that was not me who was able to play with a prototype. I actually live in Las Vegas.

I have been in touch with John about building the TAP with a K&K or some other phono stage so it would be full function. It will most likely require a two-box solution, but John was very helpful in explaining the options and how he could accommodate my request.

I'm in a bit of a transition and for the time being am using a VAC Avatar SE integrated with phono to conserve space. Ultimately I think I want to go fully balanced and may wait for John to put out the balanced version of the TAP.

Mrtennis, can you clarify which Promitheus TVC it was that you compared to the Bent TVC? Was it one of the budget (i.e., under $1k) TVC models that is built around EI-core Rev. 3 transformers? Or was it one of the newer Reference C-Core or Signature (Double C-core) models?

The first gen Promitheus that I owned couldn't be beat for $300. It had all the transparency and detail you could ask for, but the bottom end was lacking compared to a Sonic Euphoria and a Bent TVC. The Promitheus also suffered from ground issues. It has a common ground for all the inputs and outputs. I got hum if any of the inputs weren't connected to a component. Maybe Nick has fixed this with newer versions, but it was a significant problem for me. The Sonic Euphoria has an identical wiring scheme (common ground bus), but it has a wire that can be connected to an outlet to stem the problem. It still has a little hum, but not as bad as the Promitheus. The Bent, on the other hand, is dead silent when it comes to grounding issues. There are two things different about its design. The inputs don't share a common ground -- hot and ground are independently switched through the source selector. There's also a switch that lets you toggle between floating and grounding the output to the source. All in all, the Bent is very well designed and sounds superb. John Chapman is one of the most helpful and courteous fellows I've ever dealt with.

I haven't heard Nick's new C-core TVC, but I've read that it's a big improvement. I only wish he would redesign the chassis. It's one of the most unattractive cases I've ever seen. I affectionately called it the Duckling.

Mingles, Nick is now including a grounding lug on the rear of each chassis to allow the transformers to be grounded. It sounds like the same wiring scheme that you described for the Sonic Euphoria. Nonetheless, I have never encountered the hum problem that you mentioned with any of the three Promitheus TVCs I have owned. (I have owned the Reference Dual-Box rev. 3 EI-core TVC, the Reference C-core TVC, and the Signature Double C-core TVC.) They have all been dead silent in all three of my audio systems where I have experimented with them. This makes me wonder whether Nick has done something to improve on his wiring configuration beyond the addition of the ground lug.

The new Promitheus TVCs that are built around either a single or double C-core transformer improve significantly on bass frequency extension. These TVCs have a much fuller, weightier sound than that of the TVCs built around the rev. 3 EI-core transformer. In addition, the Signature (double C-core) TVC provides uncanny presence, palpability and image saturation. If you get a chance to audition the new top model (i.e., the Signature TVC), I think you will be very pleased.

I agree that the chassis for the Promitheus TVCs could certainly be more attractive. However, the looks have never bothered me much because of the way the dark color of the TVCs has tended to make them disappear in my equipment racks.

hi bob:

i can't comment on that , but i did audition one, during 2008. i think one of the considerations for me is internal wiring. i generally don't like silver. also, i prefer copper rcas, especially vampire wire.

i would conjecture that my bent would be softer sounding than any promitheus preamp, and therefore, more forgiving of questionable discs.