I have the Bent Audio TVC (which would offer similar performance to the Promitheus) and I also have the Red Wine Audio 30.2 integrated version.
I have run the TVC with the Red Wine amp (with the built-in Gold Point attenuator in and out of the circuit) - in both cases I preferred the 30.2 alone with it's own attenuator. It is very well matched and perfectly voiced to run with the Gold Point (gives you a remote volume control as well). It is voiced on the warm and full side but does not sacrifice any of the detail.
If you only have the need for a single input, I would suggest passing up the Promitheus and just save-up for the Red Wine 30.2 integrated. I'm sure it would sound great with the Quads.
Thanks for your response. How does the Bent Audio TVC compare to the Promitheus? I have heard good things about Pomitheus. That was the reason I thought I could replace the NAD's built in pre-amp section with it and then eventually use it with RWA's power amp. I also hear from online forums that RWA power amp is better than the integrated. This was another reason I decided with the Promitheus. I appreciate your response and will look forward to some more before I decide.
I've never heard the Prom but I'm sure that the Bent is comparable if not even better (as far as features go). The Red Wine integrated and the power amp are virtually the same except for the Goldpoint attenuator (also input Z - 20K for the integrated versus 100k for the power amp).
The sound of the power amp version will be greatly influenced by the sonic signature of the preamp preceding it. The TVC's are very transparent and neutral, however the Sig 30.2 integrated is just nicely flavoured as it is.
In my case, the only reason I would consider going with the power amp version is to precede it with Vinnie's Isabella preamp.
Once again I say just go with the integrated version.
Buy used RWA integrated.
If you need more gain - TVC or CIA passive will do.
The source(s) is/are more critical to a TVC, or any passive, than the amp.
I get your point. But I will have to wait for at least a year to get the RWA, since budgets are routed elsewhere currently.
Yes, I m looking at the used market too. Can you please throw some light on the "more gain" part. When it comes to "tech" terminology in the audio world...I m a noob. My concern is I will be going down from 80W/ch to 30W/ch. So will the sound (music) detiorate if I use the RWA 30.2 with the Quad 21L I own? I am really very happy with my Quads and have no intentions to change the speakers. If the RWAs cannot handle the Quads, then I will look at some other amp/preamp combination.
My source is the Marantz SA8260 that I am pretty happy with and do not intend to change it in the near future (unless it gives up). Occasionally I will also use an Oppo 970 player.
Thank you guys for your responses.
I have a 1st gen Bent TVC with S&B transformers. It's an excellent performer with stellar imaging and transparency. I had a Promitheus about a year ago. Everything about the Bent is better. The Promitheus had a buzz I could never get rid of. The Bent has a better ground design. There's a switch for each channel allowing you to float or ground the output jacks. The Bent also switches positive and negative inputs when the source is changed. This prevents crosstalk and eliminates any ground issues. The Promitheus and Sonic Euphoria have a common ground for inputs which can lead to problems.
Bent just released a new passive using autoformers. I heard it about a month ago and was impressed. In my opinion, autoformers have more bloom than TVCs. TVC's often sound thin in the midbass region. If you do the comparison, you'll know what I mean.
In my experience, the Sonic Euphoria was better sounding than the Promitheus. It had significantly better bass. It also uses autoformers.
FWIW, I think the money you put into a passive would be better spent on your goal of getting an RWA integrated.
The Bent also costs much more than the Promitheus. I heard about the buzz in AudioCircles forum, but there were ways to rectify it - and simple ones at that. Right now I cannot spend more than certain $$s on the preamp.
But you got me thinking by making the same point what Dave has mentioned above :-)
Anyone with Promitheus+RWA Sig 30.2 combination or NAD+Promitheus combination? Your inputs will be highly appreciated.
Go with integrated first.
If you need more gain (volume) buy "Goldenjack" attenuators ($50 direct). If you need more inputs get TVC.....it is great for the money(read on).
I see that you posted this question all over the place.....that is all good but the wise thing to do would be to start small. Meaning - RWA integrated. If needed.......
Add attenuators later. That should easely drive your speakers.
If you are thinking about passive TVC, I would dump the idea of the RWA integrated and go with RWA amp. There is a difference in sensetivity between the two. RWA Sig.30.2 amp is 100K which is more suitable to work with seperate preamp.
Just my 2c.
Thank you for your reply. Honestly, I do not know if I require attenuators or not. I don't even know what that would do. I will surely look up some sites and try to understand that. Yes, I was looking more at the power-amp rather than the integrated, and hence the TVC. Also, the TVS would give me more inputs compared to just 1 on the RWA amps.
The reason for posting all over the place is to get the most from other's experience. I feel that the forums are a best place to get these. And you also get to know about stuff that you were not aware of.
I really appreciate your advise - especially getting my attention to the sensitivity of the RWA power amp.
Reviving my old thread. Need to get a second opinion. My integrated amp's power amp section specs are as follows:
770 mV / 20k ohms / 470 pF
I am not techie and got this from NAD directly. Are these specs suitable for a Promitheus TVC?
You would typically like to see a higher input impedance. The number given to you by NAD, 20k ohms, is a bit on the low side. Since the Promitheus uses transformers this will be less of an issue versus resistors, but still to be considered. The input sensitivity is fine at 770mV. I assume you have a high output voltage source (>2V).
If I recall the RWA (power amp version) has a much higher input impedance. Around 100k ohms which would be fine for most passive preamps.
Thanks Clio09. I would go step-by-step. So right now I am looking at my existing NAD C352 to run as preamp for the TVC. At some point in future I will add the RWA power amp.
Not sure you're going to get the best out of the Promitheus with the NAD. One option to consider is the Lightspeed attenuator. This is a passive preamp using photo-optic technology. No transformers and no resistors. I just bought one and it is everything it is advertised to be.
Go to DIY.com and do a search for Lightspeed. There is a very long thread on the preamp. Nelson Pass even participates and IIRC uses the technology. The preamp is available for about $350. Single input and single output only. This will work with your NAD as it is pretty immune to impedance matching. Also, the new Pass B1 buffer is another option at $895. Again will work with the NAD.
Just now ordered the Promitheus Reference C-Core dual box with Elma switches. Have never heard one, but ordered it based on positive feedback/reviews from fellow audiogoners/asylum inmates/audiocircle pals. The estimated wait period in 3 weeks.
This is going to be my first "separates" component. Will eventually move to a separate power amp when budgets permit. So the "upgrade bug" finally got me!!
Let us know how it sounds after you've let it settle in a bit.
The TVC was supposed to be delivered today. But man...I missed the DHL delivery guy today. Will have to wait till Monday for their second attempt. DHL does not have the option wherein, I can take the delivery attempt ticket and collect the package myself. Oh this is killing me!!!!!!!!!
The source in the case of Promitheus TVC does not seem critical. I get my moderate listening volume even if I use an iPod and the volume knobs set at position 10 of the available 24 positions. I believe it is the power amps's input sensitivity that matters in this case.
I did not need any gain and the TVC worked fine as a preamp for my NAD's power amp section.
You were right. The input sensitivity of the NAD was fine for the TVC.
I am extremely happy that I decided to go with the Promitheus TVC. It has matched very well in my system. The initial hours were not enlightning. But after 40 hours I was surprised with the performance of my NAD!! Yeah, I know that the TVCs do their magic, but I did not think that the NAD was capable of handling that magic. Of course the full potential of the TVC cannot be handled by the NAD. I require a separate power amp for that.
I plan to start a thead later in May after I have done some critical listining with the Promitheus. This will not be a review - but a pointer to all integrated amp owners who have the capability to use a external preamp/TVC. I was so fraustrated searching the web for such a combination. The closest I came to was at a mention of how a person used his TVC set to MAX and then control the integrated amp to control the volume. That was certainly a waste of TVC - I thought.
Anyways, I keep getting surprised by the TVC - the more I listen to it and find certain nuances in my system that I never heard before. More later.
I also bought a pair of Ref C-Core TVC unheard a few months ago and i'm using it in a system that is not ideal for passive pre setup due to lowish input impedance of my Bel Canto Ref 1000 monoblocks and inefficient Dyanudio Confidence C1 speakers. But it works and works well to my ears especially with >100 hours use. Natural sounding with good resolution.
It would be interesting to hear of your impresison later.
I have added a review of the Promitheus Reference C-Core in the reviews section.