Promitheus TVC passive preamp anyone?

GHM · « **Reply #120 on:** 7 Oct 2006, 12:30 am »

NewBuyer..you have all the goodies!!! You must use one of these Dacs. Thanks for the suggestion.
I was thinking about that..since I already have the buffer. My current Dac uses the 1543 chip already. I'm not sure what chips the models you mention use. I use the buffer since my Dac doesn't have op amps and the output impedance is too high for the TVC without the buffer.

I did some checking, the dialogue does use the same Dac chip 1543. Maybe I better leave well enough alone there. It does sound great! I guess I was just intrigued by the tube.

A suggestion NewBuyer if you're not using a high end transport. Try a Monarchy DIP upsampler in between the Dac and the Source. The difference it makes will astound you! The NOS Dacs with no filtering seem very sensitive to jitter from my listening impressions. The Monarchy snaps the images into focus..I mean rock solid focus.

Mike B. · « **Reply #121 on:** 7 Oct 2006, 12:59 am »

I ordered a preamp today. I asked for a balanced unit with a phase switch and single ended inputs and outputs. I am looking forward to joining the group and enjoying this pre.

Bwanagreg · « **Reply #122 on:** 7 Oct 2006, 01:20 am »

Here is link to Nick's 6C33 page. Not much to look at yet.

http://www.promitheusaudio.com/6c33.htm

I heard an ASL version of this design a few year ago and the sound has stuck with me. It's a single ended amp with cahones. Photos of this tube don't do it justice - its a big honker. Look at a picture of the three teated beasty...
http://www.thetubestore.com/russian6c33b.html
and hold up your fist - it is about that size. It's a Russian military tube designed to survive the Apocalypse, and it looks like it. If Nick can pull off his magic sound with this tube, he may really have something. I'll email his friend this weekend to get the scoop.

GHM · « **Reply #123 on:** 7 Oct 2006, 01:31 am »

Quote from: Bwanagreg on 7 Oct 2006, 01:20 am

Here is link to Nick's 6C33 page. Not much to look at yet.

http://www.promitheusaudio.com/6c33.htm

I heard an ASL version of this design a few year ago and the sound has stuck with me. It's a single ended amp with cahones. Photos of this tube don't do it justice - its a big honker. Look at a picture of the three teated beasty...
http://www.thetubestore.com/russian6c33b.html
and hold up your fist - it is about that size. It's a Russian military tube designed to survive the Apocalypse, and it looks like it. If Nick can pull off his magic sound with this tube, he may really have something. I'll email his friend this weekend to get the scoop.

Greg that is a MONSTER! I bet those 18 wpc monsters would drive my speakers in the ground!!

youv'e wet my whistle now Greg..I gotta find out more about these beasties!

Welcome aboard the good ship Promitheus Mike! It will be great to read what you think of the little cigar box!

I never thought about a phase switch. I'm curious to what you're planning to use it for ? Thanks

NewBuyer · « **Reply #124 on:** 7 Oct 2006, 01:38 am »

Quote from: GHM on 7 Oct 2006, 12:30 am

...I was thinking about that..since I already have the buffer. My current Dac uses the 1543 chip already. I'm not sure what chips the models you mention use. I use the buffer since my Dac doesn't have op amps and the output impedance is too high for the TVC without the buffer... A suggestion NewBuyer if you're not using a high end transport. Try a Monarchy DIP upsampler in between the Dac and the Source. The difference it makes will astound you! The NOS Dacs with no filtering seem very sensitive to jitter from my listening impressions. The Monarchy snaps the images into focus..I mean rock solid focus.

Ah, I see you already have a very nice NOS DAC that uses the 1543 chip, passive I/V and no op-amps. Nice DAC!

The USB Plus Constantine DAC (and the standard Constantine) uses the NOS tda1545a chip with CS8414 digital receiver and active I/V. Sound is slightly different from the tda1543 chip (I think a bit more resolution, dynamics are perhaps a little nicer, very clean tones). Another perfect match with the Burson Buffer (best buffer match IMO), and you can further use the USB connectivity with a PC as an ideal transport.

I have tried the Monarchy unit and the GW Labs DSP. Both are great, I personally much prefer the GW Labs DSP due to transformer isolation at both input and output, the clock choices of 44.1kHz or 96kHz, balanced inputs, higher internal/external build quality, and overall better sound enhancement. As you say, both make a very nice improvement with these NOS DAC units.

I think you would find using a PC as transport would make a further improvement. If you haven't already, I hope you have a chance to try it sometime. By the way, what sampling rate do you use with your DAC? I think upsampling might make little difference to a DAC with no brick-wall filter anyway, I'm still experimenting with 44.1kHz and 96kHz sampling rates in listening sessions. However the better clock and signal conditioning makes a very noticeable difference.

Mike B., nice idea to ask for the phase switch. Do you find it makes a noticeable difference when you change phase on most recordings?

GHM · « **Reply #125 on:** 7 Oct 2006, 01:47 am »

Newbuyer..I use 24/48 upsampling. I tried the 16/44.1 with the Mark2 DIP. The difference was quite apparent. I got a wider and more open stage with the upsampler 24/48. The cymbals also weren't as hard sounding as the Mark2 DIP. I still don't know why the upsampling was so much different than the standard 16/44.1? I could live with either one as they both made nice improvements. I've been thinking hard about using my computer as a transport. This is in the works..still trying to figure out which way to go..the options are mind boggling too me.

NewBuyer · « **Reply #126 on:** 7 Oct 2006, 01:56 am »

Quote from: GHM on 7 Oct 2006, 01:47 am

Newbuyer..I use 24/48 upsampling. I tried the 16/44.1 with the Mark2 DIP. The difference was quite apparent. I got a wider and more open stage with the upsampler 24/48. The cymbals also weren't as hard sounding as the Mark2 DIP. I still don't know why the upsampling was so much different than the standard 16/44.1? I could live with either one as they both made nice improvements. I've been thinking hard about using my computer as a transport. This is in the works..still trying to figure out which way to go..the options are mind boggling too me.

I really think you would appreciate the difference with the GW Labs DSP. Same is true with using a computer as transport. I'm not entirely sure yet why the computer makes a better transport, but the difference is definitely audible. For some reason, playing Exact Audio Copy images of CD's (using an ASIO driver for bit-perfect output) makes a great improvement over the digital-output from even a nice separate transport. While I can defintely hear this difference, I really have not yet uncovered the reason for why it would do this.

Have you tried sending a 96kHz sampled signal to your DAC? IIRC, your Monarchy unit can do this after changing a jumper setting on the board, yes? Actually I'm not sure if your unit will do it, I think Monarchy enabled 96kHz capability in their later units, but perhaps not in their older versions?

GHM · « **Reply #127 on:** 7 Oct 2006, 02:03 am »

Yes you're correct my Monarchy is a 48/96 version...I wasn't sure if it would take the signal. The Dac is spec only to 48 kHz. Well from your comments, using a computer as the transport should be my next move. We're using nearly the same gear! We must also hear similar as well.
You and Greg have me stoked..him with the monoblocks and you with the computer as a transport.

lonewolfny42 · « **Reply #128 on:** 7 Oct 2006, 02:12 am »

Gymane....Might be time for you to check out the Slim Devices Squeezebox Network Music Player....

Chris

GHM · « **Reply #129 on:** 7 Oct 2006, 02:16 am »

Quote from: lonewolfny42 on 7 Oct 2006, 02:12 am

Gymane....Might be time for you to check out the Slim Devices Squeezebox Network Music Player....

Chris

Thanks Chris..that was one option I've seriously considered. Since some of you have had some issues with it. I wasn't quite sure if I should jump on it now or wait for the bugs to be worked out.

NewBuyer · « **Reply #130 on:** 7 Oct 2006, 02:24 am »

Quote from: GHM on 7 Oct 2006, 02:03 am

Yes you're correct my Monarchy is a 48/96 version...I wasn't sure if it would take the signal. The Dac is spec only to 48 kHz...

What digital receiver is in your DAC? The Mhdt Labs DACs use CS8414. It can take a max of 96kHz in S/PDIF, before then sending it to the DAC chip (tda1543 or tda1545a). If your DAC works like the Mhdt Labs units, it will accept this rate, and I would be very interested to read your feedback if you choose to try it out.

P.S. Sounds like we are both thinking the same thing about the SB, I've been wondering if I should wait before trying it as well...

GHM · « **Reply #131 on:** 7 Oct 2006, 02:26 am »

I just checked it out. It is a CS8412. I suppose I can't use the 96 khz..correct?

NewBuyer · « **Reply #132 on:** 7 Oct 2006, 05:31 am »

Quote from: GHM on 7 Oct 2006, 02:26 am

I just checked it out. It is a CS8412. I suppose I can't use the 96 khz..correct?

I believe that is correct.

Edit: Yes I just double-checked the spec sheets, one of the things changed from CS8412 to CS8414 was the ability to receive up to 96kHz (actually the spec sheet says over 100kHz).

I was curious if you would hear a sound difference with 96kHz (if your DAC could accept that rate), but I'm guessing that such differences (if any) would be subtle. As I understand it, upsampling is normally done to tame the brick-wall filter effect anyway - so since our DAC's don't use these filters, the benefit we receive from upsamplers is the cleaner separated power supply, high-quality clock, signal boosting/conditioning/isolation, and bit-extension.

Do you send the signal to your DAC with coax, or Toslink?

By the way, as you know: Using an NOS DAC with a DIP/DSP and the Burson Buffer, along with the impedance-reflecting properties of the transformers in the TVC, results in one of those rare synergies that enable a truly fantastic sounding result. We are very fortunate to have found this combination.

I hope others here are trying it out too!

GHM · « **Reply #133 on:** 7 Oct 2006, 08:36 am »

I use the coax digital output to the Dac. Yup..there's something special going on. I wasn't sure how to put it in technical terms. You've done this for me quite well! I stumbled upon it nearly by accident myself.

Nice to know others are experiencing similar results.

Good listening

JLM · « **Reply #134 on:** 7 Oct 2006, 11:03 am »

I had a RWA fully modded SB3 that I was using straight into my monoblocks. Good sound, great convenience, but PC related glitches (wireless network shared with family, viruses, occasional power outage, and my lack of computer skills) drove me to sell it. The 1 volt output was a limitation and I'm sure a TVC would have helped, but the sound was very good. It even seemed to improve when I wired it direct to the PC holding the music.

Glad to be independent of the PC with a very nice sounding Ah! Njoe Tjoeb 4000. It provides upsampling and tubes, but the volume control lacks sufficient range and chops dynamics. Has some other nice features. So I'm limping along with the pre-amp section of an old Rotel receiver (thankfully the best part of the unit) until finances allow for the Promitheus TVC. I've not tried it without the upsampling board, but as others have said it hypes the level of detail, which is at least somewhat synergistic with the FTA-2000's.

Nick mentioned a 2-input version, but can't imagine what cost saving or sound quality advantages that would make. I don't see a need for more than 2, but I've shot myself in the foot before, so why not stay with 4?

GHM · « **Reply #135 on:** 7 Oct 2006, 10:50 pm »

I understand what you mean JLM. I would just go ahead with the 4 myself.

Well I've been spending some time swapping these units back and forth doing some comparisons. The NOH is substantially heavier roughly double the weight of the cigar box Promitheus. It's also very well made with a solid feel.

From the first listen to the Bent ..it was love !! What a beautiful sounding unit. My listening impressions mimic those of the many that have listened to this unit. Absolutely fantastic back to front imaging ,micro and macro dynamics. Leaving the trails of the instruments intacted. No harshness or grain to speak of. The music has all the tempo and flow I feel it should.

I'm not one that needs 6 months to hear differences in components if they exist. I normally know within the first 30 minutes if somethings going to work for me.

The big question ..how does the Promitheus compare to the venerably well known Bent. Your not going to like this Promitheus fans! The Bent pretty much crushes the Promitheus on all fronts

. Depth, bass definition , musicality and transparency...Ah not quite

.

Actually trying to hear a negligible difference between the two hasn't proved easy. The Noh volume and ratio are slightly different. Finding the proper level for both proved to be the biggest obstacle. For one the NOH is more sensitive..even with the volume control all the way off. I could still hear music.

The Promitheus not a peep when turned down. This has been one of the toughest comparisons I've tried to make. Normally the differences are glaring and easy to pick out. I was actually expecting to hear quite a difference. Not so between these two. Every time I thought I heard more inner detail with the Bent. I would go back to the Promitheus..nope it was all there.

The Promitheus can't compete with the Bent on its solid feel , extra features or remote control..which by the way, I haven't used or plugged up the power supply for.

Across the board, so far I could live with either unit..not feeling like I'm missing anything. Accept for the remote!

Though I haven't heard them all...Without a doubt for my taste, these are the two best preamps I've heard bar none...

Big thanks to Chris for giving me a chance to try the Bent out. I'm going to continue to listen too it as it sounds fantastic!!

Here's a couple of picks so everyone knows this is legit.

lonewolfny42 · « **Reply #136 on:** 8 Oct 2006, 01:05 am »

Quote

Here's a couple of picks so everyone knows this is legit.

Ofcourse it's legit....I shipped it.

Glad it arrived ok Gymane. Its a good preamp. It last belonged to zybar/George. He sold it upon his TACT purchase.....and I grabbed it.

As for your comments...remember the Bent goes for alot more than the Promitheus....so if their close, then I'd say the Promitheus would be a very good buy for the money.

Have fun.......

Chris

ryno · « **Reply #137 on:** 8 Oct 2006, 01:09 am »

GMH
Happy to hear that the promitheus is holding it's own vs other TVC's.

I can see why there would be no difference between a 4 input and a 2.
I wonder what if there would be a difference between a single input with no switching, and one with switched inputs.
Nicholas saw my ramblings last week about this and emailed me today to see if that's what I wanted.
Since my DAC has 2 inputs, I went for it.
I'm looking forward to the comparison with my purist, which I've been very happy with.
Ryan

GHM · « **Reply #138 on:** 8 Oct 2006, 01:18 am »

Chris..you're so right my friend!

If I said the Promitheus was good for the money ..I would be lying!!

It's more like ...good for more money!!

Now if I can keep from going broke. Wanting to try out different amplifiers with the TVC, I'll be home free. Yup ..I love the little Malaysian Box.

You snagged a great preamp Chris!!

Quote from: ryno on 8 Oct 2006, 01:09 am

GMH
Happy to hear that the promitheus is holding it's own vs other TVC's.

I can see why there would be no difference between a 4 input and a 2.
I wonder what if there would be a difference between a single input with no switching, and one with switched inputs.
Nicholas saw my ramblings last week about this and emailed me today to see if that's what I wanted.
Since my DAC has 2 inputs, I went for it.
I'm looking forward to the comparison with my purist, which I've been very happy with.
Ryan

Hi Ryan.. I would think in the end it would all be the same. Basically what makes you happy. Yeah..I'm looking forward to your comparison as well. So far nothing but praise for the IRD. It must be very nice in deed!!

Randy · « **Reply #139 on:** 8 Oct 2006, 04:02 pm »

The Bent TVC preamp, a new model that came out recently, now costs around $3000. I considered it a few months ago when it cost just $2300, but now it's far too costly for me, but I'm happy with the Promitheus anyway.