Promitheus TVC passive preamp anyone?

F-100 · « **Reply #1760 on:** 29 May 2007, 04:15 am »

Gents,
I have this older TVC version that I got it from another AC member several months ago. I believe this is one of the earliest version that Nick had produced with copper wire in the trannies, copper RCA jacks, and 16 steps attenuator volume control. As you can see from the picture below, it looks very beat up so I decided to do a makeover and add a few tweaks to see if I can bring the sound quality up a few notches. Mind you that I also have another reference TVC with all the latest upgrades but for some reason I prefer the sound of this one in my system because it MUST be something related to "system synergy".

Here is the makeover:

Original TVC with beat up case.

New aluminum case with standard aluminum faceplate for now. I'll probably use some exotic wood for the faceplate in the near future. I'm also using (3) Mpingo disc made by Shun Mook Audio under my TVC as a coupler between the 3" thick maple board. Not sure if these discs have any effect but since I got them as a gift from a friend, might as well use them.

Here is a side view with Ebony wood underneath the trannies, BHP on 3 sides of the trannies, ERS cloth between the trannies and .125 " thick copper sheet used as weight on top of the trannies. I'm using both silver & copper CMC RCA jacks for dual outputs. The reason behind this is to see which one sound better in my system. Since I'm using only one input source, I removed the selector switch completely from the circuit.

BHP on the top cover for damping.

Back view. (The copper sheet are holding on top of the trannies with 3M double side tape.)

So how does it sound after all the tweaks and upgrades?

After having the TVC playing for about 72 straight hours, the most obvious difference I noticed was a wider sound stage and overall bass is much tighter. The difference was very subtle but I'm still not quite happy with the sound overall. I'm going to let it break in for another week and will do another evaluation. I believe the weakest component in this older TVC version is the attenuator volume controls so that will be my next upgrade.

To be continued...

NewBuyer · « **Reply #1761 on:** 29 May 2007, 05:35 am »

Quote from: F-100 on 29 May 2007, 04:15 am

Gents,
I have this older TVC version... I believe this is one of the earliest version that Nick had produced with copper wire in the trannies, copper RCA jacks, and 16 steps attenuator volume control... I also have another reference TVC with all the latest upgrades but for some reason I prefer the sound of this one in my system because it MUST be something related to "system synergy". ...

Actually those 1st generation Promitheus TVC's are, in my opinion, still the best sounding of all the Promitheus TVC's to date. No idea what accounts for it, but to my ears, the 1st generation ones do seem to sound noticeably better than the 2nd and 3rd generation versions (which also sound very nice too). I thought I was the only one that thought so!

tanchiro58 · « **Reply #1762 on:** 29 May 2007, 05:49 am »

Quote

I thought I was the only one that thought so! Smile

F100,

Absolutely an excellent art work. You deserve to be more than happy when listening to it and it looks cool to me too. I am looking forward to listen to your "makeover TVC" one day.

Newbuyer,

You are not the only one. I think there is one more and me who bought the first generation TVC from a same seller. After buying and listening to both first and third generations I kept the first one only. Somehow I like the first sound more than the next generation.

Tan

rollo · « **Reply #1763 on:** 29 May 2007, 02:42 pm »

F-100,
Great job man. You do nice work. Give it some time it will come around.

rollo

Oscillate · « **Reply #1764 on:** 30 May 2007, 07:54 am »

"...the 1st generation ones do seem to sound noticeably better than the 2nd and 3rd generation versions (which also sound very nice too..."

"...Actually those 1st generation Promitheus TVC's are, in my opinion, still the best sounding of all the Promitheus TVC's to date..."

Just sweeter sounding because of the longer burn-in

rollo · « **Reply #1765 on:** 30 May 2007, 03:02 pm »

Quote from: Oscillate on 30 May 2007, 07:54 am

"...the 1st generation ones do seem to sound noticeably better than the 2nd and 3rd generation versions (which also sound very nice too..."

"...Actually those 1st generation Promitheus TVC's are, in my opinion, still the best sounding of all the Promitheus TVC's to date..."

Just sweeter sounding because of the longer burn-in

Could not agree more. These trannies as all others take a long time to reach full potential. A necessary evil unfortunately. Not to start a debate here but unless both units compared did not have 500Hrs plus on them or at least equal time to break in the point could be moot.
If someone has both with equal time on them then a valid apples to apples opinion could be offered. I would be interested to hear from an owner who has conducted a comparison as described .
To date the TVC has never sounded better. "Time, time, time, is on my side, yes it is "

rollo

Gaara · « **Reply #1766 on:** 30 May 2007, 05:42 pm »

Tan,

I was the other person who bought a older style Dual Mono of Agon. I personally liked the Ref 3 I got over the older style, but only very slightly.

The highs seemed a bit more detailed and for some reason there was less background noise. Looks wise I love that the older one matches my older style Polk LSi7s wood panels perfectly (doesn't look it in the pic but it does), but I prefer the coloring of the newer units...very unique.

Jared

tanchiro58 · « **Reply #1767 on:** 30 May 2007, 06:35 pm »

Jared,

I let my friend listened to the first version TVC and he likes very much and now he has transferred the trannies to the new body (you can see on this first page). He stated the "Makeover TVC" has more tighter bass but the old sound has never changed. In my system it needs an active tube preamp since it was not enough juice and punchier bass from the first generation TVC. But it sounds much better over the Ref 3 in his system. Therefore, I might order the Apollo tube preamp later to try out in my system.

Tan

NewBuyer · « **Reply #1768 on:** 30 May 2007, 10:43 pm »

Hi rollo,

Yes the different versions definitely had plenty of break-in time (>500 hours easily). The differences are not due to burn-in!

I've also tried ver.1 and ver.3 in several systems over time too, and the same audible results were noted, not just by me. Listening preferences are so subjective though, so like anyone else around here, it's just an opinion. All the TVC's sound very nice.

rollo · « **Reply #1769 on:** 31 May 2007, 12:04 am »

Quote from: NewBuyer on 30 May 2007, 10:43 pm

Hi rollo,

Yes the different versions definitely had plenty of break-in time (>500 hours easily). The differences are not due to burn-in! I've also tried ver.1 and ver.3 in several systems over time too, and the same audible results were noted, not just by me. Listening preferences are so subjective though, so like anyone else around here, it's just an opinion. All the TVC's sound very nice.

Very interesting indeed. Trust your opinion, I do not doubt your findings just surprised I guess. Maybe we can define what is making the difference between units: trannie? wire, RCAs, Etc. If we could define the differences it would be helpfull to all. See what you can up with as a description of the mechanical and sonic differences. Then maybe we can narrow down the reason why they sound different.
With eyes open
rollo

tanchiro58 · « **Reply #1770 on:** 31 May 2007, 12:22 am »

rollo,

I believe I can narrow down to the sonic difference between version 1 and version 2 or 3 is the trannies and volume pots (I mean step attenuators) and between the two are the solid silver or pure copper wires. What is your opinion?

Tan

F-100 · « **Reply #1771 on:** 31 May 2007, 05:14 am »

Quote from: rollo on 29 May 2007, 02:42 pm

Give it some time it will come around.

You're right, Rollo. The TVC sound better everyday.

Quote from: Tanchiro58

Absolutely an excellent art work. You deserve to be more than happy when listening to it and it looks cool to me too. I am looking forward to listen to your "makeover TVC" one day.

Thanks Tan. When my other Reference TVC come back from the trip back East, I'll let you check out this "makeover TVC" for a few days so you can give me your feedback. I'm afraid that after you had listened to it, you never want to give it back to me.

patrickperry · « **Reply #1772 on:** 31 May 2007, 05:32 am »

[/quote]
Thanks Tan. When my other Reference TVC come back from the trip back East,

[/quote]

F-100,

I hope you're referring to the Near East (as in the East Coast) and not the FAR East

F-100 · « **Reply #1773 on:** 31 May 2007, 05:55 am »

Quote from: patrickperry on 31 May 2007, 05:32 am

F-100,
I hope you're referring to the Near East (as in the East Coast) and not the FAR East

It's heading your way.

rollo · « **Reply #1774 on:** 31 May 2007, 03:09 pm »

Tan,
Not really sure. I believe the wire for the trannies has always been copper. However I notice that the Rev 3 trannies have a direct connection [ wires extended ] rather than a a soldered wire from trannie. The internal hook up wire has always been silver as I know. I believe I am the only one with Neotech 7N copper. Do not know about original RCAs, if they are nickel or copper based with Gold plating. The Attenuator, maybe.
If we can determine the key link here, then maybe we have found something that can further improve the TVC. Maybe its just a synergy thing or maybe not.
We have enough detectives here to solve this mystery

rollo

guest1632 · « **Reply #1775 on:** 31 May 2007, 03:20 pm »

Quote from: rollo on 31 May 2007, 03:09 pm

Tan,
Not really sure. I believe the wire for the trannies has always been copper. However I notice that the Rev 3 trannies have a direct connection [ wires extended ] rather than a a soldered wire from trannie. The internal hook up wire has always been silver as I know. I believe I am the only one with Neotech 7N copper. Do not know about original RCAs, if they are nickel or copper based with Gold plating. The Attenuator, maybe.
If we can determine the key link here, then maybe we have found something that can further improve the TVC. Maybe its just a synergy thing or maybe not.
We have enough detectives here to solve this mystery

rollo

Hi Rollo,

The original TVC had the standard RCA jacks. It wasn't til the ref series that he introduced the silver RCA Jacks. The earlier one I have is silver wiring with standard RCA's. the Transformers in this unit are Ref 2.

By the way, what happened to the anticable?

Ray

PromitheusAudio · « **Reply #1776 on:** 31 May 2007, 05:23 pm »

Ah finally another soul confirms what i always believe

WIth the older tvc we made it for -34 db and for 17 steps.
I notice with tvcs they sound much better lower db(-34db) than higher db (-48db) and less steps (17 steps instead of 24) too. The lower steps helps to lower leakage inductance.

However the truth be told, with -34db there is so much you can adjust the volume with and most people find it hard to use. We kept getting request 1 step to loud. In the end we when with 24 steps version because its more user friendly.

However i myself will not go back to the -34 db for one simple reason, there is not enought clicks for me to use. And for some people 24 steps is already not enough so even how good the -34db was it was just not user friendly. Most people had problems with it. Too much gain.

Also with old or new TVC. My observation with my DAC, TVC always sound better with high input voltage.
My dac has a capability of various output voltages(gain) 1volts output, 2 volts output and 4 volts output.
The 4 volts output will sound much better than the 2 volts output eventhough both are at the same volume.
1 volt output was made so that people who had too much gain can use the tvc to the max. Normally playing into an intergrated, or sensitive power amp
2 volt output is normally standard power amps
4 volts output is when you play with passive alone with low sensitiviy amps

tanchiro58 · « **Reply #1777 on:** 1 Jun 2007, 04:21 pm »

Quote

2 volt output is normally standard power amps

Nick,

I have an active tube preamp about 2 volts output and a SET 2A3 parallel amp. So if I already ordered a SS DAC from you with 2 volts output. Would it be matched with my gears and with an Apollo preamp or Ref TVC later? :scratch:Thanks.

Tan

PromitheusAudio · « **Reply #1778 on:** 1 Jun 2007, 04:49 pm »

Tan
Just to be more specfic on the gain of the DAC
THe DAC can be adjusted via a jumper on the output voltage. It is not fixed and its user selectable in 3 different gains
1) 1volt output
2) 2 volts output
3) 4 volts output
So with your current active tube preamp just use either 1 volts output or 2 volts output by selecting the jumper on the PCB. I think 1 volts would be better here

With the REf TVC alone its 4 volts output. So select that on the PCB.

So again the DAC allows different gain by just selecting the gain on the PCB. and the DAC has 3 different gain setttings 1,2 and 4 volts
Hope this clears the confusion.
Does it?

tanchiro58 · « **Reply #1779 on:** 1 Jun 2007, 06:54 pm »

Quote

So again the DAC allows different gain by just selecting the gain on the PCB. and the DAC has 3 different gain setttings 1,2 and 4 volts

Nick,

Would it be better and convenient that you can add a switch to the DAC to change gain whenever I can swap or change a tube preamp or passive TVC in my system? So I do not need to open it up to resolder it again. Could you do that to my DAC? Thanks in advance.

Tan

Promitheus TVC passive preamp anyone?

guest1632