[Cincy_bob]

Jared, thanks so much for your input.

In response to your question, I am not actually replacing any of my existing audio components.  Instead, what I am really doing is living out the fantasy of assembling a second system.

My situation is somewhat complicated in that I am in the process of completing construction on a new devoted listening room that will allow my wife's living room to return to its intended use instead of being overwhelmed by all my hi-fi equipment.  However, our living room is centrally located in our house and, with my primary system in that room over the course of the past ten years or so, we have grown accustomed to using that audio system to fill the entire house with music.  The new listening room, on the other hand, is located at the far end of the house and will largely confine the sound within that room.

As a result, we would like to have some sort of small scale audio system in our living room once my "reference" system vacates that room.  So.......I have turned what was originally envisioned to be a simple high end mid-fi system into an opportunity to build out the SET amplification and high efficiency speaker system that I never had...

Sorry for the long story, but that's the rest of the story...

[guest1632]

Guys, I'm new to this forum, and I am thinking about joining your Promitheus club.  (I know, I'm late to the party...)  I have been an audio freak for many years, but I am a newbee when it comes to passive preamplification.  I had always steered away from it because my audio systems have always involved a long (15 to 20 foot) pair of interconnects between the preamp and amp(s).  I had understood that there are issues with capacitance that tend to roll off high frequencies and potentially cause other problems when a passive pre is used with anything other than a short interconnect run.  I am not very knowledgeable when it comes to the technical aspects of electronics, so I could use some help here.

Can anyone help me to understand whether a Promitheus Audio TVC would be a good match to a second system I am assembling?  I am building the system around a pair of Morrow Audio 300B SET monoblocks (10wpc, 100K input impedance, 0.25V input sensitivity) and 98dB efficient single point source crossoverless speakers.  The source will initially be a CDP and will eventually grow to include an analog rig as well.  The room calls for the sources to be connected to the TVC using short (1-meter) runs and the TVC to be connected to the monoblocks using a long (6 to 7 meter) pair of interconnects.  While it is possible I could reposition the TVC closer to the monoblocks, that would require a bunch of long runs from the source components to the TVC - which would be an ugly mess of wire that would likely score low on WAF.  (I am putting this second system into a living room with the promise that it will be a small scale system that will not impose itself on the room...)

Any input you can offer would be much appreciated!

Hi Cincy_Bob,

I do have a suggestion, and that is to put some Black Hole Padding on each transformer of your TVC. Other than a possible capacitance issue, I don't see any others.

The receipe is simple. It requires 2 strips of 9.5 x 1.5. Another two strips, 6.25 x 2 are required for the top and bottom plates.

On each of the 9.5 x 1.5 strips, you cut two 2.25 and 2.5 strips. All of the strips like the 2.25 cover the vertical length of each trafo. The 2.5 inch strips cover the top and bottom. Before the bottom is tackled, just close your TVC, and listen for awhile.

Continued next message.

Ray

[guest1632]

Guys, I'm new to this forum, and I am thinking about joining your Promitheus club.  (I know, I'm late to the party...)  I have been an audio freak for many years, but I am a newbee when it comes to passive preamplification.  I had always steered away from it because my audio systems have always involved a long (15 to 20 foot) pair of interconnects between the preamp and amp(s).  I had understood that there are issues with capacitance that tend to roll off high frequencies and potentially cause other problems when a passive pre is used with anything other than a short interconnect run.  I am not very knowledgeable when it comes to the technical aspects of electronics, so I could use some help here.

Can anyone help me to understand whether a Promitheus Audio TVC would be a good match to a second system I am assembling?  I am building the system around a pair of Morrow Audio 300B SET monoblocks (10wpc, 100K input impedance, 0.25V input sensitivity) and 98dB efficient single point source crossoverless speakers.  The source will initially be a CDP and will eventually grow to include an analog rig as well.  The room calls for the sources to be connected to the TVC using short (1-meter) runs and the TVC to be connected to the monoblocks using a long (6 to 7 meter) pair of interconnects.  While it is possible I could reposition the TVC closer to the monoblocks, that would require a bunch of long runs from the source components to the TVC - which would be an ugly mess of wire that would likely score low on WAF.  (I am putting this second system into a living room with the promise that it will be a small scale system that will not impose itself on the room...)

Any input you can offer would be much appreciated!

Hi Cincy_Bob,

I do have a suggestion, and that is to put some Black Hole Padding on each transformer of your TVC. Other than a possible capacitance issue, I don't see any others.

The receipe is simple. It requires 2 strips of 9.5 x 1.5. Another two strips, 6.25 x 2 are required for the top and bottom plates.

On each of the 9.5 x 1.5 strips, you cut two 2.25 and 2.5 strips. All of the strips like the 2.25 cover the vertical length of each trafo. The 2.5 inch strips cover the top and bottom. Before the bottom is tackled, just close your TVC, and listen for awhile.

Continued next message.

Ray

Hi Again,

Now to tackle the undersides. This requires a nutdriver, a Philips and a Flathead screwdrivers.

Putting the nutdriver on the nut, and the Philips screwdriver underneath each screw and remove both screw and nut. I'd do this with one trafo at a time.

Turn the trafo over  on its back. Be carful that no wires get stuck underneath the trafo as you do so. Then see if you can pull up some of this padding. You might just have to use your flathead driver and sorta shove it in between the plate and padding. You kinda have to pry it up as you go, and eventually it will come off the trafo. Then take that 2.5 by 1.5 and cut the width so it is only one inch. Place it so it too runs along the lentgh of the core starting and ending where the plate and core start and ends.

Then you remount the trafo. I took the time to press down on the BHP til I could tell it was nice and snug. Then I also made sure that the mounting plates that mount the trafo to the TVC were straight. Turn the trafo back over, and mount it all back. Close it all up. and listen. You'll find more detail is there.

Ray   

[Cincy_bob]

Hi Cincy_Bob,

I do have a suggestion, and that is to put some Black Hole Padding on each transformer of your TVC. Other than a possible capacitance issue, I don't see any others.

The receipe is simple. It requires 2 strips of 9.5 x 1.5. Another two strips, 6.25 x 2 are required for the top and bottom plates.

On each of the 9.5 x 1.5 strips, you cut two 2.25 and 2.5 strips. All of the strips like the 2.25 cover the vertical length of each trafo. The 2.5 inch strips cover the top and bottom. Before the bottom is tackled, just close your TVC, and listen for awhile.

Now to tackle the undersides. This requires a nutdriver, a Philips and a Flathead screwdrivers.

Putting the nutdriver on the nut, and the Philips screwdriver underneath each screw and remove both screw and nut. I'd do this with one trafo at a time.

Turn the trafo over  on its back. Be carful that no wires get stuck underneath the trafo as you do so. Then see if you can pull up some of this padding. You might just have to use your flathead driver and sorta shove it in between the plate and padding. You kinda have to pry it up as you go, and eventually it will come off the trafo. Then take that 2.5 by 1.5 and cut the width so it is only one inch. Place it so it too runs along the lentgh of the core starting and ending where the plate and core start and ends.

Then you remount the trafo. I took the time to press down on the BHP til I could tell it was nice and snug. Then I also made sure that the mounting plates that mount the trafo to the TVC were straight. Turn the trafo back over, and mount it all back. Close it all up. and listen. You'll find more detail is there.

Ray  

Ray, thanks for the detailed instructions regarding the BHP vibration damping tweak.  I think I follow nearly everything you conveyed with a couple of exceptions:   

1. Once I cut up the 9.5-inch pieces of BHP, I will have four pieces of BHP for each transformer in the following dimensions:

2 - 2.25 x 1.5
2 - 2.50 x 1.5

In addition, I will have two pieces in the dimension 6.25 x 2.  Ray, if I understand you, the eight smaller pieces (four for each transformer) should be mounted directly to the sides, top and bottom of the transformers, while the 6.25 x 2 pieces are not intended to adhere to the transformers.  Instead, I think you are telling me that these larger pieces should be mounted directly to the inside surface of the top and bottom plates of the TVC chassis.  Do I have this right?  Assuming that I am on the right track, is there any place in particular where the 6.25 x 2 pieces should be mounted to the inside surface of the top and bottom plates?

2. For the procedure relating to the underside of each transformer, once the 2.5 x 1.5 piece of BHP is cut down to a dimension of 2.5 x 1, you mentioned that piece should be mounted "...so it too runs along the length of the core starting and ending where the plate and core start and ends."  Since I have not yet seen the inside of the TVC and I'm not very experienced in the construction of a transformer, I am not sure what this means.  Perhaps the answer will be obvious once I have a first hand peek inside the unit.  If the proper orientation of this piece of BHP on the bottom of the transformer will not be obvious, I would appreciate any further instruction you can give to a non-techie.

Thanks for your patience!

[Cincy_bob]

I hate to be a pest, but I do have a couple more questions for you guys who are experienced with the Promitheus TVC:

1. I have read some comments in this thread indicating that the stainless steel top and bottom plates are potentially detrimental to the sound of the component.  I saw mention on the Promitheus web site that Nicholas might now be offering the option of using brass for the bottom plate.  (I'm not sure whether that is an option for the top plate or not.)  I sent an e-mail to Nicholas yesterday to inquire about whether this is an option for his dual box TVC.  Does anyone have any input on whether this option is available and whether it would be a worthwhile upgrade to the TVC?

2. Nicholas offers ebony cones as vibration control / tuning devices for his TVCs.  What is your advice with respect to the cones?  I suspect that the dual box TVC would require two sets of cones, which would get a bit expensive.  Are there other vibration control / coupling / isolation techniques that you regard as a good alternative for the Promitheus TVC?  I am familiar with a lot of alternative approaches, but I am not sure to what extent the ebony cones act as a unique tuning device integral to the voicing of the component.

Thanks for your help!

[Dan155]

From my understanding of it normal passive pres add their own capacitance to the line, which can cause the attenuation of the highs and other issues.  Adding a normal passive pre would cause the over all capacitance to rise, this would be worsened with your long interconnects and the higher the capacitance the more the roll off.

Well the beauty of a TVC is that it actually drastically reduces capacitance, making your longer interconnect runs a non issue. 

Just a bit of techy nit-picking: a TVC will likely have more capacitance than a resistor based pre - it's the lower output impedance that makes the difference when driving cables.

[guest1632]

Hi Cincy_Bob,

I do have a suggestion, and that is to put some Black Hole Padding on each transformer of your TVC. Other than a possible capacitance issue, I don't see any others.

The receipe is simple. It requires 2 strips of 9.5 x 1.5. Another two strips, 6.25 x 2 are required for the top and bottom plates.

On each of the 9.5 x 1.5 strips, you cut two 2.25 and 2.5 strips. All of the strips like the 2.25 cover the vertical length of each trafo. The 2.5 inch strips cover the top and bottom. Before the bottom is tackled, just close your TVC, and listen for awhile.

Now to tackle the undersides. This requires a nutdriver, a Philips and a Flathead screwdrivers.

Putting the nutdriver on the nut, and the Philips screwdriver underneath each screw and remove both screw and nut. I'd do this with one trafo at a time.

Turn the trafo over  on its back. Be carful that no wires get stuck underneath the trafo as you do so. Then see if you can pull up some of this padding. You might just have to use your flathead driver and sorta shove it in between the plate and padding. You kinda have to pry it up as you go, and eventually it will come off the trafo. Then take that 2.5 by 1.5 and cut the width so it is only one inch. Place it so it too runs along the lentgh of the core starting and ending where the plate and core start and ends.

Then you remount the trafo. I took the time to press down on the BHP til I could tell it was nice and snug. Then I also made sure that the mounting plates that mount the trafo to the TVC were straight. Turn the trafo back over, and mount it all back. Close it all up. and listen. You'll find more detail is there.

Ray  

Ray, thanks for the detailed instructions regarding the BHP vibration damping tweak.  I think I follow nearly everything you conveyed with a couple of exceptions:   

1. Once I cut up the 9.5-inch pieces of BHP, I will have four pieces of BHP for each transformer in the following dimensions:

2 - 2.25 x 1.5
2 - 2.50 x 1.5

In addition, I will have two pieces in the dimension 6.25 x 2.  Ray, if I understand you, the eight smaller pieces (four for each transformer) should be mounted directly to the sides, top and bottom of the transformers, while the 6.25 x 2 pieces are not intended to adhere to the transformers.  Instead, I think you are telling me that these larger pieces should be mounted directly to the inside surface of the top and bottom plates of the TVC chassis.  Do I have this right?  Assuming that I do, is there any place in particular where the 6.25 x 2 pieces should be mounted to the inside surface of the top and bottom plates?

2. For the procedure relating to the underside of each transformer, once the 2.5 x 1.5 piece of BHP is cut down to a dimension of 2.5 x 1, you mentioned that piece should be mounted "...so it too runs along the length of the core starting and ending where the plate and core start and ends."  Since I have not yet seen the inside of the TVC and I'm not very experienced in the construction of a transformer, I am not sure what this means.  Perhaps the answer will be obvious once I have a first hand peek inside the unit.  If the proper orientation of this piece of BHP on the bottom of the transformer will not be obvious, I would appreciate any further instruction you can give to a non-techie.

Thanks for your patience!

Hi Cincy_Bob,

This assumes that you are getting a single box TVC. That's correct. You'd put that 6.25 by 2, in the middle between both transformers. You'd put the other strip exactly on the underneath of the top plate in the same spot.They would both be going from front to back

The transformers have a U-shape frame. This frame has a flange on either end to mount it. The core which you will understand right away is where all the wires come out.

Have you placed your order yet? Which one you gonna get? Personally, I'd just stick with the single box, with dual controls. I'd get the 4 ins and 2 outs. This would give you flexibility for inputs. You can get RCA caps to put on the unused ones til you need them.

That's my 2 sense worth.   

Ray

[goldlizsts]

Hi all,

I expect my TVC next week.  Does anyone have the cut BHP sizes for the dual mono version, REF3?  Thanks.
 

[Cincy_bob]

Hi Ray -

I have not yet placed my order, but I'm getting close.  I will probably go for the version with three sets of inputs (one XLR, two RCA).  I understand that the TVC sounds different when run through the XLR inputs as compared with the RCA inputs, and I thought it might be nice to have some flexibility in this regard.  Another consideration is that I intend to run a long set of interconnects (VERY long - probably 60 to 70 feet) from my primary system's preamp to the TVC, and I expect that a balanced pair of cables is probably in order for that long a run.

I was initially leaning toward the dual box TVC since that seems to be the Promitheus "statement" product - at the moment anyway.  I don't have any real problem with the need to adjust a separate volume control for each channel.  (I lived with the Lamm L2 preamp in my main audio system for several years, and I was never troubled by the separate volume controls.)  Do you have any insight into the extent of the improvement in the quality of the sound offered by the dual box unit?  (I suspect I could find the answer to my question someplace in this thread, but the thread is so long, I don't know how to go about looking for the relevant posts...)  What are the reasons behind your personal preference for the single-box unit?

 - Bob

[guest1632]

Hi Ray -

I have not yet placed my order, but I'm getting close.  I will probably go for the version with three sets of inputs (one XLR, two RCA).  I understand that the TVC sounds different when run through the XLR inputs as compared with the RCA inputs, and I thought it might be nice to have some flexibility in this regard.  Another consideration is that I intend to run a long set of interconnects (VERY long - probably 60 to 70 feet) from my primary system's preamp to the TVC, and I expect that a balanced pair of cables is probably in order for that long a run.

I was initially leaning toward the dual box TVC since that seems to be the Promitheus "statement" product - at the moment anyway.  I don't have any real problem with the need to adjust a separate volume control for each channel.  (I lived with the Lamm L2 preamp in my main audio system for several years, and I was never troubled by the separate volume controls.)  Do you have any insight into the extent of the improvement in the quality of the sound offered by the dual box unit?  (I suspect I could find the answer to my question someplace in this thread, but the thread is so long, I don't know how to go about looking for the relevant posts...)  What are the reasons behind your personal preference for the single-box unit?

 - Bob

Hi Bob,

The difference between the single and dual boxed units are small, so I am told. The dual controls on the single unit do offer some more openness versus a single control unit. Just one more knob to turn. heheh. Suspect that the balanced one will be better for what your needs are. Whichever one you get, you will enjoy it. Hope that helps. It will take about 400 hours to break it in. After the first 100 to 150 hours will be the biggest.

To break it in, just turn the TVC up to the max and back off one or two clicks. As long as the TVC is getting any form of signal from a source connected to it, it will help to break it in. So you can actualy turn off your amp, and all will be ok. Just remember to turn down your TVC before use.

Ray

[gooberdude]

Hey Cincy,

On Promi's website somewhere is a test someone did about a year ago with 75' long interconnects...and the results were excellent.     From reports i've heard the performance of this TVC with XLR (balanced) connections is probably superior, however just in the instance of IC length regular RCA's will work.


In regards to the BHP on the trannies, just make sure you don't actually cover the trannies in BHP.... it is damping material and you don't want to add too much.    In other words, you should still be able to see a little of the metal covers on them, don't cover them completely.

I've not added BHP to the cover or bottom since i listen with my cover off, and the bottom of mine is wood.

In terms of laying BHP under the trannies, just use enough so the trannies don't touch the bottom...don't worry about dimensions...once you open the lid it'll make sense.

[guest1632]

Hey Cincy,

On Promi's website somewhere is a test someone did about a year ago with 75' long interconnects...and the results were excellent.     From reports i've heard the performance of this TVC with XLR (balanced) connections is probably superior, however just in the instance of IC length regular RCA's will work.


In regards to the BHP on the trannies, just make sure you don't actually cover the trannies in BHP.... it is damping material and you don't want to add too much.    In other words, you should still be able to see a little of the metal covers on them, don't cover them completely.

I've not added BHP to the cover or bottom since i listen with my cover off, and the bottom of mine is wood.

In terms of laying BHP under the trannies, just use enough so the trannies don't touch the bottom...don't worry about dimensions...once you open the lid it'll make sense.

Hi Matt,

 I did try it with a piece 3 by 1. It brought the mids forward, removed some of the bass, and seemed to restrict the flow. Now after I put the 2.5 x1 under the trafo, directly on the core, the flow was back, the bass came back, and more! detail in spades. It did pull the mids back. I did find that if I had it the other way, it didn't matter what I played. It had that same character about it. With the BHP on each core, then the TVC itself seemed to get out of the way, and just play music.So that's that.

Bob, since you will be reading this, there are a lot of little things you can do. Some like it with the top off, others like me preferr it on. A lot of this is unfortunately experimental in nature. So before you put the BHP on the top and bottom pieces, I'd put the TVC on each trafo. Then listen for a while. Then put the pieces on, and see what happens.Either way, you won't go wrong.

Ray

[Gaara]

Just to keep the members posted, BHP is back in stock over at Speaker City.  I talked to a customer rep about it and apparently it was back ordered for well over a month and they just got it in the end of last week.  My order shipped and will be here in a couple of days, I got the impression that they have plenty in stock.

Jared

[guest1632]

Just to keep the members posted, BHP is back in stock over at Speaker City.  I talked to a customer rep about it and apparently it was back ordered for well over a month and they just got it in the end of last week.  My order shipped and will be here in a couple of days, I got the impression that they have plenty in stock.

Jared

Good to know.

Ray

[Gpj]

Ray, I replaced an Electronic Visionary Systems PB2SA that I had been using for over a decade. This is a dual mono stepped attenuator with 36 hand matched resistors/channel and star grounding. State of the art way back then. TVC blew it away for keeps. Putting it back in now makes me wish I had gone for the transformer setup a long time ago. There is a mechanical quality to the sound that, once I have heard it, I cannot overlook. Funny how that works. Like that tiny dent in your car: your eye goes right to it every time you walk past.TVC is like paintless dent removal for me Thanks again for the summary of your tweaking. Going into the hospital for knee replacement fri. Will have lots of time for tinkering during recovery.  Gerry

Hi Gerry,

I sure wish you the best in that knee replacement. Hope all goes well, with no complications at all.

Ray

Hi Gerry,

Let me correct something. Wehn you put the Black Hole Padding on the transformers, put a piece each on the top, and the two sides of the transformer's  U shape frame. Then if you get brave, you can put the BHP on the bottom of the transformer itself.

Ray

Got it Ray.  Not up to much mischievness yet. Knee replacement:  ouch  Gerry

[1000a]

Thanks been wondering

it seems they are out of stock often on this product

added it just showed up but my amp is out of action so I must wait some more

[Cincy_bob]

Well, I placed my order for a Promitheus TVC with Nicholas this morning.  The unit I ordered is the dual-box reference TVC with brass top and bottom plates and copper wiring.  The unit will be equipped with a special -60dB transformer to give me some added attenuation for compatibility (hopefully...) with the low input sensitivity on my SET amps (0.25V).

So the wait begins...   

I suppose I should order up some of that BHP so that I have it on hand when the TVC eventually arrives...

[Whitese]

OK. I a m trying the active buffer again, this time with a Redwine Clari-T amp, and its great with the TVC...BUT, the buffer came without hook up instructions and wanna make sure I do it right...too many RCA's to guess which is input and whats out..

[AudioBear]

OK. I a m trying the active buffer again, this time with a Redwine Clari-T amp, and its great with the TVC...BUT, the buffer came without hook up instructions and wanna make sure I do it right...too many RCA's to guess which is input and whats out..

On mine the two RCA's at the outside of the case (far right and far left) are the inputs, the ones towards the centre the outputs. I've wired TVC to Buffer to Amps. So your normal output from the TVC goes to the input (the outside ones) on your Buffer. The inner RCA's on your buffer go to your input on your amp.

Hope this helps?

[Jos]

Whitese,

I got my TVC and tube buffer a couple of days ago. I bought them from Marco in Italy and had the same problem as you have: which one is the input and which one is the output? Initially I hooked it uip all wrong and had no signal at all. Turned out that the single RCA's at the far left and right are the inputs and the other ones are the outputs. Very odd. Normally it is the other way round.

I now use the TVC with my active tube pre-amp, not with the Promitheus tube buffer. Works very well. Previously I had too much gain and could hardly open up the volume control of my pre. I've placed the TVC between the phono pre and the active pre, so I suppose the TVC lowers the gain of the phono pre somewhat,
so that I am able to use the volume control of my active pre. Sound has become much more relaxed and open.
If  I use just the TVC or the TVC in combination with Nick's buffer the sound is somewhat dull but this works OK for me.

Jos