Promitheus TVC passive preamp anyone?

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PromitheusAudio

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Re: Promitheus TVC passive preamp anyone?
« Reply #440 on: 30 Nov 2006, 12:38 am »
forgot to add this
 TomekZ

WOuld you be intersted if i send you another unit to see whether the problems still persists after the 2 o'clock thingy. I would like to help you solve your problem.

CHeers
nicholas

GHM

Re: Promitheus TVC passive preamp anyone?
« Reply #441 on: 30 Nov 2006, 12:47 am »
HI guys
i am currently helping out wendell to sort out his problems. In due time should be able to sort out his problems.

Actually on gooberdudes finding, i would like to ellaborate more on my findings too.

Normally when i work, i work with my pc based audio system on. Also i have this bad habit when i switch cables i do not turn off the amplifier. My source is my comp. So what happens is when i disconnect the interconnects from the tvc and let the interconnects hang loose near the amplifer(my tvc is stack on top off my amplifer). I actually can hear sound coming out of my speakers. faint and distorted. But it is audible. I did not plug any cables in just the interconnects are sitting on top  or near by the metal cassing of the amplifer. Some how the sounds gets transmited thru the rca cables into the amp.

So same thing if you have 2 sources playing thru the tvc. Even thru the selector switch which isolates stuff, you will get some form of interference whether you like it or not. Hence this forms the same basis on which the dual mono version is better as the wires are totaly isolated and do not interfere with each other.

Also one way of preventing the transformers from coming loose from shipment is to use the nylon locking nuts. I will be changing to this to prevent any more faults due to shipment. I not how they can come loose considering i am using aready spring washer.

Gymane, i will be shipping out your stuff on next monday. Will be a big package though.

Yup now I've definitely heard this with the cables daggling free. The TVC seems to turn into a big antenna when the cables hang loose. The Bent TVC unit did the same thing.

 :dance: Thanks Nicholas... :D...I can't wait!!! :lol:

NewBuyer

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Promitheus TVC passive preamp anyone?
« Reply #442 on: 30 Nov 2006, 09:10 am »
GHM, I sure hope you will please post your impressions of the Power Energizer too when you get it! Really interested in your shared impressions about it. :D

By the way - that is extremely nice of Nicholas to offer to send another unit to TomekZ in Wisconsin for evaluation. TomekZ, what do you think about the idea?

GHM

Re: Promitheus TVC passive preamp anyone?
« Reply #443 on: 30 Nov 2006, 06:58 pm »
GHM, I sure hope you will please post your impressions of the Power Energizer too when you get it! Really interested in your shared impressions about it. :D

By the way - that is extremely nice of Nicholas to offer to send another unit to TomekZ in Wisconsin for evaluation. TomekZ, what do you think about the idea?

I sure will NewBuyer..I'll get accustom to having it in the system. Then I will remove it after a week or so and listen for changes.

Yeah..I was also wondering if Tom had contacted Nick directly. From what I've seen of Nick. He always tries to make the customer happy. Even if he looses money and time in the process. That's the making of good customer service. I doubt the other owner who sold the unit to Wendell contacted Nick either as he may not have sold this unit.

wendell

Re: Promitheus TVC passive preamp anyone?
« Reply #444 on: 30 Nov 2006, 07:11 pm »
you are correct,  the owner of the TVC that I purchased from never contacted Nick. He thought it was incompatiblility on his his systems part so in his ad he had noted that it was in "excellent working" condition considering he had about 40 hrs on the unit.

I received the unit in excellent condition cosmetically looks brand spankin' new but it wasn't working right so I opened it up and found a few broken strands in the wiring that looked like it was pinched from the top steel plate and transformer. There are other wires that pinched but did not break, in all I've found 5 broken strands.

Still waiting for Nick to respond back to me as I've sent him pics as he requested

mysticaldodo

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Re: Promitheus TVC passive preamp anyone?
« Reply #445 on: 1 Dec 2006, 10:02 am »
Just got a loaner unit of the TVC. I'm going to burn it in for 1 day and pit it againts my current ATT 600 pre-amp (also a Malaysian gem). Its nice to have some gain, I only need to go around 1 o clock when things get loud enough. With my other TVC, it needs to go from 80 to 90% of the volume  :icon_twisted:

gooberdude

Re: Promitheus TVC passive preamp anyone?
« Reply #446 on: 2 Dec 2006, 09:19 pm »
http://i132.photobucket.com/albums/q14/mattcecil_photos/DSCN3827.jpg


http://i132.photobucket.com/albums/q14/mattcecil_photos/DSCN3824.jpg


The TVC is truly a diamond in the rough.   



I have not had a chance to set it up properly until a few days ago when my turntable went in for repair.   

the change this set-up imparts on the TVC's performance is thorough, intense & unmistakable.   bass gets tighter & more musical.  its as if the TVC is exerting more control over the signal, all while letting the  sweet clarity come out.  the added grip from the bass conrols the entire sonic picture.  imaging is like the best tubed pre's i've heard...     

Been listening to the Best of Fela Kuti.  i'd always thought his recordings were subpar but they are enjoyable now, plus a few fav recordings from Dan Prothero, like Mofro 'Lockloosa', Robert Walter's 'Giving Up the Ghost' & 'Super Heavy Organ'.    its like i'm listening to Master Tapes now, not CD's through a modded XBOX.

brand new this all costs $300.   the platform is a 18"x13" 2" thick maple from timbernation.com   it sounds great, but i may get a 12"x15" 3" thick tiger maple board, which looks cool.   the footers are 2" diameter pointed brass footers from Mapleshade, and the small pointed weight is from MS also.  the cork/neoprene suspension pucks are also proprietary to MS and come free with MS platforms.

the TVC will not sound right without some attention.   it sounds great right out of the box, don't get me wrong.   but those who look into a vibration draining system like this will be rewarded bigtime    :rock:.

i'd bet Herbie's isocups may be a good option in lieu of the footers + platform + isoblocks, for those with a height restriction.

for this preamp, trying out difft tonewood platforms will take the place of swapping power cords or tubes.

i really have no concrete idea as to why this is, but gear with transformers inside greatly benefit from draining internal vibrations inherent to the gear itself...much more so than dealing with floor or airborne vibes.  the beauty of this set-up is it cures all 3.

you will need 8" - 9" of rack height to pull this off...


matt

JLM

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Re: Promitheus TVC passive preamp anyone?
« Reply #447 on: 2 Dec 2006, 10:03 pm »
Guys....

When you reference some aspect of your Promitheus TVC, please indicate specifically which model (original or reference), which version, which transformer, and what options (silver RCA, balanced, upgraded knobs, stainless steel/brass lid, etc.) so the rest of us can keep all this in context.  At over 400 posts and dozens of possible combinations, it ain't easy to tell the players without a program.

Perhaps starting a new thread in the Critic's Circle where each could specify exactly which version they're using and summarize their impressions would help keep this thread more on point and make finding this information easier.

Thanks

GHM

Re: Promitheus TVC passive preamp anyone?
« Reply #448 on: 3 Dec 2006, 12:41 am »
http://i132.photobucket.com/albums/q14/mattcecil_photos/DSCN3827.jpg


http://i132.photobucket.com/albums/q14/mattcecil_photos/DSCN3824.jpg


The TVC is truly a diamond in the rough.   



I have not had a chance to set it up properly until a few days ago when my turntable went in for repair.   

the change this set-up imparts on the TVC's performance is thorough, intense & unmistakable.   bass gets tighter & more musical.  its as if the TVC is exerting more control over the signal, all while letting the  sweet clarity come out.  the added grip from the bass controls the entire sonic picture.  imaging is like the best tubed pre's I've heard...     

Been listening to the Best of Fela Kuti.  I'd always thought his recordings were subpar but they are enjoyable now, plus a few fave recordings from Dan Prothero, like Mofro 'Lockloosa', Robert Walter's 'Giving Up the Ghost' & 'Super Heavy Organ'.    its like i'm listening to Master Tapes now, not CD's through a modded XBOX.

brand new this all costs $300.   the platform is a 18"x13" 2" thick maple from timbernation.com   it sounds great, but i may get a 12"x15" 3" thick tiger maple board, which looks cool.   the footers are 2" diameter pointed brass footers from Mapleshade, and the small pointed weight is from MS also.  the cork/neoprene suspension pucks are also proprietary to MS and come free with MS platforms.

the TVC will not sound right without some attention.   it sounds great right out of the box, don't get me wrong.   but those who look into a vibration draining system like this will be rewarded bigtime    :rock:.

i'd bet Herbie's isocups may be a good option in lieu of the footers + platform + isoblocks, for those with a height restriction.

for this preamp, trying out difft tonewood platforms will take the place of swapping power cords or tubes.

i really have no concrete idea as to why this is, but gear with transformers inside greatly benefit from draining internal vibrations inherent to the gear itself...much more so than dealing with floor or airborne vibes.  the beauty of this set-up is it cures all 3.

you will need 8" - 9" of rack height to pull this off...


matt

Jeez Matt..you got the TVC doing a balancing act. :lol: It looks interesting. I'm not sure I can go as far as you in the vibration control. But hey I'll try almost anything once! :wink:

Guys....

When you reference some aspect of your Promitheus TVC, please indicate specifically which model (original or reference), which version, which transformer, and what options (silver RCA, balanced, upgraded knobs, stainless steel/brass lid, etc.) so the rest of us can keep all this in context.  At over 400 posts and dozens of possible combinations, it ain't easy to tell the players without a program.

Perhaps starting a new thread in the Critic's Circle where each could specify exactly which version they're using and summarize their impressions would help keep this thread more on point and make finding this information easier.

Thanks

You have a point JLM. I'll make sure to state exactly what TVC I'm referring to from now on. Since I have followed the thread from beginning to end..I know what type all the fellows that have posted own. I can see it would be tough for some just coming aboard with all the post.

Just got a loaner unit of the TVC. I'm going to burn it in for 1 day and pit it againts my current ATT 600 pre-amp (also a Malaysian gem). Its nice to have some gain, I only need to go around 1 o clock when things get loud enough. With my other TVC, it needs to go from 80 to 90% of the volume  :icon_twisted:

What say you mysticaldodo? How's the TVC coming along compared to your in home reference?

ryno

Re: Promitheus TVC passive preamp anyone?
« Reply #449 on: 3 Dec 2006, 04:30 am »
Hey guys,
What are the differences between coupling the pre as Matt does, and and isolating with isofeet or something similar?
Ryan

akmal00

Re: Promitheus TVC passive preamp anyone?
« Reply #450 on: 3 Dec 2006, 09:36 am »
Hey guys,
What are the differences between coupling the pre as Matt does, and and isolating with isofeet or something similar?
Ryan

It's been ten days since I received my dual mono reference with ebony knobs TVC. It has been a revelation so far. Caused a problem as well. My main source is the Clearaudio Emotion/ Satisfy/ Benz MC20EII. My dealer promoted a power supply/ Speed controller. It made my system better in clarity and the highs and low ends before. Adding the TVC revealed that the mids especially in the vocals are compressed with the power supply connected. It is more natural and sweeter without the said power supply. That power supply is placed more than two feet away from the TVC. I think that the power supply is affecting the sound in such a way that is being revealed by the TVC. I am able to listen to my CD's now. The overall effect of the TVC in my system is great.
 
BTW, a tried with several supports, a) Ikea maple chopping board b) multilayered ply:

b) was much better.

This TVC really need good support. Here's another peek of my ply support with the wooden cones from Nicholas.

« Last Edit: 3 Dec 2006, 10:01 am by akmal00 »

NewBuyer

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Re: Promitheus TVC passive preamp anyone?
« Reply #451 on: 3 Dec 2006, 09:40 am »
akmal00 I don't know why but none of your pictures show in your posts, at least not for me...

akmal00

Re: Promitheus TVC passive preamp anyone?
« Reply #452 on: 3 Dec 2006, 09:47 am »
akmal00 I don't know why but none of your pictures show in your posts, at least not for me...

I am trying to sort out the problem currently. Sorry. Using a different browser now. Not at my home.

Are you able to view this Newbuyer??

« Last Edit: 3 Dec 2006, 10:12 am by akmal00 »

NewBuyer

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Promitheus TVC passive preamp anyone?
« Reply #453 on: 3 Dec 2006, 10:47 am »
They show up now! Thanks akmal00 for whatever you did to fix. :)

By the way, nice setup you have there! :D

How interesting that the TVC needs such careful support to sound its best... I never would have guessed this would matter with a passive component, and can't help but wonder why it should make any difference. Obviously it must make a difference, since you and others are hearing it... but what mechanism could explain it?

JLM

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  • The elephant normally IS the room
Re: Promitheus TVC passive preamp anyone?
« Reply #454 on: 3 Dec 2006, 11:16 am »
Ryan,

You asked, "What are the differences between coupling the pre as Matt does, and isolating with isofeet or something similar?"


There are 3 sources of vibration:  physical contact with the rack/floor from speakers, footfalls, etc.; through the air from the sound generated by the speakers; and self noise.

And there are three ways to try to address these vibrations: isolation, damping, and draining.  If you think about it, all electrical components are cantilevered from the circuit board or mounting plate.  This is the worst possible structure for controlling vibration (like the springiness of a diving board).  And the elements inside tubes are cantilevers within a cantilever.  Exposing them looks cool, but can lead to even more vibration related issues.  Hanging cabling is another example of poor vibration control.

Isolation is probably the most effective method for reducing physical contact and airborne vibrations, but can’t be applied to self-noise.  It’s primarily how vibrations are controlled coming and going from studios and listening rooms.  Self-noise is a huge problem in speaker design as some estimate that over half of the sound emanating from a poorly braced speaker comes from the cabinet itself.  Using an enclosed rack should reduce vibrations transmitted via the air, but moving equipment out of the room would be better.

Dampening involves conversion of the mechanical energy into heat and often additional mass.  Coupling mass normally results in lowering the resonant frequency and increasing the amount of input energy needed to begin a resonance.  A sand bag on top of your CDP or use of tube dampers are classic damping solutions. 

Anything with a spike represents the draining approach.  Spikes increase the bearing stress and therefore improve energy transfer.  If you're on a concrete slab and using a solid/spiked rack, draining is the way to go, otherwise it’s a crap shoot depending on the construction of the floor.  BTW the earth itself vibrates at 1 – 2 Hz, so it’s very hard to get away from all vibration.

Solutions like the Mapleshade stuff gets into tuning, which uses damping and draining where vibrational energy is focused into a narrow frequency range.  In the case of Mapleshade the frequency ranges of brass and maple seem to complement each other well.


Like power conditioning, vibration control is solved on a case by case basis.  Some don’t need it, some swear by it, and some swear at it.  Of course if we followed my Dad’s advice and “keep that damn thing turned down and stop jumping around up there” many of these problems would go away.    :lol:

ryno

Re: Promitheus TVC passive preamp anyone?
« Reply #455 on: 3 Dec 2006, 12:10 pm »
Thanks JLM
Very informative. So a situation where you're coupled to an  isolated  platform with damping on top could address all concerns.
Ryan

GHM

Re: Promitheus TVC passive preamp anyone?
« Reply #456 on: 3 Dec 2006, 12:40 pm »
akmal00 I don't know why but none of your pictures show in your posts, at least not for me...

I am trying to sort out the problem currently. Sorry. Using a different browser now. Not at my home.

Are you able to view this Newbuyer??









For some reason I still can't see the pics here. :scratch:

Ryan,

You asked, "What are the differences between coupling the pre as Matt does, and isolating with isofeet or something similar?"


There are 3 sources of vibration:  physical contact with the rack/floor from speakers, footfalls, etc.; through the air from the sound generated by the speakers; and self noise.

And there are three ways to try to address these vibrations: isolation, damping, and draining.  If you think about it, all electrical components are cantilevered from the circuit board or mounting plate.  This is the worst possible structure for controlling vibration (like the springiness of a diving board).  And the elements inside tubes are cantilevers within a cantilever.  Exposing them looks cool, but can lead to even more vibration related issues.  Hanging cabling is another example of poor vibration control.

Isolation is probably the most effective method for reducing physical contact and airborne vibrations, but can’t be applied to self-noise.  It’s primarily how vibrations are controlled coming and going from studios and listening rooms.  Self-noise is a huge problem in speaker design as some estimate that over half of the sound emanating from a poorly braced speaker comes from the cabinet itself.  Using an enclosed rack should reduce vibrations transmitted via the air, but moving equipment out of the room would be better.

Dampening involves conversion of the mechanical energy into heat and often additional mass.  Coupling mass normally results in lowering the resonant frequency and increasing the amount of input energy needed to begin a resonance.  A sand bag on top of your CDP or use of tube dampers are classic damping solutions. 

Anything with a spike represents the draining approach.  Spikes increase the bearing stress and therefore improve energy transfer.  If you're on a concrete slab and using a solid/spiked rack, draining is the way to go, otherwise it’s a crap shoot depending on the construction of the floor.  BTW the earth itself vibrates at 1 – 2 Hz, so it’s very hard to get away from all vibration.

Solutions like the Mapleshade stuff gets into tuning, which uses damping and draining where vibrational energy is focused into a narrow frequency range.  In the case of Mapleshade the frequency ranges of brass and maple seem to complement each other well.


Like power conditioning, vibration control is solved on a case by case basis.  Some don’t need it, some swear by it, and some swear at it.  Of course if we followed my Dad’s advice and “keep that damn thing turned down and stop jumping around up there” many of these problems would go away.    :lol:


Bravo JLM!  :thumb: Great post..you ever thought about selling this stuff? Man ..that's the best explanation I've read so far! :D I'll read up a little more on this stuff and see what I can locate at a reasonable price. Now you got my wheels turning. I gotta stop hanging around here..you guys will have me completely broke..like I'm not already there! :lol:

NewBuyer

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Promitheus TVC passive preamp anyone?
« Reply #457 on: 3 Dec 2006, 02:23 pm »
I agree, thanks JLM for that information.  :thumb:

I guess my naive question still remains though: Why exactly is any tiny vibration at all, such a detrimental thing for electronics - including a passive device like the TVC? (within reason of course, I don't mean major vibrations).

What specifically is the physical reason/mechanism that could possibly result in any sonic differences?  :scratch:

mysticaldodo

  • Jr. Member
  • Posts: 34
Re: Promitheus TVC passive preamp anyone?
« Reply #458 on: 3 Dec 2006, 03:39 pm »
Hey guys,
What are the differences between coupling the pre as Matt does, and and isolating with isofeet or something similar?
Ryan

It's been ten days since I received my dual mono reference with ebony knobs TVC. It has been a revelation so far. Caused a problem as well. My main source is the Clearaudio Emotion/ Satisfy/ Benz MC20EII. My dealer promoted a power supply/ Speed controller. It made my system better in clarity and the highs and low ends before. Adding the TVC revealed that the mids especially in the vocals are compressed with the power supply connected. It is more natural and sweeter without the said power supply. That power supply is placed more than two feet away from the TVC. I think that the power supply is affecting the sound in such a way that is being revealed by the TVC. I am able to listen to my CD's now. The overall effect of the TVC in my system is great.
 
BTW, a tried with several supports, a) Ikea maple chopping board b) multilayered ply:

b) was much better.

This TVC really need good support. Here's another peek of my ply support with the wooden cones from Nicholas.



I don't really like those wooden cones. They are a bit too small to work with especially with my pudgy fingers.  :P

Nic did mention about the power supply and its affect on the midrange. I'm not sure if the power supply he is talking about is the same with yours though. Thx for the update.



As of now, the TVC compared to my other passive is a tinge bit forward and feels more holographic (perhaps due to the forwardness). There seems to be more quantity of bass, though not quality. Regardless, I haven't even pass 40 hours of burning in yet. Are you guys sure that burning it in at full volume without switching on the power amp really works? The thing feels cold, not sure if its actually burning in  :dunno:

My other passive is slightly more polite in comparison and is slightly more laidback. The TVC feels more like a side-grade to me, but it does sound more exciting and involving with rock and trip hop recordings. I guess it could be the excitement of having a more forward sound but I do not think it is forward to the point of fatiguing. I think I might keep both  aa.

The dealer prefers my passive which he thinks is the perfect match for my power amp (they were both designed to work with each other) over the TVC. But he also feels the TVC works better with other power amps like the Jeff Rowland and Krell.

I will burn it up till 200 hours then only do a proper comparison.

The one I have is balanced version, black in colour with rhodium connections, which I prefer more to the natural reddish colour which is fugly IMO.

GHM

Re: Promitheus TVC passive preamp anyone?
« Reply #459 on: 3 Dec 2006, 03:48 pm »


 


I don't really like those wooden cones. They are a bit too small to work with especially with my pudgy fingers.  :P

Nic did mention about the power supply and its affect on the midrange. I'm not sure if the power supply he is talking about is the same with yours though. Thx for the update.



As of now, the TVC compared to my other passive is a tinge bit forward and feels more holographic (perhaps due to the forwardness). There seems to be more quantity of bass, though not quality. Regardless, I haven't even pass 40 hours of burning in yet. Are you guys sure that burning it in at full volume without switching on the power amp really works? The thing feels cold, not sure if its actually burning in  :dunno:

My other passive is slightly more polite in comparison and is slightly more laidback. The TVC feels more like a side-grade to me, but it does sound more exciting and involving with rock and trip hop recordings. I guess it could be the excitement of having a more forward sound but I do not think it is forward to the point of fatiguing. I think I might keep both  aa.

The dealer prefers my passive which he thinks is the perfect match for my power amp (they were both designed to work with each other) over the TVC. But he also feels the TVC works better with other power amps like the Jeff Rowland and Krell.

I will burn it up till 200 hours then only do a proper comparison.

The one I have is balanced version, black in colour with rhodium connections, which I prefer more to the natural reddish colour which is fugly IMO.

Thanks mysticaldodo for the feedback. :thumb: What do you use as a source? This TVC will give you exactly what you put into it. If the source is forward you'll get forward..if the source is more laid back then....you get the idea.

Has anyone tried the EcomHK Footers? They look nice and also inexpensive compared to companies charging crazy prices for that stuff. :o

I had a good laugh about the burn in comment! :lol:!! I hope that TVC never gets warm..if it does..your in trouble! :lol: