[denjo]

Your enthusiasm is appreciated, but you speak with no knowledge here.

And what good is a volume control if you can use it with good results at only a certain position? Apparently, two to three clicks below maximum?

Audiogon recently was full of Promitheus used units. Sure, they sell, because everyone and his grandma wants to try one, and without a long wait, just like me.

Marknoir

Thanks for appreciating my enthusiasm! You might want to tame your statement that I speak with no knowledge here. Does experience count? Countless swaps of active preamps, cable swaps, the heartaches that audiophiles go through?

You made a blanket statement about "most, if not all TVCs" and I was merely responding to the fact that this is a BIG generalisation. If you had said Promitheus TVCs, that would be a different statement!

There is really no reason to be discourteous! This is a civil forum and let's keep it that way!

[marknoir]

No disrespect meant, and everything you suggested does make improvement, all audiophiles know that, but some of your statements were not exactly up to the level.

With ALL ELSE EQUAL IN A GIVEN SYSTEM, including good power supply, excellent cables, clean digital source, you claim that a power conditioner will somehow improve the sound of a PASSIVE unit, and to this I have no response... except - yeah, power conditioner will improve EVERYTHING ELSE in the system, and it will sound better, but it will not be the merit of TVC.

Imagine if this TVC sounds this bad in my system, but then I improve on everything you describe, and it will sound good. Then my active preamp, that sounded 10 times better before improvement, will sound 10 times better than TVC again, wouldn't it?

Again, this discussion dies not belong here, I'm checking out, enjoy your TVC!

[guest1632]

No disrespect meant, and everything you suggested does make improvement, all audiophiles know that, but some of your statements were not exactly up to the level.

With ALL ELSE EQUAL IN A GIVEN SYSTEM, including good power supply, excellent cables, clean digital source, you claim that a power conditioner will somehow improve the sound of a PASSIVE unit, and to this I have no response... except - yeah, power conditioner will improve EVERYTHING ELSE in the system, and it will sound better, but it will not be the merit of TVC.

Imagine if this TVC sounds this bad in my system, but then I improve on everything you describe, and it will sound good. Then my active preamp, that sounded 10 times better before improvement, will sound 10 times better than TVC again, wouldn't it?

Again, this discussion dies not belong here, I'm checking out, enjoy your TVC!

Hi Marknoir,

Just was wondering if you had contacted Nicholas with your problems of the TVC sounding bad? It's certainly worth a shot.

Ray

[anubisgrau]

So I beleive still, that either Promitheus TVC has personal dislike of my system ()), or that it's reputation is somewhat hyped, by people who have not heard better. The link in one of previous posts on Stereophile's test of another transformer-based TVC showed it to be an extremely non-linear and unpredictable component, so the same is probably true about most, if not all TVCs. Otherwise. why would I see so many of them on used market now? 

+1 here.

promitheus TVC is excellent product for its price, but it too soon went into the high end orbit where criteria is much higher. OTOH it showed  very effectively how many bad active preamps are on the market in $2-3.000 range. it gave a good run for money to the most of them but certainly it is pretty far from perfect. it has the earliest resonance of all the TVCs we have measured, even worse than also pretty bad S&B trannies. no wonder they both share a similar lack of drive and dynamics. it's only systems with dynamics in spades - horns and similar - where TVCs actually don't show a lack of it because it's simply compensated elsewhere in the system.

truth to be told, i don't particularly find S&B products significantly better than promi. the differences are marginal, and if you put a price into this calculation, as well as the fact that MF pre was heavily promoted as "the best preamp in the world", you can make your own conclusion.

to be frank, i have become very cautious about many posters here on audio circle. i have even been criticized for not being too gentle with promitheus, and when i responded about my own findings why does it not sound better, about how bad it actually measures, that its early ringing must be having a detrimental effect on sound, and what kind of geometry is needed for TVC to sound better, what i found just a few weeks later is the announcement of the double-C core TVC. now it seems that the MF reference ($14.000) also features a double-C core trannies. i only know that i will keep my mouth shut next time on audio forums. a lesson learnt.

i can only laugh when i read stories about tweaking of TVC, like putting that isolating material under the trannies. guys, get the geometry of that bloody thing right, you're just fooling yourself. there's a fundamental mistake done and no hocus pocus can cure it.

if properly designed, TVC can work wonders. i haven't listened to kondo M77 to compare it with TVCs some guys near me did for their own use, but they are completely another story from any stock (commercial) TVC i've heard (promi, various S&B designs, django with amorph cores, bent, audio consulting copper trannies). TVCs can be done to sound dead neutral, flat, dynamic - like a piece of straigh wire, with no any adding or deducting from the sound - but they can't be made like that in big series, commercially. start reading the old books about transformers, it's all written there.

[guest1632]

So I beleive still, that either Promitheus TVC has personal dislike of my system ()), or that it's reputation is somewhat hyped, by people who have not heard better. The link in one of previous posts on Stereophile's test of another transformer-based TVC showed it to be an extremely non-linear and unpredictable component, so the same is probably true about most, if not all TVCs. Otherwise. why would I see so many of them on used market now? 

+1 here.

promitheus TVC is excellent product for its price, but it too soon went into the high end orbit where criteria is much higher. OTOH it showed  very effectively how many bad active preamps are on the market in $2-3.000 range. it gave a good run for money to the most of them but certainly it is pretty far from perfect. it has the earliest resonance of all the TVCs we have measured, even worse than also pretty bad S&B trannies. no wonder they both share a similar lack of drive and dynamics. it's only systems with dynamics in spades - horns and similar - where TVCs actually don't show a lack of it because it's simply compensated elsewhere in the system.

truth to be told, i don't particularly find S&B products significantly better than promi. the differences are marginal, and if you put a price into this calculation, as well as the fact that MF pre was heavily promoted as "the best preamp in the world", you can make your own conclusion.

to be frank, i have become very cautious about many posters here on audio circle. i have even been criticized for not being too gentle with promitheus, and when i responded about my own findings why does it not sound better, about how bad it actually measures, that its early ringing must be having a detrimental effect on sound, and what kind of geometry is needed for TVC to sound better, what i found just a few weeks later is the announcement of the double-C core TVC. now it seems that the MF reference ($14.000) also features a double-C core trannies. i only know that i will keep my mouth shut next time on audio forums. a lesson learnt.

i can only laugh when i read stories about tweaking of TVC, like putting that isolating material under the trannies. guys, get the geometry of that bloody thing right, you're just fooling yourself. there's a fundamental mistake done and no hocus pocus can cure it.

if properly designed, TVC can work wonders. i haven't listened to kondo M77 to compare it with TVCs some guys near me did for their own use, but they are completely another story from any stock (commercial) TVC i've heard (promi, various S&B designs, django with amorph cores, bent, audio consulting copper trannies). TVCs can be done to sound dead neutral, flat, dynamic - like a piece of straigh wire, with no any adding or deducting from the sound - but they can't be made like that in big series, commercially. start reading the old books about transformers, it's all written there.

Hi Anubisgrau,

Ok, so educate me and the rest. But before you do that, doing the various padding modifications on the TVC transformers did make a difference. I am not one to take in the garbage that's out there, but the differences were audible. Others too, can agree with that.

Now, ... tell me how to design a non-resonant transformer so we can then get the dynamics and drive.  As for the statement that the TVC isn't perfect. You're absolutely right. Best bang for the buck, If you can show me an active preamp, with drive, and dynamics, open, well defined bass mids and top, for $400, I'll buy it. Until then, I'll keep my TVC.

As for this resonance problem, how do you measure it? Then what do we need to do to fix this problem.

The TVC isn't for everyone. All I know is in my system, it sure is nice.

Ray

[tanchiro58]

Ok, so educate me and the rest. But before you do that, doing the various padding modifications on the TVC transformers did make a difference. I am not one to take in the garbage that's out there, but the differences were audible. Others too, can agree with that.

.

Ray Bronk,

I will back you up. I have already done the BHP padding to my Promitheus TVC standard and it sounds much better than the TVC Reference 3.   

Tan

[denjo]

yeah, power conditioner will improve EVERYTHING ELSE in the system, and it will sound better, but it will not be the merit of TVC.

Everyone knows that a power conditioner will have NO effect on a passive preamp! I was referring to a power conditioner in connection with the other components in the chain!! I should have made this more plain for those disposed to fault-finding!

[tanchiro58]

yeah, power conditioner will improve EVERYTHING ELSE in the system, and it will sound better, but it will not be the merit of TVC.

Everyone knows that a power conditioner will have NO effect on a passive preamp! I was referring to a power conditioner in connection with the other components in the chain!! I should have made this more plain for those disposed to fault-finding!

Actually I have owned quite a few power conditioners (Shunyata old and new versions, Jack Bybee, Audio Prism, PS Audio 300, Equitech, etc...) before but I have never found any help sonically to my entire system. To me power conditioners only make your sound constrained.

[guest1632]

yeah, power conditioner will improve EVERYTHING ELSE in the system, and it will sound better, but it will not be the merit of TVC.

Everyone knows that a power conditioner will have NO effect on a passive preamp! I  was referring to a power conditioner in connection with the other components in the chain!! I should have made this more plain for those disposed to fault-finding!

Hi,

Well, not to sure what Marknoir's deal is or was. Since he probably doesn't own a TVC, except a non comercial unit which doesn't count, he doesn't really have a clue. I think he's just trying to stir up dirt. No, the preamp was not touted as the best in the world. So again, Marknoir, if you have some solutions, I'm really interested. Otherwise, I'd suggest you take your negativity elsewhere. It was certainly nice of you to point out the bad stuff about any TVC, but you didn't give us any solutions.

Actually I have owned quite a few power conditioners (Shunyata old and new versions, Jack Bybee, Audio Prism, PS Audio 300, Equitech, etc...) before but I have never found any help sonically to my entire system. To me power conditioners only make your sound constrained.

Don't use a power conditioner. They are a mixed bag.

Ray

[*Scotty*]

Ray, The resonance referred so far in the discussion a property of a circuit having RLC components which the TVC is part of. Mechanical resonance is not part of the electrical behavior of the transformer unless the windings are loose. An electrically non-ringing TVC  is impossible to construct because you have a transformer with a different inductive value with every position of the switch that selects a different tap on the transformer. With a moving coil step up transformer there is a single inductive value and a resistance can be calculated and used to damp the ringing. With a TVC that has 23 different inductive values,one for each tap on the transformer a proper termination with the correct resistive network to stop the ringing is not possible. The different transformer core materials and designs are an attempt to manipulate the hysteresis distortion curve which can change how the transformer sounds. See link below http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html
Eliminating the rising distortion as the frequency approaches zero is not possible because as signal decreases in frequency the transformer sees it as approaching DC which a transformer does not conduct. This is a simple property of all transformers and cannot be gotten around. It is this property of transformers which causes an apparent loss in bass dynamics compared  to a good active circuit. Reading the information in the measurement section of the Stereophile review I linked to earlier will go a long way towards explaining some of the varying results people have had when using a TVC, it is not a universal cure all unfortunately. Here is the link again for those who missed it first time.
http://stereophile.com/solidpreamps/106sonic/index4.html
I would like to reiterate my earlier statement about the Django TVC. It sounded quite good, it had no timbral or tonal errors and I would characterize its performance as above average in every respect but in the context of my system when compared to my DIY buffer it was a definite step backward in performance. This was over three years ago and I have since
upgraded to a Superphon Revelation III preamp which substantially outperforms my DIY buffer. The state of the art is a moving target and it is always moving further away.
In this respect a TVC is a technological dead-end in that it will always be a transformer with a transformers electrical characteristics,it cannot be other than what it is. An active circuit in contrast is an open ended concept which will always be improved upon in the future.
Scotty

[doug s.]

...Best bang for the buck, If you can show me an active preamp, with drive, and dynamics, open, well defined bass mids and top, for $400, I'll buy it. Until then, I'll keep my TVC...

find yourself a used melos sha-1 or a used dodd entry-level preamp.  (the dodd is based on melos topology, & retailed for ~$450 new.)

doug s.

[guest1632]

Ray, The resonance referred so far in the discussion a property of a circuit having RLC components which the TVC is part of. Mechanical resonance is not part of the electrical behavior of the transformer unless the windings are loose. An electrically non-ringing TVC  is impossible to construct because you have a transformer with a different inductive value with every position of the switch that selects a different tap on the transformer. With a moving coil step up transformer there is a single inductive value and a resistance can be calculated and used to damp the ringing. With a TVC that has 23 different inductive values,one for each tap on the transformer a proper termination with the correct resistive network to stop the ringing is not possible. The different transformer core materials and designs are an attempt to manipulate the hysteresis distortion curve which can change how the transformer sounds. See link below http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html
Eliminating the rising distortion as the frequency approaches zero is not possible because as signal decreases in frequency the transformer sees it as approaching DC which a transformer does not conduct. This is a simple property of all transformers and cannot be gotten around. It is this property of transformers which causes an apparent loss in bass dynamics compared  to a good active circuit. Reading the information in the measurement section of the Stereophile review I linked to earlier will go a long way towards explaining some of the varying results people have had when using a TVC, it is not a universal cure all unfortunately. Here is the link again for those who missed it first time.
http://stereophile.com/solidpreamps/106sonic/index4.html
I would like to reiterate my earlier statement about the Django TVC. It sounded quite good, it had no timbral or tonal errors and I would characterize its performance as above average in every respect but in the context of my system when compared to my DIY buffer it was a definite step backward in performance. This was over three years ago and I have since
upgraded to a Superphon Revelation III preamp which substantially outperforms my DIY buffer. The state of the art is a moving target and it is always moving further away.
In this respect a TVC is a technological dead-end in that it will always be a transformer with a transformers electrical characteristics,it cannot be other than what it is. An active circuit in contrast is an open ended concept which will always be improved upon in the future.
Scotty

Now we are making some sense. Thanks Scotty.

Ray

[guest1632]

...Best bang for the buck, If you can show me an active preamp, with drive, and dynamics, open, well defined bass mids and top, for $400, I'll buy it. Until then, I'll keep my TVC...

find yourself a used melos sha-1 or a used dodd entry-level preamp.  (the dodd is based on melos topology, & retailed for ~$450 new.)

doug s.

Hi Doug S

You know, I was just thinking about that Dodd preamp. hmmm. Well thanks for the suggestions.

Ray

[Double Ugly]

I'm happy to see this thread resurrected, and even happier to see that for the most part folks have been able to agree to disagree.

Sure makes my role a lot easier! 

As for alternative preamp designs, I've only heard it once, but the H-Cat preamp was in the system that produced of the most "live" home audio experience I've ever heard, and I mean by a *LOT*.  Specifically, the chain consisted of a McCormack UDP-1 Universal Disc player, the H-Cat P-12R Line Stage, a brand new Spectron Musician III Special Edition amplifier and the SP Technology Revelations.

I can't define the significance of the role the H-Cat played in the presentation that evening, but I can assure you it didn't hurt it.  A few of us played around with the controls a bit while we waited for stragglers, and you could practically see the image moving forward as it became more and more defined.  There was no doubt or disagreement when we arrived at the proper setting. 

I didn't notice any tonal variations while we manipulated the settings (a huge positive IMHO), but the effect on imaging was undeniable.  Further, the sound we all heard that evening left no doubt that the H-Cat is suitable for systems capable of extremely high quality and detail.

An excellent component IMHO, definitely worth consideration if you can afford the $4k price of admission.

Having said all that, Ray, if you and/or others feel my post is inappropriate, let me know and I'll happily remove it.  It seems appropriate enough to me given the content of recent posts, but I don't want to assist in taking this topic away from what you 'regulars' would prefer it be. 

I should also note that I have absolutely nothing to gain by the success or failure of H-Cat.  It's just been a long while since I was impressed by a preamp, and this one wowed me.

[PromitheusAudio]

Please help us to post your votes for Promitheusaudio to have its own forum
here
http://www.audiocircle.com/index.php?topic=47718.0

THank you

NIcholas Chua
Promitheusaudio

[spyder187]

I just emailed this to someone asking for my impressions:

The highs are attenuated I think, leading to less forward female vocals (my favourite
music). Soundstage in terms of left and right are more separated, leading to a wider
soundstage (or maybe just perceived wider due to the increased separation. The
difference is there though due to one track where I heard the violins, there are 2
groups of violins in the background, left and right. They take turns playing and this
occurs continuously. Without the Promitheus in the chain, I can't really tell that they
are taking turns, takes some thinking to realize this and even so, some of the parts
I can't tell at all even if I tried. (This is on Madonna - Frozen)
 
As for soundstage depth, violins sound incredible on this preamp. If you listen to classical
a lot, then I think this would be the preamp for you. If I could have kept it, I would
have but I need money for another endeavour, hence why I'm getting out of audio.
I don't use my audio system nearly as much as my headphones either so it wasn't worth
keeping.
 
If I had to do it all over again, I don't know if I would get a Promitheus (it's a 50-50
chance - which is pretty darn good for any piece of equipment). It does alter the
sound and in the end it depends if you like the sound. The soundstage/imaging differences
are there as well as the attenuation of the highs.
 
Oh one more thing, the bass. It's got a weird bass to it. Definitely deeper and more
separated. The bass doesn't cover up the mids or highs which is really a good quality.
I have no clue if the bass is supposed to be there though because without the preamp
in the chain, the bass isn't as deep or as defined. It makes me wonder which is more
accurate.
 
If I write anymore, I'd be writing a story but maybe I'll post this on the forum because
it is what I heard and people do want to hear people's experiences with audio gear.
 
If you get a chance, I'd try one out, if you haven't found a preamp you really like yet.
For the price, I don't think it can be beat and I can believe all the previous reviews on
the forums too because of my experience with it. World beater, it truly could be.