[davetroy]

How does the TVC know that it's time to stop breaking in? If the TVC is always breaking in, then it's going to reach the post-break-in point and, at some point, start breaking down. 

I'm only half-kidding here. This seems to make sense to me and it's why I'm a bit skeptical of break-in. Warm up time? How does that make sense with a TVC? The thing is always on! It doesn't have an on-off switch!

[gooberdude]

Nick can fill-in those blanks, but i think he's discussed it here some pages back.  After a short length of play the trannies sound difft, this is with each play (or each day).  i want to say they become magnetized, but that's probably the wrong term. 

there's no on/off switch on yours?  that's weird.  mine's right next to the power cord inlet on the back.   

Just running a signal through the TVC gets the trannies warmed up...but after 30 min or so hit the 'LOUD' button and be ready for action.   you might have to adjust the built-in EQ when the LOUD button is engaged though.

now where is my remote control???   there it is, right next to my brain medication...

[GHM]

I was playing around yesterday with a balanced/single ended TVC. It has been sitting up for several weeks unused. As soon as I went from the Dual mono to it. The sound became bright and unbalanced. I was starting to worry that something was wrong with this unit. After solid playing for 15 to 30 mins I noticed the sound changing. There's definitely more to it than ears breaking in. The difference was so glaring from one charged unit to the one uncharged, that there was no denying that these units sound better after current flows through them.

I admit I'm a skeptic about certain practices or beliefs in audio..this isn't one of them.

[davetroy]

I'm not questioning whether 15-30 minutes of warm-up time for the trannies is beneficial. I'm questioning whether 100, 200 or even 400 hours of burn-in for the TVC is necessary or beneficial. I would not swear on my life that I'm hearing a difference between five hours and 300 or 400 hours on my TVC. That's not a bad thing, by the way. I liked it almost immediately. And, let's face it: burn in is so easy, there's no reason not to do it.

[GHM]

Hey Dave,

my comments were directed towards acresm22. I understand what you mean about the 100s of hrs. I just sit back and listen not worrying about how many hours the units have on them. As long as it is sounding good you'll get no complaints out of me.

I just shipped my Reference stereo version off for a guy to evaluate. He uses a $20,000 100 lb preamp.
I'll know buy Friday whether he'll become a TVC convert. This will depend on how his other components work with the TVC of course...

[jaspal kallar]

How does the TVC know that it's time to stop breaking in? If the TVC is always breaking in, then it's going to reach the post-break-in point and, at some point, start breaking down. 

I'm only half-kidding here. This seems to make sense to me and it's why I'm a bit skeptical of break-in. Warm up time? How does that make sense with a TVC? The thing is always on! It doesn't have an on-off switch!

I also was skeptical about burn in. On initial listening (1-4hrs) I thought it sounded great. After 100 hrs I didn't think much had changed - infact I thought the bass was worse. After around 365 hrs, boy I was surprised there was such a change. I won't go into what changed but there was a noticeable positive difference in all areas especially the mid range. This is the only time I've heard a difference with burn in (although I never looked for it before tbh).

I would also agree that it "seems" to sound better after 20/30 mins warm-up. Things have been improving although I've stopped looking actively for them. I stopped burn-in after 365 hrs. My advice do the burn especially if you can in the meantime can use another preamp - it's only 2 weeks and then at least one can then satisfy their curiosity.

  - jaspal

[gooberdude]

Just wanted to chime in that an AC member has a good deal on some fine DH ceramic cones to go under the TVC.   I've owned these before and they are a good product.

Check the Trading Post.

In addition to a required burn-in, this TVC likes footers too 

[rollo]

Hey Jaspal,

                 Good to hear from you. Thought you got lost in the snow. So are we a happy camper with the TVC? It would be nice to hear how it synergizes with your components.

  rollo

[rollo]

acres22,
              Transformers have a reputation of taking the longest to break in due to all the wiring and core to settle in . I do not know the scientific reason for this. Maybe Nicholas can shed some light on this. When I asked Lou Johnson from Conrad & Johnson this question he stated that the trannies have allot of wire to settle in as well as the steel plates. He also said that was a very simple explanation since it would take awhile to thoroughly explain the science.

 rollo

P.S. 
Not trying to start a debate on this matter, just trying to be helpfull.
 Gooberdude the ebony footers from Promitheus are very affective as well.

[gooberdude]

Hey Rollo,

what types of footers have you used up to now?   
Nicks ebony cones look cool.  the ebony wood he gets is nice.

and are you planning to use them with your double chassis hot rod TVC??

i'll rock the mapleshade ones for years!   their tone along with the maple boards & the TVC is a good match...

[rollo]

Gooberdude,
                   The footers so far have been: Bronze cones made from a boats trannie shaft, brass cones machined from 2" dia. rod, Sound Fusion sound booster 3, pumice stones, Mod Squad alum. cones, Promitheus wood, 1/2"x 1/2" maple blocks, no footers rested TVC on maple plinth, Hyperion magnetic[opposing magnets], and a Partridge in a pear tree.
           The most affective were the Sound Fusion and the ebony to date. The latest configuration is TVC on original wood pyramid footers with top off and a bamboo cutting board[6"x8"] across trannies and a wood cigar box filled with sand atop cutting board. My ebony cones will arrive shortly and probably replace the original wood feet. I used ebony pen blanks as well while waiting for Promitheus cones.
           To test each type of footer I played a 30 second piece of music using the AB setting on the CDP remote. A 30 second duration is just enough to remember. Choose a selection of music that incorporates some bass, vocals and cymbals or whatever floats your boat. listen carefully to the 30 second cut 4 times before changing the footers or anything else you are evaluating.

 rollo
P.S. Almost forgot cardboard footers made from 8 layers of 1/4" worked as well

[anubisgrau]

i've finally had a chance to hear promitheus in a normal (not-ref) version from nov 2006, 4 RCA inputs and 2 RCA outputs, against another fully DIY TVC, with a single input and dual mono volume selectors (9 steps only).

sorry to say but promitheus was clearly beaten, hands down.

still i found it amazing device for 340$ only.

however i found its tonal balance not to my taste, at least in comparison with another device. it sounded thin and dry, with not so much weight in bass and overal fluid in sound compared to the DIY TVC. but the main issue was an emotional involvement: promitheus sounded a bit "mechanical" or "confused", while the DIY TVC had tremendous ability to put together all the sound details into emotional associations - from singers swings around a microphone, to players moves around their instruments.

our small panel, consisted of 4 experienced audiophiles more keen on analogue/valve school of thinking, had no doubts about the winner and the difference was not too small. i hope that later versions of promitheus are better - there was an obvious room for a substantial improvement.

the main design difference between 2 TVCs is a core geometry. promitheus has EI cores while our DIY TVC has plain iron, double-C cores. also the DIY TVC has 6db gain.

nick, have you ever tried making a TVC with a different core geometry?

the pics of the DIY TVC are here:

[anubisgrau]

forgot to add: promitheus sounds clearly better without a steel lid. i think this is a weak spot considering that the transformers are not shielded - it probably interferes with the TVCs magnetic field. this has to be wood too.

[jaspal kallar]

i've finally had a chance to hear promitheus in a normal (not-ref) version from nov 2006, 4 RCA inputs and 2 RCA outputs, against another fully DIY TVC, with a single input and dual mono volume selectors (9 steps only).

sorry to say but promitheus was clearly beaten, hands down.

still i found it amazing device for 340$ only.

What was the cost of the DIY TVC?

    - jaspal

[rollo]

anubisgrau,
                 It was bound to happen, one negative review out of 124 pages of threads. What components did you use. From the photos it doesn't look like the system was much. Did the TVC have the Ref. 3 trannies? Did you play the unit for 20 minutes to warm it up? How did you conduct the comparison. What is the output voltage of the CDP you used. If it sounded thin and bright either it was the source or the TVC was not fully broken in. I thought the same thing until the TVC had over 350 HRs of play time. I am puzzled by the statement that it sounds this way because it is unshielded but with the cover off it sounded better. I agree it sounds better with the cover off, however doesn't the steel cover aid in shielding.
          I think most all posters disagree that the unit is thin and bright. It has air and bloom just not as much as a tubed active. What type of internal wiring is in the homemade version? If it is copper I can bet this would make a difference. If not there was a synergy problem somewhere either the CDP or cabling.
          Who's trannies did you use and how much did it cost to make?

rollo
               

[goldlizsts]

anubisgrau,
                 It was bound to happen................................. ......
rollo            

Yeap, it's bound to happen.  Our ears are so different (is that the only factor?).  Some will swear that his solid state amp has better sound than the other guy's tube amp.  The argument goes on forever.  Can't shoot the guy for his personal preference.  The key perhaps is get a concensus (the law of average?) of a bunch of people at the same session to make an argument convincing, like a RAVE, with identical peripherral equipment and setting, other than 2 TVCs being A-B compared. 

[anubisgrau]

anubisgrau,
                 It was bound to happen, one negative review out of 124 pages of threads. What components did you use. From the photos it doesn't look like the system was much. Did the TVC have the Ref. 3 trannies? Did you play the unit for 20 minutes to warm it up? How did you conduct the comparison. What is the output voltage of the CDP you used. If it sounded thin and bright either it was the source or the TVC was not fully broken in. I thought the same thing until the TVC had over 350 HRs of play time. I am puzzled by the statement that it sounds this way because it is unshielded but with the cover off it sounded better. I agree it sounds better with the cover off, however doesn't the steel cover aid in shielding.
          I think most all posters disagree that the unit is thin and bright. It has air and bloom just not as much as a tubed active. What type of internal wiring is in the homemade version? If it is copper I can bet this would make a difference. If not there was a synergy problem somewhere either the CDP or cabling.
          Who's trannies did you use and how much did it cost to make?

rollo
               

dear rollo,

could be that my short review was insufficient - and i would never call it negative.  i think that promitheus is amazing product considering the price and my opinion on it is actually very high. there was the third preamp in the session (the far left on the shelf) - electrocompaniet EC4.7 mk2 and promitheus sounded more detailed and less coloured - definitely better in general, although not a day and night difference.

i guess no one here expects promitheus to be the best preamp in the world and that it can't be beaten. with promitheus i could hear a room for improvement. i didn't say that promitheus was bright - not at all, it was just thinner, lighter and less full bodied compared to the other TVC from the session, with less air and less space and less emotional information, but still sounding excellent. i have to emphasise again that the performance of the other TVC was trully stellar - if i didn't have it with me, i would be probably left with an impression that promitheus was maybe the best preamp i tried in my system (along with pass labs x2.5, maybe).

the version of promitheus is a normal one (not ref) from nov 2006. i know there are better versions now, including mine that will arrive soon to me (reference with better connectors and grayhill switch). the unit we tried had one of the trannies a bit wobbly as there was a tiny crack under it.

is my system competent enough for such an analysis? i don't know, judge it for yourself: active ATC 20A speakers ($8000 new), thule CD150B CD player ($2000), VdH the second & MC gold cables throughout.  the CDP can be better, but i still think it can make some decent sounds.

PS. the DIY TVC has no price. it's a hand made prototype practically just put together out of curiousity to test if the TVC as such works or not. the guy who wound  its transformers spent 6 working days on that. the pots are relatively cheap, the RCA connectors are $1.5 plain ones too. i don't think the value in copper, iron and wood is more than $50 plus cost of hands (R&D aside). it is not a commercial product and it can't be bought so it is not a competition to anyone. to be honest its sound is so addictive i would kill to get one for me, but the irony is that constructors don't care about business so i would need to negotiate hard to get one made for me.

[anubisgrau]

the CDP we used for test (thule CDP150B) has a standard 2V output thru SE outputs at 100ohm impedance. the session lasted 4 hours but the difference was obvious after 10 seconds and it stayed thru the session. there was an obvious improvement with promitheus with lid off, otherwise it made no difference. there were 4 persons in panel, 3 of them with 30 years plus experience with true high end and everyone (including the owner of promitheus) had a completely similar opinion. my only doubt is if the promitheus was fully run in, but as the unit was delivered in nov 2006, the owner was confident about it although i raised this issue a few times during the set. i can't tell that 101% sure.

anyway i will have my promitheus soon to play so i will be able to confirm or withdraw the conclusions. the most fascinating thing is that i heard 2 very different TVCs in 2 days, both absolutely amazing products almost for peanuts! i want more of this excitement!

[davetroy]

Now I'm really pissed off! I can't believe the Promitheus isn't the best preamp in the world, and I spent over $400 for it! 

Seriously, "excitement" is the word to describe this TVC sound. I can't tell you how many times over the past few weeks I've turned on my stereo as background music and ended up sitting down to listen because the sound was so inviting.

By the way, Promitheus with the cover off: Is that recommended? Has anybody else noticed an improvement? Is it safe? (meaning, the cover does serve some purposes, like keeping dust out, right?)

[gooberdude]

another vote for the lid off, my man!!!    mine's been off a few weeks, tried to put it back on...just sounds better off to me.   the steel lid is non-ferrous though...

A friend of mine used to have the same ATC speaks as yours..my 1st & only experience with active speakers
or ATC speakers.   Phish was a little too much on them, but jazz was ultra slick.    he was using a Linn preamp though which i thought was bright.

Since owning this TVC i've wondered how cool it would to have a TVC + active speakers + battery powered source...    1 power cord, so simple...

What are the tiny tags on each of the tranny output wires in the special TVC?   are those just to write on or do they serve another purpose?    Nick Chua and the maker of those trannies should compare notes...nick could help him cut down the 6 day tranny construction job and he could help Nick make $1000 per pair trannies.