Promitheus TVC passive preamp anyone?

anubisgrau · « **Reply #1260 on:** 15 Mar 2007, 11:45 am »

another tweak suggestion: if possible, just remove the protective caps from your RCA or XLR connectors. this is for example not possible with some older tiffanies but works with WBTs.

promitheus sounds better not only with the lid off but also with the connectors' caps removed.

PS. my apologize - english is not my native language and i'm not sure if i was precise enough with "the protective caps". i mean you should leave ICs so you can see the soldering of a cable and a connector.

gooberdude · « **Reply #1261 on:** 15 Mar 2007, 03:07 pm »

Anubisgrua, would you be speaking of removing the barrel of the RCA plug? the outer cylinder? that's an old Mapleshade free tweak, one of the few I've not tried. i think it goes in-line with why Eichmann makes the Bullett plugs, to get the metal away from the signal. If so, it goes right in-line with using a TVC...stripping the fat from the music while still leaving lots of juicy meat.

Pretty much since Day 1 i've been on board that this TVC, or its chassis, are incredibly sensitive to footers and all sorts of other changes which involve vibrations inherently, or vibe control. My rigid turntable is the only other component i've owned that is this picky. tame the internal vibes by taping the source switch mount, removing all the other chassis screws & replacing the long metal rod on the Source switch (if your TVC has one). Then let all the vibrations escape the chassis via proper coupling footers and jettison them into a suspended tonewood vibration sink.

One crucial element to this recipe that i'm only now understanding is that it might be one of the the better sounding type of mounts available (for sane $), but its not the best performing mount by any means. An example would be with my TT: It sounds incredible now however, if i tap hard on the shelf it sits on that 'thud' will be audible through the speakers. The TT sounds better than it has a right to 'cuz of the mounting, but it doesn't keep other vibrations from entering the TT. isoblocks sounds fantastic, they're not the greatest isolators though. If you read Mapleshade's catalog re: these mounts, they never mention anything but sonic performance.

Even though many this in this hobby are subjective, controlling vibes properly may not be. there really might only be a few ways to do this that cover all the hyperbole adjectives (bass increases, air, force, clarity, 3-D, blah, blah) - problem is finding that key w/o breaking the bank! Setting anything under this TVC will change the sound a little bit though, assuming your system is revealing.

With my Imod on the way battery power has been on my mind a lot too. I would definitely consider a battery powered amp by Red Wine audio if the Imod is everything its cracked up to be....my thiels are pretty power hungry though so a speaker switch would be in order. Bob Brines designs would be my 1st pick in that direction, for sure.

a fellow AC member let me borrow his Audioprism Noise Sniffer device recently. 30 seconds with this in your home and you'll be contemplating battery power too. its amazing that our amps & sources perform the way they do with so much noise on the AC lines. the Sniffer sounds like a baby crying when turned up only halfway, and that's when its plugged into my expensive outlets. actually, there's no discerning cheap from audio grade outlets with the sniffer. the volume turned all the way up on it is a horrible, horrible experience. Music Direct still has the Quietlines on back order so i can't report on how trying to tame this issue affects my listening experience...yet.

rollo · « **Reply #1262 on:** 15 Mar 2007, 03:09 pm »

Guys,

Nicholas is ill at the moment, in bed with a fever. He will be back in action soon.
The conversations are very interesting and informative lately. Look the TVC is going to sound different in EVERY system as it basically a neutral piece. The source and the IC's from the source are critical to the synergy of your system.
To date with every piece of equipment I have inserted in my system something else had to be changed to compliment the piece. Maybe an IC, tube or speaker cable. The problem with neutral components is the up chain components must be spot on or you will hear their minuses more clearly and for the first time.
I guess pride of ownership, mine included has our defenses up. So keep the critiques coming as we can all learn from each other.
Anubisgrau, sorry if I appeared hard on you and the evaluation you conducted. Was curious of the system and method used so I could better understand your findings. I had a bad golf day and you got the brunt of it.
So to date the cover off with weight on top of trannies works well. Footers help, shorting plugs in unused inputs reduce RFI, EMI, and crosstalk. Wood dowel to selector switch, ebony rails under trannies all help in reducing vibration and provide more info and better sound staging.
It all depends on you, the tweaks all make a difference. So as a user the tweaks will be subjective to your taste and system. The more we know the more we can help each other.
The biggest surprise occurred when the powercord to the CDP was changed from the Omega Mikro active to an ESP. When the IC's were changed from CDP to TVC each one sounded clearly different not necessarily better. SO if anyone is wants to alter the sound, please start with the links to TVC.

rollo

rollo · « **Reply #1263 on:** 15 Mar 2007, 03:15 pm »

Quote from: Parnelli777 on 15 Mar 2007, 12:49 am

126 pages for this thing? Sh*t can this thread already, somebody, anybody.

Just think its the TV and change the channel. We are having fun with this, reason being that someone finally made a product that woks real well and costs little. Try one you may change your mind.
In a few weeks I will start a tour of the Ref. dual mono unit with ebony knobs for review. If you are interested let me know.

rollo

rollo · « **Reply #1264 on:** 15 Mar 2007, 03:21 pm »

Quote from: anubisgrau on 15 Mar 2007, 11:45 am

another tweak suggestion: if possible, just remove the protective caps from your RCA or XLR connectors. this is for example not possible with some older tiffanies but works with WBTs.

promitheus sounds better not only with the lid off but also with the connectors' caps removed.

PS. my apologize - english is not my native language and i'm not sure if i was precise enough with "the protective caps". i mean you should leave ICs so you can see the soldering of a cable and a connector.

Good find, WBT connectors can be bright in some systems. Removing the barrel is a positive step in sound. I removed the WBT's from a pair of Kimber 3030 jumpers connected to the Maggie crossovers and was very pleased with the results.
So if you can remove barrels do it.
rollo

Nels Ferre · « **Reply #1265 on:** 15 Mar 2007, 03:35 pm »

Rollo,

You have PM.

Nels Ferre
Orlando, FL

Paul_Bui · « **Reply #1266 on:** 15 Mar 2007, 04:18 pm »

Thanks Rollo for the tweaks summary.

kallitype · « **Reply #1267 on:** 15 Mar 2007, 05:30 pm »

THanks Rollo, sending getwell vibes to Nicholas. Drink lots of water!!!!

GHM · « **Reply #1268 on:** 16 Mar 2007, 01:00 am »

The audiophile I loaned my Reference stereo version TVC too, called me tonight to tell me what his initial thoughts were of the TVC . He listens to vinyl 99% of the time.

He felt the TVC may have had the edge on his reference in certain areas like transparency and something he says he couldn't put his finger on. His TRL preamp still has a tad more tonality. This is something I would have expected from a 100 lb tubed preamp.

Just from his comments tonight he likes the little cigar box and said he found it hard to justify the cost of his TRL unit which he loves dearly. I could be wrong but I see another TVC user coming aboard. He'll probably keep the TRL, but having given the TVC so much praise lets me know we have a true GEM here.

The other preamps from memory he's had in his system were the Aesthetix Callisto, First Sound, Conrad johnson premier 17LS , one of the BAT models and a Conrad johnson Premier 16LS . I can't remember the names of the others. He told me he puts the little TVC a head of all of these preamps besides his TRL for his taste in sound. No doubt this guy has burned through a lot of gear!

By the way, the speakers used in his setup are monster Montana/PBN EPXs.

I don't want anyone to think this is fabricated..it is not. He says he prefers not to do any postings himself.
I just wanted the owners to know..you guys have a great product! If you already hadn't figured that one out.

It won't work for everyone,but know it will take quite a bit of money to make a hint at embarrassing this little wonder box in the proper setup.

Good listening

Bill Baker · « **Reply #1269 on:** 16 Mar 2007, 01:12 am »

Hey guys, so I don't have to track through 127 pages, can someone give me the website address for this thing.

Randy · « **Reply #1270 on:** 16 Mar 2007, 01:23 am »

GHM, your friend has gone through a lot of top quality preamps, and if he says he prefers the Promitheus to them all, that's high praise indeed. And I assume he didn't use the active option with the TVC?

GHM · « **Reply #1271 on:** 16 Mar 2007, 01:29 am »

Quote from: Response Audio on 16 Mar 2007, 01:12 am

Hey guys, so I don't have to track through 127 pages, can someone give me the website address for this thing.

Here's the site Promitheus Audio.

Quote from: Randy on 16 Mar 2007, 01:23 am

GHM, your friend has gone through a lot of top quality preamps, and if he says he prefers the Promitheus to them all, that's high praise indeed. And I assume he didn't use the active option with the TVC?

No Randy it was just the TVC by its lonesome, no active output stages or buffers. I nearly fell on the floor when he told me what he thought of the unit. He's a pretty intense guy about this stuff.

Bill Baker · « **Reply #1272 on:** 16 Mar 2007, 01:37 am »

Thank you GHM. I didn't even think about searching for the most obvious.

Whitese · « **Reply #1273 on:** 16 Mar 2007, 01:55 am »

Good vibes also for Nick from south GA....

Paul_Bui · « **Reply #1274 on:** 16 Mar 2007, 02:06 am »

Quote from: GHM on 16 Mar 2007, 01:00 am

I just wanted the owners to know..you guys have a great product! If you already hadn't figured that one out.

The minute I set it up properly in my system (with home-made shorted RCA plugs, Mapleshade brass cones under it and over the trannies' top so that the unused inputs be quiet), I knew this is a gem. Even though it doesn't do imaging as wide, doesn't provide gain as powerful as my $2,000 tube pre, for such a passive component it's fantastic: quiet and cool like a precious stone, yet highs never be harsh, full and dynamic when music is, does details against a black background as though you listened at night with all the lights off.

This impression is on an only week old TVC. A few months from now, and.. TA DA!

F-100 · « **Reply #1275 on:** 16 Mar 2007, 05:25 am »

For all the TVC owners out there who listen with their top cover removed, can you please take a look at the wires from the trannies. Mine are touching the bottom steel plate. Are they suppose to be that way? If so, would that cause some kind of interference??

anubisgrau · « **Reply #1276 on:** 16 Mar 2007, 08:00 am »

Quote from: F-100 on 16 Mar 2007, 05:25 am

For all the TVC owners out there who listen with their top cover removed, can you please take a look at the wires from the trannies. Mine are touching the bottom steel plate. Are they suppose to be that way? If so, would that cause some kind of interference??

not really, these are not bare wares despite they look so

PromitheusAudio · « **Reply #1277 on:** 16 Mar 2007, 11:36 am »

Thanks for the wishes

Considering that i work from around 8 am to about 12-2am in the morning, i had the sickness coming.

Plus solder fumes does not help.

PromitheusAudio · « **Reply #1278 on:** 16 Mar 2007, 11:46 am »

Quote from: anubisgrau on 14 Mar 2007, 10:07 am

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
Thanks for the nice productive comments

I played with few core materials, and often found the bigger the better in terms of weight. In your pic's i see the double c core are way bigger than the current tvc size. I did some study and found the bigger core material often you get that effect you metnion whether it is c-core or EI core. Often the C-core is often very much more expansive to make due to the core being always more expansive to make. Also i noted down in my study the less wires you have, less taps it is easier to make the trans better as thicker wire can be used. Again it comes down to size, yes the body is often more, simple deductive reason bigger core weighter sound.

Perhaps i should make the tvc in bigger size cores. Note that the audio consultating also uses EI core.

PromitheusAudio · « **Reply #1279 on:** 16 Mar 2007, 11:51 am »

Quote from: F-100 on 16 Mar 2007, 05:25 am

For all the TVC owners out there who listen with their top cover removed, can you please take a look at the wires from the trannies. Mine are touching the bottom steel plate. Are they suppose to be that way? If so, would that cause some kind of interference??

Nope the wires are coated but if you can just leave them to be slightly above the steel plate. I normally dress them not to touch the plate but with shipping they often slightly touch the plates