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I guess the whole consideration of conductor carrying a signal being in close proximity to a sheet metal surface has gone by the wayside. Enamelled wire would be the most serious case, as it is able to be so close, due to the thin insulation. A comparison of two units, identical except for the bottom plate, would be instructive.
Russell, The bottom and top plates are Stainless steel. The later units have the wires undled in a way to insure no contact with the S/S plates. Earliar versions may require some Dynamat or equivalent material to get the most out of it. The trannies are screwed directly to the bottom plate. Removing for comparison would be difficult. I would suggest removing the top plate and compare. rollo
Quote from: rollo on 16 Mar 2007, 06:12 pm Russell, The bottom and top plates are Stainless steel. The later units have the wires undled in a way to insure no contact with the S/S plates. Earliar versions may require some Dynamat or equivalent material to get the most out of it. The trannies are screwed directly to the bottom plate. Removing for comparison would be difficult. I would suggest removing the top plate and compare. rolloI thought the metal bottom plate was an option and that wood was standard. By the way, I am talking about proximity, not contact.
Quote from: anubisgrau on 14 Mar 2007, 10:07 ami'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:anubisgrauThanks for the nice productive commentsI 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.
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:
i think the wooden bottom is best too, i'd like to see a thicker bottom plate on mine though.the wood bottom is highly beneficial if using Mapleshades pointed top Ultimate Triplepoint footers too. according to their site, sharp points into wood is best.
Its here. The dual box dual mono with Neotech 7N wiring. Your going to want this. Right out of the box you could tell. I will listen a bit tonight and then let it cook for 365HRs. It is just so natural sounding. I am amazed. The ebony cones are beautiful and well made. The ebony knobs are better than the origanal as far as grain and color is concerned. My only complaint is that the bubble wrap used for shipping leaves an imprint which is tough to remove. Maybe a piece of paper or cardboard could be used in between. Nicholas has out done himself with this effort. By the way the grounding post eliminated the very slight hum I had. Let me stress slight.
Even though it doesn't do imaging as wide...
Quote from: rollo on 16 Mar 2007, 06:25 pm Its here. The dual box dual mono with Neotech 7N wiring. Your going to want this. Right out of the box you could tell. I will listen a bit tonight and then let it cook for 365HRs. It is just so natural sounding. I am amazed. The ebony cones are beautiful and well made. The ebony knobs are better than the origanal as far as grain and color is concerned. My only complaint is that the bubble wrap used for shipping leaves an imprint which is tough to remove. Maybe a piece of paper or cardboard could be used in between. Nicholas has out done himself with this effort. By the way the grounding post eliminated the very slight hum I had. Let me stress slight.rolloi don't get one thing: has nicholas changed a wire he is using for winding? i remember you complaining about the sound of silver, but the TVC i was listening a few days ago had a copper wire - a silver wire was only to be seen behind the connectors on the back. this one is from oct/nov 06.were some earlier models wound with silver or i completely messed something up?cheers g
