Promitheus TVC passive preamp anyone?

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Pacio

Re: Promitheus TVC passive preamp anyone?
« Reply #1080 on: 22 Feb 2007, 04:19 pm »
I actually don't know Gooberdude!
As for the amp gain I have to ask Klaus if I can do myself. As for the source, my North Star Model 192 DAC is rated 2Vrms as output voltage, maybe a bit too much..and again I don't know if I can get it regulated.
One thing: I have an active preamp in the works from Nicholas and I could lower a bit the gain, but I wonder if I could compromise either the power of my Stratos Extreme and the overall sound quality of my combo TVC+active preamp..what do you think?
Thanks,
Marco

gooberdude

Re: Promitheus TVC passive preamp anyone?
« Reply #1081 on: 22 Feb 2007, 05:14 pm »
Others would be better equipped to answer you correctly, but my guess is that Nick will set you up proper when he makes the new TVC and active pre for you.


So, this might only be a temporary problem for you..

guest1632

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Re: Promitheus TVC passive preamp anyone?
« Reply #1082 on: 23 Feb 2007, 02:58 am »

I live in US no fees or duty.We have a free trade agreement with Malaysia.
rollo

Hey Rollo,

Well, got my replacement TVC. I voiced it versus the "Purist", and they both seem to have about the same tonal balance. The TVC might have a bit more topend, but that's a maybe. Coming from the TVC back to the "Purist", it's almost a letdown. At this moment, my system is by no means a killer one. The Linn amp, at least mine has never sounded better.

aRay

stereohifi

Re: Promitheus TVC passive preamp anyone?
« Reply #1083 on: 23 Feb 2007, 03:48 am »
Hi Rollo, i've read in one of the other posting that you had the S&B TVC transformers in your system.
Do you still have them, and does it compare to the Promitheus TVC's ?
Since the TX-102 of S&B just gone up by $75, Nicholas TVC seems a greater bargain indeed!!
Would you qualify  Promitheus TVC equals or even better than S&B ?
Thanks.

PromitheusAudio

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Re: Promitheus TVC passive preamp anyone?
« Reply #1084 on: 23 Feb 2007, 05:06 am »
WOW,  thanks for the long and clear answer :thumb:        This must be a very good pre then  :D

EDIT:   is it 500 including shipping?     And how much is your balanced powersupply? ( the small one),  Drop me a pm if you don't want to tell it on the boards...    I'll have to save up some money, your  products look very good!!!!!

THe price is without shipping. Shipping comes to usd550.
THe balanced power supply is US360 with shipping

Cheers
nicholas

PromitheusAudio

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Re: Promitheus TVC passive preamp anyone?
« Reply #1085 on: 23 Feb 2007, 05:11 am »
Hello to all, since  Nicholas products are from Malaysia, does somebody can share with us what customs fees, if any they had to pay, particually in Canada or US.
I,M looking for the whole pakage, balanced TVC + tube buffer, all to replace a very well known name tube amp.
Regards.

From US to Malaysia there is no tax as i know. BUt anyway we often undeclare the prices to avoid custom fees. I don't feel it is good to pass on taxes to users. Especially countries like Netherlands which has a 30% tax rate. We often declare the items to be super low in price, imagine 30% is huge. So often we declare the unit around usd20-30 only. then they either escape the tax because it too low, or pay a token amount only. Often the customs do not bother to tax the unit as the value is too low.

THank god you are staying in the US and not elsewhere, paying 30% tax is obscene.

guest1632

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Re: Promitheus TVC passive preamp anyone?
« Reply #1086 on: 23 Feb 2007, 07:13 am »


Hi Nicholas,

Got the new unit. Was curious if: I were to separate the buses ground, would the unit still work? You have the in and out ground as one ground.

Ray

rollo

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Re: Promitheus TVC passive preamp anyone?
« Reply #1087 on: 23 Feb 2007, 03:48 pm »
Hi Rollo, i've read in one of the other posting that you had the S&B TVC transformers in your system.
Do you still have them, and does it compare to the Promitheus TVC's ?
Since the TX-102 of S&B just gone up by $75, Nicholas TVC seems a greater bargain indeed!!
Would you qualify  Promitheus TVC equals or even better than S&B ?
Thanks.
 

sterohifi,
            I do not own S&B unit. My friend built a unit, with S&B trannies and Shallco attenuators. He installed them in a maple enclousure that is lined with alum. as a shield.Internal wiring is Neotech 7N copper. THe unit cost him $1200 to build.
           When we first compared the two units, initially the Bent had the edge overall. The Promitheus was not fully broken in as of yet. The main difference was the Bent unit had a bit more weight to the sound. When the promitheus was broken in we compared them again. Overrall they were very close, with the Bent leading in the body and soul area. Our preference for the Bent unit was due to the interal wiring copper VS silver. we both agreed that if the Promitheus had copper wiring the difference if any would be small. After changing the wire on the Promitheus to copper, rond 3 proved very interesting. The Promitheus was equal to if not better in some areas and the weight issue just went away.
           The difference is subjective and may be difficult to hear. So $1200 VS. $530[ref/dual mono/ebony knobs] NO CONTEST Promitheus wins out for value and performance.
     Hope this helps
rollo

StereoJoe

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Re: Promitheus TVC passive preamp anyone?
« Reply #1088 on: 23 Feb 2007, 06:29 pm »
I heard about Rothwell In-Line Attenuators, which should attenuate about 10 db the sound. The attenuators have some drawbacks like loosing some "life like" sound, some trebles smoothened, some lacks here and there but I would use them only at night and they would be removed for normal listening. (about 70 USD/pair RCA)
Any comments or suggestions on that will be much appreciated.
Thanks,
Marco

I had exactly the same problem as you. Step 1 on the volume controller was too loud for late night listening. How did I solve this? Well, first of all I didn't want to do any modification of the input sensitivity of my poweramp. I ended up with a pair of in-line attenuators from Rothwell (XLR type), and had Mr. Rothwell design their resistance equal to the inputs of my amp. I can hear no negative effects on the sound quality, and the loudness at step 1 is now perfect for background/late night listening. I can really recommend these attenuators.

//Johan

stereohifi

Re: Promitheus TVC passive preamp anyone?
« Reply #1089 on: 23 Feb 2007, 10:37 pm »
Thanks Rollo for a very informative test with Promitheus TVC vs the Bent Audio S&B TVC's. So if we go with double mono, and double boxes , and that 7N copper internal wiring, it should be the best.
So what's all the fuzz about the silver wiring. Silver is the best conductor, but it seems to prouve that a mismatch exist,(copper xfo's//silver internal wiring) i would experiment both types in that case.

I've send an email to Bent audio a month ago, i didn't got response concerning the matching bethween a source with Zout of 400 ohms at 1, 3 volts and my amp 250kohms with 1,25 volts sensivity.

Nick, would you think that i get some problems by using only your TVC without the buffer amp? I'm not using extremely long balanced wiring anyway.
In the mean time, without a preamp at all, I will also try a pair of attenuators from Scott Endler, they might be great for ajustements of very low level of volume needed for late night music, once i received my TVC from Nick..
Thanks



guest1632

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Re: Promitheus TVC passive preamp anyone?
« Reply #1090 on: 24 Feb 2007, 01:02 am »
Thanks Rollo for a very informative test with Promitheus TVC vs the Bent Audio S&B TVC's. So if we go with double mono, and double boxes , and that 7N copper internal wiring, it should be the best.
So what's all the fuzz about the silver wiring. Silver is the best conductor, but it seems to prouve that a mismatch exist,(copper xfo's//silver internal wiring) i would experiment both types in that case.

I've send an email to Bent audio a month ago, i didn't got response concerning the matching bethween a source with Zout of 400 ohms at 1, 3 volts and my amp 250kohms with 1,25 volts sensivity.

Nick, would you think that i get some problems by using only your TVC without the buffer amp? I'm not using extremely long balanced wiring anyway.
In the mean time, without a preamp at all, I will also try a pair of attenuators from Scott Endler, they might be great for ajustements of very low level of volume needed for late night music, once i received my TVC from Nick..
Thanks




Hi Stereohifi,

As a general statement, silver wiring if done correctly will give you better detail than copper wiring. Copper wiring on the other hand, may not be as detailed, but will give you a warmer "more weightier" sound. If you go back and read from the very beginning of this thread, you'll see that Nicholas has and is striving to improve the TVC. He has played around with the different wire types. With the silver wiring, if I have understood him correctly, he has settled on using double runs of 24 gauge wire. The wire that he uses in the transformers are copper, not silver. The rest of the wiring is silver. Now with the suggestions from Rollo, Nicholas might be making more positive changes.

There's bound to be some differences between the mono units and the dual control units.   I'll almost bet ya that if you were to have a separate toggle switch for each channel, instead of the double pole toggle that he uses now for the 2 channel in and out, you just might hear more of a difference. After awhile though, you'd have to go far to make it much better than it is now. Rollo could possibly comment on that one. Even in its standard configuration, the difference between the Audio First, versus the Promitheus TVC, is not worth the ten times difference in cost. I personally haven't heard both units, but going by what I read here, the standard one in the steel case, $450 or so, and the audio First about $3,000. Yes, the more expensive one will have relays to switch out each channel, maybe a more rugged case, and perhaps a smoother feel when operating the switches. But I can tell you from owning the Promitheus that I have now, I have no regrets in having it. Neither will you. Just let it break in over time, and enjoy.

Ray 

stereohifi

Re: Promitheus TVC passive preamp anyone?
« Reply #1091 on: 24 Feb 2007, 03:16 am »
Thank you Ray for all of the details of developements of the Promitheus TVC. Since i'm a DIY, i'm hesitaing bethween using S&B tvc plus my time, and ending with results that could be similar to the Promitheus TVC .
That's why i'm asking questions on users that are able to compare stuff, that i don't have in my hands right now.
I'm waiting for Nick to reply on my email regarding the TVC that i like to get. Thanks.
Regards.

PromitheusAudio

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Re: Promitheus TVC passive preamp anyone?
« Reply #1092 on: 24 Feb 2007, 08:28 am »


Hi Nicholas,

Got the new unit. Was curious if: I were to separate the buses ground, would the unit still work? You have the in and out ground as one ground.

Ray

Nope the ground needs to be there.

PromitheusAudio

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Re: Promitheus TVC passive preamp anyone?
« Reply #1093 on: 24 Feb 2007, 08:34 am »
Nick, would you think that i get some problems by using only your TVC without the buffer amp? I'm not using extremely long balanced wiring anyway.
In the mean time, without a preamp at all, I will also try a pair of attenuators from Scott Endler, they might be great for ajustements of very low level of volume needed for late night music, once i received my TVC from Nick..
Thanks

On the impedance of your stuff the tvc would work fine. On the sensitivity looks fine, that means at max volume you get max volume from your amp. However you would be playing mostly around 2-3 o'clock of the volume. The active preamp combo would do better in your system  than the tvc aloneb ecause of the low output of your source(is this a phono) BUt the tvc would work in your system no doubt about that. I know the tvc can drive long cables with no loss of dymanics when compare to the tvc driving 1.5m cable (and not comparing to an active).

guest1632

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Re: Promitheus TVC passive preamp anyone?
« Reply #1094 on: 24 Feb 2007, 09:52 am »


Hi Nicholas,

Got the new unit. Was curious if: I were to separate the buses ground, would the unit still work? You have the in and out ground as one ground.

Ray

Nope the ground needs to be there.

Hi Nicholas, I have always been under the impression somewheres that you should never mix your input and output grounds. I'm not wanting to remove  the ground bus entirely, just want to separate the two sources.

Regards,
Ray

rollo

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Re: Promitheus TVC passive preamp anyone?
« Reply #1095 on: 24 Feb 2007, 05:17 pm »
Ray,
       I felt that for my setup that a single input unit would eliminate any switch in the circuit. For me I listen to either vinyl or CD for the evening. So changing the input to listen is not a big deal. The presence of the two pole switch and additional wiring was not necessary. I tried to keep the integrity of the signal as pure as possible.
      So , if this can work for you,if you are not to lazy to make an IC change then go for it. If you must have dual inputs the two pole switch is fine only if you USE SHORTING PLUGS as this would eliminate any crosstalk emanating from the switch. With multiple inputs a selector switch is used. The rod from the control to the switch should be changed to a non ferrous material to eliminate any incoming RFI that can make its way into the switch. If you choose a wood or nylon dowel any undue resonance should be removed as well.
      While all the tweaking has been effective, remember the TVC as delivered, delivers a wonderfull sound. So you ask youself, how come all these tweaks are not standard? The TVC has been built to a price point. If all were include the price would rise dramatically. The fact we can purchase this product for the asking price allows us the option of upgrading at our own pace, budget and most importantly synergizing the TVC to our systems. Even something like a footer can alter the sound to blend into your system. Tweaking is subjective to the character of the system. so, copper wiring for me maybe silver for you. Ebony footers for rich tone Mapleshade for extra detail. The choice is yours and personal to your listening pleasure.
     So, play away and remember "it not high end unless you can tweak it,"Harry Pearson, Absolute Sound.
    rollo
       

guest1632

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Re: Promitheus TVC passive preamp anyone?
« Reply #1096 on: 25 Feb 2007, 12:15 am »
Ray,
       I felt that for my setup that a single input unit would eliminate any switch in the circuit. For me I listen to either vinyl or CD for the evening. So changing the input to listen is not a big deal. The presence of the two pole switch and additional wiring was not necessary. I tried to keep the integrity of the signal as pure as possible.
      So , if this can work for you,if you are not to lazy to make an IC change then go for it. If you must have dual inputs the two pole switch is fine only if you USE SHORTING PLUGS as this would eliminate any crosstalk emanating from the switch. With multiple inputs a selector switch is used. The rod from the control to the switch should be changed to a non ferrous material to eliminate any incoming RFI that can make its way into the switch. If you choose a wood or nylon dowel any undue resonance should be removed as well.
      While all the tweaking has been effective, remember the TVC as delivered, delivers a wonderfull sound. So you ask youself, how come all these tweaks are not standard? The TVC has been built to a price point. If all were include the price would rise dramatically. The fact we can purchase this product for the asking price allows us the option of upgrading at our own pace, budget and most importantly synergizing the TVC to our systems. Even something like a footer can alter the sound to blend into your system. Tweaking is subjective to the character of the system. so, copper wiring for me maybe silver for you. Ebony footers for rich tone Mapleshade for extra detail. The choice is yours and personal to your listening pleasure.
     So, play away and remember "it not high end unless you can tweak it,"Harry Pearson, Absolute Sound.
    rollo
       


Hi Rollo,

Well, I'll agree with you about the TVC. This thing is getting better by the minute. The base is not as pronounced as it was when I got it, but I seem to remember that this is just a phase it goes through. It is indeed the best bang for the buck. I'll try that shorting of the other inputs. Should I also short out the other outs also?

By the way, mine didn't come with any footers. I presently have it sitting on top of a video card box, which is just about the same size as the TVC.

I tried using a thick mouse pad underneatch the unit, just on its own. I thought I heard a difference, but not for the better. It was darker or dryer in character.

Ray 

rollo

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Re: Promitheus TVC passive preamp anyone?
« Reply #1097 on: 25 Feb 2007, 01:33 am »
Ray,
       Just short the inputs leave the outputs alone. as far as footers try using 4 or 5 album covers with the record inside. Stop laughing, it is very effective. Gooberdude discovered this and when I read it I couldn't stop laughing. When I tried it The laughing turned to glee. Took it a step further and used 1/4" th. cardboard[8 layers= 2" th.]. This worked well. The ebony cones from Promitheus are the most effective. check out the sticky on tweaks under $10 in audio central.
     
  have fun rollo

guest1632

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Re: Promitheus TVC passive preamp anyone?
« Reply #1098 on: 25 Feb 2007, 06:23 am »
Ray,
       Just short the inputs leave the outputs alone. as far as footers try using 4 or 5 album covers with the record inside. Stop laughing, it is very effective. Gooberdude discovered this and when I read it I couldn't stop laughing. When I tried it The laughing turned to glee. Took it a step further and used 1/4" th. cardboard[8 layers= 2" th.]. This worked well. The ebony cones from Promitheus are the most effective. check out the sticky on tweaks under $10 in audio central.
     
  have fun rollo

Hi Rollo,

Hmmm, You know, I betcha that if you get some of that stuff like posterboard, the stuff they make signs out of, and put that down, cut to fit, both inside and out of the TVC.

Another idea I've been toying with, is to get some plexiglass and maybe? put it either inside the TVC on both the top and bottom. The idea is to just flat deaden the steel plates. By using disimiliar materials, often that a way of dendening materials.

Ray 

Whitese

Re: Promitheus TVC passive preamp anyone?
« Reply #1099 on: 25 Feb 2007, 12:44 pm »
You guys are just going bonkers with the tweaks I think.......I was just thinking that if you dampen some vibration that escapes the trannies, it doesnt mean that you may impact a lot of the vibration that gets thru the chasis itself as in attachement point between tranny and structure. 

I am not one to judge really how well this stuff works as I never tried them, but I cant help but think its nuts....Everything has its own sympathetic vibration freq that is unique to all materials. Why not just figure out whats the freq of vibration range that is most noticeable coming from the trannie and then look for the material that best dampens it. (that is, if the vibrations they convey is volume and freq dependent...maybe its not (maybe its same freq but just more of it) and that makes it simpler).