Promitheus TVC passive preamp anyone?

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tanchiro58

Re: Promitheus TVC passive preamp anyone?
« Reply #920 on: 31 Jan 2007, 10:34 pm »
Tan,

Did you purchase your dual mono tvc straight from Nic or from audiogon?  You mentioned earlier that you bought one off audiogon, but I wasn't sure if it was your stereo one or your mono.  I purchased one off audiogon from Gvcycleman, at the time he was selling two dinged up dual monos, a light one and a dark one.  Just wondering because mine does not have 24 steps, it is only 16 steps + mute with -32db of attenuation.

Jared

Jared,

That is a seller who sold the dual mono TVC (light color) to me. Does your TVC have a bottom wood too? How is your TVC sounding? Mine looks beat up at the bottom and the wooden attenuator (I think I have 23 steps), one got little loose. But to me this one sounds much better than one I had before. Anyway I am thinking to get a Dual Mono Reference Stainless Steel case in a couple months. Nick told me the SS version has better sound than Wooden version. :shh:

jaspal kallar

Re: Promitheus TVC passive preamp anyone?
« Reply #921 on: 31 Jan 2007, 11:22 pm »
However, there is a slight problem: at lowest level on the volume control, the sound is still too loud for late night and easy listening. I need to figure a way around this, any hint or tips?


Regards,


I think the TVC needs a month to settle in order to fix the click #1 problem...i recall thinking the same as you initially.

it could be a gain or impedence issue too.     

Mine is a few months old now and i don't notice the 'instant sound' being a problem anymore.    however there is still sound at click 1, which is something no other pre i've owned did.

Over the next month the presentation should get real smoooooth almost to where the term 'effortless' is an understatement.

matt

I'm not sure what is meant by click #1 TBH. If I turn the volume down to the lowest click, is that click #1? Anyway at that lowest position there's not sound.

I have to say at click #1 the sound is too high to for late night listening. I don't need to in general go beyond the 10 'o clock position for normal listening. I know my speakers have a "high-ish" sensitivity , so maybe that's the reason. Also, I'm getting 2V from my DAC but I gather that's quite the average.

Where I live, the allowed time for late music playing at night is 10pm. So all in all the music at low volumes is not an issue although if I get another TVC, I'll ask Nick if there's anything that can be done for late night listening.

  - jaspal.

guest1632

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Re: Promitheus TVC passive preamp anyone?
« Reply #922 on: 31 Jan 2007, 11:31 pm »
However, there is a slight problem: at lowest level on the volume control, the sound is still too loud for late night and easy listening. I need to figure a way around this, any hint or tips?


Regards,


I think the TVC needs a month to settle in order to fix the click #1 problem...i recall thinking the same as you initially.

it could be a gain or impedence issue too.     

Mine is a few months old now and i don't notice the 'instant sound' being a problem anymore.    however there is still sound at click 1, which is something no other pre i've owned did.

Over the next month the presentation should get real smoooooth almost to where the term 'effortless' is an understatement.

matt

I'm not sure what is meant by click #1 TBH. If I turn the volume down to the lowest click, is that click #1? Anyway at that lowest position there's not sound.

I have to say at click #1 the sound is too high to for late night listening. I don't need to in general go beyond the 10 'o clock position for normal listening. I know my speakers have a "high-ish" sensitivity , so maybe that's the reason. Also, I'm getting 2V from my DAC but I gather that's quite the average.

Where I live, the allowed time for late music playing at night is 10pm. So all in all the music at low volumes is not an issue although if I get another TVC, I'll ask Nick if there's anything that can be done for late night listening.

  - jaspal.

Hi Jaspal,

You might want to have your Dac checked out. 2 Volts coming in to the TVC will work, but that's a lot of voltage. Now, if it was 2 Milivolts that's one thing. 2 volts is a candidate to destroy tweeters.

Ray

jaspal kallar

Re: Promitheus TVC passive preamp anyone?
« Reply #923 on: 31 Jan 2007, 11:48 pm »

Hi Jaspal,

You might want to have your Dac checked out. 2 Volts coming in to the TVC will work, but that's a lot of voltage. Now, if it was 2 Milivolts that's one thing. 2 volts is a candidate to destroy tweeters.

Ray

Ray, I'm not all that hot with kind of stuff. I remember writing the following to Nick about my dac:


"The normal RCA output to the (pre)amp: Output Level 2.0 V rms +/- 0.5B   (Impedance 100 Ohms)".

No idea what it means. Your probably correct though - it's more like 2 Milivolts.To be honest, my active pre had a similar trait - high-ish sound/volume at low volume settings.

  - jaspal



tanchiro58

Re: Promitheus TVC passive preamp anyone?
« Reply #924 on: 1 Feb 2007, 12:01 am »

Hi Jaspal,

You might want to have your Dac checked out. 2 Volts coming in to the TVC will work, but that's a lot of voltage. Now, if it was 2 Milivolts that's one thing. 2 volts is a candidate to destroy tweeters.

Ray

Ray, I'm not all that hot with kind of stuff. I remember writing the following to Nick about my dac:


"The normal RCA output to the (pre)amp: Output Level 2.0 V rms +/- 0.5B   (Impedance 100 Ohms)".

No idea what it means. Your probably correct though - it's more like 2 Milivolts.To be honest, my active pre had a similar trait - high-ish sound/volume at low volume settings.

  - jaspal




Jaspal,

You have way too much gain. I did have the same problem before but now I can listen to my music in the middle of the night at 10 o'clock without disturbing my family since I replace a pots volume with a Golden Point 24 steps attenuators in my amp. Besides the music is getting better and better after replacing the amp's volume control. :dance:

Regards,
Tan

guest1632

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Re: Promitheus TVC passive preamp anyone?
« Reply #925 on: 1 Feb 2007, 12:27 am »

Hi Jaspal,

You might want to have your Dac checked out. 2 Volts coming in to the TVC will work, but that's a lot of voltage. Now, if it was 2 Milivolts that's one thing. 2 volts is a candidate to destroy tweeters.

Ray

Ray, I'm not all that hot with kind of stuff. I remember writing the following to Nick about my dac:


"The normal RCA output to the (pre)amp: Output Level 2.0 V rms +/- 0.5B   (Impedance 100 Ohms)".

No idea what it means. Your probably correct though - it's more like 2 Milivolts.To be honest, my active pre had a similar trait - high-ish sound/volume at low volume settings.

  - jaspal




Hi Jaspal,

Ok, now I understand. What you just told me is different than I thought. It takes 2 volts RMS to clip your amp. That's pretty much standard fair.

Is the no. 1 position louder than say the no. 2 position? If so, then there is a problem with the TVC. If it's the same volume, there still might be a problem. Will have to ask Nick about that one. I don't have a TVC to play with yet. From what I am reading here in this thread, the first position there shouldn't be any music at all. Others might confirm this.

Ray

gooberdude

Re: Promitheus TVC passive preamp anyone?
« Reply #926 on: 1 Feb 2007, 12:45 am »
There's defintely music playing when mine is turned up just 1 click, but its not loud enough to disturb the neighbors.  Mine goes go from Off to On in 1 click. 

Jaspal, as you go past that 1st click does the volume ramp up fast, or slow & steady? 

Overall, volume is quite difft with this TVC compared to other pre's i've used.  Even though there's music at the first click, when the volume is cranked 90% of the way its not raging loud.  Its like the volume adds more body and makes the soundstage bigger rather than make my ears bleed.

Some nights i don't even change volume for 5 LP's or more, not even betw sides or when the needle drops.

Whitese

Re: Promitheus TVC passive preamp anyone?
« Reply #927 on: 1 Feb 2007, 01:06 am »
i get nothing at all at zero clicks, and little at first...I specified that I have efficient speakers though, and not using the most efficient yet.

rollo

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Re: Promitheus TVC passive preamp anyone?
« Reply #928 on: 1 Feb 2007, 01:11 am »
Hey,
        I'm running 3.3V from my source.I get music at the first click and then a gradual increase in volume as I go up the steps.Depending on the CD the volume at the first click varies from low to a bit louder.
     I agree with Gooberdude that the higher volume settings give more body and a larger sound stage.It appears to be an impedance issue that I can not answer.
      Jaspal 10PM and its over WOW big brother sucks.Looks like they sell alot of headphones where you live.The 2V output of your source is plenty.What is the gain of your amp?What is Sensitivity of speakers?
      Hey Nicholas you listening if the first step is +2DB on the volume control with a 2V input from source why are we getting different results?
       By the way how are the copper wires doing against the silver any news?
  rollo 

PS  Ray we have used sources with 7v outputs with NO PROBLEM[E-MU D/A conv.]
« Last Edit: 1 Feb 2007, 01:29 am by rollo »

NewBuyer

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Promitheus TVC passive preamp anyone?
« Reply #929 on: 1 Feb 2007, 02:39 am »
The power energizer should be classified as power conditioner. If you are looking for a isolation transformer we have our own Balance transformer
unit called Balanced Power Supply at promitheusaudio.com
Cheers hope this helps
Nicholas


Nicholas, what about the devices that get plugged directly into the Power Energizer, are they connected to the transformer secondary winding? If so, would it mean the Power Energizer is acting as an isolation transformer for those devices plugged directly into it?


Gaara

Re: Promitheus TVC passive preamp anyone?
« Reply #930 on: 1 Feb 2007, 02:54 am »
A 2v source is pretty common with the advent of digital sources like DVD players, CD players, and DAC.  I don't think I own a source that has a output less then 2v.

As for the sudden changes in volume, this should be the nature of the beast.  Any piece of equipment that uses stepped attenuation instead of continuous will do this, you go from mute to some value.  In the TVCs it should go from cutting off the signal to -48 to -46 to -44, with nothing in between.

A cd will effect the volume, as this is dependent on recording levels.  I will listen to one disc and it is the perfect volume then listen to another and have to change things.  As for this being quieter then other pres, I would assume so if it is a comparison between a TVC and a active pre.  Your average pre will have 15db of gain, thats 15db more then the Promitheus TVC has.  As for Rollo's comment, he already figured it out.  If people are using the same pre the volume can vary greatly.  I mean when you can have speakers with efficiencies ranging from 83db-108db or more this will cause large discrepancies.  Throw in different gains for different amps and you can have wildly different volumes at the same setting on the same pre.

Tan,

I thought so, how light is yours?  I thought he was selling a dark redish one and more of a light cherry one.  The one I purchased was the lighter one, it matches my computer desk quite well which is where it will eventually reside.  Currently it is in the big rig, and it matches my Bello stand pretty well as well.  It seems the seller beat up both of ours the same, mine has a few chinks on the sides and a decent one in back, but the front is clean.  When I got it the right volume knob was not functioning, but I just unscrewed it and screwed it back on and it works fine.  The only thing is it doesn't want to work centered, so it is isn't on straight, but you can't really tell.  As it turns out the bottom is wood, didn't even notice that the current models weren't.  As for sound quality I am impressed so far, I like this better then the Luminous Audio Axiom I have (TVC will be replacing this in the computer rig), better then the Endlers I have, and better then my B&K Ref 50.  It does not beat out my Modwright though, hopefully my Dual Mono Ref 3 will be able to come closer.  Currently I am using the TVC and the Endlers in tandem as 32db of attenuation is not enough for me, so I have the Endlers set to 16db attenuation to mimic a standard TVC.

Quote
That is a seller who sold the dual mono TVC (light color) to me. Does your TVC have a bottom wood too? How is your TVC sounding? Mine looks beat up at the bottom and the wooden attenuator (I think I have 23 steps), one got little loose. But to me this one sounds much better than one I had before. Anyway I am thinking to get a Dual Mono Reference Stainless Steel case in a couple months.

Jared

guest1632

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Re: Promitheus TVC passive preamp anyone?
« Reply #931 on: 1 Feb 2007, 04:32 am »
Hey,
        I'm running 3.3V from my source.I get music at the first click and then a gradual increase in volume as I go up the steps.Depending on the CD the volume at the first click varies from low to a bit louder.
     I agree with Gooberdude that the higher volume settings give more body and a larger sound stage.It appears to be an impedance issue that I can not answer.
      Jaspal 10PM and its over WOW big brother sucks.Looks like they sell alot of headphones where you live.The 2V output of your source is plenty.What is the gain of your amp?What is Sensitivity of speakers?
      Hey Nicholas you listening if the first step is +2DB on the volume control with a 2V input from source why are we getting different results?
       By the way how are the copper wires doing against the silver any news?
  rollo 

PS  Ray we have used sources with 7v outputs with NO PROBLEM[E-MU D/A conv.]

Hey Rollo,

Actually, Jaspal's problem as far as the voltage goes, isn't a problem. Once I understood what was going on, it will take 2.0 Volts RMS to clip the amp. Yeah, I remember Nick talking about the offset voltages that the TVC can take as much as 7 V witout a problem.

Ray

tanchiro58

Re: Promitheus TVC passive preamp anyone?
« Reply #932 on: 1 Feb 2007, 05:40 am »
Tan,

Did you purchase your dual mono tvc straight from Nic or from audiogon?  You mentioned earlier that you bought one off audiogon, but I wasn't sure if it was your stereo one or your mono.  I purchased one off audiogon from Gvcycleman, at the time he was selling two dinged up dual monos, a light one and a dark one.  Just wondering because mine does not have 24 steps, it is only 16 steps + mute with -32db of attenuation.

Jared

Jared,

You are absolutely right. My TVC has only 16 steps dual mono (sorry! I mixed up with my other preamp). Mine has red cherry color and I thought I purchased the light one. My TVC got beat up too scratches everywhere along a wooden frame. I got one tranny loose because the wooden bottom does not hold tight the screw. So I have to drill another hole for that screw to hold tight the tranny (look messy down there). I plan to buy a copper or brass plate or sheet to isolate the trannies and the wooden plate. But then when I listen to this one and surprisingly it beats the first one I bought also from Audiogon but it is stereo volume control with bottom and top aluminum plates. Therefore, I sold the single volume one to F-100, who is very happy over his BC3 preamp. :thumb:
How is your Reference one? I plan to order from Nick the Stainless Steel Reference TVC in a couple months. Let me know when you brake in the Reference and compare to the one you have now. :wink:

Regards,
Tan

StereoJoe

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Re: Promitheus TVC passive preamp anyone?
« Reply #933 on: 1 Feb 2007, 08:41 am »
As for the sudden changes in volume, this should be the nature of the beast.  Any piece of equipment that uses stepped attenuation instead of continuous will do this, you go from mute to some value.  In the TVCs it should go from cutting off the signal to -48 to -46 to -44, with nothing in between.
You're right, this is the nature of a stepped volume control. My CD and tuner both provide 2V, the poweramp has an input sensitivity of 1.1V while the speakers are 89dB@1W. All in all, -48dB is a bit loud. Guess I have to do something about the poweramp sensitivity or maybe add some attenuators on the IC from TVC to poweramp...

jaspal kallar

Re: Promitheus TVC passive preamp anyone?
« Reply #934 on: 1 Feb 2007, 04:38 pm »
There's defintely music playing when mine is turned up just 1 click, but its not loud enough to disturb the neighbors.  Mine goes go from Off to On in 1 click. 

Jaspal, as you go past that 1st click does the volume ramp up fast, or slow & steady? 

Mine is the same as gooberdude. There's music at the first click and it goes from Off to On in 1 click. The sound ramps up "slow and steady" after the 1st click. I would say that on the first click it's a tad too loud say if you wanted background music when having guests.

Hey,
        I'm running 3.3V from my source.I get music at the first click and then a gradual increase in volume as I go up the steps.Depending on the CD the volume at the first click varies from low to a bit louder.
     
      Jaspal 10PM and its over WOW big brother sucks.Looks like they sell alot of headphones where you live.The 2V output of your source is plenty.What is the gaino of your amp?What is Sensitivity of speakers?


Again, same as for rollo; music at the first click and then a gradual increase in volume as I go up the steps.

Funny you mention headphones; I was wondering if Nick ever thought about doing a headphone amp?

Spkr Sensitivity Level =   91dB 

Gain , not sure but the info below taken from my amp's manual:

Input imp. Of your power amp:   10k Ohm (RCA), 22 Ohm (XLR)
Input sensitivity of your power amp in mV:  381 mV (RCA), 775mv (XLR)

Ok, must add that I'm happy with the TVC even with the volume at low volumes; Perhaps Nick can suggest any modifications (in the future) that can rectify this - perhaps something like another Stereo 23 pole switch version?
 
  - jaspal.

Edit: I use XLR between the TVC and my amp.


rollo

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Re: Promitheus TVC passive preamp anyone?
« Reply #935 on: 2 Feb 2007, 01:24 am »
Jaspal,
            Input sensitivity is fine for TVC,however the input impedance might be a tad low.With 91db speakers your a perfect candidate for SET amp.
            Check out Vista-Audio.com $350USto $800US.I heard the $350 model at a NY rave meeting and I'm buying one.Simply amazing sound.
            Will put up against the consonance Cyber 211.It beat out a modified Dynaco and the top of Bat's Solid state line.We used the Promitheus with all amps and the Vista just stopped EVERYONE from talking and just listened in awe.

rollo

Early B.

Re: Promitheus TVC passive preamp anyone?
« Reply #936 on: 2 Feb 2007, 01:47 am »
I'm looking for a used 200 wpc or more SS amp with an input sensitivity in the millivolt range. Budget is <$1K.

Any ideas would be appreciated.

rollo

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Re: Promitheus TVC passive preamp anyone?
« Reply #937 on: 3 Feb 2007, 04:01 pm »
I'm looking for a used 200 wpc or more SS amp with an input sensitivity in the millivolt range. Budget is <$1K.

Any ideas would be appreciated.

    I have a Classe DR25 250W per channel into 8 Ohms.Silver faceplate but its $1200.Let me know.
 rollo

JLM

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Re: Promitheus TVC passive preamp anyone?
« Reply #938 on: 3 Feb 2007, 06:03 pm »
Call me stupid (you'll have to get in line), but with all these options of plates, wires, knobs, transformers, etc. doesn't all this add up to producing and varying different colorations?  As a purist and a "simplier the better" kind of audio-nut, that bugs me. 

Are the changes heard affecting imaging/soundstaging (or is it just frequency response)?  I know that midrange emphasis can be described as sounding "forward", so this can be a tricky call.  If I need to adjust the frequency response, wouldn't an equalizer make more sense (especially in the digital domain for those of us using digital sources)?

rollo

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Re: Promitheus TVC passive preamp anyone?
« Reply #939 on: 3 Feb 2007, 11:03 pm »
JLm,
       I guess the same reason you bought you CDP with ALL the options.
   rollo