Promitheus TVC passive preamp anyone?

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guest1632

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Re: Promitheus TVC passive preamp anyone?
« Reply #1040 on: 16 Feb 2007, 10:53 pm »
Rollo you forgot one thing, play the speakers out of phase.  This way the sound level is drastically reduced.  You could either use a y adapter and send one half of the signal to both speakers, or some test cds have mono brown noise out of phase for this purpose.  You want both speakers playing the exact same thing, but one to be out of phase.  This drastically reduces the sound level, and the blankets reduce it even further.

Jared
     


Jared,
        Thanks I corrected that probably after you read it.good looking out though.The brown noise does work well.
       This is why AC is so great.All just trying to help each other out.Now if someone could lend me their Ferrari for the month well, that would be real nice. 
rollo

Hi Rollo,

I would like to find out something from everyone reading this forum/thread.

First of all this excludes all the TVC's with wooden bottoms.

If you would take off the lids of your TVC's, and tell me, is the base plates where the transformers are mounted to the steel plate bent or curved up? This is fixable. Now you guys with the wooden boxes will definitely see this. Before I make any suggestions for fixes, let me see how right or wrong I am here.

Now, you ask, how come they're bent? Simple. The transformers are fairly heavy. With all of the throwing around for these boxes, the inershabends the transformers. Anyway, let me know. Then, I will give you a possible fix, and it might even result in better sound.

Regards,
Ray

 

tbabb

Re: Promitheus TVC passive preamp anyone?
« Reply #1041 on: 16 Feb 2007, 11:13 pm »
Rollo,

Sorry it took me so much time to get around to this.  Here is the inside of my TVC.





Babb,
           Looking good man,Is it possible to post a photo of the innards to show others what internal revisions have been implemented since the original.
          My active Prue has more bloom than the TVC,however the TVC may be more like the real thing.
          Saturday evening I attended a live event which was being recorded by John Atkinson of Sterile magazine.I noticed that decay of the sound lingered on what seemed like forever,there was sort of an initial bloom of the notes but subdued compared to colored version we get at home,which to many is a wonderfull thing.
        So ,which camp is correct?I would say both.As far as detail is concerned,it depends on where you are seated.The event was acoustic with NO PA system,so the brushed cymbals seemed subduded , meaning that the volume level of each instrument was different.
       This is why the super detail singnature of silver wire may be an issue for some listeners.If you like to sit in the first 3 rows than silver may be the ticket.
        By the way we were seated about 15 rows back center hall.What truly amazed me was the clarity of the bell of the cymbal,it just made its way directly to our ears.This I believe where silver has the edge at home.So what to do?Try both and see what floats YOUR boat.
       What I thought about the sound of the Steinway Piano was suprising,it was bright.Not like the sound I remember from a Baldwin.If we are not sure which camp,I suggest going to a live performace to remind us of what the real deal is and go from there.
       Enough rambling for now,enjoy your TVC.
Rollo

PromitheusAudio

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Re: Promitheus TVC passive preamp anyone?
« Reply #1042 on: 17 Feb 2007, 12:26 am »
NIck is info up on website already on the Active?

There is some details on the website at
http://www.promitheusaudio.com/activepreamp.htm

I am half way completing the page

PromitheusAudio

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Re: Promitheus TVC passive preamp anyone?
« Reply #1043 on: 17 Feb 2007, 12:30 am »
Is Nick's active pre still in the prototype stage or is it ready for sale?  Thanks

It is for sale and not in prototype stage.

Hi Nicholas,

Can a current TVC be fitted with the active preamp board. That way, I'd only need to use one of the outputs, and leave the other one alone. Does it use a separate supply?

Ray

Ray i don't get what you meant?  DO you mean can a old TVC be used with our active preamp? If so the answer is yes. ANd yes the active preamp has an outboard power supply which is a tube rectifer choke input.


Hi Nicholas,

If I take a current TVC,, can I buy the tube Preamp and mount it in the TVC myself? I'd use one of the outputs, and leave the other one alone.

Ray

Sorry the tube preamp is rather small and no way can fit a tvc inside.
This option is for current TVC users to upgrade

We are coming up with a single box TVC and active preamp soon

CHeers
Nicholas

guest1632

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Re: Promitheus TVC passive preamp anyone?
« Reply #1044 on: 17 Feb 2007, 01:02 am »
Is Nick's active pre still in the prototype stage or is it ready for sale?  Thanks

It is for sale and not in prototype stage.

Hi Nicholas,

Can a current TVC be fitted with the active preamp board. That way, I'd only need to use one of the outputs, and leave the other one alone. Does it use a separate supply?

Ray

Ray i don't get what you meant?  DO you mean can a old TVC be used with our active preamp? If so the answer is yes. ANd yes the active preamp has an outboard power supply which is a tube rectifer choke input.


Hi Nicholas,

If I take a current TVC,, can I buy the tube Preamp and mount it in the TVC myself? I'd use one of the outputs, and leave the other one alone.

Ray

Sorry the tube preamp is rather small and no way can fit a tvc inside.
This option is for current TVC users to upgrade

We are coming up with a single box TVC and active preamp soon

CHeers
Nicholas

Hi Nicholas,

You have it reversed. If I take your "small" preamp board or chassis, can it be, or can I put it in to a present TVC case with the present or current model of TVC? Or, ... does the case of both TVC with the preamp mounted inside of it need to be bigger?

Ray


rollo

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Re: Promitheus TVC passive preamp anyone?
« Reply #1045 on: 18 Feb 2007, 02:36 am »
tbabb,
        Thanks for the photo.looks nice and tidy inside compared to the earliar models.Wire ties and damping of trannie to S/S plate is also a good thing.
   Cool man enjoy

Ray,
       My bottom plate appears OK with no obvious deflection or bending.However the screw washers when over tightened may cause plate to deflect.
       By the way I tried a wooden dowel as you suggested between the top and bottom plate[2 1/2 in. high] good results for knuckle rap test creating a dull sound.Good idea Ray.However I prefer play with the top cover removed[or in place with screws and washers removed] and a wooden cigar box filled with sand on top.
      When I receive the ebony pieces to play with on the trannies themselves,we may have some good results.
       So Ray what you got up your sleeve good buddy.The best tweak I found this week were Q-Tips.EVERYONE CLEAN YOUR EARS it really helps.Stop laughing and clean away.
rollo

guest1632

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Re: Promitheus TVC passive preamp anyone?
« Reply #1046 on: 18 Feb 2007, 06:03 am »
tbabb,
        Thanks for the photo.looks nice and tidy inside compared to the earliar models.Wire ties and damping of trannie to S/S plate is also a good thing.
   Cool man enjoy

Ray,
       My bottom plate appears OK with no obvious deflection or bending.However the screw washers when over tightened may cause plate to deflect.
       By the way I tried a wooden dowel as you suggested between the top and bottom plate[2 1/2 in. high] good results for knuckle rap test creating a dull sound.Good idea Ray.However I prefer play with the top cover removed[or in place with screws and washers removed] and a wooden cigar box filled with sand on top.
      When I receive the ebony pieces to play with on the trannies themselves,we may have some good results.
       So Ray what you got up your sleeve good buddy.The best tweak I found this week were Q-Tips.EVERYONE CLEAN YOUR EARS it really helps.Stop laughing and clean away.
rollo

Hey Rollo,

Where does one get a cigar box? lol. I would think the hardness of the boweling would or could make a difference too. Maybe, Spruce, Oak, Walnut, Maple, and ... Ebony. Any of those would be an interesting test to see which one really made the difference. Besides, it's relatively cheap.. Dampening doesn't need to take up the entire piece you are attempting to denden. It just needs something that's dense enough, and just enough area to take away the ring.

Now some of you with the switches mounted on L brackets with extenders could say on the Selector Switch remove that metal shaft and replace it with harden wooden dowels the same size. I dare say, you will definitely hear a difference. Assuming that Nicholas made them all the same, the shaft on the Selector switch is 4-1/2 inches long, and the Volume switch is 2-1/2 inches long. (Your measurements may vary.)Be very careful on the little screws on the linkage between the two shafts. They can strip quite easily. Use a very small flat head screwdriver to loosen the screws. I did strip one.  It might be a good idea to take one of the linkage bars with you so when going to the hardware store or if you know someone who does woodworking, you can fit the size in to the linkage bar.

Rollo, I should have mine in a few days. It will be a Reference Version. Not sure is this one is the double wired one or not. So have you tried out the copper wire on yours yet? Mine is the two in and two out with Dual volume. I'm actually gonna look around for slightly smaller   knobs with either a point or slot for a better reference. That little dimple isn't quite enough to give me an exacting point of reference when I turn up the two knobs to match the loudness for each side. So if any of you guys out there have some good sources, let me know. I don't have the bucks to get the Ebony ones, so other ones will have to do.

Ray


tbabb

Re: Promitheus TVC passive preamp anyone?
« Reply #1047 on: 18 Feb 2007, 06:46 am »
Rollo,

So what are your findings after more listening?   I had gooberdude over today and I think we both agreed that the TVC when compared to my tube active was a bit on the lean side.  I think the TVC might be a bit more transparent than my active, but will need to do more listening to confirm.  I also had a brief listen to the TVC > Active combo. Only a 20 minute session.  Not conclusive on the results. I will need to do more tests to decide for myself. 

Tim



Guys,
  The TVC goes before the preamp.Tried it both ways and preferred before as Nicholas suggested.
    The difference in sound was this;TVC alone=transparent but lacking gestalt[body]  Active=Body and soul galore but lose transparency and clarity Both TVC and active=Clarity,transparency,gestalt,soul basically all you could ask for.
    The unique thing about nicks' active that it is transformer coupled with the correct gain for this purpose.
     I only listened to the combo for 15 minutes.Tomorrow an extended listening session will conclude my opinion.

rollo   

  PS  GHM is correct a buffer it is.

robert1325

Re: Promitheus TVC passive preamp anyone?
« Reply #1048 on: 18 Feb 2007, 12:27 pm »
Off-topic

How much does this active pre cost?  :D

Robert

guest1632

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Re: Promitheus TVC passive preamp anyone?
« Reply #1049 on: 18 Feb 2007, 03:28 pm »
Off-topic

How much does this active pre cost?  :D

Robert

Hi Robert,

$500 with shipping. At least that's what I recall Nicholas was saying.

Ray

rollo

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Re: Promitheus TVC passive preamp anyone?
« Reply #1050 on: 18 Feb 2007, 05:59 pm »
Good morning all,

       I changed the output wiring to single run Cardas copper hook up 22ga.The thinness is much improved.I did not change the input wiring as the selector switch to trannie required more wire than I had on hand.The mids have more  body and the bass as good as it was before has more impact and weight. Very pleased with the results so far.
      As far as the active TVC combo is concerned I was unable to run my active at unity gain as it was just too loud.Setting the vol. of the active at 12 o'clock was all I could do.
     So, how did it sound?very good but not as good as it could.However good enough to consider Nicholas' pre which is designed just for this purpose.I just had to much gain and the inclusion of the actives volume control just did not satisfy 100%.
    I feel an active preamp that has a transformer coupled output is better suited for this application.I heard enough to convince me that I want one and want it NOW with copper wiring of course[for me].
     Guys we are talking about a tubed preamp with a tubed power supply which is transformer coupled for $500 dollars and $450 for owners of TVCs.Are you kidding me.If Nicholas says the only way he will listen to HIS OWN TVC without the active is when he wants to save electricity is enough for me.
     How refreshing to see a manf. say something so bold and No I don't think its for marketing purposes.Its just the truth I believe,who is better than Nicholas?
      So save up your pennies and make the plunge I am.

rollo

robert1325

Re: Promitheus TVC passive preamp anyone?
« Reply #1051 on: 18 Feb 2007, 06:56 pm »
Would the active pre as standalone pre, be suited for my modified SB with only 1 volt output?   And what level of performance should I expect from this pre?  I mean , tubed power supply and transformer coupled does not ring any bells:P
   

Robert

rollo

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Re: Promitheus TVC passive preamp anyone?
« Reply #1052 on: 18 Feb 2007, 07:08 pm »
Would the active pre as standalone pre, be suited for my modified SB with only 1 volt output?   And what level of performance should I expect from this pre?  I mean , tubed power supply and transformer coupled does not ring any bells:P
   

Robert

Robert,
            I believe it would,however I think Nicholas is best suited to answer this.
rollo

guest1632

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Re: Promitheus TVC passive preamp anyone?
« Reply #1053 on: 18 Feb 2007, 10:45 pm »
Good morning all,

       I changed the output wiring to single run Cardas copper hook up 22ga.The thinness is much improved.I did not change the input wiring as the selector switch to trannie required more wire than I had on hand. The mids have more  body and the bass as good as it was before has more impact and weight. Very pleased with the results so far.

rollo

Hi Rollo,

Which version now of the TVC are you playing with. Does this one have the bus for pos and neg sides?

Did you wire up just one output or both?

Ray

Whitese

Re: Promitheus TVC passive preamp anyone?
« Reply #1054 on: 19 Feb 2007, 12:01 am »
i wonder if Nick does trades??  aai think his tubed and phono would be good... :thumb:

rollo

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Re: Promitheus TVC passive preamp anyone?
« Reply #1055 on: 19 Feb 2007, 05:15 pm »
Ray,
        This version is a dual mono single box ref. model with 2 inputs and two outputs.The wiring is single run silver with buss for pos. and neg.
         I changed only the single output at this time only.I am trying one step at a time.I also do not want to modify completely until the new two box dual mono with copper wiring and no buses arrives for comparison.For demo purposes in the end I will have a silver version and a copper for those who may prefer either.
          Hopefully by next week the two box will arrive.Can't wait, it should prove interesting.
rollo

guest1632

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Re: Promitheus TVC passive preamp anyone?
« Reply #1056 on: 19 Feb 2007, 05:40 pm »
Ray,
        This version is a dual mono single box ref. model with 2 inputs and two outputs.The wiring is single run silver with buss for pos. and neg.
         I changed only the single output at this time only.I am trying one step at a time.I also do not want to modify completely until the new two box dual mono with copper wiring and no buses arrives for comparison.For demo purposes in the end I will have a silver version and a copper for those who may prefer either.
          Hopefully by next week the two box will arrive.Can't wait, it should prove interesting.
rollo

Hi Rollo,

I thought you had the other units. ok, is he still bussing both ins and outs together? If so, wonder what would happen if you separated the two busses? Maybe nothing, just curious.

Ray

rollo

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Re: Promitheus TVC passive preamp anyone?
« Reply #1057 on: 19 Feb 2007, 06:23 pm »
Ray,
        That is exactly what I am anxious to find out.Buss or no buss.My only reason to eliminate the buss is it is silver.If it were copper I really do not know if it would matter.
       So in the end for me I guess it is the silver wiring.I strongly believe two versions should be offered as there are copper fans as well as silver fans.Let the buyer have the choice as both versions have their merits.I do not believe there is a better version just different which is subjective.Some systems have a synergy with copper,some with silver,the choice is personal.Different strokes for different folks.
    rollo

Mike B.

Re: Promitheus TVC passive preamp anyone?
« Reply #1058 on: 19 Feb 2007, 06:37 pm »
I have tried a variety of changes. I tried running the grounds from the inputs on the reverse phase of the balanced selector but got hum. I went back to the original grounding scheme. I replaced the output wires with 22 gauge high purity silver. This helped by adding body to the sound. I have also mounted the transformers and selector switch stand to the bottom through a layer of blackhole pad, made larger control knobs out of myrtlewood, replaced the top plate with Plexiglas, played with footers and ebony dampeners and used a cable burner to good effect. The unit sounds very good and it a sonic bargain. What it lacks is heart and soul IMO. I also have a DIY Lightspeed preamp which utilizes LDR opticouplers. It has very similar clarity and staging as the Promitheus, but it also has the drive or soul missing from the Promitheus.

rollo

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Re: Promitheus TVC passive preamp anyone?
« Reply #1059 on: 19 Feb 2007, 07:22 pm »
Mike B,

   Looks like your having fun.The silver Promitheus uses is 4N.What are you using that is more pure than 4N.The copper Promitheus is using on my TVC is 7N Neotech.
   Great idea using Black Hole Pad under trannie.Did you listen to each tweak separately to evaluate each on its own merits or was it an orgy so to speak.
     If it was one at a time could you fill us in on your findings.
     When I posted my review I came to the same conclusion.The copper wiring suggestion was meant to improve the body and soul issue.To my ears,this was a major improvement in eliminating the thinness.It is suprising to me that you found the new silver wire added body and soul as I did not.Interesting,very interesting.Could you elaborate please.
   thanks rollo