Promitheus TVC passive preamp anyone?

GHM · « **Reply #260 on:** 25 Oct 2006, 11:49 pm »

Quote from: ryno on 25 Oct 2006, 10:30 pm

Hang in there Matt, I ordered mine on the 4th and got it yesterday. Works great, no noise or hums. The only problem was a volume set screw was loose on the inside, just a good excuse to take the cover off. Just one night of use and I know it's well worth the price. Not huge differences with my purist, but the purist isn't an ordinary passive either. It's kind of funny, every difference I noticed had a positive and a negative side. The TVC has more bass, but it is a little less tight, more detail and impact, but with a slight harshness, A tighter image but not as wide or deep. Granted, the TVC is right out of the box, the differences are slight, and I didn't do any level matching or anything. After I enjoy it for a couple weeks, I'll do more serious comparisons. I've allways bought used so I've never heard break-in, It's very good now, any improvement would be sweet.
Ryan

Great Ryan..glad yours arrived safely. Yup ..the unit will improve with burn in. Although you're the only owner I've seen describe this unit as slightly harsh.

The one thing the TVC doesn't do is compress the music. If there are strong transients you'll hear them for what they are. Loose bass is also an area that I find unusual. I may have over estimated your source output impedance/voltage..never the less give it some time as things should improve.

Good listening

PromitheusAudio · « **Reply #261 on:** 26 Oct 2006, 01:16 pm »

Ryan

Glad to know your arrive safe and sound.

One thing the footer( wood base ), use it to tune the bass. If you face the pointed part down, you will get more control and speed.
If you face the pointed part upward you will get more bass and warmth.
Also the spacing of the wood cones will effect the sound by a bit. Try it.

THe preamp is revealing that changing the orientation effects the sound.

Actually all of my stuff that i make works magic with wood. Playing around with wood really helps my stuff sound better

On the harshness as mention run in.

Also to current users of the TVC, do you notice that the trans takes some time to sound good. Like when you first power up it will not sound so good. But after an hour it really sounds better.

Also later tonite will be posting Matt's preamp. Let me know what you guys think. I like it especially with the 4 pairs of CMC and the grayhill switch.

The energizer what it does it is a big energy reserve. It will store the energy in the big momma trans and when the energy is needed it will release it very quickly. Actually somehow it does the job better when nothing is plug to it, just a cable. So this cable will power the unit as well has a conduit for this stored energy to flow back into the system.

Just came back from a listening sesion to voice our new hybrid amplifer. Listening to it with the TVC and power amp was really good esp on the mids presence and highs. Bass was a bit boomy considering the room as it was very boomy when the dealer played his nagra and audio physic caldena . But could be due to the non-feedback used.

The solid state opt is used in this preamp. There is where i realise opt trans is a good idea plus safety.

NewBuyer · « **Reply #262 on:** 26 Oct 2006, 09:41 pm »

For some reason I still can't quite picture what the Energizer product looks like, or how it fits into a system. I guess I'll just wait and see.

Nicholas how have the Solid State Output Transformers been working out, are you still happy with the product? Have any users been able to provide feedback yet? It would be great to see a picture of the finished version product in the wooden chassis...

ryno · « **Reply #263 on:** 26 Oct 2006, 10:53 pm »

I wish I wouldn't have posted yesterday, I was just excited about getting a new toy. Listening to a brand new component for one night isn't a good basis for making judgments. I've had the purist for several years and am very accustomed to it's sound, so anything with more detail and impact might sound a bit harsh to me. I'm enjoying the TVC very much, and after a few weeks I should be able to make a better comparison.
Ryan

PromitheusAudio · « **Reply #264 on:** 27 Oct 2006, 01:08 am »

Ryan
No worries, your posting shows that the tvc has lots of potential when it just brand new from the soldering iron.

This is how Matt's preamp is done. What's do you guys think?

THe energizer is plug into your AC line via a power cord and that's all. It will work from there. Pretty easy to use as it works very well when it is plug in only.

On the solid state opt, it is a new idea (unheard off) not many people actually heard about it. So sad to say i have not sold any. But it is something i would like to explore more as it sounds good in the way the valve amp good type of the sound.

GHM · « **Reply #265 on:** 27 Oct 2006, 02:25 am »

Quote from: ryno on 26 Oct 2006, 10:53 pm

I wish I wouldn't have posted yesterday, I was just excited about getting a new toy. Listening to a brand new component for one night isn't a good basis for making judgments. I've had the purist for several years and am very accustomed to it's sound, so anything with more detail and impact might sound a bit harsh to me. I'm enjoying the TVC very much, and after a few weeks I should be able to make a better comparison.
Ryan

Hey Ryan..if there wasn't any excitement..this hobby would suck!

It's cool not a big deal. I'm glad there are others that get as excited about this stuff as I do.

Nice ..Nick that Preamp looks great!!

You got me lost on the Energizer now.

So this thing just plugs in the wall? Does it need to be plugged near the same outlet as the other equipment? I'm thinking it does.Never heard of anything like that before. Hey Matt where did you say you lived again..I'll intercept the DHL guy at the building entrance.

gooberdude · « **Reply #266 on:** 27 Oct 2006, 02:26 am »

Nicholas, that TVC belongs in Chicago! Come to papa...

So you simply plug the Energizer into, say, a power strip? And it sends
power to all the components plugged into it? Or is this only for 1 component?

the TVC looks killer. you just saved me the job of figuring out how to post pics next week.

many thanks. the copper internal wiring looks cool.

matt

gooberdude · « **Reply #267 on:** 27 Oct 2006, 02:27 am »

Hey GHM

I've never heard of such a product either Nicholas.

please tell us more...

GD

gooberdude · « **Reply #268 on:** 27 Oct 2006, 02:33 am »

GHM, i just peeped your system..holy cow.

I'm really interested in the Brines FTA-2000's. Do they really play
low bass? I'm not the type to get a sub, I like full range floorstanders.
at some point I will replace my Thiels & am leaning towards a single driver design
but I haven't heard any that play the way i like. haven't heard too many though..

GHM · « **Reply #269 on:** 27 Oct 2006, 02:52 am »

Quote from: gooberdude on 27 Oct 2006, 02:33 am

GHM, i just peeped your system..holy cow.

I'm really interested in the Brines FTA-2000's. Do they really play
low bass? I'm not the type to get a sub, I like full range floorstanders.
at some point I will replace my Thiels & am leaning towards a single driver design
but I haven't heard any that play the way i like. haven't heard too many though..

Matt,
Yes they play low bass. They do low bass like no other speaker I've owned to be honest. No boom or rolling bass. It is clean and natural. It only shows itself when it's suppose to. So no over the top pyrotechnics. They're not perfect.. no speaker is. They won't play as loud as mutli drivers but 100 dB is loud enough for me. I don't listen over maybe 80 any way. And that's only when I watch movies.

The sweet spot is small like a electrostatic. If you've heard a electrostatic and a magnepan..these cross some where between without the plastic sound or disconnected bass of Martin Logans and more weight than the Maggies.

Put it this way..in the midrange where a Magnepan is strongest. The F200a driver makes them sound a little slow and cloudy. They also have a VERY balanced sound..nothing tipped up or over exaggerated. They'll tell on garbage equipment all day long.

Steve Eddy · « **Reply #270 on:** 27 Oct 2006, 03:07 am »

Quote from: GHM on 27 Oct 2006, 02:25 am

You got me lost on the Energizer now. So this thing just plugs in the wall? Does it need to be plugged near the same outlet as the other equipment? I'm thinking it does.Never heard of anything like that before.

From the description, sounds like it's intended to be something akin to what the Richard Gray Power Company claims to be. The RGPC is just a large choke (something in the neighborhood of 6-8 Henry) that's placed across the AC line. However a large choke like that doesn't store any energy to speak of. At least not under AC conditions.

And a transformer, well, a transformer itself ideally doesn't store any energy at all. Though if you don't connect anything to the secondary, you're left with what amounts to an inductor.

There are no big energy reserves. At least not under AC conditions.

se

ebag4 · « **Reply #271 on:** 27 Oct 2006, 04:55 pm »

Hey Nick, any word on the aluminum version of the TVC? How about a few pics??

Thanks,
Ed

ashok · « **Reply #272 on:** 27 Oct 2006, 06:11 pm »

Hi everyone,

Sorry to butt in like this. Here is something that I found helpful in understanding how the Energizer might work.

Consider an ideal inductance L henry connected across an ac voltage source. If the current in the circuit is given by i(t) = I*sin(wt), the voltage across the inductor will be

v(t) = L di/dt

= L*I*w*cos(wt)

where w (omega) = 2*pi*f, with f being the system frequency (50 or 60Hz).

v(t) and i(t) can be used to compute the power in the circuit and the energy in the circuit, as functions of time. This will lead to the following (from Electric Circuits by Joseph A Edminster):

The plot of power (on the left) is symmetrical about the horizontal axis. Its frequency is two times that of the system frequency. The power is simply the product of v(t) and i(t).

The plot of energy (on the right) is obtained by integrating the instantaneous power over a certain time interval. The minimum value that the energy function can take is zero.

So, during the positive-half of the power cycle, energy is transferred by the source to the inductor and stored in its magnetic field. During the negative-half of the power cycle, the energy stored in the inductor is transferred back to the source.

When the inductor is returning energy to the source I suppose that the amplifier connected to the same source could make use of that energy. (I not exactly sure by what "using the energy means")

But what if the music calls for more energy when the inductor is actually absorbing it? Under AC conditions, there is no reservoir of energy from to call upon.

I would like to emphasize that my post is no way being combative or dismissive of the product. Just trying to understand.

Regards,

Ashok

Steve Eddy · « **Reply #273 on:** 27 Oct 2006, 07:06 pm »

Quote from: ashok on 27 Oct 2006, 06:11 pm

So, during the positive-half of the power cycle, energy is transferred by the source to the inductor and stored in its magnetic field. During the negative-half of the power cycle, the energy stored in the inductor is transferred back to the source.

When the inductor is returning energy to the source I suppose that the amplifier connected to the same source could make use of that energy. (I not exactly sure by what "using the energy means")

But what if the music calls for more energy when the inductor is actually absorbing it? Under AC conditions, there is no reservoir of energy from to call upon.

Yes, though we need to back up here a little bit and consider the energy stored in the inductor in the first place. That's ultimately determined by the current flowing through the inductor in the form of 0.5LI². So if we have say a 10 Henry inductor, its reactance will be 2 x pi x f x L. At 60 Hz, that comes to 3,770 ohms. With 120 volts across the inductor, peak current will be 120/3,770 or about 32 milliamps.

That means that the peak energy stored by the inductor will be 0.5 x 10 x 0.001 or just 5 millijoules (0.005 Joules).

As I said originally, there's hardly any energy being stored at all.

Also, most every power supply out there is of the capacitor input type. These only draw current from the AC line for a brief period of time at the peak of the AC voltage waveform. If we're talking about pure inductance, the phase angle of the current will be 90 degrees relative to voltage. So at the point when the power supply is drawing current from the AC line, the current in the inductor, and therefore the energy stored in it, is effectively zero.

So not only is there very little energy being stored in the first place, what little is there isn't even there at the time the power supply is needing it.

Quote

I would like to emphasize that my post is no way being combative or dismissive of the product. Just trying to understand.

Ditto.

se

PaulFolbrecht · « **Reply #274 on:** 27 Oct 2006, 08:58 pm »

Nick (or somebody else) - question for you: Are tubed output stages on sources/DAC good or bad for use with TVCs??

On the bad side, they tend to raise output impedance (some a litte, some a lot).

On the good side, I believe this can provide more current drive, either when used as a buffer (with op-amp) or as a full-on gain stage.

Thanks!

Bwanagreg · « **Reply #275 on:** 27 Oct 2006, 09:15 pm »

I'm using a tube buffered stage (Mdht Paradisea) and the sound is oustanding. HUGE bass drive and more than adequate volume. This combination is a real winner IMHO.

ashok · « **Reply #276 on:** 28 Oct 2006, 03:26 am »

Quote from: Steve Eddy on 27 Oct 2006, 07:06 pm

Yes, though we need to back up here a little bit and consider the energy stored in the inductor in the first place. That's ultimately determined by the current flowing through the inductor in the form of 0.5LI². So if we have say a 10 Henry inductor, its reactance will be 2 x pi x f x L. At 60 Hz, that comes to 3,770 ohms. With 120 volts across the inductor, peak current will be 120/3,770 or about 32 milliamps.

That means that the peak energy stored by the inductor will be 0.5 x 10 x 0.001 or just 5 millijoules (0.005 Joules).

As I said originally, there's hardly any energy being stored at all.

5 mJ need not necessarily be a small amount of energy. It is equivalent to 3.12 x 10¹⁶electron-volts. If I understand correctly, the effect of that energy depends on the number of particles (electrons) that absorbed that energy.

Quote from: Steve Eddy on 27 Oct 2006, 07:06 pm

Also, most every power supply out there is of the capacitor input type. These only draw current from the AC line for a brief period of time at the peak of the AC voltage waveform. If we're talking about pure inductance, the phase angle of the current will be 90 degrees relative to voltage. So at the point when the power supply is drawing current from the AC line, the current in the inductor, and therefore the energy stored in it, is effectively zero.

This one took a while for me to figure out. I assume the capacitor input you are talking about is the first capacitor after the rectifier. A quick simulation in PSUD helped in understanding.

With the voltage of the AC line leading the inductor current by 90 degrees, it is true that when the voltage peaks (at 0, pi, 2pi etc. for example), the instantaneous value of the inductor current is zero, and hence instantaneous energy stored in the inductor is zero. However, the energy function is at the end of its downward movement, and the inductor has finished transferring whatever energy it had stored over the upward half-cycle back to the source. And this energy is available when the power supply demands current from the source (at the peak of the source voltage). What does having this energy reserve mean? That the AC source can meet the current demand without a voltage dip? But the ac source is the electric supply from the utility company. And the demand of an amplifier should hardly cause a dip in the voltage (after inrush effects have disappeared).

Ashok

Steve Eddy · « **Reply #277 on:** 28 Oct 2006, 05:01 am »

Quote from: ashok on 28 Oct 2006, 03:26 am

5 mJ need not necessarily be a small amount of energy. It is equivalent to 3.12 x 10¹⁶electron-volts. If I understand correctly, the effect of that energy depends on the number of particles (electrons) that absorbed that energy.

Let's put it another way. 1 Joule is the equivalent of 1 watt-second. Or 1 watt of power for 1 second. 5 millijoules would be the equivalent of 5 milliwatts of power for 1 second or 1 watt of power for 5 milliseconds.

Or yet another way. Let's say you have a power amplifier with 100,000uF of reservoir capacitance and that capacitance is charged with 50 volts. That's 125 Joules of energy stored in that capacitance. 25,000 times more energy than 5 millijoules.

Quote

This one took a while for me to figure out. I assume the capacitor input you are talking about is the first capacitor after the rectifier. A quick simulation in PSUD helped in understanding.

Yes, a capacitor input power supply as opposed to a choke input supply.

Quote

With the voltage of the AC line leading the inductor current by 90 degrees, it is true that when the voltage peaks (at 0, pi, 2pi etc. for example), the instantaneous value of the inductor current is zero, and hence instantaneous energy stored in the inductor is zero. However, the energy function is at the end of its downward movement, and the inductor has finished transferring whatever energy it had stored over the upward half-cycle back to the source. And this energy is available when the power supply demands current from the source (at the peak of the source voltage). What does having this energy reserve mean? That the AC source can meet the current demand without a voltage dip? But the ac source is the electric supply from the utility company. And the demand of an amplifier should hardly cause a dip in the voltage (after inrush effects have disappeared).

Exactly!

se

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GHM · « **Reply #278 on:** 28 Oct 2006, 09:58 pm »

Has anyone seen the latest ZeroGain postings on the Promitheus v3 verses the First Music ?
Looks like the owner may send the First Music to a new home and pocket some extra money. He seems to be having as much trouble hearing a real difference between the two as I did with the Promitheus v2 vs Bent NOH using the same S&B copper trannies.

launche · « **Reply #279 on:** 28 Oct 2006, 11:17 pm »

Looks like jolly ol' St. Nicholas may need to get some more elves to help him crank out those TVC's a little faster for all the good boys and girls. When the kiddies want new toys they can hardly wait 'til christmas day. And they especially don't like seeing all the others having such fun while they have to wait patiently...mental patients...mental patience...

PS, The cookies are in the oven but all I have is lactaid at the moment, I hope that will be OK.