Promitheus TVC passive preamp anyone?

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GHM

Re: Promitheus TVC passive preamp anyone?
« Reply #1240 on: 14 Mar 2007, 05:47 pm »
anubisgrau..am I reading correctly. You said this DIY unit had 6dB of gain? You should be able to hear a significant difference if this is the case.

Gain can make everything seem fuller if you're not understanding what's happening.. You are definitely free to voice your preferences. But comparing TVCs with different gain settings isn't exactly a fair shake. I surely don't think there's a best anything for everyone..no matter the cost.

I found comparing the Promitheus and Bent very difficult, just because of the gain differences. This is something that can easily fool you ...even a 30 yr audiophile if he's not paying attention to the factors.

Thin and bright?.. :scratch:..not hardly..best go back to the source my friend. If you'd changed the source I can almost guarantee thin and bright would not be on the list.


anubisgrau

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Re: Promitheus TVC passive preamp anyone?
« Reply #1241 on: 14 Mar 2007, 06:07 pm »
hey guys  :o
don't misquote me, for god sake :lol:! i'm also a promitheus user :thumb:!!! where did i mention the word "bright" in my last posts? i've just said that promitheus sounds "thinner and lighter and less full bodied" IN COMPARISON with the DIY TVC. no way it sounded bright, i didn't say that :D :nono:
my source is not perfect but it was the same throughout the test so i wouldn't comment it. thule cd150b is a bit of a boring player but bright it isn't.
yes 6dB could make a difference - we didn't have a SPL meter to make everything perfectly fair, but the difference was really so clear that this wasn't necessary.




Since owning this TVC i've wondered how cool it would to have a TVC + active speakers + battery powered source...    1 power cord, so simple...

my thoughts exactly! i'm already thinking about powering a CDP via 12V battery, it should be simple and sound will be much cleaner for sure! :drool:


What are the tiny tags on each of the tranny output wires in the special TVC?   are those just to write on or do they serve another purpose?    Nick Chua and the maker of those trannies should compare notes...nick could help him cut down the 6 day tranny construction job and he could help Nick make $1000 per pair trannies.

i have no idea what these notes are but i will ask. i agree it would be great if all the TVC enthusiasts would share good ideas! i've already mentioned that the brain behind the DIY TVC thinks it's a shape of core that makes a difference - that's why i asked nick if he ever tried a double C core instead of EI?

GHM

Re: Promitheus TVC passive preamp anyone?
« Reply #1242 on: 14 Mar 2007, 06:14 pm »
Sorry Gordon :duh:..I meant dry. Regardless if your CD player was through the entire test. 6 dB makes a helluva difference..no matter how you slice it my friend. Hopefully when you get your TVC, you'll get a chance to try some different sources . This is the only way you will understand what I'm talking about. :wink:

Good listening

Russell Dawkins

Re: Promitheus TVC passive preamp anyone?
« Reply #1243 on: 14 Mar 2007, 06:56 pm »
regarding gain, if the listeners were attempting to match levels by ear, and it seems they were, I would think the extra gain available on the DIY was just that - available, but not used. With 2v output available from the CD player, both pres were operating at a gain reduction or else the listening levels would have been horrendous, unless the gain control on the ATCs was cut way back. So, if they were both operating as attenuators, I would think the fact that one can provide 6 dB of gain is irrelevant.

Also, steel lid - non-ferrous??

Anyway, for this consideration it doesn't matter whether the material is ferrous, just whether it conducts electricity. If it does, it is capable of playing host to eddy currents which are supposed to be the factor influencing the AC signal travelling down the wire and, if this is true, the transformers would be influenced, too.

If I were buying the Promitheus I would go for the wooden bottom panel and replace the top panel with wood or plexi.

Paul_Bui

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Re: Promitheus TVC passive preamp anyone?
« Reply #1244 on: 14 Mar 2007, 08:08 pm »
forgot to add: promitheus sounds clearly better without a steel lid. i think this is a weak spot considering that the transformers are not shielded - it probably interferes with the TVCs magnetic field. this has to be wood too.

Thanks anubisgrau for posting the comparison.  I like your finding of the lid off.  My one week new REV3 dual mono TVC sounds darn glorious out of the box with the lid off.  I think its black and cool character just lets music freely flow out of the system without force we usually hear but hardly notice with active components.

Regarding the Promitheus TVC sounding relatively thinner than another DIY TVC, I find it quite credible, considering all components upstream, downstream, and the [potential & available] gain difference.  For instance, while keeping everything else the same, I replaced the Patek amp with Clari-T monoblocks, and the smooth integration of music is gone.  While full body midrange is still intact, it seems highs and bass are not in sync, not integrated well with the rest of the music, making the sound less interesting, less musical as a whole.

TVC will keep improving, but that won't stop existing TVC users from enjoying the fresh air music coming out of their TVC based systems.
« Last Edit: 14 Mar 2007, 08:23 pm by Paul_Bui »

F-100

Re: Promitheus TVC passive preamp anyone?
« Reply #1245 on: 14 Mar 2007, 09:39 pm »
I concur that the TVC sounds much better with the top cover removed.

davetroy

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Re: Promitheus TVC passive preamp anyone?
« Reply #1246 on: 14 Mar 2007, 09:55 pm »
And dust isn't an issue? It's perfectly okay to leave the cover off?

GHM

Re: Promitheus TVC passive preamp anyone?
« Reply #1247 on: 14 Mar 2007, 10:20 pm »
regarding gain, if the listeners were attempting to match levels by ear, and it seems they were, I would think the extra gain available on the DIY was just that - available, but not used. With 2v output available from the CD player, both pres were operating at a gain reduction or else the listening levels would have been horrendous, unless the gain control on the ATCs was cut way back. So, if they were both operating as attenuators, I would think the fact that one can provide 6 dB of gain is irrelevant.

Also, steel lid - non-ferrous??

Anyway, for this consideration it doesn't matter whether the material is ferrous, just whether it conducts electricity. If it does, it is capable of playing host to eddy currents which are supposed to be the factor influencing the AC signal travelling down the wire and, if this is true, the transformers would be influenced, too.

If I were buying the Promitheus I would go for the wooden bottom panel and replace the top panel with wood or plexi.

It may seem as that the gain was just available, but having went through the same with several different TVCs. Trying to match the units up isn't all that easy. All the TVCs I've heard seem to sound better if run around 9 or 10 O'clock or lower(up to 12 O'clock), verses 2'clock or 3 O'clock on the dial. There's a fullness at the lower settings on the dial, I don't experience when running the TVC close to unity gain. I have no idea why..but I can't deny what I'm hearing. It may have something to do with the step down voltage at those certain levels verses the current output ? I don't know.

When you have one TVC that runs at a sufficient level around 9/10 O'clock verses one that doesn't reach the same volume level till 2 O'clock..there's DEFINITELY a difference in sound. Whether you've tried to match the SPLs or not. This is what I'm referring to. Unless you've experienced it, it is hard to explain.

I find the Dual mono version fuller than the Stereo version at the same settings on the dial. I also run the Dual unit several steps below the stereo version to reach the same spl level. Everything sounds fuller in the music with the TVC between 9 and 12 O'clock..no doubt about it.

I've had at least 5 different TVCs to listen too. 4 of which are of Promitheus. Each configuration had a different setting for my average listening level.
« Last Edit: 14 Mar 2007, 10:40 pm by GHM »

Paul_Bui

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Re: Promitheus TVC passive preamp anyone?
« Reply #1248 on: 14 Mar 2007, 11:04 pm »
Just wanted to add another $0.02:  The TVC plays the in-phase/out-of-phase test (Stereophile CDs, the Crown SASS microphone CD, etc.) with the most impressive distinction between in-phase and out-of-phase modes.  In fact, it lets me hear for the first time what the out of phase effect is about.         

JLM

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Re: Promitheus TVC passive preamp anyone?
« Reply #1249 on: 14 Mar 2007, 11:31 pm »
Active speakers + passive pre-amp + battery source = 2 power cords.  (One cord per speaker.)

Battery powered source options:  Red Wine Audio modded Squeeze Box, iPod, or Olive music server.  If you discount the transport another couple of options are the Altman Attraction DAC and the Ack dAck! DAC.

Hearing active speakers for the first time (compared to passive version of the same) was an ephiphany to me.  The active speakers had tons more/deeper bass output, much improved dynamics, and flatter frequency response compared to the passives.  It wasn't even close.

GHM, Paul Bui, and I all use the same remarkable single driver speaker, which is in effect are active speakers.  We also all use chip amps, which are supposed to synergize very well with single driver speakers.  I happen to use monoblocks, so my Promitheus TVC would be dual mono as well (just waiting for the tax refund).  My weak link will then be the source as I've struggled to get and keep the computer end of my Squeeze Box running, so I'm back to a CDP for now.  I'm in a new house, with a dedicated underground service/transformer, all new applicances, three audio dedicated circuits that each feed a single cryo'd Hubbell hospital grade 20 amp receptacle tied to their own earth grounding in a dedicated listening room.  So clean power is not an issue and battery power (had both RWA amp and SB) offered no audible advantages to me.

launche

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Re: Promitheus TVC passive preamp anyone?
« Reply #1250 on: 15 Mar 2007, 12:07 am »
Just wanted to add another $0.02:  The TVC plays the in-phase/out-of-phase test (Stereophile CDs, the Crown SASS microphone CD, etc.) with the most impressive distinction between in-phase and out-of-phase modes.  In fact, it lets me hear for the first time what the out of phase effect is about.         

This is interesting to me, were you able to try the same listening tests with another preamp (active) to hear what differences there were?

Thanks

tanchiro58

Re: Promitheus TVC passive preamp anyone?
« Reply #1251 on: 15 Mar 2007, 12:32 am »
Just wanted to add another $0.02:  The TVC plays the in-phase/out-of-phase test (Stereophile CDs, the Crown SASS microphone CD, etc.) with the most impressive distinction between in-phase and out-of-phase modes.  In fact, it lets me hear for the first time what the out of phase effect is about.         

This is interesting to me, were you able to try the same listening tests with another preamp (active) to hear what differences there were?

Thanks

In my system and in my opinion, TVC is an affordable and excellent passive preamp (mine is an old version dual mono) to my tube gear but since I have a custom built active preamp using two 8608 tubes and a rectifier U52 tube with output transformers. The 8608 active preamp has more details, more soundstage and especially more bass than the TVC. Both are musical but I am able to hear more separate notes of music from the active preamp. When I turn up the volume to 12 the 8608' sound has more decays and thicker than TVC. I will let you know more comparison between 8608 active preamp and the TVC Reference Dual Mono.

Cheers,
Tan

Parnelli777

Re: Promitheus TVC passive preamp anyone?
« Reply #1252 on: 15 Mar 2007, 12:49 am »
126 pages for this thing? Sh*t can this thread already, somebody, anybody.

Paul_Bui

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Re: Promitheus TVC passive preamp anyone?
« Reply #1253 on: 15 Mar 2007, 01:15 am »
Active speakers + passive pre-amp + battery source = 2 power cords.  (One cord per speaker.)

Battery powered source options:  Red Wine Audio modded Squeeze Box, iPod, or Olive music server.  If you discount the transport another couple of options are the Altman Attraction DAC and the Ack dAck! DAC.

Hearing active speakers for the first time (compared to passive version of the same) was an ephiphany to me.  The active speakers had tons more/deeper bass output, much improved dynamics, and flatter frequency response compared to the passives.  It wasn't even close.

GHM, Paul Bui, and I all use the same remarkable single driver speaker, which is in effect are active speakers.  We also all use chip amps, which are supposed to synergize very well with single driver speakers.  I happen to use monoblocks, so my Promitheus TVC would be dual mono as well (just waiting for the tax refund).  My weak link will then be the source as I've struggled to get and keep the computer end of my Squeeze Box running, so I'm back to a CDP for now.  I'm in a new house, with a dedicated underground service/transformer, all new applicances, three audio dedicated circuits that each feed a single cryo'd Hubbell hospital grade 20 amp receptacle tied to their own earth grounding in a dedicated listening room.  So clean power is not an issue and battery power (had both RWA amp and SB) offered no audible advantages to me.

Sounds like you'll be all set after the tax return.  I heard people have the same great result switching from a very good source to a so-so one.  Key are amps and speakers, IMHO.  Your relatively high power chip amps will let you use the TVC at the preferred zone, between 9 and 12 o'clock (thanks GHM for the tips).

Paul_Bui

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Re: Promitheus TVC passive preamp anyone?
« Reply #1254 on: 15 Mar 2007, 01:28 am »
Just wanted to add another $0.02:  The TVC plays the in-phase/out-of-phase test (Stereophile CDs, the Crown SASS microphone CD, etc.) with the most impressive distinction between in-phase and out-of-phase modes.  In fact, it lets me hear for the first time what the out of phase effect is about.         

This is interesting to me, were you able to try the same listening tests with another preamp (active) to hear what differences there were?

Thanks

Hi Launche,

I found very similar results as that of Tan's.  My active tube pre is more in-depth and wider soundstaging, more bass, relatively thicker/warmer (depending on which tube set used), and can play louder than the TVC.  But from there my impression is different from his.  I find details and vocal/instrumental parts easier to be discerned and followed via the TVC.  Listening to music through the TVC is almost like seeing natural life in your naked eyes; it's so relaxed, not ever a slouch in bass, and definitely not thin.  Putting it in your system means that everything else (save other TVC), no matter how good they are, is coloring your music one way or another.

launche

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Re: Promitheus TVC passive preamp anyone?
« Reply #1255 on: 15 Mar 2007, 02:09 am »
Thanks Paul and Tan.  I was most curious about the phase issue.

FWIW, I've tried several isolation devices with the TVC.

Symposium Rollerblocks
Maplewood w/isoblocks
Granite
Black Diamond Racing cones
Aurios MIB 1.1
Ginkgo Mini Clouds
Ginkgo Cloud 10
Brightstar audio Airmass V1

Gooberdude would be proud  :)
I am not this tweakie, just happen to have these for various components and tried them under the TVC.

Right now I have the TVC on the Cloud 10 which is resting on the granite.  Good results, a warmer presentation at the expense of some detail and air but a solid presentation.
For those getting a thin sound in their system, try some more/diffrent isolation and coupling etc...I hear differences that could make one think they were hearing two (or more) different units..


Randy

Re: Promitheus TVC passive preamp anyone?
« Reply #1256 on: 15 Mar 2007, 02:36 am »
Talk about powering by batteries. My former power conditioner had battery backup.  The cleanest, purest sound I ever heard was when I pulled the conditioner's cord out of the wall outlet, so my entire system, including high current amps, were being powered by the batteries. This was an intoxicating sound I could not get enough of. Managed an hour's worth of listening before getting close to draining the batteries. When full battery power becomes practical for entire systems, a new age will dawn.

Paul_Bui

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Re: Promitheus TVC passive preamp anyone?
« Reply #1257 on: 15 Mar 2007, 02:51 am »
...I hear differences that could make one think they were hearing two (or more) different units..

I concur and think that the TVC is so delicate and sensitive to every change to its physical form (resonance, wires, enclosure material, orientation, etc.) that enables it to let music flow through unfettered.

Almost forgot this:  just made two shorted RCAs and plugged into the unused RCA INPUTS, resulted in quietness from RFI.
« Last Edit: 15 Mar 2007, 03:32 am by Paul_Bui »

Paul_Bui

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Re: Promitheus TVC passive preamp anyone?
« Reply #1258 on: 15 Mar 2007, 02:54 am »
Talk about powering by batteries. My former power conditioner had battery backup.  The cleanest, purest sound I ever heard was when I pulled the conditioner's cord out of the wall outlet, so my entire system, including high current amps, were being powered by the batteries. This was an intoxicating sound I could not get enough of. Managed an hour's worth of listening before getting close to draining the batteries. When full battery power becomes practical for entire systems, a new age will dawn.

Yes, I'm waiting for DODD's Gary to release his battery amp (without volume control) so I can go totally off grid.

kallitype

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Re: Promitheus TVC passive preamp anyone?
« Reply #1259 on: 15 Mar 2007, 05:21 am »
Is Nick on vacation?  I have sent a couple emails asking to order a TVC and no response.  Anybody got one for sale????  Need 3 inputs, 2 out.....thnkx