Help with Passive Pre-amps matching
Refefer
Posts: 1,280
Before I pull the trigger on a Promitheus TVC, what do I need to know about them? I hear they are excellent when it comes to everything audio, but only if "matched" correctly. Supposedly they are sensitive to just about everything: source, amp, cables, speakers, moon phase, etc.
How does one tell prior to purchasing how well a TVC will work in my system? Is there anything obvious I can check?
How does one tell prior to purchasing how well a TVC will work in my system? Is there anything obvious I can check?
Lovin that music year after year.
Main 2 Channel System
Polk SDA-1B,
Promitheus Audio TVC SE,
Rotel RB-980BX,
OPPO DV-970HD,
Lite Audio DAC AH,
IXOS XHA305 Interconnects
Computer Rig
Polk SDA CRS+,
Creek Audio 5350 SE,
Morrow Audio MA1 Interconnect,
HRT Music Streamer II
Main 2 Channel System
Polk SDA-1B,
Promitheus Audio TVC SE,
Rotel RB-980BX,
OPPO DV-970HD,
Lite Audio DAC AH,
IXOS XHA305 Interconnects
Computer Rig
Polk SDA CRS+,
Creek Audio 5350 SE,
Morrow Audio MA1 Interconnect,
HRT Music Streamer II
Post edited by Refefer on
Comments
-
You just have to be slightly concerned about impedance matching between your source and amp. In the majority of cases, you'll be fine. Upon reading the nearly 200 pages about the TVC on Audiocircle, there have been very few cases where the TVC was not a good impedance match. Just buy it and don't worry about the technicalities. That's what I did. It was the best purchase in audio I ever made.
Caveat -- the magic behind the TVC is a good source. The TVC will reveal every weakness of your source, so I'd suggest that folks upgrade their CDP before purchasing the TVC, if necessary.HT/2-channel Rig: Sony 50 LCD TV; Toshiba HD-A2 DVD player; Emotiva LMC-1 pre/pro; Rogue Audio M-120 monoblocks (modded); Placette RVC; Emotiva LPA-1 amp; Bada HD-22 tube CDP (modded); VMPS Tower II SE (fronts); DIY Clearwave Dynamic 4CC (center); Wharfedale Opus Tri-Surrounds (rear); and VMPS 215 sub
"God grooves with tubes." -
Also might add for passive pre's in general, you might want to keep your current "active" pre until you are sure you like the sound of a passive. A passive pre isn't for everyone as they certainly can have very different sound characteristics.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
As Early B. said TVCs are very revealing of the source, being a passive they don't really add anything so they don't have as much of a sonic signature as actives do.
TVCs are different then normal pres in that they sound there best at the lowest volume settings, while anything using a potentiometer sounds best at the highest volume.
One issue that could arise would be not enough gain, or to much gain in your source. If you don't have enough gain you will be turning the TVCs volume control to high and out of it's optimal output area. Going to high on a TVC also increases the impedance seen by the amp, so if you were at the top of the range you would have a higher impedance then the source outputs. If you have a amp with a high input sensitivity and a source with a low output you will also never attain full output of the amp, which may or may not be a issue.
If you have to much gain then you will not have enough usable volume control. The TVCs start at -48db and work up from there to 0. Some people have complained that -48db is not quite enough for background music.
Both of these situations are dependent on both the source and your listening preference. I have used a TVC with sources from around .9v-2v without any issues.
Any other questions feel free to ask, I have 3 Promitheus Audio TVCs in different configurations.
Jared -
Ok, then I guess I will!
Have you noticed significant improvements/detriments through using different cables?Lovin that music year after year.
Main 2 Channel System
Polk SDA-1B,
Promitheus Audio TVC SE,
Rotel RB-980BX,
OPPO DV-970HD,
Lite Audio DAC AH,
IXOS XHA305 Interconnects
Computer Rig
Polk SDA CRS+,
Creek Audio 5350 SE,
Morrow Audio MA1 Interconnect,
HRT Music Streamer II -
Ok, then I guess I will!
Have you noticed significant improvements/detriments through using different cables?
Since TVCs are very revealing, cable changes are probably more noticeable. But, of course, it depends a lot on your other gear.
Refefer -- are you gonna use the Oppo as the source?HT/2-channel Rig: Sony 50 LCD TV; Toshiba HD-A2 DVD player; Emotiva LMC-1 pre/pro; Rogue Audio M-120 monoblocks (modded); Placette RVC; Emotiva LPA-1 amp; Bada HD-22 tube CDP (modded); VMPS Tower II SE (fronts); DIY Clearwave Dynamic 4CC (center); Wharfedale Opus Tri-Surrounds (rear); and VMPS 215 sub
"God grooves with tubes." -
I haven't noticed any difference but I am in the "all properly constructed cables sound the same" camp.
Currently using Belden 89259 with bullet plugs for anything 2ch. -
Since TVCs are very revealing, cable changes are probably more noticeable. But, of course, it depends a lot on your other gear.
Refefer -- are you gonna use the Oppo as the source?
I'm currently using the Oppo's coax out to my Lite Audio Dac-AHM1. I thought it might be a better choice deu to the dac's higher gain.Lovin that music year after year.
Main 2 Channel System
Polk SDA-1B,
Promitheus Audio TVC SE,
Rotel RB-980BX,
OPPO DV-970HD,
Lite Audio DAC AH,
IXOS XHA305 Interconnects
Computer Rig
Polk SDA CRS+,
Creek Audio 5350 SE,
Morrow Audio MA1 Interconnect,
HRT Music Streamer II -
I'm currently using the Oppo's coax out to my Lite Audio Dac-AHM1. I thought it might be a better choice deu to the dac's higher gain.
OK, then you won't have a problem. Buy it.HT/2-channel Rig: Sony 50 LCD TV; Toshiba HD-A2 DVD player; Emotiva LMC-1 pre/pro; Rogue Audio M-120 monoblocks (modded); Placette RVC; Emotiva LPA-1 amp; Bada HD-22 tube CDP (modded); VMPS Tower II SE (fronts); DIY Clearwave Dynamic 4CC (center); Wharfedale Opus Tri-Surrounds (rear); and VMPS 215 sub
"God grooves with tubes." -
when I did research before buying my passive pre (currently a CI Audio, but want to get a promethius TVC down the road), the length of the interconnect makes a huge difference. keep it below 2 or 3 feet.
After going the passive route, I learned its the way for me. detailed, but still a little laid back. I guess I just like that flatter sound. the music from my 2 channel is just that much more enjoyable.Living Room 2 Channel -
Schiit SYS Passive Pre. Jolida CD player. Songbird streamer. California Audio Labs Sigma II DAC, DIY 300as1/a1 Ice modules Class D amp. LSi15 with MM842 woofer upgrade, Nordost Blue Heaven and Unity interconnects.
Upstairs 2 Channel Rig -
Prometheus Ref. TVC passive pre, SAE A-205 Amp, Wiim pro streamer and Topping E50 DAC, California Audio Labs DX1 CD player, Von Schweikert VR3.5 speakers.
Studio Rig - Scarlett 18i20(Gen3) DAW, Mac Mini, Aiyma A07 Max (BridgedX2), Totem Mites -
when I did research before buying my passive pre (currently a CI Audio, but want to get a promethius TVC down the road), the length of the interconnect makes a huge difference. keep it below 2 or 3 feet.
After going the passive route, I learned its the way for me. detailed, but still a little laid back. I guess I just like that flatter sound. the music from my 2 channel is just that much more enjoyable.
My hope is for the blackest background possible. I hate any additional noise and I figured it would the way to get it.Lovin that music year after year.
Main 2 Channel System
Polk SDA-1B,
Promitheus Audio TVC SE,
Rotel RB-980BX,
OPPO DV-970HD,
Lite Audio DAC AH,
IXOS XHA305 Interconnects
Computer Rig
Polk SDA CRS+,
Creek Audio 5350 SE,
Morrow Audio MA1 Interconnect,
HRT Music Streamer II -
Normally a passive pre + the cables add to the source impedance for a higher impedance seen by the amp. Cable length is less of an issue with a TVC because it lowers the source impedance with each step lower in volume.
As for black backgrounds, it depends on your amp. Any noise you hear will be from your amp, in my main rig I barely hear anything even with my ear up to the tweeter. Using the same TVC in my PC rig I can hear noise about 6in away.
