"There is a good and simple reason there are so many comments on this thread favoring active line stages: the issue is real."
There are even more favoring passives. Not that either proves anything.
"But any line section that has a low enough output impedance will drive a single-ended cable quite well- this is how 50 ohm cable for video can work."
My Museatex Bitsream dac has an output of 3V@300ohms. My Art Audio amp has a sensitivity of 0.7V and input impedence of 180kOhms. I don't seem to have any problems and prefer the TVC to any active preamp I have used within my price range.
Different tools for different tastes. |
Hi Herman, Obviously I don't hide who I am :) I also cannot escape facts- and I outlined them above. Yes- a few inches of wire (often unshielded) can be a *lot* different from a few feet of cable. If you've not tried it, then do so! You will see what I mean. There is a good and simple reason there are so many comments on this thread favoring active line stages: the issue is real.
Integrated amplifiers often share power supplies and limit the ability to keep short speaker cables while at the same time putting the sources at a distance from local sound fields. There can be no question that while they might be very good, they are a compromise in these areas and always have been. But if you have no space to start with they can be a good choice. |
Mr. Sphere, So if the volume control is connected to the first stage of an amp by a few inches of wire that is OK, but if it is connected by a few feet then that is bad? I don't buy it. The difference in impedance of 3 feet of wire vs. 3 inches of wire is negligible.
Maybe, and that is a big maybe, at the very lowest volume settings it will come into play, but if you are operating down there most of the time then the system has too much gain to begin with.
And even though I'm sure you are a stand up guy, and many people here know that you are a mnaufacturer of active, balanced preamps, it should be disclosed so your advice can be properly evaluated. I'm sure if Mr. Placette answered this question we would get a completely different response. |
Pubul57
The passive does not need to be better than the active...it only needs to be "as good", ($$$) saved.
Of course, only (you and your ear) will give you that answer.
Dave |
I traded my Cat mk2 with a pair of scott endler attenuators running direct to my tube monos with the attenuators on the front of the interconnects instead of the end in to the monos.
The sound and detail was just immense compared with the Cat, although not in every position on the attenuators. This setup was very anoying to opperate with a second source, hade to be switched with the Interconnects, you get the point.Now I use a Sonic Euphoria TVC and get about 95% of the package with the convenience to tave a Remote Control . I do not regrett that I
sold the Cat, because I got my Money back I had into it.I would like to try those silver rocks from switzerland ,because I believe in having nothing or the least in between any component connection with the highest quality o parts.To you I suggest to buy a used TVC and try yourself ,You can always resale if your setup dosn't improve maybe without a loss. |
Thank you Atmasphere. I think this will prove to an interesting experiment for me. Of course if I prefer the Placette>CAT to the CAT>CAT I imagine (hope) that it will not be due to bad synergy. Does your view suggest that an integrated amplifier approach with a passive preamplfier section might by interesting. If you get the advantage of the quietness and transparency (theoretical advantage of straight wire) of a passive with and internal, interconnect-free connection to the amplfier section, with perfect designed impedance matches - would that work in theory, or is it a matter of tradeoffs at that point? |
One of the more important functions of a line section is control of the interconnect. That is why you see so many posts on this thread preferring the (allegedly) more colored sound of various preamps over passives. Passives cannot control interconnects, so their sound changes (coloration) depending on the setting of the volume control.
Once you've heard what this is about its hard to keep using passives. They just don't work, unless the volume control is located at the input of the amp itself. This can be really inconvenient if you have monoblocks!
In an ideal world, the interconnect is always neutral as the line section completely controls it. In the real world, this is more closely achieved by balanced line stage operation. But any line section that has a low enough output impedance will drive a single-ended cable quite well- this is how 50 ohm cable for video can work.
I'd think twice about selling off a good Line section in favor of a passive! If you really do like it better, it suggests to me that there is a bad synergy elsewhere in the system that the passive is compensating.
Good Luck! |
Tbg, I will definitely not give up on the CAT that fast. On the amplifier side, I keep bringing in challengers to the JL2 and while I like trying new stuff, I find that the JL2 is clearly superior to any othe amp I've heard (all these other amps (ARC, Pass, Quicksilver) I've tried sound great to me in their own right, till I go back to the CAT as a reference point). I have found the SL1 pretty hard to beat as well, I've tried Lamm LL2, Joule 150, and ARC Ref 2. Of course, these are all "good", top flight preamplfiers, but the CAT equipment just seems hard to beat for my taste and matching equipment. I would love to find that a $1,000 passive pre can beat the CAT over the long run - I'm certainly open to it. I'll report back on my "test" when I have 2-3 weeks with the Placette. Thank you all for you help. |
Pubul57,
Please give us your opinion of the Placette vs. the Cat after you've had time to evaluate and compare. |
Wait a while before selling the CAT. Go back to it after two weeks. |
Yesterday I ordered the Placette Remote Volume Control with a 30-day trial. From my discussion with Guy, it seems the impedance issues are ideal for a passive approach. I'm very interested to see if it betters my CAT Pre, not only is it $7,000 cheaper, but no tubes to "worry" about (except for the 22 in my CAT amp). I'm glad I'll have both on hand to A/B, if the Placette proves to be better or as good, it really would be an eye opener. Thanks for all you input (no pun intended). Oh, and if it works, I'll probably be posting the CAT for sale here at Audiogon. |
Thanks Jsadurni ,
From what I've read so far..the PLC is slightly different in configuration from a TVC like the K&K, Bent, Django, Music First and so on. I would try a different version before you give up competely.
Good listening |
Gmood1,
I had a PLC, I heard it for the first couple of days and loved it...certain details were better, so I bought it from a friend, two weeks later I started to notice a lot of things were missing...bass, attack, detail altoghehter, there was probably some impedance problem because it really didnt sound good...we tried it in 3 different systems with similar results, once I noticed the drawbacks I cold hear them all the time in any system.
Anyway, I am glad it is working out for you, enjoy!!!
All the Best |
Hey Oz...yup I'm looking forward too it myself! I've found one owner of the Promitheus TVC that has compared it against a Bent Audio. From his post they sound about the same too him.
I'll see and hear for myself thanks to a nice audiophile friend who has many audio toys. If they do come up fairly equal..the Promitheus will be one of the best bargains in HiFi. For $280 plus $60 shipping it has shamed all the actives or resistive passives I've played with period.
Jsadurni,
The only resistive passive I've compared the Promethius too lately, has been the Noble pot in my integrated. It's not even close. The Noble pot isn't bad by any means. When compared to the TVC. It sounds out of focus and instruments and voices suffer from slight loss of depth and separation. Also the sound doesn't flow into the room as with the TVC.
What TVC have you tried in your system Jsadurni?
Another owner of this unit. Just posted a small review on another site yesterday of the Promitheus against the Luminous Audio passive Axiom noble pot/shunt and a AVI active preamp. Again the little unit came out on top in his system as well. I think the AVI is a $2800 active preamp. So if you only consider cost as premium sound ..you maybe in for a surprise. ;-)
I may try to compare it against a Bryston BP6 in a few days. From memory of hearing the Bryston active last week..it doesn't stand a chance.LOL |
"I should have a Bent audio unit with Stevens & Billington TX102 trannies in for a comparison within two weeks."
Now THAT I want to hear about....;-}
Oz |
Hello Gmood1!!
Have you tried a resistive passive vs. a TVC in your system lately? I had a hard time but I finally got the match made and the resistors betters the TVC in my system, Im curious about your findings.
All the Best |
Just from what you've told me. The TVC should work just fine with a 100 ohm input. Here's a FAQ's page from Promitheus on how TVCs work. Unlike resistive type passives a TVC will actually lower the output impedance and increase current drive from your source or BAM. Hearing the difference between it and a pot or ladder resistive attenuator is very easy. You get a fuller sound at lower SPLs with a TVC. I should have a Bent audio unit with Stevens & Billington TX102 trannies in for a comparison within two weeks. |
Pubul57 If you want to get a feel of the passive you can get a Luminous Audio passive, they supposedly calculate the impedance and sell you the passive, it is a shunt passive with a pot to ground, A friend has one and it does let you get the feel of a passive...full resistor loaded is much better, I talked to Guy from Placcete and he told me all his passives come with a 10k impedance, this impedance can work for you, he also changes impedances according to the customers settings. You can buy a placette passive and see if it "fits" your system, Guy will help you out even if the preamp is used (very cool guy!) this way you can be sure you have the passive matcing properly. |
Thanks for all the answers. I did not even know what a TVC was before, so of course I had to do some reading. This issue of electrical compatiblity seems a bit difficiult to grasp. So I throw it out there. The output impedance of my Audio Logic DAC is 225 ohms, the input impedance of my CAT amp is 100 kohms. This is complicated by the fact that the DAC gets plugged into the Merlin BAM bass equalizer which has 40KOhm input and 100 ohm output to the preamplifier. Do these impedances bode well for the use of one of these passives to drive my amplifier? Ultimately, I want to knwo if this will sound better than my CAT SL1 Ultimate, but I guess I won't really know that till I try it. |
Hello Herman, I use the Burson buffer before the TVC and after my Dac. My Dac's output impedance is fairly high 2700 ohms. After talking with a few people, two being the owner of the Jensen transformer company and Jack of Eletraprint transformers. It was clear I needed a buffer in order to use the TVC without penalty. Now instead of the TVC seeing 2700 ohms, it sees 15 ohms input. The buffer from the specs is also capable of 12 volt output verses my Dac's 2 volts.When looked upon as a whole..from your description it is an active preamp in seperate sections. I sent this unit to an audiophile that owned a similar Dac and used the Django TVC. Before the buffer was added to his system, he got rolled off or dull highs , a flat soundstage and a over all thin sound. The buffer brought the highs up, opened up the sound making it fuller and more dynamic..from his description. So as you've said..the matching is critical. Guessing from some of the other posters description's..this may have been one reason the Passive or TVC didn't work in their systems either. |
I went from Active to passive, It was very difficult to get the passive working properly. It is hard work but it will be rewarded.
As a rule the output impedance of the source should be 10 times lower than the input impedance. My DAC has an output impedance of 50 ohms, my passive has an impedance of 1k (20 times 50 ohms) and my amps have an input impedance of 1meg. So it works nice, I tired impedances with my passives from 100k, 10k, 5k, 2.5k and 1.2k, believe me the diference from 1.2k to 1k is very noticeable, I get much better bass and fuller sound with 1k.
This is a shunt type resistor based passive with caddock resistors, and a resistor ladder going to ground, a pot does not work as good to ground!
I had a PLC and hated it....
I sometimes miss my Metaxas active SS preamp.
Best. |
Gmood, where did you put your buffer and what did you use?
What you have is basically an active preamp broken into several sections. An active preamp usually consists of some switching - maybe an active gain stage that also acts as a buffer - passive volume control - maybe another gain stage which also acts as a buffer.
Most go switching - volume control - active stage, but some, like at least some VAC preamps, go switching - active stage - volume control.
The beauty of the active is that the designer can optimize the interaction of the gain stages and the volume control. Much tougher to do out here in the real world. So people try a pasive and fail and dismiss them and blame it on the fact that it is passive. Kind of ironic really considering that at the heart of their active preamp is a passive volume control. |
The key to getting a passive system together is to ensure that everything from stem to stern (uh, I mean from source to power amp) matches properly for the passive line controller that you select (i.e., impedence, output voltage, interconnect length, etc).
If this is well done then there is a good chance that a passive could work nicely in your application; they are quiet, transparent and very honest with the music (at least in my system).
The rest of it is like any other component - Is the price worth it to you? Do the imperfections (and there always are imperfections) irritate you more or less than any other component (at least at that price)?
Listening is the final arbiter in all audio choice.
In my case it worked out very well and gets better all the time (Sonic Euphoria PLC).
Good Luck & Happy Listening! |
I owned (at the same time) the Placette and Sonic Euphoria preamps, and used them with various SS and tube systems I own. Although they are both good (have strengths and weaknesses) over all I prefer an active preamp. |
I also enjoyed Hermans post. Though I haven't used a $5000 preamp at home. I do know what musical, dynamic and transparent sounds like. The TVC has been a revelation for me.
I also prepared my setup from the start by using a buffer between the source and the TVC. No worries of impedance or gain issues. In order for me to find an active that can match it across the board would cost thousands...so why bother?
Good listening |
I'm not a fan of passive preamps. I've tried several, and they all failed to impress me for the same reasons that several others have posted. This, inspite of having proper impedence characteristics to suggest that the source would have no problems driving the amp and cables. I even tried the Portal Panache, which is designed with a passive pre of sorts and short signal runs...and it sounded much the same as the other passive units, which is to say they sound like Creek gear.
I'll not buy another. |
i have a sonic euphoria. it is the most revealing component i have auditioned in my stereo system to date.
it is an excellent analytical tool for discovering differences between other components, especially cable.
depending upon the rest of your stereo system, this product may be a boon or bane. |
Herman - enjoyed your post and helpful explainations.
I went to a passive pre - a custom made modded QED unit.
Since my original active pre was a Forte 2, not a stellar performer, the passive mops the floor with the Forte 2 in terms of transparency, space, detail, clarity, neutrality, etc... just worked for me, never thought about impedences etc. |
No regrets here. Went from a SFL2 to a DIY TVC. I bought the parts from John Chapman at Bent Audio, great guy. To be honest, I didn't think it could work. Seriously, transformers?! I just had to hear what so many were raving about.
The SFL did have a touch more drive and bass but I came to think of that as exageration. My speakers are eager to rumble at 16 Hz and the TVC was happy to oblige. Compared to the veil that was lifted, the SFL didn't have a chance. The trick is that I have very dynamic speakers and about 3000 watts of amplification, total. I also selected a CDP that has 4V into AES/EBU and low output impedance(< 100, although < 1K is all that's suggested). XLR cables between the pre and amps also raises the output. Amps aren't much of an issue for matching other than moderate sensitivity. A friend built his own after hearing mine and is very happy. His system isn't nearly as extreme but very nice.
With passives, resistive or TVC, matching components becomes critical. |
There is a lot of confusion about this. The volume control in a passive is no different than the volume control in any active preamp. It is in a different box so you neeed cables to hook it up, that's the only difference. The volume control inside a preamp is also a passive device. You can build either one with a transformer, pot, stepped attenuator, whatever.
You can successfully use a passive if:
1. the rest of system has enough gain to drive the speakers to the desired level
2. the input impedance of the passive is high enough to properly load the source
3. the output impedance of the passive is low enough to be a good match to the amp
4. you don't try to use cables that are too long or have high reactance
Those that had poor results failed to meet one or more of these requirements and finding a passive that meets all of the above for a given set of components may be impossible. Trying to use one in a system that requires the extra gain from an active preamp is doomed to fail. Many don't understand what these requirements mean, choose an ill suited passive for the job, and end up with lousy sound. That's not the fault of the passive but of the person putting together the system.
The big problem with volume controls of any type is that they always take something away. The advantage designers of preamps have is they can optimize their design for the type of volume control they choose. Unless the user of a passive takes the same care in choosing they will likely end up with poor results. |
So, you only want to hear from people that had positive experiences? It sounds like you've already bought the unit and now need support for your decision. Just kidding. But, what about comments from people who haven't had good luck with this? |
I also have tried the passive route a couple of times in the last decade. Yes, initially there is some satisfaction about clarity, blacker background, etc. However, I always wind up missing the dynamic impact and rythmatic drive that only a active preamp can bring. The active has more body and soul to the music, IMHO.
I compare it to listening to Nordost Valhalla cables. Initially they are breathtaking, but over time, I found them to be too thin and lacking musical weight for my tastes.
Obviously some will have different opinions, but they are wrong. :-)
(I'm kidding guys!)
John |
i was the very happy owner of the Balanced version of the Placette passive RVC for 5 years until about a year ago when i replaced the $1800 Placette with the $23k darTZeel NHB-18NS. the Placette replaced the Levinson #32 preamp back in 2001 and then proceeded to easily better maybe 10 to 15 preamps in my system over 5 years. this includes quite a few $10k to $15k units as well as a few other passives.
there were a couple of pre's that were at the same level of the Placette overall but with trade-offs.
i did compare the Placette to the Bent Audio passive here;
http://db.audioasylum.com/cgi/m.mpl?forum=tweaks&n=77331&highlight=mikel&r=&session=
a few above posts comment that the Placette passive lacks dynamics compared to other passives or some of the best active pre's. that was not my experience 'except' in the case of the battery powered darTZeel; which has dynamics beyond anything i have heard. my experience was that assuming that the interconnects between the Placette and the amp were kept very short (1 meter maximum and .5 meter ideally) and the input impedence of the amp was sufficiently high, the Placette offered SOTA dynamics and really micro-dynamic life that was amazing.
at $1000 list price for the single-ended version and $1800 for the balanced version the Placette RVC has such a high price/value relationship that one can hardly have any excuse not to at least try one. the passive linestage is $400 more (for the single-ended version) and has equal performance.
it remains the second best pre i have yet heard.
unconditionally recommended. |
I have had 4 passive preamps and many active ones, the passive line goes from First Sound to Axiom, I am currently using a Monolithic Passive in the meantime I receive my new preamp (active again).
Passive preamps (as noted above from others) are very transparent, fast and revealing units, only top-end preamps (Metaxas, ML or Gryphon) come close in those regards, unfortunatly for me my new systems need of the work of an active preamp to bring more roundness, dynamics and soundstaging (yes - sonic artifcats at the end).
Good luck
Fernando |
Agree with TBG. I have tried passive pre-amps (Placette) for one. Very clean, but does not have the dynamic punch. I currently use the H-Cat pre and it is IMHO, the best pre-amp that I have ever heard in my 50 years of this this wild, crazy hobby called Audiophilia. Love it, but love the music better. I used to have an old RCA windup Victrola when I was a kid and I would buy used 78 RPM records from a company that serviced juke boxes at 6 per $1.00. This was back in the l940's. Anyhow, still going strong at ths hobby. |
I had a transformer based passive for a while, (Bent Audio TVC)..."extreamly good sound" untill I made many system changes, ie...amp, speakers, and new (much larger) room. This caused my move back to an active preamp a couple of years ago.
I'm now using a tubed preamp (Audioprism Mantissa)...like Bob above, I'm "more" than happy with the Mantissa preamp I now have in place of the passive.
So, in answer to your "regrets" question...I had no regrets going passive...and no regrets (now), after going back to active
Dave |
I currently have both a Placette balanced RVC and a balanced PLC Sonic Euphoria preamp feeding NuForce Ref9.02 amps from the balanced outputs of a Marantz SA-11S1 CDP. I have compared both at length over the past 6 months against each other. I have found that the PLC sounds best to me with either my Triangle Antals or Dali Ikon 6 speakers. The RVC sounds better with my Paradigm Studio 60s. I attribute this to the PLC having better low frequency output which compliments the limited bass Antals and Dali 6s better. And the faster speed of the carbon drivers in these speakers makes up for the somewhat slower pace and more rounded nature of the PLC. On the other hand I think the RVC itself sounds faster with more detail than the PLC and creates a better synergy with the slower but better bass providing Studio 60's. When I ran the 60s with the PLC it sounded a bit congested and heavy while the RVC with the Antals or Ikons sounded too transparent and analytic. I would say, therefore, that it will depend mostly upon your system components and will even vary from recording to recording. I had only planned on holding onto one passive, but find I like them both in their own ways and still can't decide which to keep. They are both great units. Maybe after my next upgrade to "better" speakers I'll make that decision? |
I have found that a good compromise is a passive-aggressive preamp. It's kind of the best of both worlds, only more. |
I know you don't want to hear it, but I have tried five passive units over the last ten years. In each case, I gave up and went back to active units to get back the pace and dynamics of music.
I grant that there is a purity to passive units, but I cannot take them for very long. |
Pubul57,
I too use CAT amps (JL-1s), and had used them with active preamps such as the Thor TA-2000, the BAT VK-5i, and the CAT SL-1 Signature. (I also own Merlin VSM-Ms, so I am pretty familiar with your equipment). I switched to passives maybe four or 5 years ago, starting with the Audio Synthesis Passion (a great little passive line stage), to the Placette, and ultimately to the Audio Consulting Silver Rock TVC. Like the posters before me, I was extremely pleased with the switch, and also highly recommend you give a passive line stage a shot in your system. Indeed, no active preamp has provided the level of transparency or resolution that I have gotten with the Silver Rock.
I would pose two caveats, however. First, make sure that you try a passive line stage with dual outputs (i.e., one for the CAT JL-2, and one for the BAM) - I was not as pleased with the result when using an RCA adapter after the passive to split the output into two lines. Second, I was not as impressed with the Placette passive in my system as other passives that I tried (however, given that others have had more success with the Placette, take this caveat with a grain of salt). |
I had a McCormack passive into my DNA .5 amp and loved it, but was missing the dynamics. I've moved to an Audio Prism Mantissa and haven't looked back.
Yes, a passive is very alluring, and can be really great paired with the correct equipment, but it doesn't always work everywhere. However, trying to keep that level of detail and transparency and clarity is VERY hard to find in an active linestage. Be careful what you wish for, you may get it.
Enjoy,
Bob |
I was using a Joule Electra LA-100MkIII before moving to a passive TVC. THe TVC was built for me by Kevin Carter at K&K Audio using S&B TX-102 MkI transformers and Seiden switches. It is configured with dual volume and dual input selectors. It has 2 inputs and 2 outputs.
The Joule is a very musical and outstanding preamp. However, the passive TVC just matched up better with my high input sensitive solid state amp. I gained more accuracy, detail, and overall tonal balance with the K&K, at the expense of some mid range sweetmess and the musicality the Joule offered (which for a tube preamp is pretty neutral IMO). I don't regret the move, but I do miss the Joule.
I have never listened to the Placette, but have heard the Sonic Euphoria as that was on my list. The K&K is better IMO and has character (there is a liveliness to the presentation), which I think the Sonic Euphoria lacks (somewhat boring presentation, but accurate). I did listen to some resistor-based passives and prefer the TVC implementation. Again, more of a preference as I heard quite a few nice resistor-based passives. To me the TVC is easier to match up with amps and you don't necessarily have to worry about cable lengths. |
Pubul57, I went from a Mark Levinson reference 32 preamp to the Placette dual active line stage because it offered a much higher level of sonic performance. A good friend and fellow audiophile loved the Placette active, but it was not in his budget, so he auditioned the Placette passive and fell in love with it. We both believe the Placette passive gives about 70% to 80% of the Placette active line stage. He uses his Placette passive with a Threshold amp and MG 1.6's in his system.
I believe both Placette pieces are great performers and very reasonable priced, $4600.00 for the active and $1500.00 for the passive, and Guy Hammel, Mr. Placette is a great gentleman to deal with. Finally, you can do a 30 day home audition to see if his preamps are what you are looking for based on personnal taste and system synergy. |
I went to a Bent Audio TAP TVC based passive and to my ears its the best move I have made. I went from tube preamps Vac, Canary Audio, First Sound to name a few and active SS preamps, Klyne, Pass, Superphon to name a few to my Dac straight into my amps and the Bent Taps sonics surpassed them all. No looking back. |
I moved from a Cary to a Reference Line 1A. An improvement in naturalness and soundstaging. Best single improvement since upgrading to a Meridian 508.24 CDP.
Associated equipment:
Atma-sphere M60 2.3 amps
Silverline Sonata MKI
OK, one regret-every once in a while I cannot get "concert level volume" because of the CD recording level. |
Active preamps I have owned:
Modulus 3A
JJ Electronics 243
Cary V-12P(hot rodded SLP-98)
Bruce Moore Companion
BAT VK3i
BAT VK-30
Reference Line Preeminence 1
I would say my current TVC based preamp using S&B Mark I trannies beats 'em all. And BTW, I borrowed a Placette for a night, not even close.
Oz |
