Are passive preamps better?


Does a passive preamp with transformers so that its impedence can be matched with an amplifier have the potential to provide better sonics than a line preamp? I have a Simaudio Celeste preamp and a Harman Kardon Citation 7.1 amplifier. Lynne
arnettpartners
It will be quieter and maybe more transparent, which does not mean it will sound better to you. You are going to hear 50% argue for passives and 50% swear by active tubes. Ultimately you will have to try four yourself, but there are certainly very, very good passives and happy owners. I know this does not help much, but it is hard to to give a definitive answer that is warranted. I've been the passive route, and prefer my tubed Joule 150 MKII.
Agree with Pubul57,

My response to passive preamps is no.

With passive you have the hardware in the way, volume controls in the way, wire in the way, RCA (or XLR) jacks in the way but you get ZERO benefit.

Zero gain, zero contrast and zero dynamic enhancement from the original signal.
I agree with Albert and Pubul:

Right now I'm listening through Endler resistor-based volume controls ahead of Atma-Sphere MA-1s. Nice combo, but I've got a custom Audio Note kits L3 active in the UPS pipeline that'll replace the Endlers with no regrets. I've also used the DIY HiFi Django w/S&B iron ahead of Atmas as well - again nice, but ultimately lacking the energy imparted by a Blue Circle BC-3000 or Atma MP-3 (the last two actives in my system).

If one has $1000 or less budgeted to a "preamp", I'd go with a passive; otherwise, I'd save for a quality active preamp.
I had an NVA passive pre which....delivered music "as is". When I tried an Audio Note tube pre, the music became alive. So I am now an active pre camper!
Just to represent the other 50%

I like my Sonic Euphoria passive a lot. The last active I had created a lot of glare which is now gone. The active before that did not provide enough gain. The one before that sounded flat. (Supratek, Joule, BAT - not top of the line but not exactly chopped liver)

No doubt that the rig sounds different with the passive then straight from source to amp. A bit darker and smoother. Maybe more emphasis on certain details. But NO glare.

For now I am happy - lots of detail. sounds great at low levels, no tube rolling ang$t. I am sure I will go active again but for now this is working for me.
I am a happy owner of passive pre-amp based on S&B trainnies. It has 0 and 6dB of gain, which is switchable.

The sound is very transparent without loss of dynamics. I compared it with several pre-amps (for example with EAR 864) and it was clear winner.

Saying all that, I wouldn't though say that every passive is better than every active pre-amp. It depends a lot on your music taste, the rest of equipment, ... So the best way is to try several options, active and passive, in your system and then to make a decision. There are a lot of extremly well sounding active pre-amps (and not only tube but also SS) on the market.
The most important factor when considering a passive is to look at the impedance match between your source and your amplifier. A passive simply muddles things up - unless your impedance match has a lot of leeway built in, a passive simply will not work.

I have never heard a passive setup which impressed me. Quite often, the system would run out of volume when more is needed. This is especially true for classical music which is mastered at a relatively low volume.
I am using a Preeminance 1A passive ahead of Atma-sphere M-60 II.3 with the best results in my system to my ears thus far. The actives I have used (Cary, Sonic Frontiers, BottleHead, Musical Fidelity) imparted a color to the sound peculiar to each preamp that I only noticed due to the tranparency of the passive.

I would equate it to prefering water to drink over soda. Water is quenching and ulimately satisfying where as soda is great at first but leaves you with a thirst and an after taste that may not be pleasant.
Told you (see my first comment). But the comment made above - "music came alive" - pretty much describes why ultimately I preferred an active, even if it does not provide the same "see through quality" you get with passives. You will not find the answer from this thread, you will have to try good examples of both. I agree with the comment above that a budget passive is likely to sound better than a budget active.
I prefer active preamps. I've tried a few passives, but they never seem to work for me. That being said, I've noticed that many who like passive's also have tube amps. I cannot say that I have tried a passive with tube amps, so it may be a possibility.

Cheers,
John
Albertporter...You criticize a lack of "enhancement from the original signal." Wouldn't that be *distortion* of the original signal? Pleasant perhaps, but not "transparent".
Jmcgrogan2 - you hit something there. Tube amps typically have very high input impedance, much higher than the typical SS amp, and this is why passives work better with them.

However, in almost all cases at least, a very good active pre will eclipse any passive. The passives all somehow lose body and drive.
Another vote for active. I've owned a couple of passive units which sounded so "clean and open" on initial hook up I was impressed. But ultimate lack of drive and dynamics always caused me to return to an active unit.

There is one significant value to owning an inexpensive passive unit (can be assembled with <$15 for a stereo pot, two pair of female RCA jacks, some wire and a small box) -- that is to test the transparency of any "active" preamp under audition. A good unit should be as open sounding (lacking in distortion) as the test mule passive box.

Also, I agree with Sam Tellig that a "passive preamp" is an oxymoron term.
FWIW, because of Johns comments, I must say that I've used passive's with tube amps and can't say that I ever found anything about them that made them preferrable to a good active amp.

Its too easy to lose the sources dynamics because of poor matching of cables and IC's with a passive, and like every thing else in the hobby, everything between the source and speakers is either additive or subtractive. There ain't anything that is just neutral to the source, if for no other reason that you can never know what the source sounds like with out adding equipment to decode the contents of the recording. Doesn't that initial playback equipment define neutrality.

Has anyone actually listened to the recording over the studios playback system to get a fix on what it should sound like? Perhaps a recording engineer might, or some one at the recorded event might, beable to rely on aural memories if they actually heard it, but I doubt it

I doubt that anybody would recognize 'true neutrality to the source' in audio equipment so why not add an active pre-amp to those things one might use to dial in their version of neutrality or replication of the sound of a 'live' or 'close to live' event. Do what sounds good/realistic/neutral to you! Thats what everybody else is doing. Even the guys that wear hair shirts, even though they would proclaim otherwise! :-)
Newbee, I didn't mean to insinuate that those with tube amps would prefer a passive preamp. I've owned tube and SS amps and have always preffered active preamps myself. What I was saying is that I have noticed that most of the fans of passive preamps are using tube amps. It's very rare to find a fan of passive preamp with SS amps. Just something that I've noticed.
Since Lynne is using a SS amp, I would think a active preamp would be the obvious choice. To more directly answer the question:

Does a passive preamp with transformers so that its impedence can be matched with an amplifier have the potential to provide better sonics than a line preamp?

I would say yes, the potential does exist. However cable, source and amp matching would still make it very difficult to realize better sonics. IMHO.

Cheers,
John
Eldartford

Albertporter...You criticize a lack of "enhancement from the original signal." Wouldn't that be *distortion* of the original signal? Pleasant perhaps, but not "transparent".

I don't consider great gain, improved dynamics, vivid contrast and improved bandwidth as distortion. In fact, that's exactly what I'm looking for in my system.

In our group, tests between state of the art passive against excellent preamps (RE: Manley Steelhead, ARC REF, Aesthetix Callisto, Audio Note, etc) the active always won.
Pubul57 got it right. The only thing I would add is when discussing passive preamps, Placette is in a class of it's own.

No other passive is simular in design or parts to a Placette.

Hence no other preamp sounds like a Placette.

IMHO and a great many others, anyone saying they've tried passive preamps without trying a Placette, really has no idea just how good a passive preamp can sound.

Don't take my word for it. Order one, and you'll get a 30 money back guarantee to find out for yourself.
All preamps will add a coloration. Recording Engineers know that instictively when going to grab Neve, API, SSL, Manley, etc. Most peoples experiences with passives aren't that pleasant due to impedence mismatching and the neccesity for high quality internal components. Done right it works well. My home system still uses a "dual mono" PS audio passive that I keep going back to again and again for it's sheer pleasant musicality.
If you want great sound with little thought or effort avoid the passives and pick up a Manley.
I'm suprised that at least the with this group, it seems more like 80/20 for the active - not that it necessarily means anything, but it does seems to be some form of consensus amongst different listeners who have experience with both approaches; but eventually, you really have to try it to know if the passive works for you.
I currently run passive and here's why:

1. It squares with my system philosophy of simple, short signal path.

2. I only have a single source and don't need source selection.

3. I can't justify another set of interconnect cables, power cable, tubes, and the linestage itself. I use Cardas Golden reference cables and, while not the best, I'd feel compelled to use the same on the preamp.

So, for me, it just doesn't make sense to add another $2,000 to a system that only has $2,000 speakers, $1,200 amp, $2,500 phono stage, etc.
Interestingly, I had the Placette RVC and the "Active" which I owned between a CAT,Lamm, and now a Joule. The Placette's were excellent (we are hairsplitting between some very fine equipment), though I preferred the Placette "active"(it has no gain, but a buffer to ensure it can match with pretty much any load). Given that, I still ended with the Joule as it made the music more organic and more full bodied than the Placette approach (one of the finest IMHO); whether I prefer "distortion" or not I don't know, nor care, I'm more engaged with the music through the Joule. Maybe it is the difference between hearing into the recording and hearing into the performance - if that makes any sense.

I'm not sure if proper matching would really address what did not totally satisfy me with the passive, as the Placette Active has no mathcing issues (except possibly gain with some systems) and it was clearly better than the RVC in my system, not close in my view; it will satisfy many listeners. Experiment - but I do think the input impedance of most tube amps is proabably an important issue to good "matching".
Passive worked for me but I carefully selected a CDP and amps to match. Half volume will shake the house. First impression was incredible tranparency but that something was missing. After going back and forth between SS. tubes and passive several times, all the passive was missing in this combo was noise, distortion and embellishment.

Talk Thunder 3.1b - 4.2V XLR/ <100 ohms
DIY TVC (Bent/S&B) 0 gain
dual, bridged Plinius SA100 - over 38 dB gain
Genesis 350's - 96 dB
combined with the Genesis servo - that's a lot of wattage
A really good active preamp will actually be more transparent than a passive preamp for all of the reasons mentioned by Albert.

Using a passive preamp places demands on source components that they are often not ready to meet. Even with the rare capable source and good impedance match, a passive unit is a pure impediment or drag on the source and the signal with no upside.

I will go a step further and say that in the best systems the preamp is often more of a determining factor than the power amp in the overall sound quality of the system.
When I asked the question, the passive seemed more logical to me. Now the active seems more logical. I'm sure I will experiment when I have the opportunity. I think the 7.1 is probably 22k (just got in from delivering a calf and am too lazy to look it up). H/k usually is although this one is Madrigal. Thanks for the interesting disscussion. Will research Placette and Manley and Joule for sure. Don't stop. It's very interesting. Lynne
I have Wyetech Topaz 211 tube mono amps and had the Placette pre in my system for several months and although I appreciate what it does , it was a sheer pleasure to replace it with a good active ( Audion 2-box linestage ).
The music is now alive with lots of impact .
Hello, I have been using a passive preamp for the last eight years or so and had tried them prior to that. I was also trying SS and tube preamps till the passive "won" the contest for me. No loss of dynamics or sonics but improved clarity and resolution with decreased noise and colorations.

I have no need for switching as I only use a TT, though that is possible with a passive, I use "naked" attenuators (no switching). Why add unnecessary gain, colorations, expense, complication and noise if you dont need the gain?

Now it is active 12 to passive 7. Not as terribly lopsided as one would think.

Bob
I have tried five different passive units. Initially, I am always struck by the purity of the passives, but when I put in a quality active, I end up selling the passives. They have no pace or dynamics of live music. I seem, however, to be the exception in that I have had a solid state line stage for the last five years, the H-Cat P-12. Repeatedly, I have tried tube preamps, which I had always preferred, but always come back to the H-Cat.
BTW, I failed to note in my post above, I have been using a Wadia direct to an amp and one thing has become clear from my experimenting with it thru a passive and active line stage. The active line stage was additive and the passive was subtractive (better or worse is not the issue as that depends on the tonal/sonic quality preferences of the listener). If the synergy is right for you, and you're into digital this could be the way to go.

Probably obvious and redundant for most here. FWIW.
Well said: "that depends on the tonal/sonic quality preferences of the listener". I also experienced that sense of amazement[?] when I first used passives, because they certainly are different, but ultimately I felt the need to go back to active, I suspect this is a very common trajectory. ok, 65%/35%.
Albertporter...First of all, I do agree with you that an active preamp usually works best. I guess I would agree with your original comment if it said "lack of signal degradation" rather than "signal enhancement".

I don't know when passive preamps became commercially available, but several decades ago I made one to suit my particular (rather unique) matrix multichannel system. I had plenty of gain, and my solid state source components had the low output impedance to drive tube amps having high input impedance.

By the way, an integrated amp or a receiver essentially has a passive preamp in it (without the external interconnects).
By the way, an integrated amp or a receiver essentially has a passive preamp in it (without the external interconnects).

Like the Ayre AX-7e.
Eldartford,

My exact comment about passives:

Zero gain, zero contrast and zero dynamic enhancement from the original signal.

Isn't zero dynamic enhancement the opposite of improved dynamics?

I don't consider great gain, improved dynamics, vivid contrast and improved bandwidth as distortion.

My meaning was clear and exact in both situations. You seem to be more interested in taxing peoples comment with semantics than contributing to the knowledge base.
Albertporter...Just as tube circuits are known to modify the incomming signal by generating harmonics which some think are pleasant, I am suggesting that the extra circuitry of an active preamp may be doing the same thing. I think this is an idea to consider: not just semantics.

Of course "great gain, improved dynamics, vivid contrast and improved bandwidth" is not distortion. But these do not "enhance" (add to) the input signal. They preserve it. Anything added is distortion.
Of course "great gain, improved dynamics, vivid contrast and improved bandwidth" is not distortion. But these do not "enhance" (add to) the input signal. They preserve it. Anything added is distortion.

Inaccurate, a preamp always adds something to the signal, it's an amplifier. The question becomes one of improved sound or not.

Albertporter...Just as tube circuits are known to modify the incomming signal by generating harmonics which some think are pleasant, I am suggesting that the extra circuitry of an active preamp may be doing the same thing.

Tube or transistor, both add to the signal, nothing is perfect. It then becomes a question, do the benefits outweigh the negatives?
I will show my ignorance (more of it). If impedences are an issue with passive preamps, then are they also with active preamps? Lynne
Good question.

You bet impedance is an issue, actually the issue when pairing a pre and an amp. Impedance matching - or mismatching - between the pre output and amp input is the key to a successful pairing or two boxes that just aren't happy together... Call it synergy =)

A great deal can be found on the subject by those both more technical and erudite then I am - all I can contribute is that its great when it happens and noticeably not great when it doesn't. T'aint no subtle or illusory thing.
Sure. Especially when you match most tube pre-amps with SS amps. One must be careful to make sure the pre-amps output impedence is sufficiently low to properly drive SS amps which often have low imput impedences.
Thanks. That's what I thought. The 7.1 has an input impedence of 22k and the Celeste has an output impedence of 120 ohms. I have no idea how synergistic or unsynergistic that is. Lynne
Lynne, the "rule" is 1 to 10 (line stage output impedance to amp input impedance, so you should be okay.

I cannot stand the lack of dynamics on passive volume controls and suspect that is the mismatching of the source output impedance through the passive volume control to the amp input impedance. But it really doesn't matter as five attempts was enough, I am sticking with quality active line stages.
I disagree with all the passive preamp folks. Saying things like, "It will be quieter," is not always true. My Fire preamp is black background as any passive, arguably more.
Perhaps I do not understand what is meant by dynamics. My passive preamp/Atmasphere setup seems to have great dynamics to me.

By dymamics is it the range from high to low and speed in shifting from point to point in that range?

Or is it something else?
Entrope, yes, you are correct. I don't really know whether anyone has ever measured this, so it is really a personal judgment or a comparative judgment. I find that I grow bored with the music using a passive, that I find myself not shaking my foot in time with the music, and that is just lacks the leading edge of the music.
FYI - the Placette "Active" (which is a zero gain pre with a buffer)has an output impedance of 10ohms or so and will "match" with any amp input impedance and, I'm told, almost any length cable. Of course, I think it is selling for $7000 now. Some may argue it is not a passive, but it has no gain stages which is a primary reason for the quiet and transparent quality of most passives.
Pubul57, I did try the Placette "Active" briefly and did like it better than the totally passive unit. I also thought there were better active line stages.

I should say that I certainly have heard active units that were worse than the passives, the Crown 150IC and several others come to mind. The top passives that I have had are the Audio Consulting Silver Rock and the Top Dog, which is no longer made.
Thanks to absolutely everyone for the discussion. I don't know when I've learned so much about audio. I'll bet it's true that receivers and integrateds have no active preamp. That's how they sound. All of you filled a big hole in my audio experience. A lot of things came together as a result. Cheers. Lynne
The Placette "Active" approach of following passive switching and volume control functions with a unity gain buffer seems ideal to me. In practice most preamps are operated at less than unity gain overall although within the unit there may be many dB of gain. Most of it is discarded in the volume control. Most disc players, for example, have a nominal output of 2 volts rms, and 2 volts would drive most power amps into clipping.

When I built my home brew "passive preamp" several decades ago I also built what I called a "line driver" which was a unity gain buffer amp with high input impedance and low output impedance. This was necessary when I changed power amps from tube units with 250K input impedance (high even for a tube amp) to SS amps more like 20K. I was very aware of output impedance requirements from my work as an aerospace systems engineer where it was necessary to transmit both analog and digital signals through as much as 300 feet of 20-year-old wires. There was always a circuit dedicated to this "line driver" job.
Since I don't have the $7000 maybe somebody will start manufacturing them for a fraction of the cost. I copied your response, Eldartford. Last night I tried bypassing the preamp with my H/K HD7600ll which has a variable output option. This player is so old that probably no one knows it anymore. In the late 80's--early 90's it was considered as good as any player on the market, so it's not a terrible reference. I tried this years ago with another system and the result was so horrendous that I didn't consider it with this system until last night. It sounds good. I get the quieter background and improved clarity. It might sound more like my brother's and sister's surround systems with less dynamics (but what is dynamics?) Maybe the music is slightly "pinched". Not sure. The manual volume control feels like a good pot but it's not motorized. I set it at half volume and varied the volume with the remote, and this volume control is of inferrior quality, I assume. So I don't know what these settings are doing for it or to it. All I know for sure is that preamps are an annoying necessity. Lynne