[marvda1]

there seems to be the concept that a tube pre-amp and ss amp make a great match. what about the other way around, a ss pre-amp and tube power amp?  anyone have any experience with this combo?

[meilankev]

marv,

I have done numerous comparos over the last couple of years, and this is what I've found:

> For someone with a SS amp and SS preamp who would like to add "that tube sound" into the mix, replacing the preamp (with tubes) has minimal effect compared with replacing the amp.  That's the bottom line.

- I've tried this test with 2 separate SS amps (CineNova and McIntosh).  The preamps involved were my KORA, a McIntosh, and an Odyssey.  Switching out the preamps yielded a different sound,  but it was not dramatic.

- However, if you switch out the amps, the differences are much more pronounced.  I've tried 4 different SS amps (CineNova and McIntosh mentioned above, Audire Audio and Classe' Audio) to compare with my KORA monoblocks.  The "tubiness" differences were much more readily apparent.

These comparos were done mostly in my system, but also at one other ACer's home.

Of course, when switching out the amps, it forces the owner to consider amp/speaker compatability much more so than switching out the preamp (in which you have to consider gain).  So, switching out the preamp is less "risky" for an audio enthusiast.

But if you are just interested in bringing out the amount of "tube sound", switching out a SS preamp with a tube preamp cannot compare to the effects of switching out a SS amp with a tube amp.

ymmv,
Kevin

[doug s.]

i'd have to agree w/kevin about the differences, if yure not running active subs w/solid state amps on the subs.  if you run subs, & choose a relatively neutral tube amp, the differences aren't as pronounced, imo.


i've done both, & enjoy both, but tube pre & tube amp is best!     my opinion of course.  and, i also make sure i'm running subs on s/s amps...  not so much cuz i don't want tubes doing low bass (which i don't), but more cuz i want subwoofers doing the bass, & not the main speakers.  the mains will still be doing tube bass down to whatever the x-over frequency is...

doug s.

[jswallac]

I also agree with both of the above posters.  I suspect the main reason we always hear that the preamp should be tubed if you what to add tubes to the chain is based on ease of use more than ultimate sound.  Tubed preamps are not much different that SS as far as ease of use.  The tubes last a very long time, you don't need to worry about biasing, they do not run very hot, and importantly, they cost about the same as SS.  Power amps are a different story.  Speaker matching becomes much more important.  Unless you have an easy to drive load, you need a tube amp with a lot of power and that costs much more than a comparably powered SS amp.  Throw in the hassles of heat, biasing, etc. and it is easy to see why it is difficult to simply throw a tube power amp into the chain.  I do think the power amp gives the most tube sound, but it comes at a far greater price (both dollars and hassles) than the tube preamp.  But a lot of us think it is worth it.

[JohnR]

there seems to be the concept that a tube pre-amp and ss amp make a great match. what about the other way around, a ss pre-amp and tube power amp?  anyone have any experience with this combo?

In general, I think it depends on the quality of the gear, but the former is a safer option. If, however, you are asking because you are considering replacing one or the other pieces of your own gear just to "get the tube sound" then I says yikes! caution rough terrain ahead! You need to find equipment that makes you pleased to own and listen to it.

[PhilNYC]

Without regards to the "tube sound", vacuum tubes run at very high voltage with low current and transistors run at high current with low voltage. Therefore, vacuum tubes can deliver a very high signal swing without distortion due to a limited voltage supply.  This makes tubes well-suited for preamps.  Conversely, transistors run at low voltage but can deliver high current. Therefore they are ideal for use at the power amplifier output to supply the high current demand of loudspeakers.

For me personally, I think using tubes at the preamp vs. amp is a matter of using the technology best suited for the component (I generally run a tubed preamp and hybrid (tubed-input-stage, ss-output-stage) amp.  That I can roll tubes in the preamp to fine-tune the sound is a bonus...

[JoshK]

I would agree with both John and Phil here.  You shouldn't try to color your system to get an audiophile kosher system.   I still have yet to hear a tube preamp in my system that I could live with long term.  I heard some I really liked for a while but ultimately they added something that got on my nerves after a while.  You are best experimenting for yourself to gain what you find most appealing.  

Phil makes a very good point about what technology is best suited for each application.  I would argue that doesn't mean all tube preamps are better than SS, but they have a few advantages.   Tube amps have some definite inherent downsides to work with so I think it is wise to make sure your system will match with the tube amp you might consider.  Most have output transformers that can be a huge handicap for the design and many high low dampening factor.  To get best results requires careful consideration of speaker choice.  I myself feel that you should match the amp to the speakers, not the other way around.

[PhilNYC]

I would argue that doesn't mean all tube preamps are better than SS, but they have a few advantages....

I agree with this, and I didn't mean to imply that "all tube preamps are better than ss".  I gave up on trying to make all-encompassing statements in this hobby years ago...!    Tube vs. SS, Dynamic vs. Planar, Passive vs. Active, Up/Oversampling vs. Non-U/OS, etc etc....In my experience, I've found more than a few "exceptions" in both camps on all of these topics, enough to scare me away from making any kind of generalizations of that nature and simply just trust what I hear.  The only exception to this IMHO has been CD vs. Vinyl...  

[JoshK]

I didn't think you were saying that, I was just adding the point.  Came across wrong I guess.  

[beat]

I agree with much of what has been said,
quality is of great importance as is speaker matching and of course therefore your room and its treatments but most impt of all is personal taste. All I know is I love how my SS pre came together with my tubeamps. I put my bottlehead foreplay out to pasture to gain more controls..not for sonic reasons but I was pleasantly surprised. I feel..repeat Feel that the sound is less colored now allowing me to hear the amps do their thing. Then again, I have a tubed output on the CDP  

[doug s.]

all of this theoretical tube/solid-state stuff has yust been driven home firmly for me w/a real world observation, last nite.  due to personal situation, i was w/o my fave melos preamp for ~10 months.  i have been using primarily a creek obh-12, feeding a modded z-man tubed buffer stage.  amps have included thule, revox, korsun, antique sound labs, melos, & audio mirror.  nice mix of toob & s/s.  

well, last nite i finally got my new melos pre - i had traded my old one for a similar unit that had m.a.r.'s latest tubed wolume pot upgrade.  the reason for the trade was the other guy wanted my pre for its balanced configuration, & i wanted his single-ended iteration for the additional three line inputs & 2nd tape loop.  the upgrade wolume pot was an additional benefit.      

bottom line is it will be a cold day in hell when i stop using a tubed preamp!     the audio mirror set tube amp i am presently using certainly gave that tubed flavor, compared to the s/s amps i have recently used, but adding the melos pre was the single greatest improvement i've made to my ever-evolving rig over the past year.  everything has yust come alive - detail, dynamics, soundstage - WOW!  

and, it's not that the creek was doing anything wrong - i know this, cuz i was in a hurry to check out the melos, to make sure everything was up to snuff, due to recent problems w/shippers damaging stuff.  so instead of connecting each source to the preamp separately, i yust quickly plugged the creek into the melos, w/its two tunas & cdp hooked up to it.  so, even w/the creek still in the loop (w/its wolume pot now wide open), the sound quality has taken a *big* step forward.  much bigger than any prewious amp change; even bigger than when i swapped out my proac tablette 8 reference signatures for a pair of coincident victory's.  i am now wanting to hook the proac's back up to hear how they will now sound, w/a good preamp back in action.

ymmv,

doug s.

[beat]

Dang Doug,
you're making me jealous over here. Which Melos is it?

[doug s.]

Dang Doug,
you're making me jealous over here. Which Melos is it?

hi beat,

my pre is the ma333, which was melos' best unit, a two box affair (add a third box if ya have their fono stage),  w/a separate power supply (one medium-amp-sized toroid per channel).  this unit is true dual mono, two umbillical cords from the p/s to the pre, & separate wolume pots for each channel.  the remote is kinda weird - one up/down pair of buttons operates both pots, another pair operates the left channel only, to effect balance.  kind of an ergonomic mess, but the sonics are worth it.

my prior pre was identically spec'd (all mar upgrades), except this last wolume pot upgrade.  i cannot honestly compare the before-n-after of this last upgrade, cuz it's been too long, & the system & room are so different.  but, i can say that when i 1st got the ma333 a few years ago, the reaction was similar - easily the biggest sonic upgrade to the system, & that included later upgrade to tubed amp (mesa baron) from electrocompaniet s/s.

if i were in the market for a pre, i'd seriously wanna be checking out dodd audio's reference model, (as well as the used melos market), which is supposedly nicer than the original stock ma333, and tho spendy at ~$2600, if it's better than even a stock melos ma333, i'd say that's a good deal.  someone on this forum owns a stock melos ma333 & has bought the dodd reference; i am still anxious to hear his thoughts...

doug s.

[brady2004]

similar experience Beat had.   I tried Foreplay into my SS MacIntosh.  Sounded great.   After a few weeks,  I took it out.  And installed an ALPS into my Mac "power amp" as passive attenuator in the input stage.   Whoa... clear,  better everything.   Less gain,  of course ... but am using 90+ db speakers anyway ...   Same observation whether using my tube DAC or SS DAC.

Conclusion - the shortest path is the best path.

[doug s.]

similar experience Beat had.   I tried Foreplay into my SS MacIntosh.  Sounded great.   After a few weeks,  I took it out.  And installed an ALPS into my Mac "power amp" as passive attenuator in the input stage.   Whoa... clear,  better everything.   Less gain,  of course ... but am using 90+ db speakers anyway ...   Same observation whether using my tube DAC or SS DAC.

Conclusion - the shortest path is the best path.

which is why ya need to try for yourself - your conclusion is the opposite of mine.  and, while this ain't a contest, i think you'll find most folk get better results w/active preamps.  of course synergy is key.  and, re: hi-efficiency speakers possibly tilting the playing field in favor of passive/no preamp, in my case, my speakers are 97db/1w/1m.

conclusion - the most musical path is the best path.  

ymmv,

doug s.

[morricab]

Just thought I would add into the mix a bit here.  I am currently auditioning preamps to go with my tube/Mosfet hybrid amp (Sphinx Project 14).   However, in addition to that amp I also have a pair of Class D monos (Spectral Audio M250... not the American Spectral),  20 watt SET (Cary CAD572se) monos, a big 100watt EL34 push pull amp (Golden Tube SE-100), and finally a big SS amp (Simaudio Moon W5).  Of these the best sounding overall with my Apogees is the Sphinx (the SETs don't have enough power for loud but quite nice at low levels) probably because it has no feedback.  Anyway,  I had been using an Audible Illusions M3A, which is quite good, but then I got my hands on a little preamp from a little known Korean company called Silvaweld.  This preamp was as transparent (or more so) as the AI but had even better harmonic presentation.  Add to that, the music just made more sense.  Now, the Silvaweld is also a tube pre all the way and since it sounded better than the AI in most ways (it was only SLIGHTLY less dynamic) I have sold the AI.  Now before i committed to the Silvaweld I decided to play the field a bit.  I now have a tube/SS hybrid preamp (Sphinx Project 4), a passive preamp (Sonic Euphoria PLC), and another full tube pre (Jolida JD3000b).
Ok, so with the preamps there are rather pronounced differences on the Apogees. The Silvaweld has the best harmonic presentation so far but seems as if it is adding a bit of sugar overall and the sound is wonderfully coherent.  The Jolida is punchy and clear but a bit bright sounding.  The music also hangs together well.  The Sonic Euphoria seems to pass the most information (as you woud expect from an autoformer based passive) but dynamically it is a bit gray sounding and also the musicians do not hang together like either tube pre.  The Audible Illusions was good harmonically and decently transparent but a tiny bit veiled with outstanding dynamics.  Finally, the Sphinx hybrid pre, seems detail wise and tonally closest to the Sonic Euphoria passive but with a greater range of dynamics.  
As to the amps?  Well the are very distinctive with the Golden Tube being very warm sounding.  The SET is crystal clear but with that harmonic rightness that these kinds of amps possess (not really euphonic).   The digital amps have great clarity but are quite harmonically dry...especially in the upper mids and highs.  Something feels missing.  The Simaudio has great neutrality and great bass but the highs lack a bit of openness...not much but noticeable compared to the Sphinx and SET.  Also, this amp lacks that harmonic and spatial dimensionality of tubes.  Still, it has great dynamics and slam.  The Sphinx amp is tonally very similar to the SET believe it or not!  It has the Solid state slam and is very dynamic and transparent with a harmonic rightness.  Also, dimensionality is very good (but just short of the SET).  Overall, it does the most right of the amps I have and over most that I have heard elsewhere.
I would have to say that the amps make a somewhat greater contribution to the overall sound than the preamps but it is more like 60:40 rather than 80:20.  So far, I am leaning towards either the Silvaweld or the Sphinx (you would think they should go together given they were designed at the same time by the same people.).  To my ears the Sonic Euphoria is leaving too much behind dynamically and rhythmically (this coherence thing).  Dynamically I kind expected but this (relative) lack of musical coherence is surprising.  The question is this:  Is the Sonic Euphoria just telling me the truth and my DAC is not up to the task and the tube pres (and hybrid) are adding something to the music or is the Sonic Euphoria, in losing a bit of dynamics also losing a bit of what welds the music together?  Any thoughts on this.

[Psychicanimal]

A passive preamp is hard to beat.  If I ever found i'd needed tubes I'd place them in the electronic x-over following the passive pre.  Thet's the place where they'd do the least harm...

[doug s.]

A passive preamp is hard to beat....

reasonable persons can disagree - i think it's quite easy to do this, with any number of reasonably priced tubed preamps.

If I ever found i'd needed tubes I'd place them in the electronic x-over following the passive pre.  Thet's the place where they'd do the least harm...

some day a i may try a tubed x-over, budget permitting.  but, it's not a question of tubes "doing harm".  tubes in fact make the final soundwave that reaches your ears, sound more like music.  pardoning the poor grammer, tubes "do good"!     which is why, tho for different reasons than you, i think i tubed x-over is good, especially if yure running s/s amplification - it gets you that tubed magic that much closer to the speakers!  

ymmv,

doug s.

[morricab]

So far I have not found a passive I care to live with.  The resistor based ones are surely transparent, but that is not all there is to music.  Dynamics almost always suffer and this proved to even be true with this autoformer based Sonic Euphoria.  It was almost as if there was a damping effect placed over the whole sound field.  Detail arguably increased but the loss of dynamics was noticed by everyone who listened.  Perhaps because I am running extremely revealing and coherent speakers (Apogee Caliper Signatures) this deficiency was noticed more over the improvement of detail.  I don't really know.  One thing that may have caused this feeling was how the bass became disconnected from the rest of the music.   Is this due to a phase shift perhaps??  I do know that it made the music lose the tight precision I was getting from a couple of the other preamps on hand (both tube and hybrid).  It would be interesting to try again with a less coherent speaker to see if this bass scrambling effect is less noticeable on a speaker with high order xover slopes where the phase is all screwed up anyway.

[Psychicanimal]

I'm a hardcore salsa fan and the combination of the Channel Islands passive followed by a Modwright modded Marchand X-9 Deluxe electronic x-over is a winner.  There's no loss of dynamics whatsoever, the amps are fed a constant output impedance and the system exhibits the clarity & neutrality of the CI passive pre.  I have the best of both worlds...