Seriously considering tube preamp…opinions?
So, IMO, the most musical and human sound is from a single ended triode amp or preamp (SET). Think the SET is the oldest still used audio amp circuit. Used in the first Bell telephone systems (WE). Funny, SS wants to sound more like tubes and multiple output tube amps want to sound more like SETs... sort of. SETs are known for the warmth they have; that is caused by a predominate 2nd harmonic distortion. The ear assigns tonality to all forms of distortion; the 2nd is responsible for 'warmth', 'bloom' and the like. The 3rd and 4th contribute to this as well. A good SS amp might sound very tube-like; as both tube and solid state become more neutral they will sound more and more alike. IMO/IME the issue that plagues SETs is that most people simply don't use them on speakers that are efficient enough. This is because the amp should *never* be driven past about 20% of full power, otherwise the higher ordered harmonics begin to appear. The ear uses these harmonics to sense sound pressure; since music has many transients this distortion initially appears on transients, causing the amp to sound very 'dynamic'. This is why many SETs get comments about how dynamic they are despite their low power. Its distortion masquerading as 'dynamics'. Whenever you see that its because the user was using a speaker of insufficient efficiency! |
What do you consider low power? I’d probably want at least 4wpc with 94db speakers especially if they have more than one driver. I’m using Omega Super 6 with a single Alnico driver rated at 96db and works marvelously with 1.5wpc Oliver Sayes 45 based single ended amp. And a 3wpc DG-SE1 EL84 based single ended amp. Also having Oliver build me a low gain tube preamp. |
@mglik Question for you, since I'm intrigued by your comments. How efficient are your speakers? I have a pair of ~94 dB efficient speakers (in addition to Quad 2805s). It seems that 94dB is not quite in the happy zone for low powered SET amplifiers. Hence my question to you. What SET equipment are you using? What else have you tried? What are your recommendations? Thanks, in advance, for any help you can provide. Markus |
First, the only absolute is that there are no absolutes. So, IMO, the most musical and human sound is from a single ended triode amp or preamp (SET). Think the SET is the oldest still used audio amp circuit. Used in the first Bell telephone systems (WE). Funny, SS wants to sound more like tubes and multiple output tube amps want to sound more like SETs... sort of. I have two SET amps and an SET preamp. Would never change. Good to be off the "merry-go-round"! Importantly, I have a speakers I love and they work great with 1 1/2 or 8 watts. Ralph, I respect your work. In my experience with one of your amps, it had a similar character to Dave Berning's OTLs: very clean and neutral sound and kind of SS sounding. Great to listen to but lacking in the "humanness" I love in SETs. Kind of "juicy". BTW-I love to listen to Dave's prototype MicroZOTL daily with my headphones. The OTL clarity is excellent for headphones. Listening to it as I write. |
Schiit Freya+ is all you need.. 3 preamps in one.. SQ is excellent, clean and detailed.. Not a lush tubey exaggerated sound, but a modern tube sound without the bloating that some tubes preamps offer. A 128 stepped Resistive attenuation is used ! That alone makes it worthy choice regardless of price.. not to mention that the 6SN7’s make a great choice for a preamp.. I used a Transformer based TVC for decades before going back to an active preamp.. The Freya+ Added all the attributes of tubes without the downfalls.. A great Value at any price !! |
I think most of this boils down to system synergy.I'd be careful about that- if you pair a bright preamp with a dull amp, the result will not be neutral. I recommend to all our customers that whatever they buy, each piece in the system should stand on its own merits rather than hopefully being corrected for its faults somewhere down stream; the latter is a recipe for flushing dollars down the loo. The one exception to this is that not all amplifiers drive all speakers. This is true regardless of the amplifier, although there are speakers that are driven equally well by many amps. for more on this: http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php |
@english210 Since I’m a student too, I don’t have grounds to confirm what you’re saying. What I will say is that from my research here and elsewhere there is a relatively small number of makers that fulfill certain metrics above the fundamental ones related to quality of design & build and sound quality. For me, the telling metrics are: simplicity of utility and aesthetics (not trying to be too complicated, too user friendly, or a showpiece), company reputation (warranty, customer service, longevity), and popularity with serious reviewers (both journalist and hobbyist). Off the top of my head, the list fitting all those metrics and appearing repeatedly here include QS, deHavilland, Sachs, Supratek, Atmas-phere, Erhard, Herron, VAC. I’m sure I left some out, as you can see I'm leaning toward smaller but very well-established independents. And again, this is just my summary of what others have been saying and what I’ve read in professional publications. |
I’m continuing to follow this thread with great interest, being on a similar journey. Not starting from scratch, but trying to get the most out of what I’ve got, and feeling a good pre, likely a good tube pre, will be my next step. Partly curiosity, partly because the aspect of tubes that is most talked about is the emotional involvement they tend to facilitate. My room is live, so anything in the family of harsh/bright/analytical/etc is to be avoided, I’m bordering on that now. The option to audition all the choices listed here by various members is obviously not realistic, and it seems more and more clear that once specific criteria are met (ht bypass needed or not, balanced/SE preference, phone or not, etc), the vast majority of the options would provide great results. Each manufacturer has their share of proponents, with few serious detractors. Someone that chose a DS, for example, probably wouldn’t have been disappointed with a like-priced Supratek/Atma-sphere/Rogue (random brands, don’t attach meaning) in terms of sound quality. Fair to say? |
Too many days spent here in isolation. I gotta say "I LOVE YOU GUYS!" and our differences of opinion don’t mean anything to me at all. Here’s what I think. I think if we went over to one-another’s houses and listened to some music, IT WOULD SOUND KILLER, regardless of whether the preamp is SS or tube or the power amp is SS or tube. I think most of this boils down to system synergy. That’s the key. That’s the main thing. Oh, one more thing that really contributes to enjoying the sound of a system is CONTENTMENT with what you’ve got. How good does a system have to be? Just good enough that you stop thinking about what you gotta change in order to get things "right". |
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Its a simple fact that if the front end of the system doesn't get it right, the best amps and speakers downstream won't win you any of the lost signal. For this reason I do feel that a good tube preamp is paramount. But tubes bring something to the amplifier department as well. Tube amplifiers generally speaking tend to have greater soundstage width and depth than solid state, and tend to have more detail without brightness (this on account of how both technologies make distortion). |
One thing I've noticed in this thread, "The system" revolves around the Preamp. Others seem to center on power amps. Then there are people who build from the speaker, BACK. Then those that have learned that ALL the speakers, amps, preamps, and cabling are just 30-40% of the sound. The room, the Power supply, the placement, matching components, vibration control, Source, EVERYTHING else, but gear should be considered. I'm sure you've got a handle on good VAC, cabling and like. I'm not here to say one brand is better than the other, but I will say, I like tone control in my preamps, I like Lpads in my speakers. Those TWO thing are really controversial. HE speakers with lpad can be tuned and toned down. Same with Preamps, small differences in SOURCE, sometimes a tonal change, (not TOTAL).. make for a much easier fix, than gear change or just can't listen to it. One of my systems still uses 78 mono stuff from time to time, its old I mean REAL old...Those preamps are point to point. I wouldn't use that system with several sources hooked up... Crosstalk.. You won't like it, if you haven't dealt with it before. If you're looking for pieces of art, there are some truly fantastic pieces out there. If your looking at tube sound with a practical application, in mind. PtoP can be tough and expensive to get right. IMHO though ptop is the bomb, Vinyl a great valve set up... you'll be playing hooky from work for sure.. I like ALL the different stuff, A great Valve preamp and a pair of great SS amps, just crazy good..No names but Class Ds are a great combo for me. Enjoy, 51 years a ValveHead... Just wonderful.. Respectfully |
To me tube gear gives a great sense of tactility space and humanity to the sound. More natural more relaxed more spacious. But usually at the expense of some background noise, ultimate bass control and very high volumes. Obviously uber expensive tube systems minimize the negatives, while accentuating the positives. Depending on the kind of music one listens to, the tradeoff may or may not be worth it. But for vocal, classical, jazz music, music that is more old school, i.e. created with less electronica/mixing overlays and played at more natural (unamplified) instrument volumes, the tradeoffs are much worth it to go for tubes. |
I agree with @wolf_garcia ive had and experienced several solid state amps in the $2k-$5k range and none of them came close to sounding like my Line Magnetic 518 SET. Believe me I’ve tried to go solid state but there’s always something missing vs my SET tube amps. Just my opinion based on the sound I prefer. |
Allow me to disagree with those who recommend a solid state preamp. I think I’ve already suggested this , if not in this thread then and many many others . Read the Roger Sanders white paper on Solid State vs. Tubes. His website is Sanders sound systems. Very good solid state amplifiers will sound a lot like very good tube power amplifiers as long as they are operated without clipping. I believe that the preamplifier is the place to put the tubes. And get the best one you can afford. |
+1, tvad and almarg. @hilde45. Only you know what kind of sound you’re after. In reading your various threads, it seems you’re building your audio system from ground up for the long haul by considering amp, preamp, DAC and so on. My post about high efficiency speakers is directly related to your bullet point about preamp/amp combination, Tube/SS is much more advisable than SS/Tube. I was merely suggesting that high efficiency speakers are much easier to drive thus giving you larger pool to cherry pick your choice of amplification at reasonable price point. If you haven’t thought about replacing your 90db speakers, now is the time to do so before you decide on the amplifier. |
+1 Tvad. That has been my experience as well. Assuming, as you alluded to, that the specific tube amp and the specific speakers are good matches. And in that regard it should be kept in mind that different tube amps differ widely in terms of output impedance, and correspondingly in terms of damping factor, while most solid state amps have near zero output impedances and relatively high damping factors. Thus for a given speaker some tube amps providing a given power capability may be suitable matches, while others providing the same power capability may not be. In general, speakers having relatively high nominal impedances and/or relatively small variations of impedance as a function of frequency (i.e., relatively flat impedance curves) tend to be less critical in that regard than speakers not meeting those criteria. My impression is that the Salk speakers hilde45 has ordered fall into the less critical part of that spectrum, although I haven’t seen an impedance curve for them. So choosing the right tube amp for a given speaker involves a bit more complexity than choosing a solid state amp, but if chosen properly the results can be very rewarding. Best regards, -- Al |
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@lalitk I didn't mean to put words in your mouth or be disputatious! You said: Less than 96dB, say 92dB efficiency SS amp is the way to go. Some full range speakers even dip down to 2-3 ohms load, for those you need a good wattage power amp to handle the peaks.I really want to get an amp that can comfortably drive my 90db speakers and your statement seems to direct me away from the amps I'm presently looking at. (Maybe this requires more details about my speakers and I'm over-reading your comment.) I am still learning about the relationship between power and speaker sensitivity, but I've learned enough to know why your question about 8W SET amps is funny! |
@hilde45, All good points, I would steer clear of linear sounding tubes in preamp or amps if you want to enjoy and experience rich harmonic ‘distortions’ associated with good tube gear....otherwise stick with SS gear. The pre/amp combination, Tube/SS will greatly depends on efficiency of your full range speakers. The higher efficiency, say 96dB will give you greater flexibility in SS or Tube amplification. Less than 96dB, say 92dB efficiency SS amp is the way to go. Some full range speakers even dip down to 2-3 ohms load, for those you need a good wattage power amp to handle the peaks. I went from 92db to 96db speakers and couldn’t be any happier. I can drive my speakers with 8W SET, 30W class A or 200W class A/B amps. Hope this helps! |
200 suggestions! Feels like it. Some people have been repeatedly helpful to me -- had a lot of experience with different gear and have been willing to consider what I need. I really appreciate that. I actually created a master document with suggestions which were well-reasoned or which many people mentioned. I created a multi-page table populated with brands and important criteria. Here are a few general lessons I've taken away, as they made sense to me:
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Old chestnut? Tube guitar amps are generally at the end of that pedalboard chain for a reason...they sound better. A great tube guitar amp has a much snappier response than a SS amp (although many jazz dudes are into Polytones or other SS amps...a mystery but hey, you get used to anything). A great guitar player I know who owned the same SS Fender amp in the late 70s as I did (we tried...it was a London Reverb) had come to the same conclusion I had...they just didn't have the mojo...I went back to my tube amps. When the effects are off you crave the full tone and immediate snap of a great tube amp for non distorted tone, and put a great pedal in that mix and it's simply right. |
Hi Andrew, There are only a couple of companies who only make one product-a preamp. The slam dunk best of these is Audible Illusions. A “class A” Stereophile component for decades. With the continuing review “as good as any regardless of price”. I have never read this comment for any other component. For ever, I only used a passive preamp addicted to the unmatched transparency. When I finally bit the bullet and bough the active AI, I found I was wrong. The AI has all the transparency of a passive with the pronounced ability to look into the music. It is one of the few preamps that has the simplicity, purity and magic of the single ended triode. Only one tube per channel. The newest model is $5200. A factory refurbished unit can be found for about $2500. Believe AI has sold something like 60k preamps over the years. I consider a preamp as the heart of a system. Also, that the vast majority of preamps are overly complex and colored. I love the true heart in my system and would never change. My music is too important and central in my life... especially now! |
I go to a hell of a lot of live shows. Most recently Dweezil Zappa playing all of "Hot Rats". Modern guitar playing involves a lot of intentional distortion. Every hot guitarist with chops relies on a ton of effects pedals in addition to the intentional distortion produced by the tubed stacks.That depends on whether the amp is clipped. Guitar players like tube amps because they have less odd ordered harmonics when they clip, making them easier to sculpt more pleasant tones. But some guitar players don't clip their amps; the guitar players in my band (Thunderbolt Pagoda) are an example; instead they rely on their pedal effects for the sound, but prefer tubes otherwise. One is using a Marshall Major, which is built along high fidelity lines and was often used for for bass or sound re-enforcement- both applications where distortion isn't helpful. Other amps built along high fidelity are the early Sunn amps (highly sought after and using the guts of the Dynaco MkIII) and Ampeg amps like the V4. Guitar players also like to have a good 'clean sound' and good fidelity in the amplifier is crucial for that. An amp with a good clean sound easily reveals differences in pickups, 1/4" connectors and guitar cables- not all that different from what audiophiles experience in that regard. |
.also note that the guitar amp world soldiers on using a lot of tubes, with new amp designs (and reissues of old amp designs) coming along all the time. Don't fear the tube...they simply make music sound a lot like it's supposed to.While I tend to agree with most of your posts on this topic, this old chestnut has to be surrendered to the trash pile where it belongs. I play around with the guitar only, but I go to a hell of a lot of live shows. Most recently Dweezil Zappa playing all of "Hot Rats". Modern guitar playing involves a lot of intentional distortion. Every hot guitarist with chops relies on a ton of effects pedals in addition to the intentional distortion produced by the tubed stacks. If you happen to get the Sweetwater catalog (which I strongly recommend for any audiophile to see the overlap with our hobby in terms of speakers, mixers, DAC's and lots of Manley pro gear on offer too), you will see that there are more pages devoted to effects pedals than any other musician's tool under the sun. It is simply amazing. Btw, this makes me think of Raulgas with his stupid motto "musics and not distortions" [sic]. Well guess what, a lot of recorded music contains a lot of intentional distortion including even classical music, but mostly rock and modern jazz. |
Unless you're into some esoteric old tube with tonal qualities you MUST have, great tubes of all types are abundantly available...and plenty of new ones have become hits among tube geeks...new Gold Lions, KT120s and 150s, Psvane items etc., and I still haven't heard any SS amp that sounds better than a well designed tube amp...zero...also note that the guitar amp world soldiers on using a lot of tubes, with new amp designs (and reissues of old amp designs) coming along all the time. Don't fear the tube...they simply make music sound a lot like it's supposed to. |
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@tvad tvad, It appears you may be referring to vintage tubes I gather. That’s what i use, and... also some new tubes too with great success. By chance have you tried any of the latest version new production input tubes such as Sophia Blue, or PSVANE MKII, Shuguang Black Treasures, or former TJ Full Music, JJ gold pin Frame Grid tubes - in any of your preamps or for amp input tubes? |
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@schubert 6,176 posts I’m not a classical music nut, and it’s totally worth it to me. Did solid state for 35 years, Class-A, was very nice, still fatiguing at times during long-term listening sessions. Then, found good tubes, good tube amps that don’t burn tubes down, with added dynamics, no listener fatigue, way more engaging, 3D sound, musical. Two colleagues, now adding tubes and tube DACs in recording studios and mastering. Finding good tubes is key. |
It;s a very tech reason , Basically tube amps have a much faster recovery rate that our ears hear as sweet at high freqs . than SS . Massed violins are greatly helped by this . Very little other is .Also , a symphonic record needs a far greater dynamic range . A very crude explanation but I no longer have the paper on this . |
@schubert What is not worth it? @tvad I hear you on altering the original design, esp of a premium product @atmasphere Thanks for the advice about repairs. I would prefer just to deal with a local dealer, though perhaps they just ship it back to the maker? I don't know, but of course if it's under warranty and in their hands, I'm spared the hassle. |
How important is it for you to have a tube amp fixable locally rather than having to ship it back to the maker for fixes or upgrades?Repair-ability has always been high on my list. I would consider upgrades to be quite a bit different from repairs though! When I was putting myself through school I worked repairing consumer electronics. I ran into some stuff even way back in the early 1970s that clearly didn’t have service in mind when it was built! That sort of thing can be a nightmare if the equipment develops a fault; ease of servicing has always been high on my agenda- you sleep better at night :) |
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