Reproduction of acoustic instruments with tube amp

Amen. Yes, it's imperative to keep in mind that everything is part of a *system*! No one has ever listened to *just* an amplifier...

I just want to say I never heard a more realistic guitar on hi fi than with a tube amp powering apogee Stage speakers. The speakers are a very important part of the mix.

61, of course you are right about an amplifier's being supposed to reproduce the input signal it's fed - in theory. But in the real world, no amplifier can do this perfectly. So amplifiers introduce colorations, have strengths and weaknesses, sound different from one another, and may have characteristically indentifiable traits within design types - meaning that certain design schools may tend to broadly share some relative strengths and weaknesses.
By the same token, different types of music will tend to differ in the characteristic demands they place on the equipment reproducing them. Tube gear is commonly considered to be capable, when well-executed, of standard-setting reproduction of pure harmonic overtones and sonic recreation of space and objects. These strengths correlate well with the demands generated by naturally recorded and live-captured acoustic music and voice. With electronically produced and studio recorded and processed multi-track music (like most rock), the demand for the above qualities can be lesser because little genuine space or acoustically natural harmonic overtone content may be present. The traditional solid state virtues (again, when well-executed) of separation, definition, and bass weight and slam can be of more relative importance here. Obviously, and as previously intimated, these are broad generalizations, and quality amps of all types can do a capable job with many sorts of music types. But differences will still exist, and an audiophile's preference in types of music listened to will often have an impact on which set of amp characteristics are weighted with the most importance for the job.

It's always been my understanding that an amplifier is supposed to reproduce its input signal regardless of whether it was originally an acoustic instrument or not. Acoustic instruments are not inherently more complex than their electronic counterparts. A Les Paul thru an original Mesa Boogie should sound different than a Telecaster thru a Vox AC30. Electric pianos do not sound like real acoustic pianos, but a good amplifier (tube or solid state) should be able to reproduce the sonic differences between a Wurlitzer and a Fender Rhodes.

Dburdick, in direct response to your question, give the Mesa Baron a try. It's within your budget (used), produces relatively large amounts of power and gives the user the ability to tailor the sound. Best of luck.

Zaikesman, thanks for the great advice. This is exactly what I wanted to know.

VTLs are not bad amps at all but they have a tendency to "eat" tubes. They do not benefit too much(as to the value invested) from placing some fancy tubes on them so stay with stocked ones and save bucks. I strongly recommend to have a tube tester for VTL amps and test tubes every month+- depending on how heavy you listen. The bias circuitry can suffer from the bad tube and be partially destroyed. Biasing is necessary to perform at least twice per month. That is the other way of keeping track on performance stability. If suddenly you notice that one of the tubes is out of bias by large values you'll need definitely to check it. If you don't have a tube tester you must have an extra tube to place instead just in case and than somehow test the extracted one(it may be OK after all).

Yeah, it's worth giving it another try. Your ancillaries are good stuff. The reasons tube amps can sound best with vocals are generally the same reasons for the way they handle acoustic instruments. I just call the whole gestalt an ability to sound "natural", having a lot to do with the way the harmonic structure is preserved, and the way images are cast in their acoustic environments. SS bass slam and weight tend not to matter as much as these qualities when it comes to vocals and acoustic instruments. But in addition to trying better tubes themselves, it seems to me that you don't favor a "tubey" characterisic warmth that might compromise separation and definition. This would point to trying an amp (still push-pull, probably not in triode mode if switchable) with a large, wide-bandwidth output transformer (for un-rolled bass and treble extension), possibly running higher-output tubes than your VTL's EL-34's such as 6550's (and maybe more than one pair per channel?) for higher undistorted output capability (in conjunction with a beefy power supply), and possibly using an ultralinear output topology and somewhat greater negative feedback (both as opposed to the VTL) for lowered output impedance (less frequency response deviation into a 4 ohm load) and a higher damping factor (increased bass control). If you spend the money to get these things, you should also get passive parts quality on par with your Plinius, bettering transparancy and detail. The result may be a sound that, within the scale of tube amps, is more "dry" and less "luscious", with images that more favor focus over breadth and a soundstage favoring intimacy and clarity over distance and reverberance, and a small-scale dynamic character that may lean less toward "freewheeling" and more toward "controlled" traded off against increased large-scale dynamic resistance to sounding "amorphous" during complex passages. Obviously, many folks prefer tube amps for just the qualities opposite these, but you may not. Then let us know how things turn out. Good luck!

I am thinking about tubes again because the vocals with a tube amp are definitely better than any SS I have heard, and the Plinius is pretty good. I didn't say I prefer the midrange of SS, just that most instruments are more convincing to me. I don't think those two things are necessarily the same.

Esoxhntr, I have tried a few different brands of interconnects (Cardas, Audioquest, NBS, Alpha Core?) and settled on HT Pro Silway II. I use AP Oval 9 cables, and Absolute PCs. I'll most-likely keep trying amps until the end of time anyway, but just wanted some opinions from the 'tube experts'. Thanks again.

Some things to think about:
1. Your Plinius is a good amp - you might want to consider putting a tube pe amp in front of it. Both BAT or Blue Circle (BC3) would be good choices.
2. I am not familiar with your CD player, but it is also a likely suspect. After all, is it the most direct link to the source of the music. You might want to consider upgrading it or experimenting with an outboard DAC.
3. You did not mention your power cords, speaker cable, or interconnects. If you are using inexpensive models of these it might be time to consider putting some cash into this part of your system. Experimentation with cords and cabling can yield remarkable results.

Don't be too quick to blame your Plinius, it is a worthy piece of equipment, and may just need to be to be a bit "better fed".

It sounds like I just haven't heard a really good tube amp. I also suspected bad tubes in the VTL (bought used) but didn't want to spend the time/money to find out. I have had similar experience with other tube amps though as well so I guess I just gave up. I guess I'll have to give it another shot and look for a CJ or BAT here on A-gon. Thanks again for the friendly advice. I'll have to do some research to learn a little about tubes and the characteristic sound of each!

I too find Dburdick's findings surprising. The VTL ST-85 should be able to drive the Sparks no problem. I haven't heard the combo myself, but when I recently auditioned the new Thiel 1.6's with both my own c-j MV-55 and the store's VTL ST-85, I thought the latter was outstanding for acoustic (and electric) music, with a vast soundstage and very 3-D imaging. It did strike me as possibly a touch overripe through the midrange, but not excessively colored for enjoyment, and still quite transparent for the money. In that system (with Transparent wire), it frankly made my c-j sound small and pinched. Fortunately, the MV-55 sounds better at my place (Thiel 2.2's, Cardas Cross) - full, spacious, and neutral (and it far outshines my previous SS amps, especially with acoustic material). If in Dburdick's system the VTL didn't offer separation and definition with acoustic music, I would suspect a wire mis-match and/or poor tubes as possible culprits.

I agree with Marakanetz. A used BAT VK60 on this site should be in your price range. Most of the music I listen to is chamber music or acoustic guitar, and they both sound great with the VK60. I don't think you can go wrong.

I have been a tube amp user for many years. Last year I decided to try solid state as part of a downsizing exercise. After 9 mo of misery I have gone back to tubes. I just got a tube amp and am waiting for a tube preamp to ship. I have only heard 3 VTL amps including the one you owned and never thought they exhibited the virtues of tube amps. They all sounded more like a solid state amp to me. Good tube amps should excel at the reproduction of acoustic intruments provided the rest of the system is properly matched.
I don't know if your speakers match up well with a tube amp, which could also be an issue. If your budget is under $2k I would suggest you audition some Quicksilver Mono amps.

Dburdick, i don't know if the ST 85 can operate in Triode mode but i'm using VTL 185 monos with the 5.5 sig preamp and in triode small scale acoustic music is pretty much like being in the room with the musicians. seperation and definition is not a problem. in my comparisons with ss and tubes the ss amps won't touch the tubes for midrange wich is where the acoustic instruments dominate My guess is the VTL you were using didn't have enough juice to handle your speakers.

I would certainly aim for used BAT VK60 the regular stereo version. I believe that no better one can be offered to you in that price range if you are OK with used.

I agree with all of the posts here. I have found more realisim in all aspects of recorded music with tube versus ss. I changed from a cj 11a to mf2500 and lost IMO some inner detail but did gain some bass extention. My speakers are Thiel 3.6's and are relatively inefficient so I am sure the additional power of the mf2500 helped. I was amazed,however; at how well the 11a drove my Thiels. When I discussed this fact with cj (knut) he stated that tube amps produce about twice the power of ss; something about plate voltage. In other words the 11a at 70wpc is pretty close to 140wpc ss. This helped explain why the 11a drove my Thiels relatively well.

Audition Conrad Johnson Premier 11a or 12's if you get a chance. Just an idea. I adore the way acoustic instuments are reproduced by my 11a. I have no idea of the newer, possibly better tube gear out there and if I did upgrade I would go from my 11a to 12's.

Dburdick, you may not find what you are looking for within your budget limitations. The Atma-Sphere MA-1 would deliver what you're looking for, but used prices are higher than the limit you've set. Another alternative that would work well for me would be the c-j Premier 11a, and they are available used in the ballpark of the top end of your budget.

Sorry Dekay, I didn't answer your questions. I'm looking for a power amp and the room is about 10' x 12'. I use a Resolution Audio CD55 (no pre).

Thanks guys. My speakers are Audio Physic Spark III. I'm also considering trying tubes in the bedroom system which has Paradigm Studio 20 v2. I used to own a tube amp (VTL ST-85) and loved what it did for the vocals, but in then end, I went back to my SS (Plinius 100 Mk III). I didn't feel the VTL gave me the definition and separation of the instruments like my SS amps do (the others are McCormack and Coda). I don't mean this to be another "I want the best of both worlds" thread, but since vocals and the sound of acoustic instruments are the two things that I love most, if I could find a tube amp that convinces me with the instruments, I'll at least have my top two 'needs' met.

Interesting... I am with Dekay on this issue. But, we each have our listening priorities that will impact what we perceive as sounding more "real." For me, accurate reproduction of timbre and harmonic overtones are critical issues, particularly on strings and voice. With these priorities, I find a reasonably good tube amp almost always preferable given some consideration to matching the amp to the speaker it is being asked to drive. The design of the amp or type of output tube used will not give you a clear-cut guide to tube amp selection. The execution is more important than "type".

If your point of reference has been solid-state, you may need to attune your listening for some of the strengths tubes provide (midrange reproduction, timbre, overtone structure, soundstage reproduction...) and then begin evaluating whether those strengths match your priorities. I find that the mental shift in perspective is somewhat analogous to shifting between digital and analog sources. One sometimes has to re-shift one's perspective.

As to which brands/models of tube amplifiers to consider, again I would have to come back to listening priorities. For example, I have always found that conrad-johnson equipment better matches my priorities than does ARC equipment, others are just the reverse. Perhaps some posters can offer specific suggestions if you can share more about your sonic priorities and your speakers.

Interesting comment on acoustical music (small scale) as this is what any half way decent tube amp does best (this would be the "last" complaint on the list for most). Might be better off if you list your complete system (the one to be used with the amp, including room dimensions as your speakers are not very efficient and the load is not seen as being friendly by many designs). Also, are you searching for a power amp or an integrated?