For tube sound, which is more important: preamp or power amp?


I have always loved the “tube sound” - warmth, midrange, soundstage. Through the years (since about 1975), I have owned many tube and solid state amps and preamps, in various combinations. Presently, I have a tube amp and a solid state preamp. But like most of you, I am thinking of making changes, again.  Not to cloud the discussion, the specific brands are not important.  I also listen to acoustic music, females vocals, love mini monitors, EL34s, NOS tubes, and don’t care that much about bass.  So you can see that my taste fits the tube sound very well. But I have had systems that are too warm, not enough dynamics or details, and fat in the low end, too.

okay, now to the discussion.  To produce the tube sound, which is more important: the preamp or the power amp?  Let’s talk in general, and (if possible? May not be) not tied to one specific piece/brand/model of equipment.  I know there are exceptions to any general rule.  Not sure if it makes a difference to your comments, but I have no phono and am running line stage only.

As an attempt to prevent the conversation as going in a big tangent, let’s assume equality of price/quality. i.e. not comparing a $10k power amps contribution to a system to that of a $1k preamp.  Let’s also assume that the amp (tube or solid state) can drive the speakers just fine, such that compatibility does not limit the decision. And ignore mono blocks versus stereo amp differences.  

two follow ons: I have  the perception that preamps give you more bang for the buck - meaning that it takes less money to get a great tube preamp compared to a great tube amp.  Agree/disagree? And second, I have never owned a tube dac or CD player, and will assume that tubes in either of these is less critical than in a preamp or power amp. Agree/disagree?

i am interested in your thoughts.

Bill
meiatflask

Showing 15 responses by wolf_garcia

My experience is with both home audio and guitar amps over about 106 years (musician years are different due to the effects of smokey bars and frequent string changing). I currently am using a very clean and detailed balanced SS preamp paired with an amazing SEP "Fire Bottle" tube amp (unbalanced, like me) from Dennis Had and it's the best sound I've found with this particular gear pile, so there's a vote for that approach. Sorry Inna, you be wrong. I agree with both Almarg and the "handsome and talented Charles1dad" that impedance matching or ultimate grunt are points worth considering as my SEP amp would clearly wilt with anything other than efficient speakers, which means I'm in an "efficient speaker trap" with no way out, although "I like it, it's good" (Robbie Robertson line). I am going to try a Schiit Freya preamp (back ordered) soon though, and that's an output hat trick design that can be used with its tubes, passive, or FET circuits allowing instant response to this thread. I hope the Freya works…I worry...I've used about 372 guitar amps over the years including a tube pre/SS power amp (Legend A60) which sounded really good, a Music Man SS pre/tube output (OK but made my hot rodded P90s in a Les Paul Special squeak like mofos), and an all SS Fender "London Reverb" that me and a few of my compatriots jumped on initially and soon bagged. Along with these anomalies it's been all tube otherwise, both vintage and modern…now primarily using a 15 watt 6V6 based all tube push pull combo (Reverend Goblin…pretty rare but highly recommended), and an EL84 tube rectified 18 watt class A single ended Burris Royal Bluesman head. Tubular.
I've said this before and I'm sure I'm not the first: If it sounds good, it's good. Period.
I've found that the "expense" of tube power amps based on tube replacement cost is assuaged by the fact (a fact to me anyway…which is as "facty" as I need) that often the tube amp is cheaper to buy relative to the sound quality of SS amps. Case in point: I compared some expensive SS amps here and there over the years to my faithful all tube (except the rectifier) Jolida 502P power amp and the Jolida, with nice sounding tubes, sounded simply better in every case, and was inexpensive…and now I own the best sounding amp I've ever heard, a Dennis Had "Inspire" SEP, which does require relatively efficient speakers but costs around 1200 (mine was slightly used) to 1500 bucks…an SS amp with this much mojo would be more money it seems. First Watt? 3 grand if you're lucky. And the Had amp has exactly 4 tubes. You don't like heat? I get that (sort of), but have never been bothered by tube heat unless I just burnt my fingers biasing or dusting or something…my mansion has AC anyway, and I can get my valet to dust if he hasn't been drinking.
Also it’s another fact (!) that tubes are more fun…you can swap ’em out, hold them and look at them, collect them, watch and listen to them die (macabre, but part of the tube deal), bewilder friends. People ranging from my age group to my kid’s friends (mid 20’s) often have no idea what tubes are, which means I get to have fun trying to explain the damn things (guaranteed to bore the crap outta anybody). Interestingly, once explained to "normal" people, they still don’t care. At friend’s houses they’re often just yelling at Alexa to play something from a 1" speaker. I actually took a foam block and stuck some of my spare tubes in it just to look at them (that's called Art)…fun...stick a bunch of transistors in something so you can look at them…not so much fun. You can use a SS amp anywhere, preamp or amp, and although it may sound fabulous, I KNOW I’m having more fun. I rest my case.
I had an early-ish Egnator for a while and it was really interesting in that you could pan between the 6v6s and EL84s…cool. I don't necessarily collect guitar amps but have owned, borrowed, and played through a lot of different tube amps over decades and have pretty much enjoyed 'em all. I started in the 60s with my cousins white Bandmaster (a friggin' great amp that I eventually owned) and a Magnatone which I didn't initially appreciate enough, and later used early 70s Twins with JBLs that were heavy and loud although the addition of the master volume knob made them work for me. Tubuler.
I think if a tube is on, it's wearing out…I'd like to see what at atmasphere says about this.
I own a Single Ended amp with 2 power tubes and a single input tube running in Class A (also with a tube rectifier) putting out around 12 watts per side, and have no idea what sort of tube life I should expect. No specs are available from the manufacturer (Dennis Had working away in his lair apparently hand wiring these things himself…maybe with a helper) which is fine with me as the amp is so good, but I still wonder. I run the thing at least 8 hours or so a day…every day…even holidays, unless I'm not at home.
After decades of various enjoyable SS amps, the push-pull ultra linear tube amp I used in recent years (Factory modded Jolida 502P) provided tube sweetness and was, at 65 watts per side, plenty loud. Great amp. After watching a Youtube interview with Dennis Had, I got it in my head that I wanted to try one of his amps so when a 12 watt per side recent version "Inspire Fire Bottle" showed up on Ebay at a reasonable price, I bought it. It shouldn't work well with my alleged 91db speakers (albeit helped by 2 REL subs), and hey…it shouldn't sound much better than other well sorted stuff I've owned. However, it absolutely has more resolution and tonal accuracy than any amp I've owned by a wide margin…is it the simple design? Better transformers? Tube rectification? Class A single endedness? It simply makes me want to sit there and listen to stuff endlessly…things I thought sounded so-so (A recent Nora Jones CD seemed dark and badly mixed on my old amp…but sounds great with this amp…go figure) now sound killer…a cool surprise that really lives up to Had's Ebay hype in the often hilarious little rants that he posts when he sells something.
Blue glass JJ 88s! I don't own any of those but I want some! I don't think you can discount the esthetic element of tubes…I'm using a great sounding pair of Sovtek 88s from my "back up tube stash" partly because they have a groovy blue glow inside. I'm also a fan of some vintage tubes (ones I've owned that worked) and like various recent vintages of Gold Lions, but spending big bucks on older tubes seems unnecessary these days.
Somehow I've avoided Cryoed tubes…seems to be an unnatural thing to put those poor tubes through, although I might try a pair anyway to see what's what. And Danaroo, check out a Schiit Vidar (relatively cheap at 700 bucks or so) maybe as there seem to be some good designs going on with those guys, as my soon to arrive Freya will hopefully confirm (I have a little Schiit Loki EQ that is amazingly useful and well designed). What I like about new gear is the fact that I can return it if it sucks (just returned some headphones that don't fit my fat head).
Tube gear opens up a gigantic barn door of idiosyncrasies that make up the fun part of the "tubist" cult. The Schiit Vidar certainly isn't a tube amp but it was designed to be used with their tube preamps so maybe it matches well with those. Not many reviews yet so who knows?  I don't imagine there is a sonically comparable tube amp at that price, although Jolida may provide a tube solution albeit at twice the cost. I like Jolida amps. It's hard to find a relatively powerful tube power amp (except maybe a used one) at relatively el-cheapo prices unless there are some Chinese brands I don't know about. If you can afford 'em, go tube. Otherwise, listen to some of the well thought out SS stuff until you can buy that Atmasphere amp you really want.
I now have my Freya, and at this early point I can say it’s pretty damn good. The passive and FET modes are very similar sounding in my early assessment, and the tube stage is nice and hot with more than enough gain to send my Fire Bottle amp into the red zone …I replaced the "input" tubes with new Tung Sols although the original "mystery" tubes (no writing on mine at all, but they do seem to be tubes) work OK…the Tung Sols are simply dead quiet little things and sound great. No noticeable hiss or hum in Tube mode unless you stick your ear right on the tweeter in which case you can tell the tubes are there…and all in all a great sounding preamp. My previous preamp was so good it's hard to tell if the Freya is really better, but I have 15 days to figure it out.
My now "resting" preamp is a Kavent S33, which is a rebadged (not sure why) Vincent SA-91…it even says SA-91 on the circuit board. These are fully balanced aluminum clad heavy monsters with a couple of serious transformers mounted in a separate shielded side of the preamp…it’s a large seemingly overbuilt thing, and has a 10 db adjustment to get higher output if necessary, and that’s the setting I used. I note that fact because the Freya has a more normal output level and the passive and FET modes are a more typical line level that I can actually run to max with my SEP amp (clearly my speakers aren’t THAT efficient), but the Freya tube setting is much higher gain to provide lots of headroom into my rig.
The Had amp I bought has no specs…it's specless, except for the 12 watt per side and Single Ended Pentode claims in the Ebay description. Specless.

I utilize my massively powerful 12 watts per side Firebottle amp into 99db Klipsch Heresy III speakers (which, I might add, is plenty of power for these speakers), helped along with 2 REL subs adding 250 watts to the party. I like tubes for jazz and classical, and I also like tubes for rock, mumblecore, EDM, reggae, test tones, screechy animal sounds, and Harry Shearer's podcasts. The Freya's ability to go passive or FET provides an instant "what if I bag the tubes" reference, and I have a second SS Mosfet amp hooked up to the Freya outputs for extension speakers (Concentric tweeter KEFs, and I stick those in the windows to play to my deck...works great) that I can use as a SS reference if I wish as they're in the room also (sort of hidden generally but can be pointed into the room).