To Tube or not to Tube......


For quite some time now I've been thinking about switching from a solid state to a tube power amp. My Threshold T-100 has been real good to me and I do like it, but it's really the only "high-end" amp I've ever owned, so it's all I know. I'm intrigued by the "warm" sound of tubes and do have a tubed phono amp and CD player, but I am by no means well-versed in the sound of tube power amps having never really auditioned one. I know that goes against the prevailing wisdom and I should listen before I buy, but I don't think I will have the luxury of doing that.

That being said, I've gone through about 20 pages of this forum reading about the benefits and detriments of tubed power amps but nothing I've read has swayed me either way. The posts I've read have been informative re: bias issues, reliability, blowing fuses or whatever else might blow up or go wrong with the tubs, etc. So, if I were to go the tube route, I would not want deal with too much of that hassle. At lease I know that the amp I have doesn't have any such issues. That's why I was leaning toward amps like BAT with their auto biasing (I also need balanced inputs), and would want at least 60-100 wpc. I would be willing to deal with adjusting bias so long as it was a relatively simple process.

I figured I would pose my main question to the exerts here (and this I did learn for this forum): given what I already have in my system, what tube amp would be a good match for me? My pre-amp is a SS Threshold, JM Lab speakers with a "minimum impedance of 4 Ohms," EAR 834P phono stage, & Unison tube cd player.
Much appreciated.
ebuzz
IMHO - a modestly priced tube amp can often give many of the top SS Class AB amps a run for their money. Tubes offer a tonality quality and roundness and naturalness that a lot of SS amps cannot. On the other hand, SS offers speed, dynamics, bass control and punch.

Somewhere in the middle we have Class A amps. I am very interested in hearing the new Pass XA.8 amps.

If you can afford to, it might be best to have both SS and tube amps. Get tired of one, switch to the other for a while. But this is more $$ and more real estate too.
Jerred...Jerred Dunkerson, now a VP at Jolida. He was helpful in a few conversations about my amp...nice guy.
Tube anything is great but it's all about the synergy and how long you've lived with the system. I recently rid myself of tubes and I'm hap hap happy. I know that will change in a couple of years and I'll be happy with tube once again. That's the merry go round for me. I love it and don't want to get off the merry go round.
Yes that's what I meant 502P. And I wanna be just like Jason. Is that YOUR recommendation?
You mean a Jolida 502p I assume, and if you get one make sure to get the FACTORY upgrade done, as it's not expensive and makes you a better person, and more like Jason Statham who bought a Jolida from Jared, who told me Jason was a nice guy.
I know that's the preferred way to go Unsound, but I don't have that luxury. I don't know of any place to go to.listen to potential replacements and don't want to hunt out a dealer, listen to what they have only to purchase here on Audiogon. I can't afford to buy what I want new. Alas.
I suggest you audition any potential replacements before letting go of what you have.
Budget? Well on the high end we have a new VS 115 at $5k ( but I can sell my T-100 for $1k, so in reality my cost is only $4K); and on the low end there's the Jolida at approx $1000.
Ok so lets assume I decided to pull the trigger and go with tubes. Which amp would get the most votes: an ARC VS 115; mcIntosh 275 V; Jolida 502B or a BAT VK 75SE? Or maybe one of the nice Krell or Mark Levinson SS amps I see for sale here? I am a little concerned by the issues raised in this thread > Solid State to replace Audio Research REF110?
Tubes keep those Russian birds flying
Hmmm, maybe that's what bankrupted the Soviet Union...trying to find matched quads of NOS 6CCC3Bs ;-)
Yes, that is what I heard. Tubes keep those Russian birds flying no matter what!
Also, tubes will survive the electromagnetic pulse of a nuclear air burst...isn't that comforting?
Mikewerner, one argument for tubes you may not have considered: semiconductors are going obsolete all the time. Just try finding output devices for a MOSFET amp made in the 1980s and you will see what I mean.

In the tube world we don't have this problem quite so much. Heck we can buy 6SN7s a hundred at a time no worries. That is a tube that was thought to be obsolete 40 years ago.

I own several analog synthesizers as I play in a band. The ICs in my Prophet 5 are a little hard to come by. Curtis Instruments, that made the ICs, is gone and the chips, if you can find them, are now going for $150 for single units on ebay. Right now the semiconductor industry really does not want to make linear power devices, so talk to any amp manufacturer and you will see why class D is up and coming- they are made from devices you can actually buy. FWIW, the semiconductor industry really does not care about what we audiophiles want.
Are SS amps more reliable? Over decades I've had many tube guitar amps with almost zero failures during rough service, and plenty of SS hifi, PA, bass, and even SS guitar amps that have had serious issues, so I doubt SS amps are actually "more" reliable. I can wait the 30 seconds it takes for tubes to warm up, and unless you have high output mono amps or something with a lot of tubes, it's a few hundred bucks every few years in mandatory tube cost with a lot of great, relatively inexpensive new tubes out there with no actual reason to buy pricey NOS tubes unless you feel like it. Plenty of tube options might be better than ever as far as cost and sound are concerned. My tube amp hastle: turn amp on, enjoy it, turn amp off.
Ebuzz, I am not saying anything crosswise to the comments above. But I do suggest you look at the OP currently running about tube amps and electrostats. You may find the comment from Ralph, Al and George to be informative. Also, I posted a link to an EPDR (a refined definition of impedance which takes into consideration phase angles) article, which is really helpful.

Here's some cheap advice which may cost some bucks. I'm a tube head -- ARC gear all-around. My former amp was an ARC VS-115 which was a really terrific amp -- 128 wpc into 8 ohms; 335 joule power supply. I used the VS-115 to drive Paradigm Signature 8 (v3) speakers, which I wouldn't describe as tube friendly.

I think the VS-115 was able to do a pretty good job driving the S8s because the amp had muscle in terms of watts and power supply. Plus the S8s have a 92 db sensitivity rating. My current amp is an ARC Ref 150. It definitely has the muscle (150 wpc into 8 ohms and 1040 joule power supply) to drive my wife nuts when I play Michael Jackson or the 1812 Overture. :)

Oh ... and I also use a sub-woofer to take some heat off the S8s and the amp.

So here's my cheap advice that is expensive. I don't think you're gonna find anyone out there to give you a speaker's EPDR rating. But ... at least try and look for bench test specs for the speaker you have or are looking at. You see impedance numbers that drop below 4 ohms over a wide low frequency bandwidth, some serious negative phase angles (more than -40 degrees) over the same bass region, and a low sensitivity rating (lower than mid to high 80 dbs), you'd better plan on getting a high power/high current SS beast.

It gets tough when you are looking at the "intermediate" speaker with moderate sensitivity ratings, impedance and phase angle specs. I think the EPDR article either expressly said, or at least implied, if not sure, get an amp with the most muscle you can afford. And that goes double with tubes, especially so with the amp's power supply specs, which is where the reserve power will come from when the 1812 cannons kick-in. :)

Bruce
OH Mike..... Just when I thought I knew what I was doing!!!! Can you say Monkey wrench! Thanks for the advice. I'm sure there is much validity in what you say!
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I have moved in the other direction. Tubes to solid state.
Rarely have I looked back.
Tubes are such a hassle.
Either they are breaking in or wearing out...
Warm -up time is expensiveÂ…
Power is often lackingÂ…
You can never know if your tubes are just right - leading to uncertainty and tube rolling...
Then there are the insane prices for NOS tubesÂ…
If you have a SS amp that is satisfying to you, stick with it and save yourself lots of money and headaches.
Plus, SS designs are more reliable, no question about it no matter what some say.
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You won't find phase angle in most manufacturer's specs, but if Stereophile's JA did a review, he usually provides that info graphically. but like Unsound says, they are likely to be fine for tubes.
Well, I do have my eye on a ARC VS-115 and a BAT V-60 if the A-gon member still wants to sell it as well as the Jolida.
I think if you can get enough sound from a power amp with 4 output tubes, you've made yourself a somewhat less heat producing choice, and buying tubes is cheaper...I've had my eye on those Cary 120S amps but hesitate to buy one when I think about the 8 power tubes to roll.
The specs you provided would indicate a suitable match for a tube amp, though having the phase angle would further help. Considering the other specs, I doubt it would be an issue. Though tube friendly, they aren't ss unfriendly.
"Should I use the 4 ohm or 8 ohm tap?"
Yes ;-)
Only your ears can say for sure.
consider the Music Reference RM200 for sale here. Not warm sounding but great tube sound, bulletproof reliability, properly fused output tubes, multiple speaker taps, tube longevity, easy to bias & live with - only 4 output tubes putting out a real 100wpc.
Ebuzz- They would be considered 6 ohm w a relatively flat impedance curve. Together w the 90 db sensitivity (and assuming no really unusual phase angles) they would be considered "tube friendly".
Unisond: I confess that I am not as conversant in all the technical terms we use in this business or what they all mean. I checked the specs and on the back of the speakers it says: "impedance mini 4 ohm". But in the brochure that came with the speakers it says:
"nominal impedance 6 ohm
Minimal impedance 5 ohm
Sensitivity 90 dB
Max power175w"
So are they 4, 5, or 6 ohm speakers?
I'm not at all familiar with your JM Labs Daline 6.1's. I'm not familiar with their sonic signature, their impedance range, phase angle, sensitivity, etc.. As such, I can't earnestly recommend or condemn tubes or ss amps with them. I am familiar with your Threshold, and it is a fine amp. I'd suggest you not rid yourself of it before trying anything else. Sometimes, the old Irish saying holds true: "Better the Devil you know, than the one you don't".
Thanks Z, you've eased my fears about things blowing and biasing problems so I won't worry about that anymore. I'm not real concerned about heat either, it's a pretty big room and my Threshold gets pretty hot too. I'm sure amps like the Carvers are out of my price point right now. I am looking at the Jolida, an ARC VS115, a BAT 60 & maybe one or two others. All of which are used &/or here on A-gon. I'm the sort that seems to stick to one thing for years so I want to get the best one I can afford now b/c it will be here for years.
Tube!

My first tube amps were Jolida 502p power amps and the I moved up to a pair of Jolida 1000p powers amps running bi-amped to my speakers. I have moved on to a pair of Bob Carver Cherry 180m mono blocks.

First, from my experience, biasing is not a big deal. The Jolidas were manual bias but even with me using them for hours on end in my Home theater setup I never had an issue with tube bias. I never blew any fuses and had only one tube failed after probably 3000hrs. The only problem I had was one of my Jolida 1000p (which was very low in serial number) had an issue that when watching a movie at very high volume and if the movie had a particularly loud noise like a single gun shot it would trip only one of the amps, even tho multiple other amps were also hooked up. Jolida replaced it with a brand new one at no charge.

My current Bob Carver Amps are Awesome, and if you can afford them. Would recommend a pair. I have had absolutely no problems with these amps. I have thousands of hours on them. They have a bias system that is not quite auto but you have one knob and a built in meter that adjusts all the tubes at once.

So I would not worry about bias or blowing fuses.

The main negative I can say about Tube Amps is the heat they can generate, when I had my Jolidas I had five stereo tube amps running a Home theater setup. The Jolida but out tons of heat even when listening at a low level. But they Carver amps do not put out anywhere near the heat of the Jolidas. Of course even Solid State True Class A amps put out a lot of heat, thats what the heat sinks are for. So it really might not be a negative after all.

I say go for the Tubes!

I have Tube pre-amp with tube regulated PS, tube DAC, tube amps, heck if I could find a Tube Blu-Ray player I would buy one. I have seen the tube mod that Modwright sells for the Oppo player but I hate the look of those players.
For speakers of medium to low sensitivity, the best solid state designs have probably eclipsed anything that tubes can do. At lower price points, tubes may be more competitive with solid state, depending on power requirements. Tubes probably still rule for high efficiency drivers, regardless of price.
I use a new model Jolida 502p with factory upgrades that is one of the biggest "bangs for the buck" in tubedom, at about half the cost of any comparable high quality power amp. The XLR balanced inputs were important to me also as I have a balanced preamp, and simply like XLRs. The amp has bias adjustment pots on the top of the amp so they're accessable and really easy to use (LED indicators that work very accurately) although you only need to check them every few months at most. The output is selectable at 4 or 8 ohms and this thing has plenty of power at 60 to 85 glorious tube watts per side and I can run KT120s no problemo. It sounds beautiful and effortless, with a modern full range tube sound.
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>Viridian: I'm kinda a hands on guy, & don't have a problem tube rolling, or playing with bias, but I don't want to do it ALL the time. When I get in the mood to experiment, then I can experiment and play around, but if I want to just listen, then that's all I want to do at that time. But like I said before, I don't to have to worry about things blowing up b/c a tube blew.
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I owned the VS-115 and didn't consider it "warm" sounding, there are many choices at your price point!!!!!!!
> Dan: thanks. I can't really make any other changes to my system other than the Amp. I'm happy with the rest of my gear (for now) and my speakers. The JM Labs are fine for me and at 4 ohms should be easy to drive with almost any tube amp. I do have my eye on a used Audio Research VS 115. The main things I don't want to have to be concerned about is having to send the unit in for repairs because something blew somewhere or have to spend $thousands to replace tubes over and over again.
My opinion is that there are speakers that mate well with tubes and speakers that mate well with SS. It doesn't make sense to me to "Try a tube amp" as much as it makes sense to "Try a tube setup."
Maybe this will help you to better understand the issues. It's part of my post from another thread, but applies here:

Even though it's a little off-topic here, I feel I should explain WHY (very genrally speaking ;~) tubes seem to be better than transistors at 'preserving' an audio signal: it is in fact because of a tube's SHORTCOMING as an 'electrical valve' - it is slow to turn on and off (like a light bulb.) And so there is some 'overlap' as one tube (of a pair) hands the signal off to the other tube. Transistors by contrast, are extremely high-speed devices which turn on and off instantaneously -- and if a pair of gain stage transistors are not PERFECTLY (and laboriously) matched, there will be a little time 'gap' as one hands off the signal to the other, where some subtle parts of the signal will be lost.

Unfortunately, many audiophiles believe that electrostatic speakers require gobs of current (NOT) and so drive them with huge solid state amplifiers. Thus missing out on the enormous pleasure their electrostatic speakers could provide! They need only stop and remember that the amazing Quad 57 was, from the very beginning, driven with a low-powered tube amps. Later on, no solid state amp has ever been able to improve their amazing ability to reproduce the human voice.

Thanks for your kind indulgence ;~)
Yes try a (or some mono blocs) tube power amp/s.
OK now-
Many are auto biased these days even big expensive jobs like may Jadis DA-60 which is an integrated but you get the idea. Not all will have the slow rich liquid rolled treble type sound people associate with tubes, in fact many(most) new tube amps sound quite precise and sparkle up top. Try them you might like them, I love them.
PS: they are much less of a hassle than people think they are.
Ebuzz, I was in the same position as you, very curious about tube amps. That led me to change speakers, from Dynaudio Contour 5.4's, to 12" custom built Tannoys.

I briefly tried a Sophia Baby amp, which I liked, but I needed to go further. I purchased a VAC PA 35.35 EL 34 push-pull amp. That was a good match, at 35 Wpc.

I had always been wanting to try 300B tubes, but I didn't think there would be enough power. I took a chance on a very modestly priced SET 300B amp, from Assemblage Audio, which was owned by Sonic Frontiers. I had factory upgrades done on the amp, and settled in with it.

Turns out, it's the best amp I've had with my Tannoys. I just installed some fairly expensive EML 300B XLS tubes yesterday, and now I am hearing the closest thing to live music I've ever heard in my home.

You may not be willing to make similar changes, but for me, the results have satisfied, and rewarded, me with music listening in a way I most likely wouldn't have experienced otherwise.

For your speakers, something along the lines of the VAC PA 35.35 would do nicely. Thirty five watts per channel may not sound like much, but with the large transformers it has, it produces plenty of current for a good many speakers.

You will get many different opinions, and there are many, many, ways to get to the place you wish to be, musically speaking. What I've done has gotten me where I wanted to be, and searched for, for forty years. This is where I will remain.

Best of luck, have fun,
Dan