You are here

Log in or register to post comments
z038
z038's picture
Offline
Last seen: Never ago
Joined: Oct 7 2007 - 12:30am
valve vs transistor amp tradeoffs

I'm charting a path toward upgrading my entire system, but I've yet to drop a dime on anything but my new Rega P5 TT. I'm just in the learning and planning stage. I want to have an idea of my destination before I start auditioning equipment.

One choice is whether to go with a tube amp or a solid-state amp. I gather this can affect things like speaker selection. So the main point of my question is what are the trade-offs between these technologies other than sound. OTHER than sound. I will audition amps in my price range to decide on sound qualities. I'm not looking for brand recommendations either. It's all the other aspects of living with a system that I'm interested in.

From my research so far, I believe the following are generally true:

- Tube amps usually cost more than solid state amps of similar quality.
- Tube amps are heavier than solid-state amps.
- Tube amps generate more heat than solid-state amps.
- Tube amps are often larger than solid-state amps (I'm not really sure about this one, I'm judging from pictures.)
- Tube amps have higher maintenance costs since tubes must be replaced occasionally.

And what about:

- Power consumption?
- Sensitivity to voltage irregularities?
- Listening room characteristics?
- Ability to support stereo audio and also home theater style applications?

Are there any other differences between products built using the two different technologies that might be an important consideration when planning a stereo system?

bobedaone
bobedaone's picture
Offline
Last seen: 6 months 1 week ago
Joined: Feb 1 2007 - 12:27am
Re: valve vs transistor amp tradeoffs

Tube amps also require a small amount of tinkering ability, as the tubes must be biased periodically. Not to include a product recommendation, but I'll mention that PrimaLuna includes auto-bias circuitry, and is the only company I'm aware of that does (for any sort of "sane" price, anyway).

In general, solid state gear has more provisions for incorporation into combined stereo/HT setups. For instance, some models have a "unity" input or "home theater pass-through" that allows for simpler integration with a processor. You might be able to find tube gear with that feature, but it is less common.

Another important consideration - and you're doing yourself a favor by waiting on the speaker upgrade - is that tube amps tend to be less powerful. Now, that's not the whole story because distortion harmonics tend to be different from solid state amps, but it's wise to pair relatively sensitive speakers with tubes.

By the way, congrats on the P5! It's a great table. I'm saving for a P3 right now.

Good luck!

Jan Vigne
Jan Vigne's picture
Offline
Last seen: Never ago
Joined: Mar 18 2006 - 12:57pm
Re: valve vs transistor amp tradeoffs


Quote:
From my research so far, I believe the following are generally true:

- Tube amps usually cost more than solid state amps of similar quality.
- Tube amps are heavier than solid-state amps.
- Tube amps generate more heat than solid-state amps.
- Tube amps are often larger than solid-state amps (I'm not really sure about this one, I'm judging from pictures.)
- Tube amps have higher maintenance costs since tubes must be replaced occasionally.

The items you mention are due to a tube amplifier's use of output transformers and a fairly large power transformer. (You can buy output transformerless [OTL] tube amplifiers, but I wouldn't if I were you.) "Quality" is an iffy thing to define so I wouldn't necessarily consider it to be a one for one trade. Many tube amplifiers offer better quality parts and construction since there are often fewer parts and simpler circuits in tube equipment. I would say this would certainly be true of a tube pre amplifier where the cost of output transformers doesn't enter into the picture. So you trade one thing for another.

Heat is also a relative thing since solid state power amps biased toward class A operation are not cool running devices by any estimation. So, while transistors and tubes running in similar modes of operation will probably have the tubes running warmer, there is no set rule for this. (My McIntosh tube amps run cool enough that at idle I will have to check the tubes to make certain the amps are on while just feeling the transformers won't always tell me.) Tubes will need replacement. How often depends on the amplifier and the tube. Low level tubes such as dual triodes are relatively long lived in most applications. Power output tubes will require replacement more often. High quality tubes last longer than cheap tubes - and sound better also. However, the ease with which you can swap out tubes also allows for tube rolling which can provide an increase in performance far beyond what you can buy for equal dollars in solid state gear. The swap from a Chinese 6DJ8 to a NOS Amperex 6922 would make a tremendous improvement in sound quality that you could not obtain for equal dollars in a solid state device. There are no common solid state equivalents to a 300B, 2A3 or 845 triode.

Power consumption and voltage sensitivity are relative to the quality and size of the amplifier. It's unlikely you'll be looking at 200 watt tube power amplifiers. A tube amplifier is more likely to withstand constantly fluctuating over/under voltage conditions than a HT receiver jammed with integrated circuits. I've run the same tube power amps for over twenty five years. I've replaced several HT receivers in the last ten years.

I don't have a clue what "listening room characteristics" are other than a hot running amplifier, whether tube or solid state, will make your listening room hot; and tubed power amplifiers look very impressive in a darkened room. Solid state amplifiers look like chunks of metal in a darkened room. Since the characteristics at the top of this post are generally true, you don't find many HT amplifiers driven by tubes.

I suggest you consider an amplifier that is capable of driving your speaker selection and that your speaker selection not make life difficult for your amplifier. This should be the case whether you choose tubes or transistors.

Other "differences" would depend on the amplifier. SET's do not sound like push-pull amplifiers. You don't find many single ended solid state amplifiers however. There is the potential to tailor the sound of your amplifier to your tastes with a tube amplifier as you have the ability to drive most amplifiers from several different output taps with each tap pairing better with any particular speaker load. Most tube amp owners would tell you a KT66 or a KT88 sounds different than an EL34 which will sound different than a 6L6 or 6550. A KT66 from one tube manufacturer will sound somewhat different than a KT66 from another manufacturer. The overall differences are slight and in most cases less than what you might get by moving your speakers to another location in the room. But they are real and should be considered when you are using tubes.

Read these two articles; http://www.stereophile.com/amplificationreviews/740/index.html

http://www.symphonysound.com/articles/tubefriendly.html

Ideally tubes and solid state should represent the music with equal degrees of truth. That's seldom the case and certainly not true for most of the lowered priced equipment on the market. You might consider a hybrid to get a taste of tubes without most of the associated downsides of tubes. MOSFET's can give you a taste of tubes without the downsides of solid state.

Monty
Monty's picture
Offline
Last seen: Never ago
Joined: Sep 16 2005 - 6:55pm
Re: valve vs transistor amp tradeoffs

Tube gear can lead to abnormal, borderline psychotic behavior. Things like hoarding rare vacuum tubes...enough to last several lifetimes. The accumlation of tubes that you can't use...yet, but might someday in the future. Spending cold winter nights in the garage with multiple tube testers and cardboard sleeves, carefully matching triode sections and trying to write really tiny to fit all the information you think is relevant onto a 1 inch square piece of cardboard. Staying up late at night to snag the Ebay auction of a lost hoard of 200 tubes just so you can get the one tube that will hopefully match that other rare tube that you have in your growing collection of tubes that will now last 10 people 10 lifetimes.

Well, that's what I've been told anyway.

cyclebrain
cyclebrain's picture
Offline
Last seen: 2 years 6 months ago
Joined: Jun 16 2006 - 11:40pm
Re: valve vs transistor amp tradeoffs

Tube amplifiers don't usually have the bandwidth that a solid state amp does becuase of either having to transformer couple its high impedance output to a low impedance output or to capacitively isolate the output from the high voltage tube supply. Not a problem in well designed tube amp.
Tube amps have a much less harsh output when driven into clipping then a solid state amp. But then again with a tube amps lower power output it is more easily driven into clipping than a solid state amp.
Buy what you like.

z038
z038's picture
Offline
Last seen: Never ago
Joined: Oct 7 2007 - 12:30am
Re: valve vs transistor amp tradeoffs

Thank you all, especially Eric and Jan, for the comments and links. That first link to the review of the CAD-805s was great. I ended up reading all the later reviews of that amp too. It makes me want to go listen. I suspect my tastes will exceed my eventual budget, but that's no reason to restrain myself from listening.

Ah, but I have much more reading to do, including reviews of notable solid-state amps, and tube amps of the push-pull design as well as other SET amps.

Jan Vigne
Jan Vigne's picture
Offline
Last seen: Never ago
Joined: Mar 18 2006 - 12:57pm
Re: valve vs transistor amp tradeoffs


Quote:
... trying to write really tiny to fit all the information you think is relevant onto a 1 inch square piece of cardboard.

Not one of my hundreds of spare tubes have a piece of cardboard smaller than 2.5 square inches.

z038
z038's picture
Offline
Last seen: Never ago
Joined: Oct 7 2007 - 12:30am
Re: valve vs transistor amp tradeoffs


Quote:

Quote:
... trying to write really tiny to fit all the information you think is relevant onto a 1 inch square piece of cardboard.

Not one of my hundreds of spare tubes have a piece of cardboard smaller than 2.5 square inches.

I thought vacuum tubes were still being produced. Why hoard them unless you have a device that uses one that is no longer made, and there is no modern electrically compatible equivalent and sonic near-equivalent?

Why would any manufacturer of new electronic components built using tubes market a consumer product that relies upon scrounged, hoarded, salvaged, or rare New-Old-Stock elements?

Caveat emptor, certainly, but unless the manufacturer has a supply of the rare parts sufficient to satisfy current and anticipated production needs and customer service and repair demands for a reasonable period, it seems foolish to build new products that require them. At least it would seem worthy of a disclaimer to the consumer that the item relies upon rare parts that are known to be in short supply and no longer in production.

Jan Vigne
Jan Vigne's picture
Offline
Last seen: Never ago
Joined: Mar 18 2006 - 12:57pm
Re: valve vs transistor amp tradeoffs

Well, you've hit upon one of the distinguishing characteristics of tubes. There are some very good tubes being produced today but the reality of the situation is that the best sounding tubes generally do not make their way into O.E.M. products. This is true more so for small signal tubes, i.e. dual triodes or most pre amp tubes, than it is for power output tubes.

I suspect I'll get challenged on this but most manufacturers could buy better sounding tubes than they do for use in their production stock. Some manufactuers are open about their choices and others would prefer to look the other way and pretend the current manufacture Russian 12AX7's they choose are the best sounding tubes they could use.

As an example, Audible Illusions realizes the O.E.M. tubes they use in their pre amplifiers can be bettered but they intentionally choose not to use the tubes that sound the best. Why? Because they feel they must provide a consistent product a consumer can buy knowing the pre amplifier they take home is the same product the reviewer heard. To do that they must have a consistent supply of tubes for the units they produce and for the units they repair or refurbish. Additionally, they must provide their product at a consistent price point as suggested in that review, not a price that fluctuates every few months based on supply and demand for NOS tubes. Obviously, NOS tubes are not being produced any longer which makes the hoarders of NOS tubes a more powerful consortium than O.P.E.C. oil princes.

Tube rolling is a favorite sport of many tube equipment owners. As suggested above some people become obssessive about this and spend their life searching for the few NOS tubes which will bring sonic Nirvana to their system. Some people pay what most of us would consider outrageous prices for some of these NOS tubes going so far as to save these most special tubes for those most special nights when they wish to be alone with their systems. (Ahhhh, the thrill of slipping an original Western Electric 300B out of its silken coverlet!!!) NOS tube dealers can make the high priced hookers around a C.E.S. show look cheap and tawdry. And, while some very good tubes are being built today, few of them equal the truly great tubes that were manufactured when the world ran on vaccum tubes. As I said, the change from the new stock Chinese 6DJ8 to a NOS 1960's Amperex 6922 will bring tremendous improvements in sound quality almost without fail to even the most deaf amongst us.

However, unlike the high priced hookers, the market for NOS tubes, particularly NOS power tubes which burn out faster than small signal tubes and are therefore more rare, is unstable in terms of supply and pricing. Rather than buy those NOS Amperex tubes for use as factory fittings most manufacturers will buy the best new tubes they can find, probably a Russian tube of some sort. This allows them to keep cost down to the consumer and have a consistent product for long periods of time. When an owner sends a pre amp into Audible Illusions for repair or updating, they will get back tubes that match what they heard in their original unit. No surprises. The tubes might not sound as good as the NOS tubes the owner can buy but the pre amp will sound just as it did when first purchased - at least as far as the tubes are concerned. If the owner wishes to pursue NOS tubes to tailor the equipment to their own personal taste, they are free to do so with AI's blessing. As an assist to Audible Illusions owners, AI goes so far as to suggest on their web page which tubes will sound and work best in the pre amps. But for their new pre amplifiers Audible Illusions has a lage stock of tubes that are quite good - though not quite the best possible - to build and use for many years to come. So, the tube unit you buy today will have consistent sound tomorrow. You might say it has consistently less than the best sound possible; but, if you feel that's true, you can go hunting for the best NOS tubes you can afford.

Stereophile has run reviews of a few products, the Musical Fidelity NuVista units come to mind, which are built knowing a finite number of parts are available. There was also a pre amplifier reviewed recently which was built with almost entirely "obsolete" components. I can't remember the product name but the tubes and internal components; caps, resistors, switches, etc., were NOS products that had been gathered by the manufacturer for a very small quantity run of very high quality products. These products are the exception rahther than the rule in tube gear.

z038
z038's picture
Offline
Last seen: Never ago
Joined: Oct 7 2007 - 12:30am
Re: valve vs transistor amp tradeoffs

It does make sense. Prudence most likely guides the majority of tube amp makers in choosing to use the most available rather than the best sounding albeit more scarce tubes. The ability to produce a consistent product for a known manufacturing cost that is offered at a competitive and somewhat stable price is a key component to success in the market.

I'm amazed that so many different tubes can be substituted for the O.E.M, supplied tubes, but I'm not at all surprised that different tubes would yield a different sound.

I googled 300B tubes and found some extravagant options available. I doubt I'd spend $850 for a matched pair of Western Electric 300B's in silken coverlet and velvet-lined wooden box, but I know what I'd do with them if I did. My philosophy of life dictates that I enjoy myself now while I can, rather than hope to be able to enjoy it later. The future will take care of itself; it is the present that matters. So I'd just pop them into my amp and use them all the time until I used them completely up.

The store where I bought my TT sells Prima Luna and Audio Research tube gear. Soon I will stop by to give them a listen.

I love your metaphors Jan. Thanks again.

cyclebrain
cyclebrain's picture
Offline
Last seen: 2 years 6 months ago
Joined: Jun 16 2006 - 11:40pm
Re: valve vs transistor amp tradeoffs

A downside to tube gear is that they use a vacuum in the tube. And we all know that sound doesn't travel in a vacuum.
So how can they be any good at producing sound.
But a solid state amp uses semi conductors which as we all know "semi" means that only half of the signal will be conducted. Can't be a good thing.
I still prefer the straight wire with gain amplifier.

z038
z038's picture
Offline
Last seen: Never ago
Joined: Oct 7 2007 - 12:30am
Re: valve vs transistor amp tradeoffs


Quote:

I still prefer the straight wire with gain amplifier.

I'll take two. Make 'em monobloc's please. Who did you say manufactures them?

cyclebrain
cyclebrain's picture
Offline
Last seen: 2 years 6 months ago
Joined: Jun 16 2006 - 11:40pm
Re: valve vs transistor amp tradeoffs


Quote:

Quote:

I still prefer the straight wire with gain amplifier.

I'll take two. Make 'em monobloc's please. Who did you say manufactures them?

Well I wasn't quite ready to announce my new product yet, but since you asked. I'm still working out some minor details with the cryo system and also the power required for the particle accelerator. Minor details. Just need some investment capital. Also that "straight wire" part is quite literal. Any bends in the wire cause audible coloration to the sound becuase of the greater electrical distance on the outside of the bend relative to the shorter inside of the bend.

piinob
piinob's picture
Offline
Last seen: Never ago
Joined: Aug 14 2007 - 11:31pm
Re: valve vs transistor amp tradeoffs

"There was also a pre amplifier reviewed recently which was built with almost entirely "obsolete" components. I can't remember the product name but the tubes and internal components; caps, resistors, switches, etc., were NOS products that had been gathered by the manufacturer for a very small quantity run of very high quality products. These products are the exception rahther than the rule in tube gear."

Jan, Are you refering to the Shindo componants AD talked about in is columns?

Jan Vigne
Jan Vigne's picture
Offline
Last seen: Never ago
Joined: Mar 18 2006 - 12:57pm
Re: valve vs transistor amp tradeoffs

Sounds right. Outrageously expensive. Someone said dup has two on order.

CECE
CECE's picture
Offline
Last seen: Never ago
Joined: Sep 17 2005 - 8:16am
Re: valve vs transistor amp tradeoffs

The latest marketing gig is to build over priced stuff with obsolete parts, and claim they sound better. Didn't that 3 piece DZ something or other use the chips no longer made by Philips cus' they are OBSOLETE, but this outfit claims they sound better, yupper, brilliant design. I guess Philips/Sony developed DSD SACD cus their old stuff couldn't be improved on...YET there are outfits doing upgrades on old stuff also claiming they will improve your old stuff by removing obsolete stuff, yet one company starts out new with old stuff and says it sounds better....only in teh world of audio nonsense. And when ya need 3 chassis to make a CD only player, right there, it's goofy!!! How can EMM labs or Onkyo or Marantz make some Universail, or CD/SACD players that smoke DarTZeelTell whatever for mortal prices, and it uses the most modern chips? Why does EMMLABS upsample Cd to 2X of sACD...yet Dart Z' Ell says lets use the 20 year old Philips chips, cus they sound best, souning like a bunch of nonsense on teh part of teh $45K obsolete 3 piece stuff. Miswired too!!!

dcstep
dcstep's picture
Offline
Last seen: Never ago
Joined: Sep 16 2007 - 4:59pm
Re: valve vs transistor amp tradeoffs

My first amp was a tube, intergrated Scott amp, which was mighty fine, back in the 1960s. I had a brief stint with a SS Sansui and then moved to Bryston in the early 1980s. Last weekend I replaced the SS Bryston amp/preamp with a Conrad Johnson CA200 "control amp." I like the sound, reliability and packaging of SS. Oh yeah, the speakers that I tend to like seem to work best with more than 100 wpc, so cost and size becomes more of an issue with tubes. Finally, my system is hiden in an armoire in the living room, so size is a high priority to me.

Friends have very fine sounding AR and Cary systems. I'm not saying that SS sounds better than valves, or vice versa. To me, the best of each sound really good. OTOH, I've heard both formats sound crappy.

I DO have a tube phono preamp and a tube headphone amp. These devices make relatively compact packages and are critical in the system. I find that tubes early in the chain add a very subtle euphonic attack that works well with a SS backend that can really take hold of the speakers and make them sit up and sing.

Starting with a good TT and/or digital front end, IMHO, is the most important part of the chain and the SS vs. valves question pales in importance. You've taken the first step with your TT upgrade. I also like to use a high output MC cartdridge, like the Sumiko Blackbird at 2.5mv, so that I don't struggle with noise being introduced at the front end. I've read reviews of my Pro-ject Tube Head that call it noisy, but in my system, with my high output cartridge, that's not an issue at all.

So I suggest focusing on the size, power and cost tradeoffs and listen to both formats, chosing the one that's fits best in your scheme of things.

Let us know what you do.

Dave

Elk
Elk's picture
Offline
Last seen: 3 months 2 weeks ago
Joined: Dec 26 2006 - 6:32am
Re: valve vs transistor amp tradeoffs

Good, simple practical and realistic advice, Dave.

I love both SS and tubes.

greenelec
greenelec's picture
Offline
Last seen: 3 months 1 week ago
Joined: Feb 10 2006 - 12:37am
Re: valve vs transistor amp tradeoffs


Quote:

- Tube amps usually cost more than solid state amps of similar quality.

I have found the opposite to be true. I think it is much harder to design a good sounding SS amp and costs much more than an equivalent tubed amp.

KBK
KBK's picture
Offline
Last seen: Never ago
Joined: Sep 30 2007 - 12:30pm
Re: valve vs transistor amp tradeoffs

I have real preference for tube-voltage driven SS output sections.

In other words, Hybrids. Tubes with balls and slam.

Shindo is one of the original guys from...from..from.. oh dang. I can't remember. One of three guys. One of the others being the Airtight dude. Oh. If you hit me on the head real hard, in an effort to try and help me remember, I'd be crawling around on the floor in circles (avec some blood) muttering something about Luxman.

As for older 16 bit non oversampling ladder DAC's, the philips Crown Select units. They tend to sound better than the oversamplers and the one bit units. seriously. 100% serious. Take that chip and give it modern support, and it will suprise the hell out of you.

Lesson:We don't always move forward!

As for old NOS parts, there is a certain synergy between them, and there are also issues with the 'inonic noise' (can be described as 'shot noise' in transistors) from signal transfer being more 'complementary' to the human hearing mechanism, on old carbon resistors. Seriously. One of those little secrets. You see, the given resistor materials are not always linear in how they handle a given voltage and current load, one that is complex. Knowing these sort of things is half the battle. This is part of the lore that is not shared, as it is part of what puts the bread on the table at the end of the day.

Yiangos
Yiangos's picture
Offline
Last seen: 2 years 10 months ago
Joined: Sep 7 2005 - 8:41am
Re: valve vs transistor amp tradeoffs

I will have to agree in a way with Dup on this.And the funny thing is,those obsolete Philips dacs were replaced with something we were told it is better !

  • X
    Enter your Stereophile.com username.
    Enter the password that accompanies your username.
    Loading