Tube Versus SolidState

[skeptic]

"Please explain how transistors avoid wearing out and can you also speculate on what caused my old SS amp to die after a dozen years? There weren't hidden tubes in there, were there? "

Transistors themselves don't wear out. If their crystaline structure breaks down even slightly, they will almost certainly undergo catastrophic failure. That is why manufacturers take the extraordinary precautions they do to protect them. When your amplifier failed, unless it was abused in some way, the failure was due to failure of another component. That it not to say that the initial failure didn't take out some transistors with it but that was not the primary cause. Capacitors are the most frequent culprits. Sometimes the power transformer fails. I just had an equalizer lose a power transformer after 20 years of reliable service and no replacement is available.

I personally gave up on tube amplifiers around 1968. I got tired of their less than clear sound. I've heard some very good tube amplifiers such as NYAL but I have no intention of going back to tubes. I like many of the amplifiers most audiophiles reject and I'm thrilled that there are so many of them on the used market at giveaway prices. If you want an excellent amplifier for a two channel sound system, consider a used Marantz receiver of about 70 wpc or greater in mint condition. You will get a very reliable piece of equipment that performs excellently by most people's standards for a fraction of the cost of a new unit on nominally comparable power.

[DMK]

"Please explain how transistors avoid wearing out and can you also speculate on what caused my old SS amp to die after a dozen years? There weren't hidden tubes in there, were there? "

Transistors themselves don't wear out. If their crystaline structure breaks down even slightly, they will almost certainly undergo catastrophic failure. That is why manufacturers take the extraordinary precautions they do to protect them. When your amplifier failed, unless it was abused in some way, the failure was due to failure of another component. That it not to say that the initial failure didn't take out some transistors with it but that was not the primary cause. Capacitors are the most frequent culprits. Sometimes the power transformer fails. I just had an equalizer lose a power transformer after 20 years of reliable service and no replacement is available.

I personally gave up on tube amplifiers around 1968. I got tired of their less than clear sound. I've heard some very good tube amplifiers such as NYAL but I have no intention of going back to tubes. I like many of the amplifiers most audiophiles reject and I'm thrilled that there are so many of them on the used market at giveaway prices. If you want an excellent amplifier for a two channel sound system, consider a used Marantz receiver of about 70 wpc or greater in mint condition. You will get a very reliable piece of equipment that performs excellently by most people's standards for a fraction of the cost of a new unit on nominally comparable power.

So if I read you correctly, you're saying that both tube and transistor amps can have reliability issues, a statement to which I agree.

I have little doubt, based on the ones I've heard, that tube amps from 1968 had less than clear sound. But I find the gap between modern tube amps and SS amps being bridged, particularly over the last 5 or so years. A good tube amp sounds more similar to a good SS amp than different, the main difference being in a sonic quality that I can only describe as "life", which the tube amp usually has and the SS amp doesn't. But that's just me.

Thanks for the advice on Marantz - I currently own a Marantz pro CD recorder and after literally thousands of copies (I archived some 800 pre-recorded cassette tapes to CDR, not to mention several CD copies and a few LP's), it's still going strong. But my next foray into the equipment ranks will likely be surround sound for music, should SACD take off... or whatever format comes out in surround. I've liked what I've heard so far but I need to coax the manufacturer of my speakers into making a center channel. So far, he's being difficult....

[skeptic]

"So if I read you correctly, you're saying that both tube and transistor amps can have reliability issues"

In Pilot Radio's first foray into solid state, every amplifier they shipped out blew up after eight hours of use. At one point, according to my sources, they were coming back faster than they were going out.

Didn't you read the thread some months back about someone's Krell amplifier which kept blowing up. They'd fix it, return it and after playing OK for a while would blow up again. The output stage kept failing. Finally the problem was traced to a cracked electrolytic capacitor. Often, a component failure causes a cascading series of events. Unless you get to the root cause, it can and usually does happen again. There is no known aging process for transistors themselves. The atoms are locked tightly in their crystal matrices and are not likely to drift around. Absent damaging effects of excessive heat or ionizing radiation, transistors should have no problem lasting for hundreds of years. Of course simulations, tests, and mathematical analysis can only predict what will happen, the real test is the test of time.

Tubes begin deteriorating from the moment they are made. Even with no use, the glass envelope will allow some air to enter very slowly and it will ultimately be significant over an extended period of time. The "getter" inside some tubes will only absorb so much. Before vacuum tubes were installed in repeaters in the Atlantic Cable, they had to prove themselves reliable by giving 25 years of continuous service without a problem. I don't have any statistical info but many tubes fail for the same reason transistors fail and that is because another component failed first. However, because of the enormous heat generated by tubes, this is far more likely over an extended period. Users of tube amplifiers are encouraged to test and replace the output tubes periodically. Once upon a time, this was a minor inconvenience but today, many of these tubes are very expensive.

Beware the Chinese made KT 88. My reports from friends a few years back were that they did not perform well. That may have changed since. You are now forced to buy tubes which may have been made in Russia or Serbia. Svetlana is one source commonly used. Luckily for audio fans, electronics technology in the USSR lagged about 30 years or more behind the US.

Most tube amplifiers of the past didn't take kindly to operating without a connected load. I don't know what the situation is today but I wouldn't be surprised if it is still true. On the other hand, opearating a ss amp without a load is not a problem.

[topspeed]

of your rather passionate debate, but has anyone else noticed that our esteemed thread starter has yet to chime in on this?

Why are you guys even bothering?

Geez, we go 'round and 'round with this thing every couple of months, like Skep noted, and for what? Because you like to debate?

This topic is as inane as the planar/'stat vs. dynamic or acoustic suspension vs. bass reflex debates.

[92135011]

Topspeed,
What's even more is that it sounds almost exactly like the other debates.
Similar comments. Similar evidence. Similar everything.

[skeptic]

What is arcane or esoteric in many hobbies is often fun. It makes the people who shop for them, buy them, sell them, use them, admire them, feel that they have made a discovery and are among the priveleged insiders who know where the real gems are burried. In a world where mass production means low cost and limited production or merely finding and restoring antiques means high cost, the fancy pricetags associated with this class of products can be considerable and nobody wants to feel or admit that they have been had. You can call people today almost anything and they often won't even flinch at the worst insults but suggest that they are stupid and their blood will boil.

Vacuum tubes, vinyl phonograph records, class A amplifiers, high efficiency horn speakers, moving coil phonograph cartridges, these things have been around in one form or another for 50, 60, even 70 years but most were long forgotten by all but a few until their recent revival. Throw in some exotic cables and you have a perfect description of the modern audiophile's high end sound system. They cling to it like a religion and heaven help you if you say anything bad about any of it.

[DMK]

[QUOTE=topspeed]

Why are you guys even bothering? [/QUOTE

Because some else might be reading the thread, as you did. That someone might read one side of the issue and be swayed without knowing the whole issue. If you feel it's "inane", I'm afraid you don't have much of a grasp of the issue. Yes, tubes and solid state amps are a preference. But it is not true that one is "right" or accurate and the other wrong and inaccurate. That's the part I'm debating. I will certainly never convince Skeptic of anything but perhaps a newbie to tubes will take note.

If this debate is a problem for you, please feel free to skip over it. It's a public board and you're free to read or not read whatever you like.

[topspeed]

That someone might read one side of the issue and be swayed without knowing the whole issue. If you feel it's "inane", I'm afraid you don't have much of a grasp of the issue.

You assume too much. Do you know what happens when someone assumes too much? You make an ass out of you and umption. If someone has the temerity to believe one opinion over another without exercising enough diligence to form one for themselves, then they get what they deserve. This thread was started by a sh*t stirrer. You've been around long enough to recognize that there is no right or wrong answer to this query. Only opinion. Think about it,

"why I would or would not want tube or solidstate

Are you kidding?! Let's do the Ford vs. Chevy or Yankees vs. Redsox while we're at it (I'd do Dodgers vs. Giants but let's face it, the Dodgers suck...and I'm a fan!). Here's an idea: buy whatever sounds best to you.

Yes, tubes and solid state amps are a preference. But it is not true that one is "right" or accurate and the other wrong and inaccurate. That's the part I'm debating. I will certainly never convince Skeptic

Exactly.

perhaps a newbie to tubes will take note

Only if they weren't completely disenfranchised with this "discussion" many threads ago.

If this debate is a problem for you, please feel free to skip over it. It's a public board and you're free to read or not read whatever you like.

Hey, I've said it many times before that I learn more from these sites than any mag. I just don't find any value in a debate based on personal preference and perceptions.

For the record, I don't lean one way or the other in this matter. I just buy what sounds best to me regardless of how it's made. Novel approach, huh?

[DMK]

You assume too much. Do you know what happens when someone assumes too much? You make an ass out of you and umption. If someone has the temerity to believe one opinion over another without exercising enough diligence to form one for themselves, then they get what they deserve. This thread was started by a sh*t stirrer. You've been around long enough to recognize that there is no right or wrong answer to this query. Only opinion. Think about it, Are you kidding?! Let's do the Ford vs. Chevy or Yankees vs. Redsox while we're at it (I'd do Dodgers vs. Giants but let's face it, the Dodgers suck...and I'm a fan!). Here's an idea: buy whatever sounds best to you.

Exactly.

Only if they weren't completely disenfranchised with this "discussion" many threads ago.

Hey, I've said it many times before that I learn more from these sites than any mag. I just don't find any value in a debate based on personal preference and perceptions.

For the record, I don't lean one way or the other in this matter. I just buy what sounds best to me regardless of how it's made. Novel approach, huh?

Assume? You must be joking! It happens all the time around here! Yes, I've been around long enough to have read such posts for years. Someone asks a question and gets a one sided answer that they blindly follow. Yes, they get what they deserve. So let's give them both sides and then what they deserve is balanced. Another novel approach, no? If YOU learn more from this site than any mag, why are you denying that learning to others that perhaps don't have the foresight you have to seek out both sides of the issue?

You're right; a debate based on personal preference and perceptions is worthless. So let's take the tube/solid debate down to its essence and strip away the gloss. The debate on one side is that tubes are euphonic, colored, with bloated bass, rolled off highs and high distortion numbers. This side of the debate is based on numbers and pre-conceived notions. When someone with seemingly a lot of technical expertise but no listening experience spouts it, it becomes believable to newbies. then they scratch tubes off their list without ever taking the time to audition some and discover if they can use your approach and find out which sounds best. It's a fallacy called Poisoning The Well. And it happens (and is effective) all the time. Oh, and it works both ways. I could post that measurements in audio don't matter and people might believe it. If you doubt that, take a looks at the cable debate! When enough people believe a one sided story, they buy $3000 interconnects. And btw, Yankees vs Red Sox might be an interesting debate with all the deals those two have won and lost this year.

[skeptic]

" I will certainly never convince Skeptic of anything "

Since I am convinced by facts, not personal preferences, apparantly you won't.

In the debate between tubes and solid state, I have said many times that there are excellent examples and horrible examples of both. I stick with the observation of my experience which confirms my understanding of how both types work that at their very best, the best solid state amplifiers outperform the best tube amplifiers. What does outperform mean? They not only test better but they sound better. And as for the "average" solid state versus the "average" tube amplifier, I have had the same experience.

What does sound better mean? Clearer, wider range, better able to get the most accurate sound out of most of the speakers they are connected to. If other people have a different opinion or experience, that's fine with me. I don't sell this stuff and these are merely machines, not a religion to me. I also have no position on whether the best rotary engine would outperform the best reciprocating piston engine although I note that most serious auto racing mechanics and drivers choose the later.

[topspeed]

I also have no position on whether the best rotary engine would outperform the best reciprocating piston engine although I note that most serious auto racing mechanics and drivers choose the later.

Well, the main problem is that rotary's have a problem with torque production which limits the drive out of the corners. To offset that, they are lighter, smaller, and it's easier to extract better hp/cc numbers out of them. Does this offset the better torque and "racing characteristics" of pistons? It did at the '91 Le Mans. Unfortunately, after that Mazda withdrew from big time int'l racing. Rumor at the time was the 787b was to be replaced with a 5 rotor if I remember right (it was awhile ago). Hmmm, coulda been interesting...

As for the topic, here's a completely unbiased and objective answer:

Solid State: easier to maintain, not as sexy as glowing tubes (yes, even JRG amps look dowdy next to a Hovland), good ones can be practically bullet proof with little or no attention.

Tubes: require more owner interaction, more succeptable to damage if tubes are left uncovered, not as prevalent as ss amps thereby limiting choices to a some degree, good ones can be practically bullet proof but will require attention.

That's it.

BTW, the Yanks are the evil empire

[DMK]

[QUOTE=skeptic]" I will certainly never convince Skeptic of anything "

Since I am convinced by facts, not personal preferences, apparantly you won't.QUOTE]

Touche. But I wasn't aware that reliability was a personal preference.

[RGA]

Just a note at least about class A. If the best SS amp is indeed Krell then why is it class A. If McIntosh makes the best SS amp why is their best amp a Tube? Why do so many Bryston owners clue in and buy tubes...more to the point why does the reverse not happen. Admittedly the sample is Audio Asylum...or posters here. But it sure does SEEM like this is the case.

Ahh we all love that lush midrange...is it adding or does the bryston subtract? Makes no difference if the former sounds better.

And which sounds beter is subjective - those sure are not objective facts.

[E-Stat]

I personally gave up on tube amplifiers around 1968. I got tired of their less than clear sound.

Given your love of classical music, that is a shame. Virtually all of the best tube amps available today were developed after '68. Practicality is not thy name, but to these ears, there are sonic advantages. That has been my experience since '81 when I purchased my first ARC preamp. Given that the circuit designs haven't radically changed and the tubes themselves haven't evolved, what has changed? Quite a bit.

1. Higher quality passive parts including lower noise resistors, better capacitors, better connectors, better wire.
2. Better transformers for those that are not OTL.
3. Much larger and stiffer power supplies. My pair has 1000 joules.
4. High power designs required by many speaker designs are now common.

While I'll concede the top end to solid state designs, from there downwards there are tube amps that match or beat the best SS designs I've heard. Bass? You bet. My VTLs have better punch than my Threshold Stasis. More importantly, it has better harmonic resolution on upper bass material like concert drum and tympani. You can discern details like the size of the mallet used. The Joule OTL amps are better still. The midrange is owned by tube designs, IMHO. Massed strings are reproduced with the full harmonic richness and "rosin" of the real thing.

I tried a trick suggested by a poster over at AA that was supposed to make my SS design sound like the tube. He suggested putting a resistor in series with the speaker cable. While that did have a subtle tonal effect, in no way did that magically give the Threshold the kind of midrange purity that the VTL has.

Tubes are relatively expensive, a pain to maintain, and clearly not for everyone. I'm still anxiously awaiting a SS design to change my mind. I'm told the Pass XA-160 and the big GamuT amps come the closest. I would very much like to hear them.

rw

[skeptic]

"1. Higher quality passive parts including lower noise resistors, better capacitors, better connectors, better wire.
2. Better transformers for those that are not OTL.
3. Much larger and stiffer power supplies. My pair has 1000 joules.
4. High power designs required by many speaker designs are now common."

Except for #2 because solid state amplifiers don't usually have output transformers, the same can be said for solid state equipment too. Installing a resistor in series with the output reduces the effective amplifier damping factor (adversely) altering the bass response on some speakers. It will not alter the other factors which cause solid state and tube amplifiers to make loudspeakers sound different.

Bob Carver once boasted that given 24 hours, he could make any amplifier sound like any other amplifier by changing its "Transfer Function." Transfer function is a fancy term electrical engineers use which loosely translated into english means frequency response. I think he was right. Most if not all of the subtle differences between many amplifiers can be compensated for in this way. (BTW, Carver designed and sold both ss and tube amplifiers.)

OK, here's a trick you CAN use to make some judgements about amplifiers which comes from old time engineers. Listen to an amplifier playing at very low volume. Use efficient speakers for this test if possible. Put your ear right up to the speaker. This keeps the signal near the zero crossing point for class AB amplifiers and you may be able to detect crossover notch distortion in either transistor or tube amplifers. In good designs, this can be corrected by adjusting the bias current. In poor designs, you are just stuck with it. The best method is to use a distortion analyzer but if you don't have one, the manufacturer's instructions for adjusting it can be used. Unfortunately, this doesn't usually come with the equipment, only the service manual has it and you often need to be a technician to make use of it.

Since the same tube designs used in the 60s are used today, the circuit possibilities have not changed much. There is really nothing new under the sun. A KT88 is still a KT88 and a 12AX7A is still a 12AX7A. You can push the tubes harder to get more power out of them but that's nothing new. Transformer iron such as supermalloy were well know in the 50s and 60s and audio output transformers were once mass produced. Today, they are far fewer and further between. Does changing all of the parts in a vacuum tube design help? Better power supplies could. As for the others, maybe yes, maybe no. IMO, the best vacuum tube amplifiers will have solid state power supplies. NYAL gave an extensive presentation at the NY chapeter of the AES in 1983 and while bringing Futterman's tube design up to then contemporary standards, there was no doubt that they would use a ss power supply to optimize it.

[E-Stat]

Bob Carver once boasted that given 24 hours, he could make any amplifier sound like any other amplifier by changing its "Transfer Function."

Except of course for his Silver 7 tube amps. His reply during an interview was he got "close as possible".

You can push the tubes harder to get more power out of them but that's nothing new.

Or choice "B", use more of them.

Does changing all of the parts in a vacuum tube design help?

The answer would be yes. If you don't think capacitors have a "sound" then replace any signal caps with electrolytics and get back with me.

IMO, the best vacuum tube amplifiers will have solid state power supplies.

Many current tube designers like Luke Manley of VTL share that belief.

rw

[skeptic]

"Many current tube designers like Luke Manley of VTL share that belief."

While the audible effects of signal processing through vacuum tubes versus various types and configurations of transistors can be debated endlessly, the superiority of the solid state diode over vacuum tube diodes is beyond dispute. The use of vacuum tube diodes for some new retro vacuum tube amplifiers is a marketing ploy rather than a real attempt to get the best technology has to offer, MikE's opinion of his "Moth" amplifier notwithstanding.

[E-Stat]

The use of vacuum tube diodes for some new retro vacuum tube amplifiers is a marketing ploy rather than a real attempt to get the best technology has to offer...

I can offer zero in the way of any technical explanation, but here's one right stuff engineer who would disagree and is not usually subject to stylish whims:



It would be interesting to hear Bill Z. Johnson's commentary since only the big Reference Audio Research amps use tube rectification. Having said that, the two best tube amps in my experience, the VTL Wotans and the Joule Electra Rite of Passages, both use SS regulation.

rw