Tom Bombadil
AK Member
"Vacuum tubes are not good for power amplifiers."
"Are Vacuum Tubes worth it?" By Paul McGowan
- Thread starter Tom Bombadil
- Start date
primosounds
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Who is Paul Mcgowan?
vinylkid58
Super Member
Are tubes worth it? Whatever "it" is would seem to be a personal decision. Are they "worth it" to me? Hell yes! I started with solid state back in 1971 with a Dynaco SCA80, progressed to a Hafler DH220; then found a Dynaco ST70 in the local Pennsyaver and was astonished that is sounded much better than both of the more recent solid state products. I have been listening to tubes ever since. OK, in the way of full disclosure, I purchased a Classe solid state amp as a backup system in case all my tube gear was "on the workbench." Did it sound better than my home made SE 300B amp? Not a chance!
He is a purveyor of expensive solid state equipment. Again full disclosure: I use his company's high end DAC.
Tom Bombadil
AK Member
Famous high end audio designer. CEO of PS Audio (He's the P). Long time partner and friend of Arnie Nudell.
Tom Bombadil
AK Member
He did sing the praises of using tubes in line stages.
Tom Bombadil
AK Member
PS Audio's BHK Signature preamp ($5999) uses 12AU7s.
primosounds
Powered with pure tube sounds.
I got tired of checking out Youboob videos because after less than 5 minutes into it, the poster would spout some nonsense that would make me go wtf.
Audio is highly subjective, since the software in each of us is unique.
mashaffer
Super Member
Better question..."are transistors worth it?". 
For me the answer to that question is... for subwoofers sure.
For what it is worth I think he has it pretty much backward. Even transistors are OK for a line stage as they don't have to swing a lot of voltage and can have plenty of headroom built in.
The long and short of it is that both types of devices have strengths and weaknesses (transistors make really nice switches for example). I wouldn't like trying to replicate my PC or digital organ with vacuum tubes but I sure would use the fire bottles in the audio chain.
Some day I would even like to try a tube subwoofer using OTL driving a series string of high efficiency drivers but until then sand gets the nod for under 32Hz.
For me the answer to that question is... for subwoofers sure.For what it is worth I think he has it pretty much backward. Even transistors are OK for a line stage as they don't have to swing a lot of voltage and can have plenty of headroom built in.
The long and short of it is that both types of devices have strengths and weaknesses (transistors make really nice switches for example). I wouldn't like trying to replicate my PC or digital organ with vacuum tubes but I sure would use the fire bottles in the audio chain.
Some day I would even like to try a tube subwoofer using OTL driving a series string of high efficiency drivers but until then sand gets the nod for under 32Hz.
CopperWizard
Super Member
I've watched many of his videos. They are very informative. Some of the opinions I disagree with.
Not to be snarky- but I've seen and heard his TOTL PS Audio amps, and I've also seen and heard the TOTL VAC tube amps. Guess which ones pretty much everyone thought sounded better?
The one thing that these talks don't mention- is that a good single vacuum tube, is far more linear of a stand-alone amplifying device, than any single transistor.That's just a simple fact. Just look at the conductance curves... the lines are far straighter, and more evenly spaced, on good tubes (such as KT88s, 6DJ8s, 12B4s and such).
From my observances over the last decades of working with amps of all types- the only real reason transistor amps sound as good as they do, is that transistors are cheap enough that you can use LOTS OF them- either with some of them acting to make it possible to correct the errors in the rest (high levels of open-loop gain- which facilitates high levels of negatve feedback, which has its own issues), or with lots of them arranged as in some sort of high-power digital-to-analog converter or something analogous to that (which also has its own issues- filtering, harmonics, and such). Tubes need no such complexity...
That said- transistors can act to improve tube amps. The most evident example of that, IMHO, is the iQ Auto Bias circuit used in VAC amps. It's basically a processor- based on transistors- that keeps the idle current stable in all the output tubes, regardless of tube age, condition (within reason- if the tube is totally worn out or broken, it will just tell you to change the tube, though), or the signal going through the amp. That wouldn't be possible without semiconductors...
Regards,
Gordon.
The one thing that these talks don't mention- is that a good single vacuum tube, is far more linear of a stand-alone amplifying device, than any single transistor.That's just a simple fact. Just look at the conductance curves... the lines are far straighter, and more evenly spaced, on good tubes (such as KT88s, 6DJ8s, 12B4s and such).
From my observances over the last decades of working with amps of all types- the only real reason transistor amps sound as good as they do, is that transistors are cheap enough that you can use LOTS OF them- either with some of them acting to make it possible to correct the errors in the rest (high levels of open-loop gain- which facilitates high levels of negatve feedback, which has its own issues), or with lots of them arranged as in some sort of high-power digital-to-analog converter or something analogous to that (which also has its own issues- filtering, harmonics, and such). Tubes need no such complexity...
That said- transistors can act to improve tube amps. The most evident example of that, IMHO, is the iQ Auto Bias circuit used in VAC amps. It's basically a processor- based on transistors- that keeps the idle current stable in all the output tubes, regardless of tube age, condition (within reason- if the tube is totally worn out or broken, it will just tell you to change the tube, though), or the signal going through the amp. That wouldn't be possible without semiconductors...
Regards,
Gordon.
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invaderzim
Super Member
I'm looking forward to the follow-up video "Are generalizations helpful?"
invaderzim
Super Member
Prior to that amp he didn't like them in the line stage either. I guess it is admirable that he is able to admit when he is wrong and change his opinion but who knows what else he is wrong about
True, we might as well be arguing if red or blue are better colors.
Tom Bombadil
AK Member
Yeah, I think Bascom H. King showed Paul the light on line stage tubes.
H713
New Member
I'm with you on this one.
Would you prefer to outfit your concert hall with a bunch of tube power amps to drive the line arrays, or would you buy (for probably less money) a bunch of rackmount amplifiers from the likes of Crown, QSC or MC2? I know what I'd choose.
In the same way, transistors are probably the way to go for subwoofers, at least in most situations. I love my tube amps, but really, when it comes to bass frequencies, even the big stuff won't touch a good (large) solid state amp. My heathkit AA-121 for example (Big OPTs, 40W out of 2 EL34s), is pretty good but it can't touch my MC2 MC450.
In a small room with reasonably efficient speakers, I have yet to hear something as sweet as a small EL84 based PP amp (though I haven't gotten to try big SE amps). I have a monoblock (sadly only one...) that is essentially a single ST35 channel, and it's an amazing amp, but it's only about 15 watts per channel. Good luck using that in a big room with inefficient speakers.
The bottom line is this: Both have their pros and cons, so stop making generalizations. Neither option is "bad" so to speak. And let's all be honest, there are craptacular tube amps and craptacular solid state amps. And I don't want to hear anything about reliability... the aforementioned MC2 amp is about as reliable as it gets, but there are SS amps that will blow up if you walk past them too quickly. Same with tube amps.
The more of Paul's videos I see, the more I'm convinced he's full of shit.
