A question for tube lovers

[Bridges]

In the old day I liked to use a tube preamp (Audio Research) with a SS amplifier. Of couse everything was analog from recording to vinyl.
Now my set up is all digital.
I am tempted to try a tube preamp again.
Today's tube lovers argue that SS pre-amplifiers block out some harmonics, (pleasing distortions for others).
Are these missing harmonics not already blocked out in the digital recording process and delivery?
Would I be wasting my time and money?

 

[Deleted member 21219]

Today's tube lovers argue that SS pre-amplifiers block out some harmonics, (pleasing distortions for others).

No, SS electronics don't BLOCK OUT harmonics at all; they simply don't GENERATE them. Some tube lovers use tube gear that DOES generate harmonics that some listeners like.

Are these missing harmonics not already blocked out in the digital recording process and delivery?

Please see the reply above.

Would I be wasting my time and money?

In my opinion, yes you would. Tube PRE-amplifiers are a rather different affair from tube POWER AMPLIFIERS. It is not difficult to construct a tube preamplifier that sounds, essentially, like an SS preamplifier. Therefore, to design and construct a tube preamplifier that has audible harmonics means that that pre is pretty damn bad.

Most of the "tube sound" that people talk about is in relation to amplifiers, not preamplifiers. That being said, there are a few tube preamps that have an deliberately affected sound. Some people like to walk that path ..... I don't.

Jim

 

[DVDdoug]

I'm NOT a "tube lover".

A good tube or solid state amp doesn't have any particular sound characteristics. It will have distortion and frequency response better than human hearing, and hopefully inaudibly-low noise levels.

It's (probably) not blocking anything. It MAY be adding harmonic distortion. But, most amps don't distort (clip) unless over-driven, and no good amp will distort (audibly) under normal conditions.

A poorly designed tube amp may also have frequency response variations. Of course, high frequency roll-off will reduce high-frequency harmonics.

If a tube amp does have a particular sound (defect) it will be different from every other amp... There is on one "tube sound".

It's not hard to make a good tube preamp, it's just expensive.

It's harder, and more expensive, to make a tube power amplifier because it needs an "impedance matching" output transformer, and good-quality power-output transformers are difficult and expensive to make. Tube preamps don't need transformers in the audio path, and solid state electronics are "naturally" low impedance so neither solid state preamps or power amplifiers need audio transformers.

A lot of guitar players like tubes because of the way they distort when overdriven. And they usually have their favorite amp to go with their favorite guitar. That "tube distortion" can be simulated in a solid state amp, but you'll never convince the guitar player of that!

 

[Bridges]

I'm NOT a "tube lover".

A good tube or solid state amp doesn't have any particular sound characteristics. It will have distortion and frequency response better than human hearing, and hopefully inaudibly-low noise levels.

It's (probably) not blocking anything. It MAY be adding harmonic distortion. But, most amps don't distort (clip) unless over-driven, and no good amp will distort (audibly) under normal conditions.

A poorly designed tube amp may also have frequency response variations. Of course, high frequency roll-off will reduce high-frequency harmonics.

If a tube amp does have a particular sound (defect) it will be different from every other amp... There is on one "tube sound".

It's not hard to make a good tube preamp, it's just expensive.

It's harder, and more expensive, to make a tube power amplifier because it needs an "impedance matching" output transformer, and good-quality power-output transformers are difficult and expensive to make. Tube preamps don't need transformers in the audio path, and solid state electronics are "naturally" low impedance so neither solid state preamps or power amplifiers need audio transformers.

A lot of guitar players like tubes because of the way they distort when overdriven. And they usually have their favorite amp to go with their favorite guitar. That "tube distortion" can be simulated in a solid state amp, but you'll never convince the guitar player of that!

Most of these guitar players use lots pedals wa- was and saturation producing and phase shifting gear before the amp. So they are not listening to results produced by the tube sound of their beloved tube amplifiers.

 

[Bridges]

No, SS electronics don't BLOCK OUT harmonics at all; they simply don't GENERATE them. Some tube lovers use tube gear that DOES generate harmonics that some listeners like.



Please see the reply above.



In my opinion, yes you would. Tube PRE-amplifiers are a rather different affair from tube AMPLIFIERS. It is not difficult to construct a tube preamplifier that sounds ,essentially, like an SS preamplifier. Therefore, to design and construct a tube preamplifier that has audible harmonics means that that pre is pretty damn bad.

Most of the "tube sound" that people talk about is in relation to amplifiers, not preamplifiers. That being said, there are a few tube preamps that have an deliberately affected sound. Some people like to walk that path ..... I don't.

Jim

Are there any good affordable vintage power amps worth checking out? Will there be lots of maintenance and tinkering? Frequent biasing, tube rolling and other tasks?

 

[Deleted member 21219]

Are there any good affordable vintage power amps worth checking out? Will there be lots of maintenance and tinkering? Frequent biasing, tube rolling and other tasks?

I don't really know. There are others here who may be able to help you.

As regards tube rolling .....

Tube Rolling: Does it Make a Difference?

I recently reviewed the Mhdt Pagoda tube DAC. Owner was kind enough to send me three other tubes to test with it. Here are the set of tubes I received: Let's start again with the tube supplied with the unit (GE 5670) Now let's switch to Tesla 6CC42 (GA): Other than slightly more mains...

www.audiosciencereview.com

Jim

 

[DonR]

Are there any good affordable vintage power amps worth checking out? Will there be lots of maintenance and tinkering? Frequent biasing, tube rolling and other tasks?

Given the lethally high voltages present in tube equipment, often coupled with dubious safety considerations by modern standards and decaying capacitors and resistors, I would avoid vintage tube equipment unless you are well-versed in electronic circuit theory and repair.

 

[Blumlein 88]

Are there any good affordable vintage power amps worth checking out? Will there be lots of maintenance and tinkering? Frequent biasing, tube rolling and other tasks?

Define affordable or list a few you think would fit the bill.

If vintage amps are working fine and/or checked out by someone they aren't too terrible usually. Replace tubes when worn out. A good tube tester helps you figure out what is worn out. Biasing is usually not too much of a chore and normally only something you do periodically. Like twice a year or something. Conrad-Johnsons are a good choice. Most all the caps are types that can last a lifetime other than just a few electrolytics that are not too big a chore for a competent person to replace. Simple circuits too. I'd say the same for VTLs or Audio Research. Of course they aren't the cheapest of vintage types.

One possibility is to use a tube headphone amp as a preamp. Some of those do function more like small tube power amps and can give some of the same sound. Tube sound is a coloration though pleasing to many. The idea SS blocks out tube sound is rubbish. Good SS can pass on tube sound accurately. The issue is most tube pre's are not at all like tube power amps, and don't color the sound the way tube power amps do.

 

[Bridges]

Define affordable or list a few you think would fit the bill.

If vintage amps are working fine and/or checked out by someone they aren't too terrible usually. Replace tubes when worn out. A good tube tester helps you figure out what is worn out. Biasing is usually not too much of a chore and normally only something you do periodically. Like twice a year or something. Conrad-Johnsons are a good choice. Most all the caps are types that can last a lifetime other than just a few electrolytics that are not too big a chore for a competent person to replace. Simple circuits too. I'd say the same for VTLs or Audio Research. Of course they aren't the cheapest of vintage types.

One possibility is to use a tube headphone amp as a preamp. Some of those do function more like small tube power amps and can give some of the same sound. Tube sound is a coloration though pleasing to many. The idea SS blocks out tube sound is rubbish. Good SS can pass on tube sound accurately. The issue is most tube pre's are not at all like tube power amps, and don't color the sound the way tube power amps do.

I have a tube headphone amp Xduoo MT-604, highly recommended by "the cheap audio man" on youtube as a preamp with special cables only 45€ for the cables.

I would need a tube power amp with XLR inputs probably rare.

I also have a Musical Fidelity Tube buffer, If I put a tube buffer at the input stage of a ss preamp and another tube buffer at the output stage would that not be the equivalent of a tube preamp?

 

[raindance]

A tube preamp isn't two buffers. It is a gain stage followed by a buffer. It can be argued that the gain stage is what adds the tube character to the sound. Typical tube buffers (cathode followers) are notorious for adding the wrong kind of distortion, namely odd harmonics. Gain stages can produce even harmonics. Tube rolling in a buffer will produce few changes in sound unless you roll in a tube that is shot.

I still maintain that tube preamps that sound "tubey" are badly designed and operate the tubes under-biased into their non linear operating region. There's no magic in this. Well designed tube preamps sound just like solid state.

Most tube preamps (not buffers which have no gain) have massive amounts of gain and sound different because they make the signal much louder and there is this silly idea that they make everything sound more "powerful" because the volume control doesn't have to be turned up so far. It is a known fact that the louder sound will be preferred by a typical listener and there's also this psychological thing about where the volume is pointing which is actually meaningless.

There is far more tube magic to be gained using a tube amplifier, provided the stars align and the highish output impedance of the output transformers cause your speakers to behave in a "pleasant" manner, but this is a crap shoot and you'll forever be chasing the "right" speakers.

 

[Bridges]

A tube preamp isn't two buffers. It is a gain stage followed by a buffer. It can be argued that the gain stage is what adds the tube character to the sound. Typical tube buffers (cathode followers) are notorious for adding the wrong kind of distortion, namely odd harmonics. Gain stages can produce even harmonics. Tube rolling in a buffer will produce few changes in sound unless you roll in a tube that is shot.

I still maintain that tube preamps that sound "tubey" are badly designed and operate the tubes under-biased into their non linear operating region. There's no magic in this. Well designed tube preamps sound just like solid state.

Most tube preamps (not buffers which have no gain) have massive amounts of gain and sound different because they make the signal much louder and there is this silly idea that they make everything sound more "powerful" because the volume control doesn't have to be turned up so far. It is a known fact that the louder sound will be preferred by a typical listener and there's also this psychological thing about where the volume is pointing which is actually meaningless.

There is far more tube magic to be gained using a tube amplifier, provided the stars align and the highish output impedance of the output transformers cause your speakers to behave in a "pleasant" manner, but this is a crap shoot and you'll forever be chasing the "right" speakers.

I agree with your description of tube preamps and tube buffer,this is something I suspected all along.
Regarding your last paragraph, I also agree, an add, that this whole audiophile business is a crap shoot. As an example my secondary system is now my primary system by pure chance.

 

[Blumlein 88]

The kind of tube headphone amps I have in mind have a transformer output. Essentially built like a one watt tube power amp. Tube buffers and such either sound bad or have no real sound. Putting tube buffering around an SS preamp is not the same effect.

 

[mhardy6647]

Any buffer with a "Sound*" -- is a very bad design.

_______________
* And, boy howdy, they're out there.
Fortunately, they seem to have fallen out of favor in the past decade or so -- although nowdays there's a host of really cheap, really silly little two-tube line-level "preamps" that succeed in doing little but damage to whatever signals pass through them.

 

[Purité Audio]

Are there any good affordable vintage power amps worth checking out? Will there be lots of maintenance and tinkering? Frequent biasing, tube rolling and other tasks?

That’s why people buy them.
Keith

 

[MattHooper]

In the old day I liked to use a tube preamp (Audio Research) with a SS amplifier. Of couse everything was analog from recording to vinyl.
Now my set up is all digital.
I am tempted to try a tube preamp again.
Today's tube lovers argue that SS pre-amplifiers block out some harmonics, (pleasing distortions for others).
Are these missing harmonics not already blocked out in the digital recording process and delivery?
Would I be wasting my time and money?

As others have said, any decent SS preamp (or amp) isn't blocking anything, let alone harmonics. If anything they are letting through more sonic information than
a tube amp design that has audible distortion.

If you are looking for a tube premp on the assumption it will get you "purer" or more direct or accurate sound than a competent solid state design, that's the wrong assumption.

However, if you are interested in trying a tube amp or pre-amp because it's possible you might enjoy the sonic difference they can produce (which isn't guaranteed, but IF so it will be distortion of one form or another of the signal), then that makes more sense.

I'm not one to give advice on this regarding specific gear and it's a crap shoot to play with buying tube gear, hoping to get some effect you prefer. BUT...some people enjoy that aspect of playing with tube gear. I do. I wouldn't give up my CJ tube preamp, as I prefer the sound in some ways to my solid state preamp. But I'm in a minority around here.