Which has better measurements? All-tube or hybrid amplifiers?

[magicscreen]

Which has better measurements? All-tube or hybrid (tube+solid state) amplifiers?
In theory the hybrids has in my opinion. You can use op-amps for output buffer for example.
But really this is the case?

 

[Veri]

If those two are your options, hybrids. Of course.

 

[solderdude]

A cheap Bravo amp won't outperform a well made transformer coupled all tube amp.

So... it depends on the circuit and components used.
It would be much cheaper to build a hybrid though to get similar technical performance.

Then again... when using all tube or tube hybrids one isn't going for top specifications.

 

[DeLub]

option C: solid state

 

[solderdude]

Is an amp with FET's and bipolars also a hybrid ?

 

[tomelex]

Is an amp with FET's and bipolars also a hybrid ?

I would think the generally accepted meaning of hybrid in audio is "mixing in tubes", not differences in solid state devices architectures.

 

[magicscreen]

Is an amp with FET's and bipolars also a hybrid ?

I do not think so.
But of course there is race as well, which is better, JFET vs MOSFET vs bipolar.

 

[solderdude]

JFET looks the most like a tube in operational properties, just with different voltages and SS.

What about Nuvistors and bipolars ?

Is a Tube amp with an opamp in it for operation a hybrid or does it have to be in the audio path to become a hybrid ?

 

[tomelex]

There are plenty of tube amps that the only solid state is the rectifier(s), but they still consider them tube amps not hybrids, so I would guess that if there is a mix of ss and tube in the "signal path" as conventionally known in the trade, (not technically known) then its a hybrid, but all in my opinion as I think you bring up a good point as has anyone officially defined hybrid, and if they did, who are they to do that!

 

[pma]

JFET looks the most like a tube in operational properties, just with different voltages and SS.

What about Nuvistors and bipolars ?

Is a Tube amp with an opamp in it for operation a hybrid or does it have to be in the audio path to become a hybrid ?

Electrons in vacuum, as signal carriers, define tubes. That is the main basic difference from solid state components.

 

[sergeauckland]

By hybrid tube/SS, it rather depends on whether the output stage is the SS or the tube.

If the amp has a SS output, but tube somewhere in the earlier stages, then it should be indistinguishable for an all SS amplifier unless the tube is used deliberately to introduce distortion.

If the amp has a tubed output, with output transformer, then pretty much all the ills of the output transformer will still be there. The main benefit by having a SS stage somewhere before the output is that phase shift will be lower, allowing more feedback to be applied than would be possible with an all tube often RC coupled front end and phase splitter. This will reduce distortion significantly below what an all tube amplifier would be capable of.

However, in both cases, I question the point of it all. If the amplifier has reduced distortion, why not just keep it all SS and save the hassle. It would then seem it's just marketing, to appeal to the tube enthusiasts who want something glowy to show off.

S.

 

[solderdude]

That was the funny thing with the Xcan series.
The Xcan V1 had opamp input stage and tube followers (2 sections in parallel) as output stage.
All the later ones had tubes as input stage (LTP) and SS as output stage (makes a lot more sense for low imp. headphones).
There still is a cult following for the Xcan series.

 

[PaulD]

I do not think so.
But of course there is race as well, which is better, JFET vs MOSFET vs bipolar.

The issue is not which active device is used for amplification - all can be used to make an excellent amplifier, even vacuum tubes. The difference is in the implementation. For that, it is far cheaper (and I mean at least an order of magnitude) to make an excellent amplifier with solid state devices. Making a vacuum tube amplifier the quality of a Purify class D amp would take 10's of thousands of dollars!

There are some designers, like SIY, who enjoy the challenge of designing with vacuum state devices, but even they do not dispute that solid state devices are generally superior and certainly cheaper for equivalent performance.

 

[Objectivist01]

option C: solid state

Nothing beats a solid state.