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PREAMP technology shift? - Class A/ balanced/ dual-mono/ zero feedback vs. op-amp preamps

Hi all,

Even ten years ago, it seemed that the gold standard for solid-state pre's was some combination of the following: Class A/ balanced/ dual-mono/ zero feedback or local feedback. Recently, I'm seeing a range of well-reviewed preamps, from Schiit to Rowland, that use new, high-quality op-amps in their circuitry, to the extent that I wonder if op-amp technology, and chip manufacture in general, has gotten so good that some of the tried and true markers of quality (MOSFETs, Class A circuits) are not in the market except at the highest end, and even then, see also Jeff Rowland. Or is it that manufacturers are looking to less power hungry designs (I know that Rowland was concerned with meeting EU efficiency requirements in its latest designs) and so avoid Class A, for example? Does balanced/ dual mono seem less popular because separates are now less popular than integrateds? Have we reached a tipping point with op amps?

Here's a more focused question. I have invested in a 90s era Aragon 8008BB dual mono balanced amp, but i have an early 90s B&K PRO10-MC that I want to upgrade. Is a Schiit Freya a significant step up, or should I save my pennies for a used, more recent example of the old school: Classe CP500, Pass Labs Aleph or X2.5, or a good example of a newer approach, the Rowland Capri. Speakers are Vandersteen 2CE Sigs. Input impedance of the Aragon is 44 kOhms. 

The tube route is always possible, but I like the idea of a no-fuss, very clean ss, valuing sound stage and detail over warmth, which makes me think I'd be wasting my time with the Freya (any shoutouts for its JFET stage?)

Thanks for letting me wonder aloud!

Paul


paulburnett
timlub
2,039 posts
 
Manufactures using op amps makes all the sense in the world to me.  We all preach that the shorter the circuit path,  the less involved, the better sounding....well really anything.  
As these micro parts improve,  incredibly short signal paths of opamps actually should sound better than the same circuit wired by hand.
So,  If a smart circuit design can be shoved into an op amp??? Someday, op amps will be the norm in many high end pieces of equipment.
teo_audio
2,197 posts
 
They already are.

the problem for me, is that they tend to be very ’mono’ in their dynamic expression. Meaning the dynamic expression is very one note or one singular expression of dynamics.

Pinched, is another word to describe their sound qualities.

Where real music has a plethora of dynamic responses and behaviors that all move in and out of one another..

It is difficult if not impossible to get past this as the traces are fine and everything is made out of silicon, so all the bits of the sonic presentation - sound likened to that.

It takes a bit of time to hear it, but it can’t be unheard, once realized.

This is where discrete components come in and people buy discrete circuit audio gear.

Opamps used as well as they can be, does indeed move up the ladder of sound quality and can and do sound quite good. But if we are talking about pinnacles, and trying to get to pinnacles, they don’t apply, in my experience or expectations.

There is a lot of overlap in these qualities of opamp vs discrete circuits, thus arguments and discussions are born. A not so perfect discrete circuit can be eclipsed by a well implemented opamp circuit.

When all things are equal, which they never are..in that case, discrete is better than opamps.
paulburnett OP
42 posts
 
Twist!  I just found out that the Schiit Freya is only balanced out from the tube stage, and further, that my Aragon 8008BB shorts the balanced input when using single-ended (jumpers in place on the balanced ins if using RCA), which means I would really need to love only the tube stage and never use either the passive or jfet buffer. It's a bit of a baffling design choice. I guess Mike Moffat really love his tubes. And yet, many tube-only preamps are also single-ended only. 

Will Schiit ever consider making a  fancier pre that's balanced all the way? Throw the Mani's guts into a shielded corner? I'd pay a fair bit more for that. 

In the meantime, now back looking at balanced SS. 
atmasphere's avatar
atmasphere
11,662 posts
 
Why? There are fully balanced/differential tube line sections available.
ghosthouse's avatar
ghosthouse
4,300 posts
 
@paulburnett 
"...the Schiit Freya is only balanced out from the tube stage...."

Paul - I'm not sure that accurately represents Freya functionality.  
There might be some confusion based on a statement in the Freya manual.  See the Freya connections page and this note under "2. Single-Ended Inputs"...

Note: Freya does not convert single-ended to balanced, except when using the tube gain stage.

My understanding is that this statement applies to single ended inputs only.  If you are using a singled ended connection from source to Freya with only a balanced connection from Freya to a power amp, you won't get sound except in tube mode.  

I have asked Schiit for confirmation.   

In my experience, balanced sources connected via XLR work fine using the Freya's balanced out connection whether running Freya in Passive, JFET or tube mode.  

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