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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
perazzi28's avatar
perazzi28
231 posts
 
Specifications may or may not (most often not) relate to great sound quality.  2 different preamplifiers that measure similarly will often sound very different. If you limit your search to "big name brands" you may be missing some opportunities.  To say nothing of the fact that as your original question regarding "design philosophies & circuit topology" render a cloudy picture. As a sidebar the audio industry has no standards on anything.  Even preamplifier output values.  IMO preamplifiers are the weakest link in the audio chain.  I have always been a proponent of full-featured preamplifiers and single ended vs balanced.  Unless you have no aspiration on spinning vinyl then you can simplify your search to line level devices.  Concentrate on in home auditions and listen. 
Good luck!

skiroe's avatar
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skiroe
131 posts
 
I would just cut to the chase and go Pass Labs.  The integrity and dedication of this man over the years,  and his willingness to share with the DIY community,   and the consistent quality of his product makes it almost a no brainer IMO.    I have a class A amp of his and everything about it is  just simply art in every respect-- which of course its sound reproduction is paramount.     I have cut back on my "habit"  as I am working on making a major move out of the area otherwise I am itching for a Pass preamp. 
bagwell368
13 posts
 
^ I agree on Pass.  My first the Threshold Stasis 3, then the Aleph 3 and 5, then the great X150 (probably the best used 'cheapish' general amp one could locate).

The P and L and Xono and others have been great preamps, LS's, and phono stages as well.  I've 'slummed' for 20+ years with the Pass designed GFP-750, which died (accidental).

Retired now, so the budget has taken a hit, so the Freya looks like a good choice to go w/ my X-150, Schiit Gumby. Been using the Ragnarok as a line stage, so the Freya will be a step up.

In terms of Schiit, like to see them make an amp that runs class A up to 25 watts, and A/B up to 100+. The Vidar (in mono) and Ragnarok do not handle loads under 4 ohms.

In terms of tubes.  I like them in pre-amps (ARC SP-15 onward) but never could stomach tube amps - even very expensive ones in the bass, and retubing cost?  My lord...
teo_audio
2,197 posts
 
you can always spend a bit fixing up the pro 10mc, refreshing its capacitors with newer higher spec ones (minimally...all the old electrolytics have to go)..and then look at changing the opamps in it to higher spec newer designs.

this is the least expensive ticket with the highest return, in your current scenario.
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.
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