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Phono Stage - The great analog tragedy

In the world of analog playback, there is an interesting observation. There has been tremendous innovation in the field of 
Turntable - Direct, Idler, Belt
Cartridge - MM, MC, MI
Tonearm - Gimbal, Unipivot, Linear Tracking

For all of the above designs we find some of the best reference components designed in the 50s, 60s, 70s and 80s. Most of the modern products are inspired from these extraordinary products of the past. But when it comes to phono stage, there is hardly any "reference component" from that era. They just standardized RIAA curve for sanity and left it. Manufacturers made large preamps and amps and allocated a puny 5% space for a small phono circuit even in their reference models, like a necessary evil. They didn’t bother about making it better. 

The result? It came down to the modern designers post 2000 after vinyl resurgence to come up with serious phono stages for high end systems. Unfortunately they don’t have any past reference grade designs to copy or get inspired from. Effectively, just like DACs, reference phono stages is also an evolving concept, and we don’t have too many choices when we want a really good one which is high-res and natural sounding. Very few in the world have figured out a proper high end design so far. And most of the decent ones have been designed in the past couple of decades. The best of the breed are probably yet to come.  

It is a tragedy that our legendary audio engineers from the golden era didn’t focus on the most sensitive and impactful component, "the phono stage"

pani
arnieco
8 posts
 

in the 60’s, 70’s analog circuitry was quite common. It was usually discrete components, no IC’s.

Most of the experienced engineers had good knowledge on how to build an amplifier. There was no reference component (IC) that was used. Rather many different designs. The standard to follow were the riaa curves as you noted.

Now, there are many electrical engineers in the US (and likely other countries) that are not experienced in analog circuitry, as it simply isn’t common.

 

lewm
13,777 posts
 

Arnieco, your thesis is the opposite of Pani's.

Any phono stage requires lots of gain, more than any other audio component, and a filter that conforms to the RIAA standard de-emphasis curve.  Except for tubes, today's parts (discrete transistors, ICs, capacitors, resistors, inductors, diodes, etc) are simply superior to even the very best available 50 years ago. Furthermore, the RIAA standard has not changed since the 50s, and there are only so many ways you can build that filter into a phono gain stage. In fact, there are on line calculators that would allow anyone to build an RIAA network any of several ways. The designer does not even have to be a genius. So it stands to reason that today's electronics can be superior to anything available 50 years ago, if the manufacturer cares enough.  But likewise I think the old gear can be modernized using the superior parts now available. So there is no real issue or certainly no tragedy.

louminati
1 posts
 

I'm not sure whether it qualifies as a "reference" component or technology (and who is even qualified to make that judgement), but I will forever be a fan of my strain gauge setup. The strain gauge cartridge does not use or require an RIAA playback filter and represents a radical departure from the standard MM/MC setups.  It's magic to my ears and I wish there were more modern options for them, but I suppose I'm fine as long as my old equipment keeps on trucking.  Cheers!

lewm
13,777 posts
 

I have no dog in the fight, but some would argue that it takes some circuitry to make playback using a strain gauge conform to the RIAA pre-emphasis that is built into every LP during the production process.  In other words, without some filtering the strain gauge output won't conform closely to RIAA. Whether you can hear that error or not is a matter for dispute.

larryi
4,350 posts
 

Strain gauge cartridge output is dependent on the amplitude of the movement of the stylus while most other cartridges have output dependent of the velocity of the stylus movement.  Amplitude sensitive cartridges can sort of get away with no equalization--the frequency response curve will not be perfect, but it is, arguably good enough.  SoundSmith originally went with no equalization with their cartridge, but relented when the market complained about this approach.

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