2. analog
  3. 194727-369

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
pindac's avatar
pindac
3,105 posts
 

Extracts are about Phonostages Produced in the late 60's and up to the mid 70's

Spec quotation from Mid 70's  

 " distortion was lower than the residual distortion of the test equipment, so for the development of this model it was necessary to start using a computer-controlled audio analyzer capable of analyzing harmonic distortion to a 0.00005% order, and with this equipment the total harmonic distortion measured from the phono (MM) input to the Record Out terminals (20Hz — 20Khz, total from second to tenth order) and shown in the specifications was an astonishing 0.0007%. "

A Spec from the 1960's 

( 30 Hz to 15 kHz (± 0.3 dB deviation from RIAA curve)

The same Brand from the early 70's

Phono: 74 db (Sensitivity 3 mv)
70 db (Sensitivity 1 mv)

 Phono : within ± 0.3 dB of the RIAA standard curve

 

Different Brand from the later 70's

RIAA deviation 20 Hz to 20 kHz ± 0.2 dB
Signal-to-noise ratio (IHF-A network) Phono:88dB

 

pindac's avatar
pindac
3,105 posts
 

The Link has a timeline for evolving products becoming available for Analogue Replays both pre/post RIAA.

It could be read as when the evolving Transducer was ready for a Teacher, the evolving Phon' appeared and Vice-Versa.

I'm sure those who have a knowledge of how a circuit works and are not historians, will see the earliest versions of circuitry that may be a favourite. 

https://www.darlingtonlabs.com/audio-history/blog-post-title-two-3nr8k

jhills
622 posts
 

@dover 

Not sure where you're going with your comment, buddy.

Never got anything audio or audio info from Sears or Wall Green.

Keep your assumptions to yourself hotdog. 

jhills
622 posts
 

I don't dispute that there were some very good MC cartridges back in the 70s and 80s I had a medium output MC Audio Quest cartridge in1983 that cost nearly $1,300. It worked just fine through the phono stage on my Audible Illusions pre. The few Audio Philes that I knew, using a low output MC cartridge, as mentioned by lewm, used a rather inexpensive gain, not an expensive, dedicated phono stage.  

 

pani OP
1,232 posts
 

Let me make the OP more direct. Suggest 3 phonostages built in the golden era (1950 - 1985) which would do justice to a $30k turntable with a $5k cartridge (assuming appropriate Tonearm) today

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