What Makes a Good RIAA or Line Stage?

Dear Thom: Ok, its done.

Ralph bring here a critical point in the phono stage: high overload, and not only is a good thing but a necessity.

We found that with increment on the overload we can have lower distortion and better quality performance all over the frequency range.

" that often bad recordings will reveal that more than good ones! ", IMHO both could tell us a lot of the performance designs: in a good designs the bad ones will sound " less bad " and the good ones a lot better, the average sound will be " good sound ". In a " bad dsign " the bad recordings will sound unlistenable and the good recordings only " ok ". At least that's what we experienced about, others could have different experiences.

A good design is the sum/add-up of many subjects and the right synergy between them: an accurate RIAA eq per se means nothing if it not coming along: low distortion, low noise, high gain, high overload, high common mode rejection, right lay out, precise ground planes/star grounding, wide bandwidth, low output impedance, right output attenuator/volume control ( by the way this subject is the Aquiles heel in many designs. ), linearity, execution/build design, etc, etc. and many other parameters that you already posted about.

The challenge is to link all those parameters when some of them " fight " one against " other " or when we have to fight with non-linearities or high order harmonics like in the bipolar design that we are using.
Here it is when we have to use not only the technology that we can reach but the experience, know-how and skills that every single designer has and that is different form each other, that's why exist several differences/approach on the Phonolinepreamp designs, some ones better than others or simple differents.

Obviously that any single of us could think that our design is the best one and many of us could think that we can prove it. We think that our design is different.

Regards and enjoy the music.
Raul.

Hi Ralph, Jonathan, Raul ...

Back to our regularly scheduled programming. This is good stuff ! I need to take it in small chunks.

This concept of immunity from input overload is a critical one. Listen up to these wise folks folks.

If you're scratching your head and wondering if you screwed up your tonearm setup (or if your cartridge is unable to track a passage), try borrowing another RIAA stage ... hopefully one which is known to be both immune to input overload as well has having a lightning fast slew rate (the ability to respond quickly to transients without overshoot).

If you're not practiced at listening for this, you may well assume you have a mechanical issue to resolve (cartridge or tonearm setup) when the real problem may be with your electronics. Don't beat yourselves up about your setup skills until you validate what you're really hearing.

Cheers,
Thom @ Galibier

A quick note on riaa fm practical experience only. The necessities: Overload margin, stabilised power, fully corrected and stabilised curve, channel identicity. The last two are more than just difficult -- they're horrendously painstaking, boring (think of "trimming" to get the "right" R -- and once you get there, you realise that your next pole is off...), and expensive: anyone ever try to really "match" components? -- and I don't mean those that do this for a living... Goodness! Trying to match the 1st stage loading before riaa was a trial... let alone further up.

This is only fm a small experience trying to make my own phono as, the ones I could afford were miserable and the ones I wanted were out of reach financially.:)

Dear Jcarr: +++++ " Many instruments have very different tonal balances depending on the angle and distance that you listen to them from, and you need to physically put your ears where the microphones are to verify whether what you think you should be getting is really what is inscribed on the LP or not (and don't forget that mikes have different frequency responses from our ears). I am fortunate enough to have friends who are recording engineers and have allowed me to sit by the microphones (sometimes on a ladder!), tap into the mike feed, go back to a normal seat in the audience, listen to the analog tape master on the same day, and then a few days later, listen to the lacquer masters. Very, very educational. I encourage you to search out opportunities to experience this. " +++++

This statement/experience is of paramount importance to understand the statement " truer to the recording ".

A week ago ( during my visit to San Diego ) Norm, Tim and I were talking exactly what you posted: that what we have to " hear " is what the micro's " take " and not want to hear what we perceive at our seat in the hall: that's too different, a lot different.
This is an e-mail that I send to those people following on that subject:

+++++ " De: Raúl Iruegas [mailto:silviajulieta@prodigy.net.mx]
Enviado el: Martes, 20 de Febrero de 2007 12:10 a.m.
Para: 'ctm_cra@yahoo.com'
CC: 'timryanbmw@yahoo.com'
Asunto: Essential 3150.
Importancia: Alta

Dear Norm: Our “ hot “ conversation last night was really “ teaching “ for all of us ( I think ).

I would like to share with you some additional thoughts about:

For many years I asked why the sound of my system was more transparent, better soundstage, tonal balance, etc, etc than the sound that I heard at the music hall, after some time suddenly I “ find “ that the recording microphones have a very different “ seat “ position than mine, it is not only that the microphones are nearest to the source ( instruments and instrument “ room “ area ) but in more “ clean “ environment: Tim, you and me normally seated at 6-8 rows ( 20-25 meter ) where the sound that we perceived against the one that goes through the microphones are truly different ( not only by the distance subject ) for the dispersion ( reflections, diffusion, hall time delay, etc, etc, ) through the absorbing/diffusion of the “ hall environment that includes all the people that surround our seat place.

Now, the sound engineer on the recording process always try to choose the best microphone for its quality reproduction that include ( between other subjects ) very wide frequency response ( this depends on what kind of music they would to recording ) and the lesser frequency range deviation from flat: this means ACCURACY. With out this accuracy the sound recording will be more colored and normally the sound engineer does not want to have a “ colored “ sound session. This same sound engineer choose the best monitor speaker he can get and the main subject a bout is a “ whole “ accurate characteristic monitor speaker, not a colored one ( I hope ).

So, the recording must be an accurate one to the live event.

What is the “ critical mission “ that any ( decent ) phono cartridge has? ( TT/tonearm ), well to try to reproduce what is on the recording in the better accurate manner, with the less distortion/noise/colorations.
This signal that comes from the phono cartridge has to pass through the Phonolinepreamp and this audio device has the “ absolute mission “ to reproduce in an accurate way ( yes I know that other subjects about, but please forgot for the moment ) exactly what the cartridge get from the recording that was made through the microphones that were in a different position that our hall seat that is the way that you like to hear in your home.

Norm, I want that you think in deep about not thinking who is right here but using common sense and trying to help the true music reproduction. It is not a fact that what you like or what Tim and I like but what is the “ true “ or near the truer.

This “ truer to the recording “ accuracy approach does not means : analytical, cold, polite, lean, etc, etc sound reproduction, that I´m sure the Essential 3150 does not have, it must be accurate and “ pleasant “ and this is what we have to look when any one heard the Essential 3150. I´m not saying that the Essential 3150 already achieve that goal in a perfect manner but it is very near to that target.

In my humble opinion all the music lovers must support that kind of audio devices design approach because in that manner all of us could help to the music and most important could help to growing up faster the quality reproduction on the high-end audio device performers: any.

Anyway, we really had a great time during my visit.

Kind regards.
Raul. " +++++

Regards and enjoy the music.
Raul.

Raul, this is a different thread. I have just read your same post in your Essential thread. Why do we need two Essential threads. Please give us a break.
Thom attempted to start a new thread exploring some very interesting ideas regarding phono stages in general. Several designers have responded and have made this a great thread for some of us to learn new things about design philosophy. Please, please give it a rest.