What Makes a Good RIAA or Line Stage?


Hi Doug,

In a currently running thread on a certain RIAA / Line stage beginning with the letter "E", some very provocative comments were made that are of a general nature.

I fear that this conversation will be lost on the many individuals who have soured on the direction which that particular thread has taken. For the purpose of future searches of this archive, those interested in the "E" thread can click this link.

For the rest of us who are interested in some of the meta concepts involved in RIAA and Line Level circuits, I've kicked this thread off - rather than to hijack that other one. In that thread, you (Doug) mused about the differences between your Alap and Dan's Rhea/Calypso:

... the Alaap has the best power supplies I've heard in any tube preamp. This is (in my admittedly unqualified opinion) a major reason why it outplayed Dan's Rhea/Calypso, which sounded starved at dynamic peaks by comparison.

Knowing only a bit more than you, Doug, I too would bet the farm on Nick's p-s design being "better", but know here that "better" is a very open ended term. I'd love to hear Nick's comments (or Jim Hagerman's - who surfs this forum) on this topic, so I'll instigate a bit with some thoughts of my own. Perhaps we can gain some insight.

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Power supplies are a lot like automobile engines - you have two basic categories:

1. The low revving, high torque variety, characteristic of the American muscle car and espoused by many s-s designers in the world of audio.

2. The high revving, low torque variety characteristic of double overhead cam, 4 valves per cylinder - typically espoused by the single-ended / horn crowd.

Now, just as in autos, each architecture has its own particular advantage, and we truly have a continuum from one extreme to the other..

Large, high-capacitance supplies (category 1) tend to go on forever, but when they run out of gas, it's a sorry sight. Smaller capacitance supplies (category 2) recharge more quickly - being more responsive to musical transients, but will run out of steam during extended, peak demands.

In my humble opinion, your Alap convinced Dan to get out his checkbook in part because of the balance that Nick struck between these two competing goals (an elegant balance), but also because of a design philosophy that actually took music into account.

Too many engineers lose sight of music.

Take this as one man's opinion and nothing more, but when I opened the lid on the dual mono p-s chassis of my friend's Aesthetix Io, my eyes popped out. I could scarcely believe the site of all of those 12AX7 tubes serving as voltage regulators - each one of them having their own 3-pin regulators (e.g. LM317, etc.) to run their filaments.

Please understand that my mention of the Aesthetix is anecdotal, as there are quite a few designs highly regarded designs which embody this approach. It's not my intent to single them out, but is rather a data point in the matrix of my experience.

I was fairly much an electronics design newbie at the time, and I was still piecing my reality together - specifically that design challenges become exponentially more difficult when you introduce too many variables (parts). Another thing I was in the process of learning is that you can over-filter a power supply.

Too much "muscle" in a power supply (as with people), means too little grace, speed, and flexibility.

If I had the skill that Jim Hagerman, Nick Doshi, or John Atwood have, then my design goal would be the athletic equivalent of a Bruce Lee - nimble, lightning quick and unfazed by any musical passage you could throw at it.

In contrast, many of the designs from the big boys remind me of offensive linemen in the National Football League. They do fine with heavy loads, and that's about it.

One has to wonder why someone would complicate matters to such an extent. Surely, they consider the results to be worth it, and many people whom I like and respect consider the results of designs espousing this philosophy of complexity to be an effort that achieves musical goals.

I would be the last person to dictate tastes in hi-fi - other than ask them to focus on the following two considerations:

1. Does this component give me insight into the musical intent of the performer? Does it help me make more "sense" out of things?

2. Will this component help me to enjoy EVERY SINGLE ONE of my recordings, and not just my audiophile recordings?

All other considerations are about sound effects and not music.

Cheers,
Thom @ Galibier
128x128thom_at_galibier_design
Dear Thom: Fortunatelly, like JH told us, there are different " roads " to meet the " border " and the freedom to do it.

Any one has its own " principles and priorities " and music bias in the sound reproduction.

Thom IMHO the best noise is no noise. Now, if we can't dissapear that noise then a good noise is " better " than a bad noise.

We are not " specs/number " lovers per se, but in some way we have to reflect what we are hearing through our designs.
We think that our designs not only have to " sounds great " but to measure great too and if we could achieve both targets that's will be great, don't you think?

I agree with JH about the emotional link with the music through and audio system, with out this interaction between the music and us it does not matters specs or design.
We try hard to have that link in the sound reproduction perception and at the same time to meet very low noise/distortions/colorations and accuracy ( like in the RIAA eq ).

Thom, I know that in theory almost all designers have ( between others ) these targets on mind but when we heard at those designs and when we read the specs I almost always ask me where/why some of them loose those targets. I'm not saying that we are perfects, far from that, but maybe we take care more in deep about simple " things " in the design philosophy, like José told us: the technology is there ready to help us, we only have to use it.

Jcarr: +++++ " The magnitude of RIAA error is not particularly useful unless we also consider the range of frequencies that are affected by the error. in practice, a 1dB deviation that only hits one note is not going to be very noticeable, but a 0.1dB error that spans an octave or more can be quite noticeable. " +++++

I agree with this statement if the RIAA was a line instead than a curve where if one " note /discrete frequency " moves all the adjacents moves too usually more than 2 octaves, we perceive these kind of deviations like a colored sound: these colorations belongs to the audio device but not to the original recording.

I agree with Jcarr about: +++++ " The results of using NFB have a lot more to do with the capabilities and sensibiities of the designer than NFB per se ... " +++++

this is something that José and I discuss several times and the conclusion was the same that Jcarr posted: depend of the designer, where to use, how to use it, how much use it.

Btw, JH and Thom we are not marketing oriented ( we don't manipulate the signal to achieve a " marketing signature " or something ), we are on the audio device design because we like it and because almost all the designs out there can't achieve our goals/priorities in the music sound reproduction in the way we like it, as a fact we design to meet our targets not the consumer ones, we think that through our audio/music experiences, honest on the design, open mind and having the live event like reference we could meet ( or ve near ) the consumer priorities. Maybe we are wrong but it is the way we think.

There is no single parameter that define perse the audio device design, usually all designs have to meet several goals to be " listenable ", how different from others?: that's depends on the designers skills, designers goals and execution of the design in a finish product.

There is no perfect designer/design, we all have limitations of different kind and always have limitations on the quality/tolerances of the parts that we use it: all these parts have limitations and in theory those limitations will be our limitations. Other subject about is the cost/retail price that is a important limitation when we want to share/market the audio device between some price range level.

Regards and enjoy the music.
Raul.
Dear Thom: +++++ " 2. Will this component help me to enjoy EVERY SINGLE ONE of my recordings, and not just my audiophile recordings? " +++++

This is controversial: if the audio device is " colored " and that colorations don't meet your music sound priorities maybe it does not like you even with your audiophile recordings. If those colorations ( faulty ones ) goes with your priorities you will love with all your recordings, this is fine with me but it is not for what I'm looking for.
Certainly I'm looking to enjoy my recordings, enjoy the music sound reproduction but never with " false " colorations/distortions, I can't tolerate this way because my ears/brain tell me that is wrong that it does not " sound " in that way in a live event ( of course that we are too far from the live event ).

The music perception is totally a subjective event and for this point of view every one have a different opinion and I respect all of those opinions. I'm trying to be nearest to the live event through be truer to the recording on our designs.

Some of us are more tolerant to the noise/distortions than others, I'm not ( and José is less tolerant than me ) and like you posted you are. Two different point of view from two different persons, nothing wrong with that these differences make our day fun.

Regards and enjoy the music.
Raul.
Dear Thom: This is the subject of your thread: +++++ " What Makes a Good RIAA or Line Stage? " +++++

We all already talk about many subjects for a better audio device design and I think that other one is lay-out, two same designs could sound different with different lay-out. Not many people think seriously about but the circuit board layout is of paramount importance for the performance in audio devices.

Regards and enjoy the music.
Raul.
Hi Raul,

Yes, layout is indeed important. Jim Hagerman is too modest to admit it in this thread, but he put enormous amounts of work into the layout of the Trumpet. I recall him mentioning that he went through some 14 major architectural layout changes.

In order to get the best performance out of a single chassis design, he kept returning to the two tiered layout. Yes, grounding schemes and general layout plays a big part the final product - especially one so sensitive to noise as an RIAA stage.

We're all coming from a perspective that all of the components under consideration are at a very high level of resolution - that we're all after a design that will give us as much resolution we can get. I'm debating those special components which make it past the final cut if you will, and "fun factor" has to be a major acceptance criterion. Anyone who tells you otherwise is either lying or is a tortured soul.

Surely, once you've peeled away layers of distortion, input overload and such, you can never tolerate these flaws in a component. As I've written on several occasions, a poorly designed RIAA stage can overload and sound uncannily like tracing distortion. Nobody wants this, and yet there is a surprisingly large number of highly regarded components which exhibit this and other design flaws.

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This thread is taking a philosophical turn, but I think that's o.k. because it gives us insight into the whole person - be it the designer or the end user.

I always look at any design as a manifestation of the designer's personality. I've known a couple of audio designers who could be characterized as having obsessive compulsive disorder. Their designs were equally dysfunctional. In spite of their painstaking attention to detail, their end product was as flawed as their personalities were.

I am not arguing for being sloppy and careless in stating the above. Please do not misinterpret this as being the case.

I have to "out" you on this whole "false colorations" thing however. Your "it has to be perfect" mantra is really tiring me out. You are beginning to sound like one of those Audio Puritans.

Given a choice of a "correct" design (whatever the heck that is) which doesn't allow me to enjoy 30% of my record collection and a "flawed", colored design which allows me to pull out ANY record in my shelf without having to ask if its sonics are "worth" putting on my record player, I'll take the latter in a heartbeat.

I can't begin to count the number of components I've owned which took all of the fun out of hi-fi because they were "accurate".

I'm sorry, Raul but as good as the Essential is, it is as colored as many of the other fine RIAA/line stages I rank in the top tier (and the Essential is a fine piece). Please get over it and realize that no one can be all things to all people.

Is the very fine Essential is more harmonically correct than many of the other fabulous components out there? Absolutely not. The Essential to my ears is very much an Avery Fischer Hall type of component - a very lean and modern sound. Other fine units we've discussed in various threads cover other parts of the sonic spectrum - ranging towards pre-renovation Carnegie hall, for example.

Which one is correct? Both are correct and neither is. At some point, one is forced to choose, and here's where the "fun factor" helps to break the tie.

I'm coming down on you hard, because in your writing, you are portraying yourself as being 180 degrees apart from my sense of you and your goals after our fun day together two weeks ago. I think you are more in the "audio fun" camp than you prefer to admit in public. This may be a language thing, but consider yourself "outed". Please don't redouble your efforts to prove me wrong. Resistance is futile.

Close your eyes, take a deep breath, and let your hair down. You'll feel better. I promise you.

Regarding Audio Puritans, I will go so far as to discourage perspective Galibier customers from buying one of my turntables if they give me so much as a hint that they are Audio Puritans. Life is too short to work with someone whose sonic goals are that different from mine. I would prefer that they purchase a mainstream turntable and let me spend a weekend climbing a cliff or going skiing.

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About marketing ...
"The lady doth protest too much, methinks"
You don't need to tell me that your work came out of passion, because as I mentioned earlier, none of us are buying 40 foot sailboats from our income in audio. All of us are about passion, and I applaud yours and Jose's efforts, because you have achieved something very special. Is it better than everything else out there? Absolutely not. Let's not create a mythology here. This is what I object to.

We need to return to the subject of this thread. I'm getting tired of this.

Cheers,
Thom @ Galibier
Jose, or anyone else, have you correlated RIAA error to colorations? As in, error of x amount or of y type leads to a z coloration.

Dan, in my experience the term "coloration" involves 2 facets:

On one hand you have a measurable deviation of flat frequency response of X dB, sustained over Y Hertz of bandwidth, which will cause an identifiable sound similar to that produced by the bands of an equalizer. ABX tests have been conducted showing that the audibility threshold is lower as the bandwidth of the deviation is increased. This simply means that we are more sensible to this error when it spans several octaves. RIAA stages are particularly vulnerable to this kind of coloration, simply because the RIAA curve is made up of 3 turnover frequencies affecting big portions of the audible band.

On the other hand, coloration is also a characteristic sound caused by a circuit's more intrinsic factors that can't readily be measured with conventional frequency-domain analysis. Nevertheless it manifests itself as a "fingerprint" in the sound (punching bass for instance). This type of coloration, at times enjoyable, will reveal itself more with the passing of time. This is mainly the reason why ABX kind of tests commonly reveal the first type of coloration, but fail with the second.

Enjoyable or not, decreasing coloration is a good thing in order to preclude our ear from extrapolating the musical signal into a predictable sound.