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.

----

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
>>Again, your quality sound reproduction targets/priorities are a little different from ours<<

Indeed, and that is the beauty of freedom and liberty. As designers we can choose different paths. The result is that the marketplace is offered more choice.

I do not disagree with your approach. It is sort of what I used to do. However, chasing good numbers sort of limits potential. I am discovering that the only way to reach the next level is to get caught up in the emotion of the music. It is the unmeasurables that begin to matter. Great technical performance is a good start (I would almost say mandatory), but it can also be a trap. And that was the point I wanted to make. Don't get caught in a marketing game where specifications rule.

So in that sense, I am more in the camp of Thom. I can live with a +/-0.75dB RIAA error if the compromise gets me better connected with the musicians and their message. For me, this emotional connection is more important than absolute accuracy.

jh
Yes, the beauty of the marketplace is that we all have choices. I buck strongly when someone tells me that they have achieved sonic perfection and that I am a member of the great unwashed peasantry if I fail to appreciate their brilliance.

Sure, as manufacturers, we're all proud of our achievements. Why else would we make so many financial sacrifices to achieve what we consider to be lofty goals? Trust me - none of the small guys are buying 40 foot sailboats off of their audio income. This should be taken as a given (personal pride), and we as manufacturers shouldn't beat someone over the head with it.

I try to deal with my customers from a point of respect, realizing that there are many reasons for them to prefer another product - from personal taste as far as what a hi-fi system should do in order to bring them enjoyment, to the fact that they may want a piece of gear that is a bit more plug 'n play, to ... well, you get the idea.

So in that sense, I am more in the camp of Thom. I can live with a +/-0.75dB RIAA error if the compromise gets me better connected with the musicians and their message. For me, this emotional connection is more important than absolute accuracy.

I am reminded of an article that JC Morrison wrote in an old issue of Sound Practices. I wish I could find a copy of it on the web to link to. In that essay, Morrison broke the audio world into two camps:

1. The Audio Puritans - folks who would accept anything as long as they were told it was correct. Correctness frequently involved great suffering in the listening experience. No matter ... they are Puritans after all, and have a tradition to uphold.

2. Everyone else. Folks who actually want to have fun with their tunes.

Guess which side I gravitate to?

Cheers,
Thom @ Galibier
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.