Feedback Is An Artist’s Best Friend

Chefs, filmmakers and audio circuit engineers all share one interesting habit in common. It’s ubiquitous in all of their methods, the timing is predictable, and you can catch it if you’re paying attention.

In each of these artistic fields, a mountain of work precedes the final result. And, in each field, the final result — the audience’s honest reactions to the finished work — means absolutely everything to the creators. 

As the experience they’ve prepared is laid out, a laser focus comes over them. They watch. They listen. A chef stares down every hint of an expression as you devour the creation. A film director lives for honest tears. An audio circuit designer hangs on your every word as you describe sonic epiphanies.

Feedback, and that need for the artist to see the experience unfold in another person is what I’m talking about today. A couple of weeks ago, my best audio buddy and analog engineer at PS Audio, Darren Myers, asked me to come over to the house and listen to his nearly-finished phono stage for PS Audio’s Stellar line.

Some may know Darren as the designer of two of PS’ best-selling and most dependable products, the Stellar M700 and S300 amplifiers. Fewer folks know he was the lead engineer on the new Sprout100, personally designing the filters in the digital stage, and that he brought in new ideas implemented in the current PowerPlant line of “regenerators” from PS.

Nowadays, he is leading or involved in a hefty number of projects, but the current one is his alone, and he hopes it will be a statement piece and a benchmark for himself as a designer. It’s a phono stage — the hardest amplification circuit to build well — for PS Audio’s lower-priced Stellar line.

PS Audio M700 Monoblock Amplifier

Phono stages are known as some the most difficult circuits to design in amplification because of the gobs of gain that is required to turn a minuscule cartridge signal, something like .3 millivolts (yes, that’s right, just 3/10,000ths of a volt), into a respectable line source looking for 2 volts.

Amplification tends to make noise, if you hadn’t heard. Whereas normal amplifiers add 30dB or so to the sound, music from a record sees gain of 60 dB or more — 90 total, after the amp — so the goal has to be to keep the self-generated noise of the phono preamplifier down to an absolute minimum. This one Darren has made can swing 30 volts (!) on the output, and has noise levels rivaling the Audio Precision test equipment it’s measured with. Intriguing, to say the least.

He asked me to come over to listen to a change he had made in his new phono stage. I’d heard all about this ambitious project for the better part of a year: that it is a discrete version of one of the finest op-amps ever made, with his own additions; that it thrives without much magic-robbing feedback; that it has a chance to be special, and it is certainly unique.

The system that Darren and I trust the most right now is one that he developed over the last year or so, and we’ve both grown very used to it. The anchor to this system is, of course, a pair of REL subwoofers. We’ve heard quite a number of subwoofers between the two of us, and we both prefer the musicality of REL subs. When we’re listening critically, we like speakers to share the same traits as the RELs — honest, linear, and engaging. Similar to the transient response and transparency of panel speakers, but without the drawbacks and lack of dynamics. 

In general, he likes them placed just inside the arc of the speakers, which are usually on stands. Sitting on top of the subwoofers, on IsoAcoustics stands, lifted to listening height with books were the Harbeth P3ESRs. 

Local brews in hand, he fired up the turntable on the massive plinth overlooking the rest of the rack, and he put on a pristine pressing of Roxy Music’s Avalon. Immediately, our conversation quieted and we were both simply taken out by the musical experience. Just smacked in the face by this overwhelming connection to the music, with no thoughts or comments about the sound for quite some time.

Eventually we did touch on the sound during breaks between records, but in general, the sound quality as a discussion topic was greatly overshadowed by the amount of fun we were having, and my insistent chatter about all the recording things I was catching. I was trying to guess which parts were overdubs, catch background singers going flat or describing the environment around the mics. Or, picking out when two parts were recorded in booths versus the parts that were playing in the same room together. 

Listening to Gary Burton’s Matchbook was another revelation, and an excellent test for someone like me who believes deeply in the capabilities of digital, and who is also a big fan of Gary’s. I’ve heard many of his recordings on state-of-the-art digital equipment, and it would be hard to beat some of these audio memories. I think of him as one of those guys who always sought out excellent production and made recordings you might consider excellent at any stage of the game. Matchbook was recorded in 1975, presumably to tape. To hear that kind of meat on the bone in a vibraphone recording from 1975 was my revelation.

Again — am I talking about the phono stage? No! So was the ‘stage doing an incredible job? YES! If there was a problem at all with the sound, we would have focused on it right away. But no – we just heard music that day, pure and simple. This thing was ready.

It’s always a memorable audio experience for me when I visit Darren’s place, but this being the culmination of so much thinking, tinkering and sweating by my friend, all based on something of a leap in terms of approach, made it special. That he’s trying something in this design that nobody’s done before, in the hopes that it sounds better, makes the result even sweeter. 

I’d say he is very comfortable when it comes to exploring the audio circuit unknown. But even an artist of his caliber needs a bit of good feedback from a trusted source from time to time.

May 29, 2019 - Posted in: Simple Pleasures