Author Topic: Pioneers in audio design  (Read 3199 times)

Offline jimbones

  • Audio Neurotic
  • *****
  • Posts: 1290
  • Two plus Two Speakers
Pioneers in audio design
« on: November 10, 2015, 09:40:08 AM »
OK so I just received December issue of AS and got me thinking of a new thread for discussing pioneers and designers in audio. In the issue are mention of different designers.  I'd like to know more about John Curl. Apparently his work is ground breaking even legendary and i know little about it.  :-s Sonic merits aside, what made his designs so popular?

 
Rogue RP7 Pre, Art Audio Vinyl Reference Phono,CJ Premier 12 Pwr, VPI Classic II/Dynavector 20X2L, Roon Rock, Auralic Vega DAC, Emotiva ERC-3, MIT, TWL, WireWorld, Wywires, Shunyata

Offline rollo

  • Industry Participant
  • *
  • Posts: 6982
  • Rollo Audio - Home demo the only way to know
Re: Pioneers in audio design
« Reply #1 on: November 10, 2015, 10:13:00 AM »
  If I remember correctly it ws the Vendetta phono stge tht got everyone's attention. Then his circuits.
  However the sound s you dismiss is the whole enchlada.


charles
contact me  at rollo14@verizon.net or visit us on Facebook
Lamm Industries - Aqua Acoustic, Formula & La Scala DAC- INNUOS  - Rethm - Kuzma - QLN - Audio Hungary Qualiton - Fritz speakers -Gigawatt -Vinnie Rossi,TWL, Swiss Cables, Merason DAC.

Offline jimbones

  • Audio Neurotic
  • *****
  • Posts: 1290
  • Two plus Two Speakers
Re: Pioneers in audio design
« Reply #2 on: November 10, 2015, 10:21:29 AM »
What I meant to say is that we all know it must have had great sonic's to be considered a great design. What made it great besides a general statement that "it sounded great" (low power consumption, better this better that). Be specific.
Rogue RP7 Pre, Art Audio Vinyl Reference Phono,CJ Premier 12 Pwr, VPI Classic II/Dynavector 20X2L, Roon Rock, Auralic Vega DAC, Emotiva ERC-3, MIT, TWL, WireWorld, Wywires, Shunyata

Offline rollo

  • Industry Participant
  • *
  • Posts: 6982
  • Rollo Audio - Home demo the only way to know
Re: Pioneers in audio design
« Reply #3 on: November 10, 2015, 10:33:04 AM »
  Not a techie so no knowledge.

charles
contact me  at rollo14@verizon.net or visit us on Facebook
Lamm Industries - Aqua Acoustic, Formula & La Scala DAC- INNUOS  - Rethm - Kuzma - QLN - Audio Hungary Qualiton - Fritz speakers -Gigawatt -Vinnie Rossi,TWL, Swiss Cables, Merason DAC.

Offline jimbones

  • Audio Neurotic
  • *****
  • Posts: 1290
  • Two plus Two Speakers
Re: Pioneers in audio design
« Reply #4 on: November 10, 2015, 11:21:51 AM »
http://www.gspr.com/parasound/jc_6_points.html

So here are some of his philosophies that made his designs unique for the time.



1. Balanced Complementary Topology

Solid state amplifier designs have a certain amount of distortion generated by each active part. If the parts can be used in push-pull or in differential mode, then much of the inherent distortion can be canceled as it is being generated.

2. FET's Where Possible

FET's are inherently more linear than bipolar transistors. FET's have a voltage gain that is proportional to the square root of the current in the FET. Bipolar transistors have a voltage gain that is directly proportional to the current in the transistor. FET's are more linear over a greater current range.

3. No Signal Capacitors

Removing any need for input, output, or feedback capacitors, removes a potential distortion source, and can lower cost as well.

4. Class A When Possible

All else being equal, Class A is better. It has lower overall distortion, and the higher harmonics are reduced significantly.

5. Quality Parts

We have researched the potential problems with passive parts. Most passive parts have some measurable distortion. Some distortion mechanisms are subtle and are difficult to measure, but are detected in listening tests.

6. Regulated Driver Stages

The output stage can demand a great deal from a power supply. It is impractical to make a virtually perfect power supply in a cost effective product. We regulate the driver supplies to remove any potential distortion in the drivers, when the output stage makes a strong demand on the power supply.

 

My hope is that we can add discussion of designers to the thread to keep it going.
« Last Edit: November 10, 2015, 11:55:47 AM by jimbones »
Rogue RP7 Pre, Art Audio Vinyl Reference Phono,CJ Premier 12 Pwr, VPI Classic II/Dynavector 20X2L, Roon Rock, Auralic Vega DAC, Emotiva ERC-3, MIT, TWL, WireWorld, Wywires, Shunyata

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Re: Pioneers in audio design
« Reply #5 on: November 10, 2015, 11:27:30 AM »
Vendetta reviews:
http://www.tonepublications.com/analogaholic/the-vendetta-scp-2-phono-stage/

http://www.stereophile.com/phonopreamps/640/

http://www.analogplanet.com/content/parasound-halo-jc-3-phono-preamplifier


Biography
The John Curl on wikipedia is not our John Curl... but here's some biographical sketches

http://avmax.tech2.in.com/features/science-and-technology/designer-profile-john-curl-parasound/928464

http://www.cnet.com/news/former-rock-engineer-designs-fab-high-end-audio-gear/

Technical discussion with Parasound president:
https://www.youtube.com/watch?v=fZwS-oyqc3w


From pinkfishmedia.net forum topic about "The Best Audio Engineers,"
http://www.pinkfishmedia.net/forum/archive/index.php/t-27155.html
2006, posted by Howard Popeck:

"John Curl.

Engineer. Designer of the Mark Levinson ML2 and JC1-AC, that's maybe why the JC1 is called JC1 :) Tom Colangelo modified John's designed, so the names changed from JC to ML1. John Curl designed for Levinson, Dennisen, Parasound & others. Take a look at his bio.

http://www.marklev.com/history/CURL_BIO.jpg

He owns the US patent US4035737: Low noise amplifier

Now at Parasound.

He was the man that Bob (now Robert) Stuart told me in 1976 was one of the few audio engineers that he true admired and respected."
« Last Edit: November 10, 2015, 11:30:09 AM by richidoo »