Planar Speaker Asylum

Welcome! Need support, you got it. Or share your ideas and experiences.

Return to Planar Speaker Asylum

Message Sort: Post Order or Asylum Reverse Threaded

Acoustat New Desigh Interface

64.7.42.221
Posted on January 10, 2025 at 17:12:55
blgtrio
Audiophile

Posts: 124
Location: Maryland
Joined: May 17, 2007


Mike Burgert, who is Roy Esposito's successor doing restoration work on Acoustats, has come up with a new MK-121C interface design. Some photos of his work are shown. If you are interested, go to the Acoustat group on Facebook to find out more.

https://www.facebook.com/groups/167493963322951

Scroll down to where it reads "Coleen Schwartz is with Mike Burgert"

 

Hide full thread outline!
    ...
RE: Acoustat New Desigh Interface, posted on January 10, 2025 at 17:46:58
E-Stat
Audiophile

Posts: 39933
Joined: May 12, 2000
Contributor
  Since: April 5, 2002
 Seems Colette's version has a new rotary HF control that she sets (curiously) at the eight o' clock position. Even Mike asked about that. Definitely has a different diode bridge section on top.

My Esposito modified interface includes his "air mod" where the rheostat is replaced by a fixed resistor. That's where I find it sounds the best.

 

RE: Acoustat New Desigh Interface, posted on January 11, 2025 at 08:13:36
mraudio
Audiophile

Posts: 489
Location: Northern Colorado
Joined: November 4, 2006
 Thanks for the post! I never have and never will be on Facebook. Is there any other place to get info on these?

Thanks!

 

RE: Acoustat New Desigh Interface, posted on January 11, 2025 at 08:42:42
blgtrio
Audiophile

Posts: 124
Location: Maryland
Joined: May 17, 2007
 FB is the only place I know of where Mike Burgert (Roy Esposito's successor) posts his Acoustat mods and updates.

 

RE: Acoustat New Desigh Interface, posted on January 12, 2025 at 12:06:56
InfinityApogee
Audiophile

Posts: 240
Location: Sk
Joined: February 14, 2014
 I would like to have them in my 2+2 :)

 

RE: Acoustat New Desigh Interface, posted on January 12, 2025 at 18:23:15
Sondek
Audiophile

Posts: 10134
Location: Fort Worth
Joined: May 17, 2000
Contributor
  Since: April 5, 2002
 Still got your servos, or considering another change?

Interesting looking work, these new interfaces. Glad to see some new approaches. Wonder how they sound?

 

RE: Acoustat New Desigh Interface, posted on January 14, 2025 at 12:46:51
blgtrio
Audiophile

Posts: 124
Location: Maryland
Joined: May 17, 2007






Yes Sir, The servos are performing beautifully. I'm using this Staccato op amp which was recommended by Carl. I hope you are enjoying yours as well.

 

RE: "I never have and never will be on Facebook" ..., posted on January 14, 2025 at 15:20:45
andyr
Manufacturer

Posts: 12635
Location: Melbourne
Joined: September 2, 2000
 Sometimes you have to face your fears head on!

I had the same attitude towards FB ... but then I had to join an LP12 group, as one of my customers on it was raving about his latest acquisition. :-))

 

RE: Acoustat New Desigh Interface, posted on January 14, 2025 at 18:34:30
Sondek
Audiophile

Posts: 10134
Location: Fort Worth
Joined: May 17, 2000
Contributor
  Since: April 5, 2002
 That's one sweet lookin servo.

Yers are purdier than mine are. Carl does nice work.

 

RE: Acoustat New Desigh Interface, posted on January 17, 2025 at 11:49:54
blgtrio
Audiophile

Posts: 124
Location: Maryland
Joined: May 17, 2007
 Mike, tell me again which op amp you are using in your servos?

 

RE: Acoustat New Desigh Interface, posted on January 17, 2025 at 16:50:06
Sondek
Audiophile

Posts: 10134
Location: Fort Worth
Joined: May 17, 2000
Contributor
  Since: April 5, 2002
 Oldies,but goodies.

The venerable Burr-Brown OPA627.

 

You should really try, posted on January 21, 2025 at 17:13:35
E-Stat
Audiophile

Posts: 39933
Joined: May 12, 2000
Contributor
  Since: April 5, 2002
 discretes from Sparkos or Burson Labs.

 

RE: You should really try, posted on January 22, 2025 at 16:44:36
Sondek
Audiophile

Posts: 10134
Location: Fort Worth
Joined: May 17, 2000
Contributor
  Since: April 5, 2002
 I've discussed using those very opamps with my amp builder.

Seems it's not possible without a substantial rebuild of the amps to utilize them. The input socket would need to be rebuilt to accept newer discretes.

Not impossible, but lot of work and expense.

 

Question, posted on January 22, 2025 at 16:52:01
E-Stat
Audiophile

Posts: 39933
Joined: May 12, 2000
Contributor
  Since: April 5, 2002
 which package type for the OPA627 is used?

If the TO-99 case was used, that makes sense. Most discretes are direct replacements for a wide range of chip based op amps using the common 8 pin dip package.

 

RE: Question, posted on January 22, 2025 at 16:58:30
Sondek
Audiophile

Posts: 10134
Location: Fort Worth
Joined: May 17, 2000
Contributor
  Since: April 5, 2002



That's what I got.



 

Yep, TO-99 case, posted on January 22, 2025 at 17:06:39
E-Stat
Audiophile

Posts: 39933
Joined: May 12, 2000
Contributor
  Since: April 5, 2002
 not found much today. The LM-301s found in my PAT-5 from the mid 70s used the same package.

When I replaced OPA-2134s/2604s in a Music Hall DAC, it was a quick swap using socketed DIP8.




 

RE: Yep, TO-99 case, posted on January 22, 2025 at 17:09:43
Sondek
Audiophile

Posts: 10134
Location: Fort Worth
Joined: May 17, 2000
Contributor
  Since: April 5, 2002
 Same experience for me when I ditched the stock opamps in my Fosi gear and replaced with Sparkos.

Five minute job even getting the casework open and shut.

 

Page processed in 0.031 seconds.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2025, Audio Asylum, all rights reserved ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]