Zero Distortion: Stacked Quad 57s

bonzo75

Member Sponsor
Feb 26, 2014
22,587
13,610
2,710
London
A report from visiting a guy on my last US trip, after Rhapsody, who had stacked Quads with various Slagle electronics and amps and Allnic 5000.


 

bonzo75

Member Sponsor
Feb 26, 2014
22,587
13,610
2,710
London
Love the EMIA gear. Were you able to discern the contribution of the plasma tweeters to the system performance?

No I couldn’t isolate the various parts of his system
 

Kingrex

Well-Known Member
Feb 3, 2019
2,890
2,382
350
A static picture to zoom around on would be nice. Can't see much on my phone otherwise.

Was it home built speaker boxes?
Crossover?
How many amps of what type?
 

bonzo75

Member Sponsor
Feb 26, 2014
22,587
13,610
2,710
London
A static picture to zoom around on would be nice. Can't see much on my phone otherwise.

Was it home built speaker boxes?
Crossover?
How many amps of what type?

it’s mentioned there, triamped and who built it
 

jeff1225

Well-Known Member
Jan 29, 2012
3,013
3,265
1,410
51
Great write up of a very unique system. I see an Edgar seismic sub, is it hooked up? That sub supplied the best bass I've ever heard.
 

Audiohertz2

Well-Known Member
Jun 8, 2023
556
309
70
After seeing and listening to many many variations of stacked 57’s over the decades this one is unique for sure ..!


Regards
 
  • Like
Reactions: bonzo75

bonzo75

Member Sponsor
Feb 26, 2014
22,587
13,610
2,710
London
Great write up of a very unique system. I see an Edgar seismic sub, is it hooked up? That sub supplied the best bass I've ever heard.

yes it is hooked up
 

Audiohertz2

Well-Known Member
Jun 8, 2023
556
309
70
BTW,

Once you introduce an EQ into the system and better , EQ changes to each track played all bets are off as its impossible to be a better match than in a strict no adjustment setup.

Regards
 

bonzo75

Member Sponsor
Feb 26, 2014
22,587
13,610
2,710
London
BTW,

Once you introduce an EQ into the system and better , EQ changes to each track played all bets are off as its impossible to be a better match than in a strict no adjustment setup.

Regards

yes why I said I would like to listen to it without EQ as well
 

dave slagle

Well-Known Member
Apr 9, 2020
57
154
105
myemia.com
A static picture to zoom around on would be nice. Can't see much on my phone otherwise.

Was it home built speaker boxes?
Crossover?
How many amps of what type?
Hey,

JP is fighting the registration spam-bots so until he can respond and I will handle many of the technical questions in the meantime.

The speaker cabinets are made by a craftsman in Maryland to this specific project.

In the original '57 design a single amplifier drives an input transformer that steps the signal up to feed a high impedance passive crossover which directs the music to the appropriate panels.

JP's 57's use a line level crossover integrated into a pair of push pull 300B amps loaded with step-up transformers tailored to the panel frequency response. JP has added some additional subtle crossover shaping to the panels directly. One key aspect is the dual 300B amps reside in the base of the speaker to avoid the need to step down the voltage to drive speaker cables to then step it back up to drive the panels. In a typical situation the output of a 300B will see a 25:1 step-down to get to 'traditional' speaker level. This is then stepped back up by a factor of 70 for the highs and 280 for the bass to drive the electrostatic panels. This instance has a pair of 300Bs feeding a 1:2 output transformer to drive the HF panels and a second pair feeding a 1:8 to drive the bass panels. Screen Shot 2023-12-30 at 2.57.53 PM.jpg Screen Shot 2023-12-30 at 3.00.55 PM.jpg

dave
 

dave slagle

Well-Known Member
Apr 9, 2020
57
154
105
myemia.com
Love the EMIA gear. Were you able to discern the contribution of the plasma tweeters to the system performance?
The plasma tweeter adds a significant amount of air and ambiance to the overall setup.

dave
 

dave slagle

Well-Known Member
Apr 9, 2020
57
154
105
myemia.com
BTW,

Once you introduce an EQ into the system and better , EQ changes to each track played all bets are off as its impossible to be a better match than in a strict no adjustment setup.

Regards
This becomes a very slippery slope and ultimately comes down to what you are trying to achieve. If the goal is replication of some mythical straight wire with gain then I agree with your premise. However; if the goal is creating the most enjoyable individual listening experience then it can be argued that every piece in the chain is a tone control and we are all simply twiddling EQ knobs with each and every equipment swap.

dave
 

Carlos269

Well-Known Member
Mar 21, 2012
1,556
1,223
1,215
BTW,

Once you introduce an EQ into the system and better , EQ changes to each track played all bets are off as its impossible to be a better match than in a strict no adjustment setup.

Regards
yes why I said I would like to listen to it without EQ as well

No need to be afraid of well designed and executed equalizers. Crossovers, both active and passive, are fixed filters while equalizers are adjustable filters but they are both filters so if you are going to take aim at the use of equalizers you need to understand that response shaping is already taking place in the crossover. No need to fear equalizers or think of them differently than crossovers. The crossovers allowed the designers to “voice” the speakers and equalizers allow the end-user to “voice” the system in the most basic of ways. There are far more advance and effective ways to tailor the sound of a system than with an equalizer but at least equalizers are sound sculpting tools, even with their limitations.
 
Last edited:
  • Like
Reactions: jeff1225

Lagonda

VIP/Donor
Feb 3, 2014
3,484
4,771
1,255
Denmark
Hey,

JP is fighting the registration spam-bots so until he can respond and I will handle many of the technical questions in the meantime.

The speaker cabinets are made by a craftsman in Maryland to this specific project.

In the original '57 design a single amplifier drives an input transformer that steps the signal up to feed a high impedance passive crossover which directs the music to the appropriate panels.

JP's 57's use a line level crossover integrated into a pair of push pull 300B amps loaded with step-up transformers tailored to the panel frequency response. JP has added some additional subtle crossover shaping to the panels directly. One key aspect is the dual 300B amps reside in the base of the speaker to avoid the need to step down the voltage to drive speaker cables to then step it back up to drive the panels. In a typical situation the output of a 300B will see a 25:1 step-down to get to 'traditional' speaker level. This is then stepped back up by a factor of 70 for the highs and 280 for the bass to drive the electrostatic panels. This instance has a pair of 300Bs feeding a 1:2 output transformer to drive the HF panels and a second pair feeding a 1:8 to drive the bass panels. View attachment 122529 View attachment 122530

dave
Very cool setup! :)
 

Carlos269

Well-Known Member
Mar 21, 2012
1,556
1,223
1,215
The plasma tweeter adds a significant amount of air and ambiance to the overall setup.

dave
Dave,
Did Bonzo report it accurately that you bypassed the use of the Acapella ION TW-S1 plasma super-tweeters’ internal PL-519 tube amplifiers in favor of your push-pull 300B to drive the modulator? Or are you simply just taking the high-level signal of the 300B amplifiers to drive the Acapella plasma tweeters’ internal PL-519 tube amplifiers?

I also cross my Acapella ION TW-1S plasma super-tweeters at 8.5KHz. I had the internal crossover upgraded in my units. The plasma super-tweeters add a lot to the sound and that is clearly evident when you switch them off.
 
  • Like
Reactions: JohnP and jeff1225

Carlos269

Well-Known Member
Mar 21, 2012
1,556
1,223
1,215
This becomes a very slippery slope and ultimately comes down to what you are trying to achieve. If the goal is replication of some mythical straight wire with gain then I agree with your premise. However; if the goal is creating the most enjoyable individual listening experience then it can be argued that every piece in the chain is a tone control and we are all simply twiddling EQ knobs with each and every equipment swap.

dave

Well said. It’s funny how audiophiles view equalizers as the bogeyman while they crudely attempt to accomplish similar objectives by some of the most bizarre ways, with unpredictable or prescriptive results.
 

dave slagle

Well-Known Member
Apr 9, 2020
57
154
105
myemia.com
Or are you simply just taking the high-level signal of the 300B amplifiers to drive the Acapella plasma tweeters’ internal PL-519 tube amplifiers?
the line level signal that drives the quad amps also drives a permalloy 50 amp that drives the speaker level inputs of the plasma.
 
  • Like
Reactions: Carlos269

DasguteOhr

Well-Known Member
Sep 26, 2013
2,406
2,572
645
Germany
Dave,
Did Bonzo report it accurately that you bypassed the use of the Acapella ION TW-S1 plasma super-tweeters’ internal PL-519 tube amplifiers in favor of your push-pull 300B to drive the modulator? Or are you simply just taking the high-level signal of the 300B amplifiers to drive the Acapella plasma tweeters’ internal PL-519 tube amplifiers?

I also cross my Acapella ION TW-1S plasma super-tweeters at 8.5KHz. I had the internal crossover upgraded in my units. The plasma super-tweeters add a lot to the sound and that is clearly evident when you switch them off.
Check out this site.
This guy upgrade plasmatweeter, important for the frequency is the quarzcell diameter bigger they work from 2.5khz as full tweeter in two way design. Only for infomation if you interested
 
  • Like
Reactions: Carlos269

Carlos269

Well-Known Member
Mar 21, 2012
1,556
1,223
1,215
Check out this site.
This guy upgrade plasmatweeter, important for the frequency is the quarzcell diameter bigger they work from 2.5khz as full tweeter in two way design. Only for infomation if you interested

Great site and one of the best resources on plasma tweeters. Please keep in mind that the lower the crossover point the lower the efficiency of the Acapella plasma tweeter. In order to maximize their efficiency I use them at the highest recommended crossover point of 8.5KHz.
 

About us

  • What’s Best Forum is THE forum for high end audio, product reviews, advice and sharing experiences on the best of everything else. This is THE place where audiophiles and audio companies discuss vintage, contemporary and new audio products, music servers, music streamers, computer audio, digital-to-analog converters, turntables, phono stages, cartridges, reel-to-reel tape machines, speakers, headphones and tube and solid-state amplification. Founded in 2010 What’s Best Forum invites intelligent and courteous people of all interests and backgrounds to describe and discuss the best of everything. From beginners to life-long hobbyists to industry professionals, we enjoy learning about new things and meeting new people, and participating in spirited debates.

Quick Navigation

User Menu

Steve Williams
Site Founder | Site Owner | Administrator
Ron Resnick
Site Co-Owner | Administrator
Julian (The Fixer)
Website Build | Marketing Managersing