Resonance Control -
for finer detail, tighter
imaging and a more
solid tone.
 


Vibrations in the audio range, whether airborne (sound) or structure-borne (sound conducted through equipment stands, etc.) are something that vacuum tube electronics are particularly susceptible to. These vibrations combine with and modulate the audio in your electronic components, and are responsible for blurring of details, smearing of the soundstage, and a reduction of fullness, presence and weight to the sound.
     All electronics, and tube gear in particular, are affected by the sounds in your listening room. The large coupling capacitors and the tubes are microphonic to a surprising degree. Even normal electrolytic capacitors used on solid-state amplifiers, and the circuit board itself are microphonic. Because everything is mounted to a stiff, resonant circuit board that is nothing more than a sounding board, they resonate to every whisper of sound in the room, every vibration carried into the chassis.
     For twenty years I've wanted to do something about this, but never could figure out how to damp the circuit board to eliminate resonances. In the SA-5000 I devised an elaborate suspension system that decouples the circuit board from structure-borne vibrations. Yet the circuit board itself remained undamped and still responds to airborne vibrations (sound).
     What is needed is some kind of damping material that can be applied to the bottom of the circuit board, yet is easily removed if access to the bottom of the board is required for servicing. What would do the trick?
     The solution eluded me until now: a solution so simple and elegant that I feel a little foolish for not having seeing it: Felt. A thick pad of wool felt between the circuit board and the chassis completely damps out all resonances. Completely.

The improvement to the sound is stunningly audible and includes:

  • Increased lateral and depth space between instruments and voices,
  • More detail: sounds which had been smeared over are now clearly audible -- you'll hear things you never heard before,
  • Deeper, fuller tone, with more presence, pace and impact,
  • Instrumental and vocal lines are much easier to follow -- if you're a harmony buff, or like to follow what the piano or bass player is playing, you'll find every note much more hearable,
  • Reduction of fatiguing edginess,
  • More musical, "believeable" sound.

By eliminating the vibration-susceptiblity of the circuit board, the sound of your Counterpoint product is transformed. It sounds like it was built with point-to-point wiring.

This technique is not something I can do to every model, due to construction details. And some products are harder to do than others, or require more or thicker damping pads, so prices vary accordingly. See below for details.

 
MODEL
(click on model number to view other available upgrades for this model.)
AVAILABLE?
PRICE
SA-2
NO
--
SA-3 OR /3.1
NO
--
SA-4
YES
$100/AMP
SA-5 OR 5.1
NO
--
SA-7 OR 7.1
YES
$85
SA-8
NO
--
SA-9
YES
$100
SA-11
NO
--
SA-12/100 and NP100
YES
$100
SA-20/220 and NP220
YES
(MOTHERBOARD ONLY)
$120
SA-1000
YES
$120
SA-2000
YES
$120
SA-3000
YES
$120
SA-5000
YES
$120
NPM
YES
$120/AMP
NPS100
YES
$120
NPS200 (three circuit boards)
YES
$180
NPS400 (three circuit boards)
YES
$180
DA-10
YES
$120
SOLID-1
YES
$85
SOLID-1M
YES
$55
SOLID-2 (three circuit boards)
YES
$180
 

NOTES:
1. (Setup Fee may be required if resonance control is done without other upgrades to product. Varies with difficulty of disassembly/assembly of model.)
2. Wool felt is dimensionally-stable, fireproof and unaffected by the voltages present in tube products.
3. By the way -- there is no rocket science here. The fee we charge to install this great modification is for the labor and knowhow -- the materials are not expensive. Anyone can do it as a DIY project if they have the skills. You'll need to disassemble your amp or preamp, determine how the circuit board is mounted, remove it, determine how thick the felt needs to be, and order some F-13 gray felt from www.mcmaster.com, cut it to size, pierce it to clear the circuit board mounting standoffs, set it in place and reassemble the amp or preamp. The fee we charge is for the labor and knowhow, obviously the materials are not expensive.

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Please call me or e-mail me if you have any questions that I've not answered here.

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C O P Y R I G H T ©  1 9 9 8 - 2 0 0 8   A L T A   V I S T A   A U D I O  L.L.C.
2027 Charleen Circle · Carlsbad, CA 92008 · USA
PLEASE SCHEDULE APPOINTMENT
Email: mike@altavistaaudio.com
Email preferred but if you have to call:
Tel 877-517-4247 (U.S. toll-free) or call + 760 519 0193 (9 a.m. - 5 p.m. Pacific Time, Monday - Friday)
fax + 484 348 3O82

Pricing Updated: 1 May 2003