New! Announcing the latest PA-3 version!!! PA-3 pictured at left!
PA-3D Front-End Circuit Boards: for Hafler DH-200/220/500 and XL-280/600, plus custom installations
THE DESIGN: Design simplicity has always been a trademark of Musical Concepts products. The new PA-3D is a straightforward, effective amplifier topology with a single-ended front-end. Now we have LED biasing of the current source in the differential 'front-end' to complement the original LED biasing in the driver stage. The DC offset control has been improved. Added space allows even larger power supply caps in the Platinum version. Some eyelets have been increased in size for easier wire insertion. The resistor outlines have been enlarged making conversion to the Platinum version upgrade easier and more attractive. The copper 'thickness' on the board has been increased by 50%, while we have reduced the 'trace' width in signal carrying areas for less 'bounce effect' from the board material.
THE SOUND: Forget all the new technical improvements, the sound quality is the real treat. The degree of perceived dynamic range, bass power and overall delicacy is astonishing. Yet, there is a tremendous sense of effortless power. The delicacy, liquidity and naturalness make you think you are listening to a vacuum tube amp. Then along comes bass detail and overall clarity that makes you reconsider that thought. There is a sense of majesty and air-moving power that must be heard. PA-3D modified Hafler amps will honestly compare to the finest sounding amplifiers available today.
Kit builders - you must set the output stage bias with a multimeter (digital with 2 Amps or more DC capability preferred). Then you set the DC offset voltage at the speaker outputs.
PA-3D
modification kit
$329 kit, $459.00 installed - kit
includes all items shown including specially alloyed eutectic solder 
---------View
the installation manual! --------- This file is 460kb and requires Adobe
Acrobat Reader to open on your computer.
PA-3D
Signature
$479 kit*, $659.00 installed
Incomparable BlackGate® caps (FB and current source) for higher
resolution, clarity and just plain naturalness, IXYS or Schottky Rectifiers for great bass,
smoothness and that same word naturalness that keeps coming up. We use
additional power supply
bypass capacitors for superior resolution from top to bottom and a taut,
resolved bass quality.
*kit is for a more experienced modifier
PA-3D
Platinum
$1299 kit*, $1599.00
installed
This exotic modification includes all Signature mods, plus about 50 exotic Platinum-Grade
resistors, Cardas Copper Binding Posts, exotic OFC RCA jacks, additional PS bypass caps. See some of these items on
Components page, see the RCAs and binding posts on
our Connectors page. Our latest PA-3D Platinum is truly
a superb amp that demands comparison to any amp available!
*kit is for a more experienced modifier
PA-3D
Platinum Ultra
$2995 installed only for DH-200/220 & XL-280, $3195 for
DH-500, $3395 FOR XL-600
Our magnificent, incomparable PA-3D Platinum Ultra mod is truly State of the Art and
beyond State of the Art as it is practiced by so-called high-end manufacturers.
Although we at Musical Concepts have modified many expensive well known
amplifiers we've never seen build quality even remotely close to the Ultra. Just
imagine, if you dare, what this incomparable product might sell for if it had
some fancy over-hyped manufacturer's name on the front panel. Consider that the
Platinum Ultra has all the mods included with the Platinum mod plus far more.
The DH-200/220 and XL-280 has a 625W dual secondary toroid power transformer.
The main power supply is dual-mono with four large BlackGate® caps which are the
finest you can buy for power supply applications. The DH-500 and XL-600 have
twin 500W toroid power transformers and four BlackGate® main filter caps which supply totally
dual-mono operation. Since the
original Platinum Ultra was offered we have added the BlackGate FK 100uF/100V
caps to the front-end power supply. At the new price we also include a new high
in-rush current power switch and an IEC power cord socket with hi-current cord.
Resistors: 1% Metal Film Resistors, Platinum Grade TaN resistors for Platinum version
Circuit Board Material: Highest quality FR-4, G-10, mil-spec, dual-sided, 'plate-thru' circuit board with 3 ounce copper (twice as thick as the foils in many so called "audiophile" designs)
Capacitors: High Performance Film and Electrolytic caps
1st. Stage: Very tightly Hand-matched differential pair with LED biased current source
Driver Stage: Class-A, Cascoded driver stage features LED biasing and Ultra-Linear connection
Power Supply: 10 times more capacitance than the original Hafler circuit board design, 27 times more with the Platinum version
RCA Jacks: High Quality Gold-Plated with Teflon® insulation (OFC/Gold-plated with Platinum)
Binding Posts: Cardas® Copper with Platinum version
On-Board fuses allow removal of originals from chassis for even more 'mod room'
Pre-assembled circuit boards - hand soldered with sonically superior solder
Sonically superior bypass caps provided with kits, extra pair provided for XL-280 and XL-600
Special Eutectic alloy solder provided in kit version
Up to 12ga wire can be used with 'hi-current' pcb eyelets
More
Power Amplifier options:
TP-200 and TP-500
toroidal power transformers
LC-200/LC-500 replacement power supply caps
Comment: We are often asked if these dual-mono mods are "worth it". "I mean I can buy a more expensive amp and maybe I should go that way", says the customer. Well, stop and think about it! In the case of the smaller amps you have 100,000 microfarads of capacitance and a dual-wound toroid power transformer with twin bridge rectifiers. Now consider the larger amps! You have 156,000 microfarads, twin bridge rectifiers and twin toroid power transformers. These are items that don't come cheap. You would expect to pay much more than your outlay for these massive power supplies if you buy a new amplifier, period! Suddenly it becomes a "no-brainer"!
Dual-Mono power supply conversions: $599 factory installed into DH-200/220, XL-280 - these include four of the LC-200 filter caps and one dual-wound TP-200 toroid power transformers plus all extra hardware and installation!!! To see a sample dual-mono installation in a DH-500 click here!
$749 factory installed for
DH-500/XL-600
- these include four of the LC-500 filter caps and twin toroid power
transformers plus all extra hardware and installation!!!
We install
Cardas connectors and/or OFC RCA jacks into any amp stock or modified. See our "Connector"
page for these hi-quality RCA jacks and binding posts!