PA-3E Front-End Circuit Boards: for Hafler DH-200/220/500 and XL-280/600, plus we
do some custom installations in other MOSFET amps.
The Design: Design simplicity has always been a trademark of Musical Concepts products. The new PA-3E is a straightforward, effective amplifier topology with a single-ended front-end. We have LED biasing of the current source for the differential 'front-end' to complement the LED biasing in the ultra-linear connected cascode driver stage. 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 high frequency extension with 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 solidity, accurate timbre, simple majesty and air-moving power that must be heard. PA-3E modified Hafler amps will easily compare to the finest sounding amplifiers available today.
What’s New in the PA-3E?: So as far as the schematic goes there is little change. We were happy with the sound of the PA-3D after all. Then what gives? Well, the layout has been changed a bit for one, but the big change is the adoption of an ultra high quality resistor for almost universal use in the mod. These 100% tested, mil-qualified resistors are made with even higher quality materials than the previous parts which were already equal to parts used in many higher end amplifiers. Yes, these resistors cost 3 to 10 times more depending on wattage rating but we believe the difference is worth every penny. They sound clearly superior in the sense of lucidity, soundstage and overall naturalness. Now all PA-3E series mods have superb sounding resistors.
Attention kit builders --- you must set the output stage bias current with a multimeter (digital type with 2 Amps DC or more capability preferred). Then you set the DC offset voltage at the speaker outputs.
PA-3E Modification
$399 kit, $529.00 installed - kit includes all items shown (with two circuit boards) including specially alloyed eutectic solder.
---------View the installation manual! --------- This is a large file and requires Adobe Acrobat Reader in order view and/or print it on your computer. It's probably already on your computer. If not get Adobe Acrobat Reader here.
PA-3E Elite Modification
Superb SILMIC II caps (FB, power supply and current source positions on PA-3E) for higher resolution, silky frequency extension, clarity and just plain naturalness. IXYS HyperFred rectifiers replace the standard rectifier bridge. They have great bass, smoothness and that same word naturalness that keeps coming up.
PA-3E Elite: $499 kit*, $629.00 installed
PA-3E Elite Plus Modification
This exotic modification includes all Elite mods plus Cardas Copper Binding Posts, exotic OFC RCA jacks and our PS-200 power supply board with 108,000uF of capacitance and superb IXYS HyperFred rectifiers. See some of these items on Exotic Parts page, see the RCAs and binding posts on our Connectors page. Our latest PA-3E Elite Plus is truly a superb amp that demands comparison to any amp available!
PA-3E Elite Extra: $875 kit*, $1100.00 installed
PA-3E Elite Ultra Modification
Our PA-3E Elite 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 Elite Ultra has all the mods included with the Elite mod plus far more. The DH-200/220 and XL-280 has a 625W dual secondary toroid power transformer. The main power supply is our PS-200J with four four high resolution Jensen 4-pole 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 twin PS-200J power supply boards. This power supply operates with totally dual-mono performance. The Elite Ultra also includes a new high in-rush current power switch and an IEC power cord socket with hi-current cord. This is the finest mod we have to offer.
PA-3E Elite Ultra modification: $2795 installed only for DH-200/220 & XL-280, $3195 for DH-500, $3395 FOR XL-600
Dual-Mono Power Supply Conversion
See our PS-200 page for dual-mono power supply conversions for some amps. It is recommended for new dual-mono conversions. Improve the transparency, focus, imaging, bass solidity and resolution abilities of your amplifier with the tried and true optimization of your power supply for a mono amplifier level of sonic results. The ability of the amplifier to sound more "together" and unstrained is greatly improved.
$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!!!
$749 factory installed for DH-500/XL-600 - these include four of the LC-500 filter caps and twin TP-500 toroid power transformers plus all extra hardware and installation!!! To see a sample dual-mono installation in a DH-500 click here!
More Power Amplifier options:
TP-200 and TP-500 toroidal power transformers
LC-200/LC-500 replacement power supply caps
SE Series, DH-120, 9000 series amps - We do THX stuff, Too!
LX modification techniques include a very thorough mod with changes in the Feedback Loop, existing RFI input filter, Bias Circuitry, Power Supply, bypassing, compensation caps, etc. The result is a remarkable improvement in perceived wider dynamics, greater naturalness, warmth and transparency! Save yourself from dry, bright sound today!
ELITE modification uses all the LX techniques and more. ELITE replaces your main power supply bridge rectifiers, front-end power supply rectifiers(some amps) and important small value electrolytic caps, such as the DC restoring cap in the FB loop. We use the remarkably natural sounding Silmic II capacitors. Additional power supply bypass caps linearize the highest frequency performance of the power supply.
ELITE SOUND - Picture a smooth, extended top-end, wide but perfectly scaled dynamics, tremendous coherency and a fatigue-free listening experience. Picture cymbals with light airy frequency extension and not a bit of harshness. Now picture yourself enjoying instead of analyzing!
Hafler LX Modification is $399.00/inst., Elite versions with Soft-Recovery rectifiers, SILMIC II and more caps is $599.00
See our "Connector" page for hi-quality RCA connectors and binding posts that we can install for you!
