Hafler DH-101, DH-110 and SE-100 Modifications

 

 

A very complete, over 50 parts, Phono/Line/Power Supply mod. Line stage only modifications have been added

 

The phono stage receives a thorough refreshing with new film input coupling cap, new RIAA caps and resistors, much lower frequency roll-off point via much larger DC restoring cap in feedback loop. A high quality multi-turn adjustable DC offset pot is used to eliminate the traditional DC coupling cap at the output of the stage.

 

Your line stage is now DC coupled with added phase integrity. Typically there is a capacitor at the input and output which corrupts the signal! Larger time constants via FB loop modifications are engineered into the design to give a more spacious stage with better instrument location clues, an authoritative natural quality.

 

Power supply is enlarged with superior capacitors and high frequency bypassing producing better stability and noise performance.

 

LX Elite modification utilizes superb quality Elna Silmic II capacitors, superior film caps, Schottky power rectifiers, additional superb sounding resistors in strategic locations and all the great high-quality parts/procedures from the standard modifications. Elite has a more majestic sweep of power and emotion. It gets the musical timbres more correct and complex at the same time. Instruments have a more pinpoint location within the image. At the same time it even more relaxed and tempo accurate. Superb!

 

LX PREAMP MOD: Line Stage Only Modifications: $169/kit, $289/installed in line stage only for most Hafler preamps, mod is installed only for SE-100.

Complete Preamp Modification(RIAA + Line): $349 installed(full mod), $199 kit/full mod #

Update modifications for earlier versions of our Musical Concepts standard modification: $229 installed only  #

 

NEW!!! LX ELITE MOD:  Line Stage Only Modification:  $199/kit, $329 installed in line stage only for most Hafler preamps, mod is installed only for SE-100.

Complete Preamp Modification(RIAA + Line): $499 installed(full mod), $299 kit/full mod #

Update modifications for earlier versions of our Musical Concepts standard modification: $379 installed only  #

 

#Due to the construction techniques used in the DH-110 it is subject to noise and loss of channel issues which are strictly mechanical. Correcting these issues in the right way is time consuming. Extra charges may apply to preamps that are not clear of these issues when they are received for service.

 

 

 

MC-3 Preamp Circuit Board Modification

 

Phono, line stage and four individual power supplies are on board. Make no mistake! This is a "State of the Art" sound. Preamps with the MC-3 board are often accused of sounding tube-like, vividly three dimensional and very dynamic while retaining a solid bass authority. We plead guilty. The MC-3 fits HAFLER DH-101 - kit available. Factory installation available for the HAFLER DH-101, HAFLER DH-100, DH-110 and SE-100 preamps. <<<<<<CUSTOM INSTALLATIONS are available. We have installed this board in many other preamps including the Dynaco PAT-4 / PAT-5, Mod Squad Line Drive, Spectral and even a tube preamp.>>>>>> The OPS-8 listed below is always recommended, and sometimes required. HAFLER DH-100, DH-110 and SE-100 preamps require the OPS-8 when used with the MC-3

 

 

 

 

 

 

 

 

 

MC-3 circuit card: $299 kit (with dual mono/dual concentric volume control*). Installation $150 (DH-101) to $175 (DH-100/110 and SE-100). *Volume control not included with Hafler DH-100/110/SE-100. Important Note: tone controls/filters are eliminated.

>>>>For Elite versions, add $100 for Line Stage/Power Supply ( includes outboard power supply mods ), $75 extra for Phono stage.

 

 

 

Hafler Preamp Model 915 and Tuner/Preamp Model 945

 

Similar in concept to our well respected Hafler DH-101 mod, here we have many mods to line stage, coupling caps, feedback circuit and internal regulated power supply. The quality of the sound is enhanced with wide dynamics, sweet tonal quality and more precise soundstage. An already good product, becomes a finer more sophisticated instrument. Recommended - OPS-4B Outboard Power Supply, described below.

 

915/945 mod: $399.00 installed. Elite version is $549.00 installed

 

 

Preamplifier Options

 

OPS-4B outboard power supply is for Hafler DH-101, DH-110, 915 and 945. It has one +30VDC and one -30VDC output. OPS-8 has dual + 30VDC outputs, i.e. dual-mono required for MC-3 circuit board. They are equipped with a quiet toroid transformer and high-quality capacitors. OPS-8 is dual-mono configuration for MC-3 preamp board. 

 

Expect excellent dynamics, low noise, tonal purity, maintenance of distinct instrumental clarity at even high volumes.

 

We do a lot of custom power supplies from the basic to the exotic. Call with your ideas.

 

OPS-4B: $Call(built and tested) with shielded output cable. Installation $75.00

OPS-8: $Call kit (built and tested) with shielded output cable. Installation:$75.00

 

 

 

 

David Hafler Co. Preamp Modifications