David Hafler Co. Preamp Modifications
Hafler DH-101,
DH-110 and SE-100
A very complete, over 50 parts, Phono/Line/Power
Supply mod. 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 and adjustable DC offset
adjustment to eliminate the traditional DC coupling cap at the output of the
stage. Typically there is a capacitor at the output too which further corrupts
the signal! Also consider the MC-3.
LX PREAMP MOD: $199 kit, $329 installed, mod is installed only for SE-100. Updates for earlier versions:
$229 installed
MC-3
Preamp Circuit board
Phono, line and power supplies are on board. Make no
mistake! This is a "State of the Art" sound. The MC-3 fits HAFLER
DH-101 - kit available. Factory installation available for the HAFLER
DH-100, DH-110 and SE-100 preamps. The OPS-8 listed below is
always recommended, and sometimes required. HAFLER DH-100, DH-110 and SE-100
preamps require the OPS-8.
MC-3 circuit card: $299 kit (with dual mono/dual concentric
volume control). Installation $130 (DH-101) to $155 (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 Signature versions, add $175 for Line Stage/Power Supply ( includes outboard
power supply mods ), $175 extra for Phono stage.
-
Phono stage with excellent RIAA response
-
Adjustable DC offset in phono eliminates need for output capacitor
-
DC-Coupled line stage with very wideband performance
-
Totally discrete transistor circuitry, no ICs
-
Totally dual-mono construction on one board
-
Dual-Mono regulated power supply
-
Completely independent power and ground systems
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. Recommended - OPS-4B Outboard Power Supply, described
below.
915/945 mod: $329.00 installed. Signature
version is $529.00 installed.
Preamplifier Options
OPS-4B, OPS-8 Outboard Power Supply
OPS-4B is for Hafler DH-101, 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 large
toroid transformer and 40,000mfd of capacitance. OPS-8 is dual-mono configuration for MC-3.
This power supply is large enough for a small power amplifier!!!!!!!!
OPS-4B: $229 kit (built and tested) with shielded output cable. Installation $45.00.
OPS-8: $249 kit (built and tested) with shielded output cable.
Installation:$45.00