Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

Hafler DH101 preamp repair and mods?
Hafler DH101 preamp repair and mods?
Hafler DH101 preamp repair and mods? Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 6th October 2018, 05:18 AM   #171
Bonanza is offline Bonanza
diyAudio Member
 
Join Date: Apr 2010
Location: Always on the move!!!
Thanks for the great advise Chris....

Just for testing, I removed the wires going to the tone switch and jumpered between 5 and 8 and left 7 and 6 open to simulate the tone switch in the on position and all my a/c hum is gone, I suspect the tone switch is picking up 60 cycle hum from the power switch next to it. I think I'm going to mount 2 relays under PC4 and use the tone switch to trigger the contacts.

BTW, I do understand that this was a budget preamp in it's day, and it's not my only preamp. I just want to see what sonic improvements can be had by updating this preamp with modern components and building techniques.

I think for what these units can be purchased for and with some money spent on quality parts and time invested, these are very good value.

Bonanza
  Reply With Quote
Old 6th October 2018, 06:29 AM   #172
jameshillj is offline jameshillj  Australia
diyAudio Member
 
Join Date: Feb 2005
Location: Melbourne
A bit of an aside from your project Bonanza

Abit of a 'side-note' for those that do like tone controls at a reasonable price, Shiit Audio have produced a simple 4 band equalized box called Loki 1, for a grand total of U$149 - it's a very transparent and neutral little unit with very useful bandwidth centres and can make a huge difference to the sound of some of the 'deficient' mixes and also just a bit of fun to play with - nothing like the cheap ones of years ago.

It's good that you're enjoying the Hafler preamp project. I once did a similar thing with a NAD integrated amp and was quite surprised just how good it ended up.
  Reply With Quote
Old 6th October 2018, 06:50 AM   #173
Bonanza is offline Bonanza
diyAudio Member
 
Join Date: Apr 2010
Location: Always on the move!!!
Thanks for the tip...I went to their website...Interesting product line!
  Reply With Quote
Old 6th October 2018, 07:14 AM   #174
jameshillj is offline jameshillj  Australia
diyAudio Member
 
Join Date: Feb 2005
Location: Melbourne
Yes, it's fascinating how their product line has developed and many of their items are 'relatively cheap' (not all, mind you!) and that they have also included a number of headphone listening products

It's an area that's seen rapid product development in the last few years and some of the products reflect the influence of 'pro-audio' too, unlike the 'hifi scene', altho this is slowly changing too.

Mind you, some of the prices in the headphone area are totally mind boggling too.
  Reply With Quote
Old 6th October 2018, 02:07 PM   #175
jackinnj is offline jackinnj  United States
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Hafler DH101 preamp repair and mods?
My son has my DH101 and DH220 -- they were purchased new, as kits at an audio fair on Long Island in the early 1980's. Subsequently added the MC pre-pre.
  Reply With Quote
Old 6th October 2018, 07:57 PM   #176
anatech is offline anatech  Canada
diyAudio Moderator
 
anatech's Avatar
 
Join Date: Jun 2004
Location: Georgetown, On
Hafler DH101 preamp repair and mods?
Hey Jack,
I bet the fun of putting them together was worth every penny. Now your son has something that you built with your own two hands. That has got to be special Especially since they sound pretty good.

-Chris
__________________
"Just because you can, doesn't mean you should" my Wife
  Reply With Quote
Old 14th January 2020, 09:13 PM   #177
sfox52 is offline sfox52
diyAudio Member
 
Join Date: Jan 2016
I am sure the answer is buried in this thread somewhere, but how can I bypass a wonky balance control on a stock DH 101?
  Reply With Quote

Reply


Hafler DH101 preamp repair and mods?Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Hafler xl-280 mods Audionirvana Solid State 5 11th November 2010 05:25 AM
Hafler Preamplifiers - DH101 vs. 915 bcrescen Solid State 6 14th July 2008 10:30 PM
Hafler DH 101 preamp mods Zen Mod Solid State 6 3rd May 2004 01:24 AM


New To Site? Need Help?

All times are GMT. The time now is 12:43 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright ©1999-2020 diyAudio
Wiki