For the past dozen years or so, I have been using a Hafler DH-110 preamp in my system.  Functionally it does not offer much that my older DH-101 doesn’t, other than an extra set of outputs.

Along with my other upgrades, I decided to swap the DH-101 back into my system.  Having read some accounts online, many audiophiles still remain impressed at how good of a preamp the DH-101 is.  I built this DH-101 back in  1982, and the leap forward in sound was amazing at the time.  Having swapped it back into my main system, I am pleased to say it sounds as good as ever.

One comment about the DH-101 is that the background is very “black”.  This means that the music comes out of virtually total silence, adding no noise to the music at all.  Granted, I can crank the volume all the way up and hear some sort of hiss or hum, but my power amp would turn itself off at half the volume setting.  Even after years of non-use, the “blackness” is still there, even though the capacitors are over 30 years old now.  Upgrading the caps might be an option in the near future, to freshen up the preamp to original specs.  But until then, it is sounding awfully good.

In comparison, I now feel that the DH-110 sounded different–perhaps a bit softer or even duller.  The DH-101 seems more precise, more immediate, but not exactly brighter per se.  A buddy of mine way back then commented about my then-new DH-101:  “Damn, that bass is tight!”  We were spinning the Earth Wind & Fire Raise album at the time, and the bass was just totally on cue, whereas the hacked integrated amp I previously used just sort of slurred the sound all together.  The DH-101 gives me more inner detail and to me, seems to breathe a bit better through the midrange than the DH-110.

One annoyance of the DH-110 is the detented volume control.  This is not a stepped attenuator, but just an extra wiper on the potentiometer that makes the control operate in steps as opposed to a smooth transition.  The problem, though, comes with newer components that have such a high output that it is nearly impossible to get a low volume that you are comfortable with since the correct volume is between steps on the volume control.

The rotary switches were also becoming more corroded in the DH-110.  I had done a full strip-down a couple of years ago and sprayed all of the switches with deoxidizer, but the frequent channel dropouts in recent months drove me to finally retire it for the time being.  I would probably press it into service in a second system at some future point, perhaps even replace the capacitors and see if the sound improved.

The DH-101 has been a nice fit with the tube buffer and the change in speakers. It is much like having a familiar old friend back in the system.  I have toyed with building a tube buffer stage into the preamp, as it would just fit the space provided.  That would really take it over the top!  I would, of course, offer an option to bypass the buffer if needed.

One thing that disturbs me is the poor condition of the RCA jacks on the back.  But, I have a cure for that, and it may be something I can market via this website: an upgrade that many have hoped for, but few (if any) have attempted.

There is one more system upgrade coming…stay tuned!