Hovland HP 100 - owner insight needed

I'm considering purchasing an HP 100 but I've read a few threads on some concerns with the early production volume control.

1. Can someone share how the serial numbers are derived? I would like to purchase a 'later' model, but don't know what would represent earlier vs later serial #'s.

2. What exactly happened with the early volume controls (were they less than adequate from the start or do they deteriorate over time)?

3. Any other general things I should ask/inquire about when purchasing the HP 100 would be most helpful.

Thanks for all your advice and best wishes for a wonderful holiday season,
The old volume controls have black resistors and have been rumored to develop pops and buzzing due to contact deterioration, the new ones have blue resistors with stepped attenuators. The older versions were also susceptible to hum, the newer versions have largely ameliorated this problem by a transformer change. I you are still interested, I happen to have one for sale with the MC phono section. It has the latest revisions and updates. Do a search and I think you'll find more discussions about this topic here in Audiogon. Hope this helps. Happy Holidays!
The HP 100 , coupled to a Levinson amp and B+W Silver 30 speakers was one of the most memorable moments in my long audio history . If it had remote I would have purchased it .
The early models had volume controls that were loose. I talked to Alex and he quoted $800 as a fix:(. I thought I was being smart when I sold it on this site in favor of a "D" version that was sold before I could purchase it.

The company or review didn't say, but the most transparent output isn't the "CD". Do a search on my name for the answer as I don't remember which input it is.
A "problem" with the stepped attenuator on the Hovland is that the steps are a bit too wide for very fine adjustment of volume (this, to me, is an issue with almost any stepped attenuator with less than 80 steps). Other than this, I liked the Hovland a lot (a friend had one).

As good as it sounds with the tubes it comes with, the sound can be substantially changed by using different tubes in the unit. By experimenting, one can probably improve the sound of the unit (what constitutes an improvement is a matter of personal taste/system matching). For my friend's unit, Amperex Bugle Boy 12AX7s, particularly for the phonostage, made a huge improvement in the sound.