Hello Ueyteuor,
Looks like you've found a lovely historical artifact !
The sq comparison between the HR head-amp units of 10 yrs ago & today is probably a bit unfair since our new stuff will blow away this Home Amp of yore.... Of course, today's HR amps are slightly more pricey too, obviously another big factor to consider!

...
All that being said, if you happen to have gotten a nice $ deal, the amp sounds good to you, AND it meets your current listening needs, this old HR Home Amp will perform the task at hand very nicely and deliver improved audio performance/sq to any set of hi-end cans connected to good sources.
FYI-Sadly, this unit is not upgradeable in any way.
Cheers,
Jorge
HR Sales/Product Manager