[Mr.Radar]

I can't believe I didn't do this when I first got this amp!

Before I go into detail let me back up... I always enjoyed my EMU 0404 -> HSC (AD8620) -> DT770/80 combo, but lately I haven't been satisfied with it. Something just wasn't right and EQ'ing didn't seem to help. Tonight, for some reason, I suddenly got an impulse to try changing the AD8620 out for one of the OPA134's in my CHA47. Dissasembling the HSC wasn't the most straightforward process but I eventually figured it out, and after bending half the pins on the 134 I finally got it out of the CHA47 and into the HSC. When I first tried it (I don't remeber what I listened to) I was blown away! The highs were clear but not overly bright like before (even without EQ'ing), the mids have life that I've never heard before from my system, and I'm finally getting that excellent "subwoofer bass" the DT770's are famous for! The musicallity has increased tremendously and I'm also hearing improvement in soundstaging, but I'm not really that great in judging that. I'm simply blown away (points to avatar) by the difference one little $5.40 chip can make (especially since I switched out the supposedly superior AD8620 for a "lowly" OPA134). It is as if, to use an audiophile cliche, a veil was lifted. For all you HSC owners out there try out different opamps, they can make a world of difference.

Now, if only my records would arrive soon so I can actually use my new turntable...

 

[nakedtoes]

How do u open it up.. i unscrew the 4 screws but i do not know how to carry on.. Thinking of doing some op amps rolling too..

 

[Oink1]

If the case is anything like my 'new' Classic you undo the 4 screws @ the rear, pull the pannel away slightly then just slide the lid out backwards