Buzzing Fender HRD

I've owned one for years(although it finally just blew up! lol). MANY feel they are very bright amps. And many times they tend to lean towards the "shrill" side. These amps are very reliable and CAN sound great, but it does require some modifications. New speaker and tubes tends to do wonders for the amp. Here's a great site with some very useful insight into these amps..

http://studentweb.eku.edu/justin_holton/

For me, a new speaker is the secret to this amp that doesn't require too much trouble. There's also some repair solutions on this amp for some common problems. Hope this helps!

How does he adjust the EQ?  I was told I had a pretty bright sound when I first got my HRD.  I always did the Clapton thing and turned all the pretty knobs up high as they go using my master volume on distortion channels to control the overall sound.  I now use all the distortion this thing can muster so More gain mode set at 12.  I hate this amp without the pressence so I turn it up to 12 as well.  Your thinking man that must be shrill.  Its not because I adjust out most of the treble in the EQ by turning it to about 5-7 depending on my type of guitar (ususally a strat.)  Bass is set 2 numerals lower then the Treble so if I'm 7 on the treble I'm 5 on the bass.  I love mids so 12 for mids.  It sounds good at this point for me, and depending on how much thickness I want I'll turn my tone control on my guitar down for certian things and when I need to shine I've got a no load control when I set the strat to 10. 
My last and secret weapon is a compressor pedal in the effects loop.  Its a cheap thing I got off of ebay but basically I'll turn the level up wide open and the sustain up about halfway and use the pedal as a boost rather then what its supposed to be used for. I also have a Morley Wah pedal the lets me put a 25db boost to the front end of the amp.  So My advice is get a distortion pedal that doens't plug in to a wall.  Also those pedals are very bad for rf interferrance when you run them wide open.  I'd ditch the blues driver and use the distortion channel, its better then people give it credit for, but its not a marshall, and the distortion doesn't touch the clean channel.