Using an HT-5C, 4cm, no noise problems. Using the HD's pre-only amps straight to the HT-5C power amp sounds like crap, harsh, hissy. Using the full amps, with or without (HD) cab sims sounds great. Using the Blackstar's pre's with 4cm and effects only also sounds great. Using any of the HD's overdrives with the Blackstar's OD channel more than barely cracked sounds terrible, but might be I just need to spend some more time dialing it in. All the HD's OD's sound good on the clean channel. So far, I prefer the studio direct setting to the combo setting, but that might be the setting I need to make the pre-only HD amps sound right. Not enough hours in the day for all the possibilities, I wind up getting distracted by playing the guitar....
