a Mesa/Boogie Express Plus 5/25. I use an HX Effects currently with the Boogie. I get hella noise when USB is plugged in. I got a USB isolator but the one I bought (while it does prevent hum) also prevents USB operation. Apparently there are different levels of functionality of these and I probably need the $60 one instead. Or I just only plug it in when I need to. As it turns out I barely use it anyway.
I’ve been through a few things in pursuit of DIY DSP nirvana for guitar.
- I did a LOT of stuff on the FV-1
- got an “Elk Blackboard”, but (a) not a pedalboard ready format, (b) company seemed to shift focus to “Aloha OS”, leaving support/future of Elk Audio OS uncertain (IMO). I used the OB-X sequencer demo. It’s cool. I never developed anything for it.
- Tried Raspberry Pi 3 running “SooperLooper” with USB audio, total disaster.
- Tried MacBook Pro running Ubuntu Studio, low latency, RT kernel, USB audio. Built SooperLooper, Hydrogen, a few other things. Made some DSP patches in Faust. Could not get acceptable latency without XRUNS (glitches). XRUNS drive me crazy. My Windows machine has been cranking audio into USB interfaces all day for years so I can only surmise that Linux audio needs a LOT of help to work properly. I’d accept that the Pi’s USB implementation may pose some insurmountable obstacle, but a MacBook?
So, I’m a bit concerned about (a) ground loops caused by connecting various audio bits together with different ground references, (b) generic digital electrical interference based noises (e.g. whines that change depending on what the device is doing), and (c) glitches or artifacts caused by misbehavior of the software such as XRUNS. I’m just planning on using mono in - mono out. in the effects loops of whichever amp. As a bonus I might try stereo, returning to the FX return of the “other” amp which would just be for amplification and a possible trip through a cab simulator.
Some people are having troubles and it’s not clear what the breakdown is between (a), (b), and (c). I would really like to develop and offer some plugins, and I would like to use the box. I know that people don;t generally come to the forum to say how happy they are. So this is an opportunity for someone with a similar setup (i.e. using it in the FX loop of a tube amp) to tell me how great or awful that is. For example I think these are just unbalanced 1/4" in and out. So if going balanced solved the whole problem I don’t know how I’d adapt to that.
I do have a stereo passive DI box which I got for the other setup but I have never used it since disconnecting USB solves the problem.