Schmalle

After setting Global Settings > MIDI/Tap to MIDI PC Send OFF, did you repower your amp? Otherwise it might have been in PC mode and therefore didn't react to CC messages. Did you set the dip switches on the amp to MIDI channel 1?

Increase the reverbs High Cut. Think of it this way: you mix the dry signal with duller reverbed version of it which makes the sum of both duller, too.

'Super glassy', 'harsh' and 'thin' are all adjectives that indicate a lack of bass and/or low mids.

An A/B recording would help to objectify the described tone loss.

A TubeScreamer has an input impedance of about 500kOhm or higher and an OD1 about 1MOhm.

To give you an idea of the amount of signal loss due to DA/AD conversion: Try a patch cable in the FX Loop directly connecting send and return. Then A/B the sound with and without the Loop in the chain. As for me I don't hear any other than a little extra noise.

Could you name those overdrive pedals you use? Have you used a preset with only the FX Loop in it? Have you set the input impedance to 1MOhm in the input block to make sure it's not an issue ?

It's probably a level issue. Have you set the Global Settings > Ins/Outs > Send/Return to Inst? When it's set to Line the signal your overdrives receive are pretty hot.

... or a detailed instruction.

Please share the preset and if you can record the phenomenon.

TGP-member John Mark Painter has a thread by called replicating my favorite pedals with Helix that might be of interest.

Are splits and mixers before / after the cabs the same?

@AlchemyStrat Post a patch of which you are sure the problem occurs.

Sorry, my answer applies to HX Stomp only.

Make shure Global Settings > Ins/Outs > Return Type is set to Return. If it's set to Aux In the return signal will be directly forwarded to the outputs.

Check what sources you hear via USB. Read page 56 'USB Audio' of the current manual for details.

I doubt that. The main reasons are tradition, cost efficiency and the industrial standard (guitars with simple electronics) - a balanced signal would need a more sophisticated amp input stage and guitars would need a balanced out and therefore active electronics. I get your point - it's not the cable by itself that sounds better - but if one signal contains RF interference or ground hum noise and another doesn't which one of them sounds better?

From the manual: A solution for the OP problem would be setting Global Preferences > Preferences > Auto In-Z to Enabled. Another is to change the input impedance via snapshots.

Your amp's return path probably is faulty. Connect a cable from amp's send to return left/mono directly to confirm that.

This is an echo chamber - you already know you want to buy the HX Stomp so do it already. (or the Pod Go if the form factor suits you better)

The mic distance influences volume - just like in real life.

According to the MIDI programming manual for the EVH head it reacts to PC messages not CC messages. Maybe this thread helps:

No they are not isolated. So you have a ground loop in your setup, but 50/60 cycle hum is not an issue. Electromagnetic fields can be induced via ground loops though.To minimize the risk of that the two cables to the JC-120 should be laid next to each other with no distance between them. You could even twist them a few times.

Yes, there are multiple ways: Solution 1 Put a fx return block 100% mix in parallel (signal line B) near the end and a cab block behind that. Then the mixer after that with signal A pan 100% left and signal B 100% right. A) O--- FX blocks------------------------------o-----O B) \_Return L --- IR--/ Putting the loop send of the amp in the return of the HX Stomp. Now Out L contains the signal for the amp and Our R contains the IR signal for PA. Solution 2 A) O--- FX blocks----------FX LOOP ------------ IR-------O Put the send signal from the Stomp into the amp input and the amp send signal into the Stomp return. The outs now contain the PA signal. Solution 3 A) O------- FX blocks----o-----O B) \--- ---- IR------------/ Put the loop send of the amp in the right input of the HX Stomp and guitar in the left input. Use a Split Y with BalanceA L100 and BalanceB R100 in the beginning. At the end a mixer with signal A pan 100% left and signal B 100% right. Now Out L contains the signal for the amp and Our R contains the IR signal for PA.

Have you excluded the guitar as cause?