Josef5150 Posted October 13, 2020 Share Posted October 13, 2020 Ok, I am really struggling to get a usable signal out of this setup, I've got it cabled up in the normal fashion, and currently am using a spignal path with ONLY the loop in it. the problem im getting is as soon as I try to use the loop with the guitar amp preamp i get feedback/oscilation. Ive got the guitar input set to instrument level ( obviosly) and no mater what combination of levels I use on the loop i cant get reasonable audio level back inte the amp without oscilation. Ive actually gotten to the point where i am measuing the effects loop levels on VU meters ( analog stand alone ones) to fault find this to no avail. With just a VU meter patched in the amp effects loop i am seeing Line level signal (+4dbu), but am unable to put anything like this level back into the amp from the HX without oscilation. to get the oscilation to stop i have to ramp le level down by around 20dB, in whoch case I get no real usable volume out of the amp. Quote Link to comment Share on other sites More sharing options...
zappazapper Posted October 15, 2020 Share Posted October 15, 2020 I use a 2-channel reamp box for both the send to my amp's front panel input and the output to my amp's effects return. Keep in mind that "line level" and "instrument level" actually have less to do with voltage than they do impedance, and what a reamp box does is convert a low-impedance line level signal to a high-impedance instrument level signal. I don't know if the Line/ Instrument settings on the Helix units do anything to impedance, or what impedance my amp's front panel input and effects return expect; what i do know is that neither setting gives me comparable amounts of gain to plugging straight into the amp, and neither setting stops the "feedback/oscillation" you're talking about. My reamp box solves both problems. Quote Link to comment Share on other sites More sharing options...
Josef5150 Posted October 15, 2020 Author Share Posted October 15, 2020 Thank for that, I hadnt even considered Impedance, thats a very good point! Anyway... the plot thickens...the unit works fine on my other amp.... Ive been through and checked all the levels and they are se same on both amps so go figure... JCM 800 with added tube effects loop = Happy HXFX Valvestate 8080 combo = HXFX squeals like a pig! for obvious reasons I'd like the option of being able to use a small combo rather than a head & 4x12... I'll take a look at the loop schematics and see if anything jumps out impedance wise. I wonder if its somthing woth this specific amp. Quote Link to comment Share on other sites More sharing options...
zappazapper Posted October 15, 2020 Share Posted October 15, 2020 I would just get a cheap reamp box anyway. They're handy. Most players have DI boxes kicking around even when they don't have a specific use for them because they're just handy to have when you need one, and a reamp box is just the opposite of a DI box. Everyone should have one, AFAIC. I didn't buy mine to be part of my guitar setup, it was just something I tried out and it worked out fabulously. https://artproaudio.com/product/dual-rdb/ This is the one I got. There are much better reamp boxes but for 4CM I don't think you need to go crazy. Quote Link to comment Share on other sites More sharing options...
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