Hi Mica! Yes I played around with the Orion output gain pot and I found that it lowered the amp input gain as it should. So that lowered my final output volume. When I compensated for the volume loss, by any means, elsewhere in the system, I got the distortion back.
Hi again Jim, you know, checking the bass output that way is an idea I had not considered exactly. Same with the Mesa headphone test; I will try both ideas. I Relatedly though, I plan this weekend to take my amp and bass out of state to a guy who can hook up a good signal generator to the amp, and voltmeter/o-scope test the output, and o-scope test the bass output for distortion, and then do the same with the amp output with the bass as amp input. Meanwhile I do have a voltmeter and I will test what you say. It could answer some questions before I haul things out of state.
Hi Gary, so you found the same? I was HOPING to have run into somebody here who uses the same amp.
Gary, I use the effects loop at times, yes, but not in my troubleshooting. I tried troubleshooting with effects connected through the loop and otherwise, but I found that effects added too many irrelevant variables to work around, insofar as the problem occurs without them. The effects loop mix control on the rear of the amp did not seem to help, although admittedly I did not try every possible permutation of other control settings while also manipulating the mix control. I tried the mix at 10 and at 5. Those two mix settings made no relevant difference, as I just indicated here a few lines up. Additionally I have found that running effects through the loop or not through it (i.e. inline between the bass and the preamp input) amounts to the same, relevant result here -- the same distortion. Of course when I do not use the loop I turn the mix control to zero; a Mesa rep told me that leaving it turned up can cause distortion, although I had not noted any difference in that specifically. I will go ahead and use the loop tonight and see how a bit more manipulation of the mix might help.
The tubes? They are about a year old, and they all tested fine about 5 months ago. I'll have them looked at again this weekend.
Gary, what is a TC Elec M-one? Speaking of pedals, I bought an ISP Noise Decimator which works while you play as well as when the strings are quiet. It appears to be irrelevant because it has not helped.
Gary I'd love to know what cab(s) you use, and what speakers are in them, including the speaker power rating, the speaker freq response, and the cab impedance if you know all these things off the top of your head. This info would be very important to me. Additionally, do you now use an alembic with your Mesa? And, are you a loud player?
Another question, Gary. If you have fixed the distortion you had, with effects out of the signal path (so that we can make a good comparison here), how high can you go now, with good sound, on the gain and master vol controls, and with which preamp input? And, these two settings, are they with an Alembic or one of your other basses? I know these are a lot of questions, and to whatever extent you can answer them I will be thankful.
These are good suggestions everybody. I wholly appreciate them and I will appreciate more.
Now here's a bit of news on the situation, acquired last night since I last wrote. I took Jim up on something he said about using the padded input, although Mesa says the amp is fine to use either input with any bass, and although I have tried both inputs before. Last night I found that with the lower gain input I could tweak other things and get a very slightly louder audible volume without distortion. Very slightly louder. I also lowered the pickup nearest the bridge. It was set high originally. I set it all the way down. It too allowed me a bit more good audible output. But the two little boosts I mention here do not add up too a significant amount. Helpful, yes, but not a fix. I still wouldn't be able to fend for myself if my rig had to provide all the bass sound at a small gig with a loud band. I've still got the idea that I will end up having to get new output, ie cabs. Something like maybe 2 big SVT cabs at 4 ohms each. Something like that ought to make up the difference while keeping my controls at the same non-distorted settings I feel confined to using. I might end up looking for relevant suggestions before making such a money decision, as I originally posted here. I will update here as I try more things and get some up to date, electronic testing out of the way.
THNX all, Turk
