ADA Depot - A Forum To Support Users of ADA Amplification Gear
Non ADA Gear => Rack Gear => Topic started by: El Chiguete on December 08, 2014, 05:41:33 PM
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Hear this quick video I made. https://www.youtube.com/watch?v=RxzcGasjfoc&feature=youtu.be (https://www.youtube.com/watch?v=RxzcGasjfoc&feature=youtu.be)
Now that I'm looking to finalize mi rack setup I want to takle this noise/hiss that I get when I run any effect before my preamp. Here is again the description I put in the youtube video:
"I connect my ADA MP-1 preamp by 4 cable method to my Lexicon MPX G-2 and if I connect my guitar direct to the input of the Lexicon (to have effects in front of the MP-1) I get this hiss/noise. Notice that if I turn off the effect (in this case a simple volume pedal) that goes infront of my preamp, bypass the hole unit or connect straight to the MP-1 (and still using the effects that go after the preamp) the NOISE GOES AWAY!
Is this a ground loop problem? or something else?
BTW the signal that goes from the SEND of the Lexicon to the INPUT of the MP-1 is adjustable and it doesn't matter what level I put it at, the hiss/noise is still there!"
What do you guys think?
PS:
I have the amp at high volume and what the camera picks up seems to be louder... in person you don't hear it that much when you play, but you can hear it.
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Hey El, a little perplexing, so when you unplug guit it goes ape shit with the hiss. At high gain a bit of mains hum is often there, but you get that when you plug in, and when you unplug, it should be relatively quiet. So somethings not quiet right. What's plugged into what BTW???
Ideally you'd be Guitar (maybe but no more: analogue wah/vol pedal (already stuffing your tone BTW, and please don't put anything digital before your MP1)) > MP1 MP1 out L/R to poweramp. Now you need to mix fx into the signal, to prevent AD/DA conversion crap on your pristine analogue signal, you need to mix in the lexicon in parallel and stereo. Any decent mixer with 2 fx send can do this but cheap way is the Art SplitMix (the same as what MikeB did (check posts)). It makes a big sonic difference and will help your gain structure. If you still have hiss after not putting Lexicon in front of MP1, needs more thought, but as I said what is your current patch ?
Cheers R
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Do you have a V1 or V2 MP-1?
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Nolan: I have nothing plugged in before to my MP-1 except the Lexicon. I wouldnt use effects before it all the time just on special ocations that I would need to... actually even if I run like "4 cable method" if I dont have any effects turned ON on the chain before the SEND of the Lexicon it actually changes to true bypass and there is no AD/DA convertion.
Marshall: I have version 2.01... that is V2 yes?
I sended a messege to McLeanAB for him to share his thought on how he connected his MP-1 and other preamps to his Lexicon MPX G-2.
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Hey El, the way I suggest is the best IMHO and I wouldn't use it in front of MP1 (I'd mix it in full wet in parallel). But to to track down your noise issue, can you just try basic Guit > Mp1 > poweramp > cabs (any noise ?), and add things one at a time checking. (here's a thought bubble (ready to be popped LOL), I'm suspecting the Lexicon can run at either line level or inst level ? and knowing lexicon they probably allow that at both input and output ? i.e. selectable) so careful with your gain structure.
MJMP means V1 and V2 hardware. e.g. If it has the inst/line switch on top it's V1 MP1 hardware. V2 models don't have the switch and (IIRC) the rear input is inst level.
Cheers R
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Hey El!
Man, I'm not sure... I've never done the 4 cable thing... I only go line out of my preamps into the MPX-G2, so I'm not sure what it could be unless there's some setting in the Lexicon that should be something else, or some send/return level that's accidentally cranked...
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Hey El, the way I suggest is the best IMHO and I wouldn't use it in front of MP1 (I'd mix it in full wet in parallel).
Yeha I totally inderstand but how can you mix in full parallel a vol pedal in front of the MP-1 for example?
But to to track down your noise issue, can you just try basic Guit > Mp1 > poweramp > cabs (any noise ?), and add things one at a time checking.
Going Guit > Mp1 > poweramp > cabs I have no noise, going Guit > Mp1 > post effects > poweramp > cabs I have no noise either, its only when I run the SEND of the Lexicon to have effects before the preamp that makes noise... now that I think of it I will try today to use the normal output of the Lexicon in to the MP-1 just to see what happeds.
(here's a thought bubble (ready to be popped LOL), I'm suspecting the Lexicon can run at either line level or inst level ? and knowing lexicon they probably allow that at both input and output ? i.e. selectable) so careful with your gain structure.
Yes it have, and I have it now at -6db the SEND level.
MJMP means V1 and V2 hardware. e.g. If it has the inst/line switch on top it's V1 MP1 hardware. V2 models don't have the switch and (IIRC) the rear input is inst level.
Cheers R
Yes I have the V2. In "theory" by adjusting the SEND level it should be enought... but maybe I should mod the rear input of the MP-1 to line level... btw I asked for that mod a couple of months ago but then after reading the Lexicon manual and understanding how to adjust the SEND level I opted no to do it, but now I'm wondeting if I should.
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Hey El!
Man, I'm not sure... I've never done the 4 cable thing... I only go line out of my preamps into the MPX-G2, so I'm not sure what it could be unless there's some setting in the Lexicon that should be something else, or some send/return level that's accidentally cranked...
Yeha I have no noise problem going from my MP-1 to the Lexicon its just when I want to use an effect infron of the MP-1.
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Ok, can understand an analogue wah or vol (or wah/vol) pedal before MP1, but not digital fx (unless it does inst level out (and preferably analogue pass through), but then mono blah!) the noise you're getting is gain structure issues IMHO.
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You also need to use good very low noise cables (as short as possible),because a bit of noise will be amplified alot by the mp-1.
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Forum bros I made a mayor brakethrough that took the noise away... I lowered the RETURN volume going in to the Lexicon from the MP-1!!! I have to say that I had it maxed out before but I don't understand exactly why this helped because is making the adjustment after the MP-1 comes back to the Lexicon and I would imagine that it made more sence to lower what went in to the MP-1 first, but things sometimes you don't know exactly how they work but you just know that it works better now!
After trying out different options even thou the manual of the Lexicon says "Note also that whenever there are no active effects between the guitar input and the Insert Send, a relay automatically switches in a “straight-wire” bypass path. This ensures that there is nothing between your guitar and your amp unless one or more pre-gain effects are active." I still can hear some little change in tone (a little brighter and a bit less tube sizzle). If I don't really need to use pre-effects I'm thinking I will go straight to the MP-1 most of the time now!
I will do more fine tunning to see if I can get that tone change back to original but for now it's way better!
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Hey El, correct me if I'm wrong, you are using MP1 in Lex loop ? If so while on paper this is (looks like) a good idea, in reality it's the worst way to patch it (IMHO). Sort a direct analogue signal path from Guit > MP1 > poweramp > cabs (and BTW get this sounding good first!!) and mix the Lex in in parallel, full wet to add fx don't let the fx drive your tone, they are their to enhance it !! jeje You'll get a much better tone this way IMHO (also if you use a small mixer (even the ART Splitmix works fine with the right cables), to combine (mix in fx to your lovely analogue signal) you'll get a better sound and easier to get the gain structure right (which it seems was your problem (lex rtrn to high))). Cheers R
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Yes rnolan you are correct both times. The Lexicon has a Send and Return so you can do the 4 cable method of connecting things together... BUT that is only for now because I should be ordering a mixer to have things in parallel!... I'm starting another thread for that now :)
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Hey El, way to IMHO :thumb-up:
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RNolan,i think you can use the 4 cable thing if you want to use the wah and compressor etc,these are effects that need to come before the preamp.
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Hey MJMP, definitely they (wah, comp) should come first. but digital delay/reverb should come after and be mixed into the analogue path. My take on the 4 cable thing is MP1/2 A/B into digital (analogue) fx L/R fx out > pweramp > cabs (chain through method). But maybe the Lexicon lets you patch in and out of it at various points ? I'm not familliar with it. But from what El posted, the Lex is being the centre of the universe instead of the ADA (so MP1 in Lex loop (being a (very good) distortion pedal)), not that that's wrong, but all your gain structure gets usurped by the Lex. So the best of both worlds, Guit > Lex, Lex send (with wah and comp) > MP1, MP1 A/B > desk/mixer > poweramp > cabs, MP1 headphone out to Lex retrns, Lex out L/R to desk/mixer. This will work I think ? but interesting sorting out the gain structure.
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As you say now the Lex is kind of the center of the universe but that will change when I get the mixer... actually I will run the MP-1 outs in to the Lex hoping that the GREAT chorus of the MP-1 will work well in stereo in to the Lex.
After all of this latest connections experiment I came up with a crazy idea, to build or buy a MIDI or relay looper to go either straight to the MP-1 or to pass thru the Lex input when needed. MIDI would be great but I believe I could build a relay switcher for a lot less and I can control that with the Lex because it has 2 build in relays to change for example channels in an amp! I believe this would work http://www.geofex.com/article_folders/rmtswtch/rmtsw.htm no?
BTW if you know of a something like this that I can just buy instead of build (and not be a $300 dollar pedal) let me know.
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EC, i cheked the manual and there are no internal relays in the G2,so what you want to do won't work.Only the R2 (midi footpedal) has these relays.
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Yeha well I have the R2 also.
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Ahhhhh ok no problem then ,my bad :facepalm:
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Hey El, go with the mixer set up we've talking about on the other thread. Just coz you can doesn't mean it's the right thing for you (but hey I'm always up for an interesting patch, and you come up with interesting thought bubbles LOL). My approach (paradigm) is Good clean analogue path from guit to cabs, MP1/2 being the tone generator (well your fingers are really), then mix in in parallel (as desired) digital things that help. There are are lots of ways to use this and that, I wonder in the end if it's worth it ? KISS principle works well and always have an eye on your gain structure.
MP1 chorus is great, will work fine IMHO