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rack EQ help


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I need a two channel rackmount graphic EQ with no more than 15 bands per channel. The catch is that I need the first channel to run before the preamp on my Marshall TSL and the second channel to run in the FX loop.

 

I want this to be my signal chain: guitar -> tuner (can't decide between a Korg rackmount or my Boss TU-2 on the floor) -> EQ channel 1 -> GCX Audio Switcher -> amp.

 

I can't plug the guitar directly into the EQ can I? I'm not exactly sure how the whole line level thing works, but I don't think that will work. I was leaning toward the dbx 215 Graphic EQ, but I just got off the phone with one of their tech support guys and he said it wouldn't work.

 

How can I run a rack EQ IN FRONT of my amp?

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I sent you a PM. I have a pedals in bewteen (2 tube screamers). Any buffered effect like that will convert impedance. One without a buffer, like my true-bypassed Crybaby will not do the trick.

 

If you don't want a pedal bewteen the two, you need a box to convert the impedance. Someone else could chime in on what might work, but I think a direct box like Whilwind sells for $40 would do the trick. There are of course more expensive ones, like Axess, but I'm not sure of the advantage. Mayber quieter?

 

My pedals work great.

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Originally posted by Woody777

What about my trusty Boss TU-2? Thanks for the help, BTW.

 

 

I don't know. If you look at the manual, if it has specs, look at the input and output impedance. Typical guitar pedal input impedances are like 400-500 ohms I think, yet the output impedance will be really low, like 5-25 ohms. Also look at the dbx215 manual - I think the input impedance is 15 or 20 ohms, somehwere around there. If the Boss has a big conversion from input to output like that, you should be ok.

 

I don't know much about these things, but I was told that once you hit your first buffered effect you're all set. I guess buffered effect means the high impedance guitar signal is dropped to low impedance. The high impedance seems to be the problem, I think. But I wish I understood the technical reasons.

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...and as I said, by having pedals between my guitar and the dbx215, I have no probelm. I tried plugging directly into the dbx215 and it didn't work. It sounded weak and crappy, but as soon as I put the pedals in between, voila!

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...and as I said, by having pedals between my guitar and the dbx215, I have no probelm. I tried plugging directly into the dbx215 and it didn't work. It sounded weak and crappy, but as soon as I put the pedals in between, voila!

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this is from the Boss website...

 

Input Impedence 1 M ohm

Output Load Impedence 10 k ohm or greater

 

that seems like a pretty big conversion, right?

 

And I guess if it doesn't work there are products out there that will, right?

 

I think you know what you're talking about billstets, but could a third party possibly verify some of this info?

 

Thanks!

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I don't really know what I'm talking about, just what works! I did a couple of quick searches.

 

First of all the dbx input impedance is 20K ohms, so there shouldn't be any impedance mismatch.

 

More importantly, I'm not sure now that it's the impedance that's the only issue. I did a search on "buffer." I believe the buffers in effects are designed to counteract signal loss, particularly high end, from cable runs and active effects in the signal chain. This is why you only have capacitance on the highs in your first cable run from guitar to pedal, because then the pedal's buffer counteracts that problem after that. This is all to avoid tone suckage, like the old wahs that didn't have true bypass and no buffers. Even when they were off, they sucked tone. I'm thinking that maybe this buffering boosts the signal or something? I don't really know. We need someone knowledgeable to chime in. But I'm concerned that your tuner may convert the impedance, but not provide the buffer you need to go into the dbx215. The signal may be too weak. You may need a direct box or buffer.

 

The real professional one is the Axess, which goes for $120. A lot of pros use it, I think to drive multiple amps or signal routings without signal loss. For your purposes, I wonder whether the $40 Whirlwind, or something similar, would suffice. I mean, my TS9 reissue and/or Maxon OD808 seem to do the trick.

 

Well I hope someone who knows what they're talking about chimes in for ya. But the good thing is that, yes it is definitely do-able. I asked the same question when I got my dbx215 last year, and a simple guitar pedal with a buffer was the answer from the gearheads.

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Thanks for the info! I don't see why your Tubescreamer would work and my tuner wouldn't, but who knows. I do know that the Boss pedals have very good buffers, but it sounds like that may not be the only thing we're dealing with here. Any experts care to jump in here?

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Originally posted by Woody777

Thanks for the info! I don't see why your Tubescreamer would work and my tuner wouldn't, but who knows. I do know that the Boss pedals have very good buffers, but it sounds like that may not be the only thing we're dealing with here. Any experts care to jump in here?

 

 

Well I think it is the buffer that's the issue. If the Boss tuner has a buffer like other Boss effects pedals, then it will work. I just wasn't sure how you tell if it has one. I mean I don't know if just because it drops the impedance like other pedals necessarily means that it has a buffer. That's why we need an expert!!

 

Bump for Woody777 so he gets an answer.

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BTW, a sidenote:

 

I'm not paying attention to the tech side of whether the imp. will work or not, however, pre- and post- gain EQ's freakin' kill. You can sound like anything. Remember to boost the pre-gain eq at around 300-500 Hz and cut the post-gain eq at 600-800Hz:)

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Originally posted by guitarslinger213

BTW, a sidenote:


I'm not paying attention to the tech side of whether the imp. will work or not, however, pre- and post- gain EQ's freakin' kill. You can sound like anything. Remember to boost the pre-gain eq at around 300-500 Hz and cut the post-gain eq at 600-800Hz:)

 

 

I'm surprised more people here don't use pre and post EQ - it makes every amp I've ever owned sound tighter, more aggressive and cleaner. It's a must in my setup now.

 

But does anybodu know if my TU-2 will work as a buffer in front of the dbx 215?

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