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PRE and POST equalizer TIPS needed!


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Hey guys!

 

I'm going to experiment wit my dbx215 eq and put second eq channel just before my preamp in order to play with some freq. little more.

 

My goal is to get that midrangy sound with ultra tight bass and cutting highs but in a way a bit scooped. Just like meshuggah, bulb or fellsilent.

 

I have C7 Blackjack with rewounded JB-7 wich is now more clearer and articulated. Rest of the gear is mentioned below.

 

Right now I use one equalizer channel after the preamp and cut everything above 4kHz, boosting around 1-2kHz, cuting 400-600Hz, and boosting 100Hz.

 

My question is: When I put another eq channel before preamp, what is the best ratio of eq bands of pre and post equalizer to start with to get the mentioned sound?

 

Thanks

 

A.

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If you boost mids before your gain stages, you'll get nicely saturated, very present distortion sounds. Then bring the bass & treble back with a scooped curve after your distortion. That'll keep the mids & treble clean & tight while giving you some in-your-face distortion.

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What works for me, but your mileage may vary, is to use a pre eq curve that is the opposite of the post eq curve; it sounds counter intuitive but it works, the end result is that you clean up the frequencies you'll actually boost later on; for instance if you favor a scooped metal tone, use a frown pre eq curve (boost the mids), the end tone will be crunchier and cleaner with less gain needed.

Hope that helps !

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If you boost mids before your gain stages, you'll get nicely saturated, very present distortion sounds. Then bring the bass & treble back with a scooped curve after your distortion. That'll keep the mids & treble clean & tight while giving you some in-your-face distortion.

 

 

yup

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I just realized the problem!

 

I should not connect my guitar directly into my dbx 215 equalizer in order to boost some frequencies, because the output impedance of my guitar is much higher than the input impedance of dbx equalizer!!!

 

I'll need some kind of impedance transformer!

Can somebody suggest something for this to work properly?

 

Will ordenary stompbox work as a high-to-low ohm impedance transformer,

or will I need an active DI box, as I read somewhere, wich will demand constant usage of battery power supply?

 

 

I 'll appreciate if anybody with similar experience and knowlage shares the options with me!

 

 

THANX!

 

A.

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Alekke, I had the same problem going from my guitar directly into a rocktron ProQ equalizer; i was advised to use a clean boost, for instance a MXR MC-401 (http://www.thomann.de/fr/mxr_mc401.htm), cobuilt by bob Bradshaw. This way your guitar has a strong enough signal to enter a rack unit.

 

Me, I gave up on the idea, and just use an EQ pedal in front of my amp and rack to get a single pre-EQ curve, the one i need most often for distortion.

 

I hope that helps !! :)

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OK, this is not what I expected. Heres what happened:

 

I tried to connect the dbx215 eq before the preamp, I even use racktuner before my guitar hits the equalizer to lower the impedance cause dbx rack eq has only 20-40kOhm input, and all I got was noisy overdrive instead of crushing hi gain that I had before connecting eq pre gain.

 

heres some specifications from dbx 215:

 

Inputs

Connectors: 1/4" TRS, female XLR (pin 2 hot)

Type: Electronically balanced/unbalanced, RF filtered

Impedance: Balanced 40k?, unbalanced 20k?

Max Input Level: >+21dBu balanced or unbalanced

CMRR: >40dB, typically >55dB at 1kHz

 

Outputs

Connectors: 1/4" TRS, male XLR (pin 2 hot)

Type: Impedance-balanced/unbalanced, RF filtered

Impedance: Balanced 100?, unbalanced 50?

Max Output Level: >+21dBu balanced/unbalanced into 2k? or greater

>+18dBm balanced/unbalanced (into 600?)

 

System Performance

Bandwidth: 20Hz to 20kHz, +0.5/-1dB

Frequency Response: 50kHz, +0.5/-3dB

Dynamic Range: 108db

Signal-to-Noise: 90db

THD+Noise:

Interchannel Crosstalk:

 

 

So whats the story here?

Is it possible that it cant operate with guitar outputs?

Can it really be connected after a guitar and how, or not?

I read somewhere that between that and instrument input are 20dB difference.

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There is a mismatch between levels, not only impedance. (if I understand your setup). Your guitar signal enters the EQ about 30dB lower than what the EQ expects, so you have ground noise, because the amount of "musical" signal that goes through is very low. I had the same problem. As I said you need to use a clean boost between your guitar and the EQ. But then, you may have problems because your preamp sees a far stronger signal entering it? I haven't gone that far, so I can't help you there.

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Damn!

So question is how could I put this together?

I'm sure that the impedance is always going from smaller to higher, so it should not be the problem.

 

I use my eq's ch1 after a preamp and before poweramp, and I don't think that my poweramp sees any stronger signal that it should.

 

Is there any one that managed to connect the setup this way?

 

I have an irresistible need for using my eq's ch2. :)

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