Too much gain into guitar pedal (Clavinet)

[Gary75]

I bought a Mojo Overdrive guitar pedal, and for the price sounds really nice on the effects loop on my Rhodes. However when I put my D6 and Wah through it, it distorts. That is until I turn the Clavinet volume down 1/5 volume and then it sounds great. I guess it's too much gain into the pedal. (New battery in D6, Wah running off PSU) Aside from turning stuff down, is there anything else I can do? I'm not running into anything apart from my mixer (Rolls MX122)

 

 

[Ulf]

> I bought a Mojo Overdrive guitar pedal,

...

> it distorts.

 

Isn't that exactly the point of an overdrive pedal...

 

I guess you mean the nice fat (harmonic) distortion is lost and replaced by less musical harsh tone?

[Baldwin Funster]

Nothing wrong with sending a low signal into the pedal. It was designed to work at a much lower input level and impedance level than a line level output but if you aren't getting a lot of hiss from the extra gain needed to bring the pedals output up to line level by the next gain stage in the signal chain than its ok. Nothing more you can do except expensive modifications to the pedal or add a pad via a direct box. You will still need to gain the signal back up to line level to drive the next device or amplifier.

[Doerfler]

I too have experienced different results with various pedals on vintage keyboards. Unfortunately there is only trial and error. Under these circumstances buying from places with a 30 or 45 day return policy is a great way to try things out as you might not be able to get your clavinet into your local mom and pop shop.

I have never used overdrive on my Rhodes so I don't know the sound you are looking for. Ring Mod and tube amps for sure, maybe that's the sound you are after.

I use one of these on my clavinet. FULLTONE CUSTOM SHOP FULLDRIVE 3 | 20TH ANNIVERSARY EDITION Love it.

[Al Coda]

In the past, I blew the BBD chip in a EH Deluxe Electric Mistress Flanger for several times w/ my Clavinet D6.

Same w/ Schulte Compact Phasing A.

 

A.C.

[MurMan]

Nothing wrong with sending a low signal into the pedal. It was designed to work at a much lower input level and impedance level than a line level output but if you aren't getting a lot of hiss from the extra gain needed to bring the pedals output up to line level by the next gain stage in the signal chain than its ok. Nothing more you can do except expensive modifications to the pedal or add a pad via a direct box. You will still need to gain the signal back up to line level to drive the next device or amplifier.

Kas is on the right track. You have two problems: The signal from the Clav is line level and too hot for the pedal. The signal out of the pedal is instrument (guitar) level and needs to be brought up to line level for you mixer. (Kas - instrument signals are high impedance.)

 

You can connect the clav to the pedal using a 1/4" attenuator pad. I prefer the resistive attenuators (no transformer). Note that you have a level-matching problem on the input, not an impedance-matching problem. (It's not a problem for a low-impedance source to drive a high-impedance input.)

 

The easiest way to get the output of the pedal up to line level is to send it to the mic input of the mx122. Hopefully you're not using this channel.

 

edit: Of course the simplest solution is to just turn down the clav. But, depending on the input circuit of the pedal, there's a chance of blowing something like A.C. mentioned. The attenuator would take care of that.

[WesG]

Like Murman, I like resistive attenuators. Build a resistor voltage divider. Use large enough total resistance to stay above the output impedance of your clav (which is probably 600ohms).

 

A 5K log pot (wiper is output) makes a great variable divider. Anything between 1K and 10K is probably fine. Or you can use discrete resistors.

 

https://en.wikipedia.org/wiki/Voltage_divider

 

Wes

[Gary75]

Excellent knowledge and advice guys, thank you. I shall set about the attenuation circuit. Yes I save CH1 on the Rolls specifically for the D6!

[Al Coda]

The signal from the Clav is line level and too hot for the pedal.

 

The signal might be too hot for SOME pedals, but as long as the Clavinet D6 is original, it´s output isn´t line level.

The output was designed to operate guitar amps which have HiZ inputs.

 

When I started using mixers, we modified the Clavinet D6 w/ a line level pre-amp and used mixer channel-inserts for rackmount FX instead of stomp boxes.

We used the old Roland rack series then, SDD-320 Dimension D, SBF-325 Flanger/Doubler, SPH-323 Phaser ...

 

I had the issue w/ the 2 devices mentioned above only, but not w/ other stomp boxes like the Mutron III, Mutron Phasor II, Vox and Morley Wah pedals and also not w/ the BigMuff Pi.

 

IMO, a compressor/limiter (w/ noise suppression) like a Rocktron 300A would do the trick.

It has the advantage it´s mono and the compressor itself and the HUSH noise reduction circuit have separate I/Os, so the Clavinet could run into the compressor and out of the compressor to the pedals, then plug the output of the last device into the HUSH and go to the amp from there.

 

It´s occasional peaks killing sensitive chips from vintage stomp boxes like the Reticon BBD chip is.

 

The vintage MXR Flanger uses the same BBD chip, but has a signal gain reduction built in to protect the chip for the price the FX signal becomes weaker when the unit is feeded w/ hotter signals than HiZ.

 

A.C.

[MurMan]

The signal from the Clav is line level and too hot for the pedal.

The signal might be too hot for SOME pedals, but as long as the Clavinet D6 is original, it´s output isn´t line level.

The output was designed to operate guitar amps which have HiZ inputs.

Thanks for clarifying that. But the OP's symptoms sound like the pedal is being over-driven. Isn't an attenuator a much simpler and more reliable fix than an external compressor?

[JeffLearman]

(It's not a problem for a low-impedance source to drive a high-impedance input.)

Nice post but this statement is not generally true. It's true in this case, but you wouldn't want to plug a dynamic mic (low impedance source) into a high-Z input. For weak signals, matching impedance transfers the most power across the interface and thus yields the best S/N ratio.

 

Also, while passive electric guitars are hi-Z (say, 250 kOhms to 500 kOhms), active electric guitars are line level, and the inputs of most stomp boxes are basically line inputs (but often with higher impedance and a bit more gain). The outputs of stomboxes are pretty much line level outputs. We've all used rack line-level devices in our guitar FX chains, haven't we? (Oops, wrong forum, never mind.) So, it's odd that a line output would blast a stompbox.

 

Regardless, if the clav is overdriving the pedal, turn the clav's volume down or use an attenuator.

 

A clav's output is nominally 10 kOhms, according to this. It's active, so it'd make sense to have a line level output. Line level outputs are fine for driving a guitar amp.

 

[Edit] I see AC says they're not line level outputs. OK, no problem, but I don't know what change you'd need to make to a preamp to drive a guitar amp rather than a line level input, and guitarists drive guitar amps with line level outputs all the time.

[JeffLearman]

I also agree with AC's recommendation for type of device. Personally, I'd use a noise gate with a gain control, because a noise gate is useful anyway.

[Al Coda]

Thanks for clarifying that. But the OP's symptoms sound like the pedal is being over-driven. Isn't an attenuator a much simpler and more reliable fix than an external compressor?

 

IMO it´s looking for the issue on the wrong side.

I´d say the Mojo OD pedal itself is the culprit, not the Clavinet when in good working condition.

Can also be the Clavinet´s original preamp has an issue,- it´s not the best piece of electronics and it´s aged.

Maybe it needs to be rebuild/overhauled or replaced by a better one.

 

The OP said the pedal works good for the Rhodes, but that´s different signal/frequency spectrum.

Can be that OD stomp box isn´t the best for a Clavinet D6.

 

I´d try different FX before making the low level (HiZ) signal coming from Clav´s pickups and poor preamp even lower level.

 

Clavinets improved,- a D6 has a bit hotter level than a Clavinet C p.ex..

 

That said, I never heard about a Clav needs an attenuator for driving a FX chain.

It IS a solution, but only one of many solutions.

A compressor/limiter is also only one of these.

 

In fact, it SHOULD not be necessary, which would be the best solution.

 

OTOH, a Clav behaves similar to a electric guitar.

A compressor is welcome because according to the settings of the rocker switches, the Clav produces a wide range of tones and different levels.

Some understanding of the settings is essential ...

understanding the clavinet tone controls

 

The OP doesn´t mention which settings produce the unwanted sound w/ his OD-pedal, but normally, it WAS necessary to adjust the CLavinet´s output volume according to the settings in use.

It has a volume knob.

 

Usage of a compressor/limiter also allows a wide range between just only limiting peaks and/or boost/attenuate output level (use makeup gain on the compressor), or also use it as an effect where you really hear the compressor pumping or focussing the attack of the tone p.ex..

It´s really a matter of taste.

 

Some like the coloration some compressors offer.

That´s why I owned (and still own) the Rocktron 300A as well as DBX166 and also a cheapo Alesis 3630.

 

When we recorded electromagnetic instruments incl. Rhodes and Clav, a compressor was in the ballpark always.

For recording, the Valley People 440 was always the best !

I never owned one, but it was in every studio I recorded.

But in opposite to live gigging, the (hi-quality) compressor was inserted into the recording console´s channel and not the 1st device in a FX chain.

 

I hope it helps !

This is my last post for next future.

I´ll be on a move in a few hrs and will be disconnected from the internet for some time beginning march 31.

 

A.C.

[MurMan]

(It's not a problem for a low-impedance source to drive a high-impedance input.)

Nice post but this statement is not generally true. It's true in this case, but you wouldn't want to plug a dynamic mic (low impedance source) into a high-Z input. For weak signals, matching impedance transfers the most power across the interface and thus yields the best S/N ratio.

I made two simplifying assumptions in my statement that I should have clarified: this applies to common audio signals (instrument, mic, & line) connected over short distances, say 50 feet or less, to an amplifier. This appears to be the OP's situation.

 

The signal that the amplifier senses (and thus amplifies) is the amplitude that reaches it's input. The amp is not sensing the power transferred to the input stage. Therefore, transferring the maximum power isn't the goal and impedance-matching isn't needed.

 

Your impedance matching example would apply to a mic driving the resistive-capacitive load of a long cable, but not to the op's case. Cable loading is negligible for short audio cables and can be ignored.

 

(Something to think about: If you want to transfer the max amplitude to a load and the cable-effects can be ignored, you want a severe impedance mis-match: zero source and infinite load impedance.)

[MurMan]

IMO it´s looking for the issue on the wrong side.

You could be right. A good tech could diagnose this better than the forum.

 

I'll defer to your knowledge of older gear. But I still like simple solutions.

[Doerfler]

Can be that OD stomp box isn´t the best for a Clavinet D6.

 

that's where I was going with my post.

[Gary75]

The D6 is completely stock and near mint condition. The preamp has had some of the aged components replaced using the Vintage Vibe kit and is not noisy. All I'm looking to do is avoid using any dedicated amps and to get a tone using a pedal. It works great into a Vox guitar amp, but it's some cheapy I picked up, and the Mojo pedal sounds far better. (Vox Ad15vt xl). The Vox amp is geared towards metal players!

 

I have just ordered this as its so cheap

 

https://www.vein-tap.com/product/the-leech-guitar-attenuator/

 

I also have a Buddha Chakra compressor pedal, a Boss NS2 gate, passive and active DIs as well as a Crybaby GCB 95F

 

So I'm assuming that I would go D6-attenuator-compressor-Wah-Mojo-

 

Not sure if I need the gate in there?

 

And also, do I need a DI on the end to run into the XLR channel. I'd assume it wouldn't be good practice to run TS jack to XLR cable from the end pedal (Mojo)

 

Mojo pedal worked fine on Rhodes but it was plugged into the true effects loop on my suitcase rail. At that point it is before the preamp coming straight off the Rhodes harp.

 

Shit, I only wanted to play Higher Ground!

 

http://s18.postimg.org/jyiz70q15/image.jpg

 

 

 

 

 

 

[WesG]

I won't comment on Clavinets since I don't own one.

 

But I will point out that an attenuator is a better device for attenuating an overly-loud signal than a compressor, provided you want to maintain your original dynamic range.

 

Wes