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Old 11-30-2008, 11:48 PM   #1
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distorted g-k?

have a gallien-krueger 700rb mark II bass amp i bought used. it sounds distorted when i play thru it so, i used different basses (active and passive), different outlets (in different houses/rehearsal spaces), bypassed the speaker, and later bypassed the head playing my ampeg head into the cab... but to no avail. (the boost knob has also been turned all the way down as to not add any more grit) don't know much about electronics, but i need some help! this amp would sound great if i could just get rid of that distorted sound. i love distortion and all, but i want it on my terms!
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Old 12-01-2008, 05:07 AM   #2
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This amp has 2 seperate power amps for bi-amping.
A 50 watt one for the tweeter and a 480 watt one for the main output.
Do both power amps distort ?
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Old 12-01-2008, 02:34 PM   #3
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g-k problems

after some fiddling, the noise seems to be here and there, although mostly here. i noticed that i'm getting a lot of crackling from the speaker when i turn the knobs. dirty? is that easily fixed? is this thesource of my problems? thank you for your patience, as i am "electronically impaired"!
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Old 12-01-2008, 02:50 PM   #4
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also...

completely forgot to answer your question by the way, it's early... when i push the button to bypass the woofer it seems to go away for the most part, except for the crusty sounding knobs of course.
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Old 12-01-2008, 06:24 PM   #5
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Well a good starting point is to clean the pots and switches.
Some reference here....General Maintenace\Cleaning
http://music-electronics-forum.com/s...ad.php?p=58082
Caig Labs' De Oxit Fader Lube is probably one of the best products
but you might have to ask at radio shack for something a bit less expessive.
Isopropyl alcohol also works but it tends to also clean out the pot shaft lubricant making the control seize .
You may be lucky , it could just be the noisy pots and switches.
It's worth getting some good cleaner that won't make the situation worse.
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Old 12-02-2008, 02:46 AM   #6
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cool, thank you very much for your help! is this something i could do myself given my limited experience with electronics and the resources you gave, or should i have someone more qualified take a look?
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Old 12-02-2008, 09:20 AM   #7
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Well if its just in need of cleaning you should be able to manage that.
Weigh up the cost of the solvent against having an experienced tech clean it and perhaps tend to some other minor faults.
To clean the pots(knobs) remove the cover and fitting the extension tube to the spray squirt it in the opening where the solder lugs protrude.
This may mean you have to tilt it or prop it upside down to allow gravity to assist to spread the solvent on the pot track.
Then rotate knob backwards and fowards to help clean the track.
With switches any opening you can find even where the shaft enters may require the button to be removed.
pot=potentiometer - volume/tone control - knob
As its a good amp if you can afford it take it to an expert.
At worst some output transistors may need replacing.

Last edited by oc disorder; 12-02-2008 at 09:28 AM. Reason: forgit sumpthin
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Old 12-03-2008, 03:15 AM   #8
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VERY COOL!!! thank you for your help, you have no idea how much you've helped!
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