EHX - Tube EQ

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
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borislavgajic
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Post by borislavgajic »

hand drawn audio path.......
have a nice day

boris

what is that 2sk30??? so it is not puuureTuBe :hmmm:
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modman
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Post by modman »

:thumbsup
Hey, thanks for sharing!
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Conguito
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Post by Conguito »

borislavgajic wrote:hand drawn audio path.......
have a nice day

boris

what is that 2sk30??? so it is not puuureTuBe :hmmm:
I know that this is an old post, but I coludn't resist to say something about this circuit.
I think that in this schematic the 2sk30 is used to have a constant cathode current, it's an alternative biasing technique, you can adjust the current in the cathode with the 10K trimpot that you can see in the lower part of the triode. This schematic is really strange......the guitar signal goes partially in the first triode and in the triode with this FET.......at the first sight I don't think that this circuit won't work too well or that it doesn't work, in the triode with the FET you can see that the grid is connected to V+ thru a 2M7 resistor..........I've never seen a circuit like this, I have seen other Tone Stacks with Valves and they are much simpler than this.
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soulsonic
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Post by soulsonic »

My guess is that the FET is used as a high-impedance input to a common-grid stage. That might explain how it would work; when you think about the triode being arranged as common-grid, it makes more sense.
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Post by ppluis0 »

Hi all

Sorry for revive this thread.

Someone of the forum had the opportunity to see this thing?

I wondered how it could make a tube parametric eq... :scratch:

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Best Regards,
Jose
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Post by ppluis0 »

Sorry for ask again without doing the appropriate search. I need some more training using the search button... :oops:

I see that posting recently which speaks of a known Ork.

(Thats a denomination very funny indeed :D )

Best Regards,
Jose
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