Dumble stack vs. Fender stack - wiring difference

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TimS
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Joined: Fri Jul 13, 2007 1:03 am

Re: Dumble stack vs. Fender stack - wiring difference

Post by TimS »

Darkbluemurder wrote:I used the same cap values - 330pf treble, 0.1uf bass, 0.047uf mid. I replaced the existing 10k midpot with a fixed 10k resistor to ground and added a 250kA mid pot for the mid cap. I tried to use as many of the Fender stack parts to see what the difference in wiring would be.
Thanks. That's the closest I've seen to a direct comparison of the two wiring schemes, but I'm pretty sure that the 250k mid pot is the primary cause of the increase in midrange versus the Fender stack with a 10k midpot.

Glasman, since it appears that you already have the software tools set up for this sort of thing, could you do me a favor and run a couple of spice simulations? I'd really like to see the skyliner and bluesmaster wiring schemes compared using the same treble/mid/bass caps, slope resistor, and pot values and with no fixed resistor from the bass pot to ground (so the only difference between the two simulations would be the way the mid pot is wired). Any chance you might be able to try this for me?
TimS
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Joined: Fri Jul 13, 2007 1:03 am

Re: Dumble stack vs. Fender stack - wiring difference

Post by TimS »

Actually, on second thought a 5k resistor from the bass pot to ground would simulate the effect on the bass frequencies of a 10k linear mid pot on '5' , so that would probably be the most scientific way of testing.
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glasman
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Re: Dumble stack vs. Fender stack - wiring difference

Post by glasman »

TimS wrote:Actually, on second thought a 5k resistor from the bass pot to ground would simulate the effect on the bass frequencies of a 10k linear mid pot on '5' , so that would probably be the most scientific way of testing.
I will see if I can set this up after I get back to the hotel tonight.

Gary
Located in the St Croix River Valley- Afton, MN
About 5 miles south of I-94
aka K0GWA, K0 Glas Werks Amplification

www.glaswerks.com
TimS
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Joined: Fri Jul 13, 2007 1:03 am

Re: Dumble stack vs. Fender stack - wiring difference

Post by TimS »

glasman wrote:I will see if I can set this up after I get back to the hotel tonight.
Thanks, I appreciate it.

I'm really curious to see what disconnecting the mid pot from the bass pot actually does. It seems to me that it should give more independent control of the midrange without affecting the bass frequencies as much, since the resistive path from the bass pot to ground will no longer vary according to the setting of the mid control. What I don't know (and am hoping to find out) is what sort of effect it might have on either the frequency ranges controlled by those pots or their relative amplitudes.
TimS
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Re: Dumble stack vs. Fender stack - wiring difference

Post by TimS »

Actually, does anybody know how to get in touch with the guy who made the Tone Stack Calculator? I'm wondering if he might be willing to add a Dumble stack to the tool since those amps have become quite popular as of late, or at least share the source code so someone else could do it. Depending on what language and environment he used, I'd be willing to give it a try if I could get the necessary files.

There doesn't seem to be any way to contact him through his website since he stopped taking new forum signups, but perhaps someone here might already be a member and be able to pass the request on to him.
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LeftyStrat
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Re: Dumble stack vs. Fender stack - wiring difference

Post by LeftyStrat »

TimS wrote:Actually, does anybody know how to get in touch with the guy who made the Tone Stack Calculator? I'm wondering if he might be willing to add a Dumble stack to the tool since those amps have become quite popular as of late, or at least share the source code so someone else could do it. Depending on what language and environment he used, I'd be willing to give it a try if I could get the necessary files.

There doesn't seem to be any way to contact him through his website since he stopped taking new forum signups, but perhaps someone here might already be a member and be able to pass the request on to him.
It is written in Delphi :-(

The source is available here:

http://www.duncanamps.com/tsc/linux.html

I've been planning on implementing a version in something that might be more portable. I currently run the windows version in Codeweavers CrossOver windows emulation on my mac.

I'd also like to add quite a few other tone stacks to it. What would really be nice is a plugin architecture where people could create new tone stacks for it.

Of course, why stop there, how about a digital emulation mode where you could run audio through it and listen to the results. :shock:
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jelle
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Re: Dumble stack vs. Fender stack - wiring difference

Post by jelle »

:D

I want one! :wink:

GREAT IDEA! I guess nothing beats testing stuff in an actual amp but this would be a really quick way of testing before getting the soldering iron out.
tele_player
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Re: Dumble stack vs. Fender stack - wiring difference

Post by tele_player »

Somebody could just write a few lines of SPICE code to get the simulation.
dbeeman
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Re: Dumble stack vs. Fender stack - wiring difference

Post by dbeeman »

I'd really like to see this too.
dB
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