I De Tweeded my 5F6A Bassman! !

a fine line between stupid and clever

Postby Geek » Thu Mar 03, 2011 1:44 am

IIRC, they have minumums for custom. Finding a dealer to go through is a #$% too (Digikey will not go-between on custom units).

Cheers!
-= Gregg =-
Fine wine comes in glass bottles, not plastic sacks. Therefore the finer electrons are also found in glass bottles.
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Postby Casey4s » Fri Mar 04, 2011 8:42 pm

Geek & Greg

Thanks for your help with this. I appreciate your expertise and expierience.

Next problem, if you can call it that, is that I get too much gain too soon. I would like to make the pot max at what would now be closer to 60% of the rotation.

Can I simply change the pot to 750K or 500K (which I have on hand) or is it more complicated that that.

I am also going to change the heater ground again. I didn't like the trimmer, and I am back on floating 100 ohm resisters. I am going to find a +V termination somplace, any suddestions?

I want to get this where I want it before I go into the next two mod phases.

Then I can give it a rest...

Thanks
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Postby Hotsauce » Fri Mar 04, 2011 9:30 pm

Measure the pot at the max setting you want, and add a resistor of that value in series to the wiper.

That way you can crank the pot and not go higher than the resistor value.

John C.
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Postby Casey4s » Sun Mar 06, 2011 10:21 pm

Thanks John

I'll give it a shot tomorrow.
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Postby Casey4s » Wed Mar 09, 2011 7:37 pm

John,

I tried that but, what I want is to get more useable sweep on the lower end, and less overall gain.

I am going to try a 1M resistor in parallel and try it. If it is in the ballpark and then I am going to replace it with a 500K Linear pot and see how it feels.

Thanks for the help everyone....
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Weber Active Tone Control

Postby Gingertube » Wed Mar 16, 2011 8:19 pm

Looking at the schematic of the Weber Active Tone Stack, the pots SHOULD be linear for correct "center flat" response.

CAUTION: We come unstuck with pot tapers ALL the time - that is because there is no international standard for what A, B, C etc mean.

IN GENERAL:

In USA

* A - Audio or Log taper
* B - Linear taper
* C - Reverse Log taper
* G - Graphic taper

In Europe

* A - Linear taper
* B - Audio or Log taper
* C - Reverse Log taper
* G - Graphic taper

Here in OZ we are used to this since we get stuff from all over. If in doubt set the pot to about mid travel and check wiper to each end with multimeter. Equal readings => linear.

Cheers,
Ian
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Postby Casey4s » Fri Mar 18, 2011 12:48 pm

Thanks for the post Ginger Tube, I like linear taper over audio in several other applications too. I did the 500K L substitution and I felt the degree of gain is more predictable with the Linear taper. I might go back to a 1M but Linear or I also might try one of the Clarostat 1.5ML pots I have lying around .

Thanks for the input guys.


This is an interesting clip pots, their construction and it explains the "False Audio" taper pots.

Link:
http://www.guitarkitbuilder.com/content ... eters-work
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