Using a 500k instead of 1meg for the bass in a standard tmb tone stack

[Tone Junkie]

I want to put dual tone stacks into this marshall chassis and plates I have so I have to use concentric pots they dont make 1 meg that I can find so 500k will have to be in the bass how do i make it behave like a normal 1meg. pot . Someone else i talked to said the 500k wouldnt make much of a difference but i find that hard to believe. Thanks Bill

[Raybob]

Alpha makes 1 meg linear dual pots.  They have them at CE Distribution.  Someone else must carry them too.

Raybob

[VMS]

Someone else i talked to said the 500k wouldnt make much of a difference but i find that hard to believe.

You can try the 500k pot in this Tone Stack Calculator and see for yourself:

http://duncanamps.com/tsc/index.html

I think the sweep behaves a bit better with 500k pot.

[topbrent]

I want to put dual tone stacks into this marshall chassis and plates I have so I have to use concentric pots they dont make 1 meg that I can find so 500k will have to be in the bass how do i make it behave like a normal 1meg. pot . Someone else i talked to said the 500k wouldnt make much of a difference but i find that hard to believe. Thanks Bill

How often do you turn your 1M pot all the way up?
 
If you are not a "bass on 10" kind of player, then you probably won't much notice the difference in net effect. 

I made this quick comparison chart to illustrate the effects between the various bass pot values.

[jjasilli]

Lots of good points already made.  If all else fails google "tone scaling" or search this forum.  Basicallty, in an RC circuit, if you halve the size of the pot, then double the size of the cap (and vice-versa).  You get the same tonal result.  If necessary, you can re-scale the entire tone stack in that manner.  You can pre-test your new cap & pot values in the Duncan TS calculator. 

[Tone Junkie]

Thanks guys that was a big help kind ease my worries its kind of a bass heavy build already so it would be better with less. Im putting a marshall 2203 on one channel and an slo lead on the other. Im going through kind of a high gain thing right now. I can suppliment the bass if need be with a fixed resonance mod if necessary. Raybob the dual 1meg alfa pots are not concentric, they both turn at the same time it would defeat the whole purpose of having two separate tone stacks in one space. But thank You anyway.
As usual you guys give me a bunch of great idea,s to work with, Thats why I love ya (in a strong male non mushy type of way of course). The reason I picked those two pre amps is the slo is the best of the modern high gain the 2203 gets all the classic rock plus if you back of on the volume knob it cleans up real well. I built one a 59 bright 2203 and liked it. but unfortunately i sold it to buy more parts, Im addicted hopelessly to amp building  as are some of you.Bill

[jeff]

It'd be like only being able to turn a 1MA pot up to 7. Bass pots to me always seem to sound like they dump their load early and turning them up higher has less effect anyway.

[Tone Junkie]

As someone on another site said look just do it and if there is something that you dont like you can fix it when its done quit talking and build it already, sounded good to me, boards almost finished caps came in today. Drilling new holes all over. Im like a kid in a candy shop. 
Thanks Bill