MXR - 6 and 10 band Equalizer  [schematic]

Discussion regarding early stompbox technology: 1960-1975 Please keep discussion focused and contribute what info you have...
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Froebel
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Post by Froebel »

Can I fit the linear slide resistors externally with wires

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Froebel
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Post by Froebel »

Hey see if this helps
I am trying to make a PCB layout with Eagle Layout Editor
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MXR Schematics
MXR Schematics

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Govmnt_Lacky
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Post by Govmnt_Lacky »

Not to poop on anyone's parade but...

It clearly stated on the MXR schematic for the 6-band that ALL of the slider pots are:

"CTS spld taper 15K. 10% resistance at 25% rotation. 90% resistance at 75% rotation."

I see most of the diagrams that people are generating as having 50K sliders :?:

After looking at several taper curves, it appears that this taper reflects an EQ (W) taper as pointed out earlier in this thread.

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Fix_Metal
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Post by Fix_Metal »

Govmnt_Lacky wrote:Not to poop on anyone's parade but...

It clearly stated on the MXR schematic for the 6-band that ALL of the slider pots are:

"CTS spld taper 15K. 10% resistance at 25% rotation. 90% resistance at 75% rotation."

I see most of the diagrams that people are generating as having 50K sliders :?:

After looking at several taper curves, it appears that this taper reflects an EQ (W) taper as pointed out earlier in this thread.
6b is different than the 10b

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Dirk_Hendrik
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Post by Dirk_Hendrik »

Govmnt_Lacky wrote:Not to poop on anyone's parade but...

It clearly stated on the MXR schematic for the 6-band that ALL of the slider pots are:

"CTS spld taper 15K. 10% resistance at 25% rotation. 90% resistance at 75% rotation."

I see most of the diagrams that people are generating as having 50K sliders :?:

After looking at several taper curves, it appears that this taper reflects an EQ (W) taper as pointed out earlier in this thread.

Although I agree qith you that the combination of a reverse los and a log taper over the full travel, making a w-taper indeed, gives a superior response but functionally the value doesn't make a difference at all. Take 20k linears and the circuit still behaves like an EQ with the same min-max cut boost values. Make em 100k linear and it still behaves like an EQ with the same min-max cut boost values
Sorry. Plain out of planes.

http://www.dirk-hendrik.com

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jimosity
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Post by jimosity »

On the ten band, is it possible to bypass the AC input and have it run right off of DC?
Does that mean it needs 15vDC or can it be modded to run on 9VDC (maybe with a charge pump and bipolar supply?)?

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lead2203
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Post by lead2203 »

Dirk_Hendrik wrote:
Govmnt_Lacky wrote:Not to poop on anyone's parade but...

It clearly stated on the MXR schematic for the 6-band that ALL of the slider pots are:

"CTS spld taper 15K. 10% resistance at 25% rotation. 90% resistance at 75% rotation."

I see most of the diagrams that people are generating as having 50K sliders :?:

After looking at several taper curves, it appears that this taper reflects an EQ (W) taper as pointed out earlier in this thread.

Although I agree qith you that the combination of a reverse los and a log taper over the full travel, making a w-taper indeed, gives a superior response but functionally the value doesn't make a difference at all. Take 20k linears and the circuit still behaves like an EQ with the same min-max cut boost values. Make em 100k linear and it still behaves like an EQ with the same min-max cut boost values
I have a bunch of these 15K sliders NOS from MXR if anyone need them.

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Fix_Metal
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Post by Fix_Metal »

jimosity wrote:On the ten band, is it possible to bypass the AC input and have it run right off of DC?
Does that mean it needs 15vDC or can it be modded to run on 9VDC (maybe with a charge pump and bipolar supply?)?
You need ±15VDC to have the same original rails.

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