Help w/2000 Fender Pro Jr Tweed Amp...

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zozoe
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Help w/2000 Fender Pro Jr Tweed Amp...

Post by zozoe »

Greetings again, I seem to have misplaced all my notes, but I need to tweak or replace both the Vol and Tone pots... I don't want to alter their 'range' as much as I need to fix the tape. The majority of the sweep on the VOLUME control lives between 1 and 3, & I want to more smoothly level out the gain between 0 & 10...

Similarly, the bulk of the high end on the Tone control lives between 8 & 10, and here again, I'd like a better & more gradual Tone sweep across the 0 & 10... My previous attempt at rectifying this led to both suggestions going from a Linear pot to an Audio, as well as to go from Audio to Linear on both pots, & perhaps to clip the Tone Cap....

So, now I'm confused as to what's in there now, & what to change to... I don't have the schematic & I'd finally like to tackle this. Kindly set this straight & rell me what & where to buy the necessary parts.

Also, to replace the cheapo input jack, do I require a shunting type or what?

As some of you might already know us that these amps are near impossible to get inside of, & I have zippo experience with printed boards, so off to my guy I go.....

Many thanks in advance 🕉🎶🎸
sluckey
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Re: Help w/2000 Fender Pro Jr Tweed Amp...

Post by sluckey »

zozoe
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Re: Help w/2000 Fender Pro Jr Tweed Amp...

Post by zozoe »

Now that I look closer at that Tone pot, that's an '8', & not a 'B', so both are audio pots I take it?

Thnx again ॐ💃🕉🎶
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martin manning
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Re: Help w/2000 Fender Pro Jr Tweed Amp...

Post by martin manning »

On the Pro Jr schematic I see 250kΩ10A for the volume pot, so 10% audio, and 250kΩB for the tone control, so linear.
Stevem
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Re: Help w/2000 Fender Pro Jr Tweed Amp...

Post by Stevem »

When Fender makes these amps if they would simply swap these those two pots folks would be a lot happier!
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zozoe
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Re: Help w/2000 Fender Pro Jr Tweed Amp...

Post by zozoe »

Lastly, what would clipping the bright cap do? I'm assuming it would just open up the treble tap, giving me all the high end on the amps got, as if the Tone control was on 10...? Thnx
thetragichero
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Re: Help w/2000 Fender Pro Jr Tweed Amp...

Post by thetragichero »

bright cap allows some of the high frequency to pass when the volume pot is lower than 10, so it will actually lessen high frequency content when clipped
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zozoe
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Re: Help w/2000 Fender Pro Jr Tweed Amp...

Post by zozoe »

thetragichero wrote: Sat Jul 02, 2022 1:11 am bright cap allows some of the high frequency to pass when the volume pot is lower than 10, so it will actually lessen high frequency content when clipped
And I assume it disables the Tone pot?
Thnx 🕉🎵
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martin manning
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Re: Help w/2000 Fender Pro Jr Tweed Amp...

Post by martin manning »

zozoe wrote: Sun Jul 03, 2022 2:53 am
thetragichero wrote: Sat Jul 02, 2022 1:11 am bright cap allows some of the high frequency to pass when the volume pot is lower than 10, so it will actually lessen high frequency content when clipped
And I assume it disables the Tone pot?
Thnx 🕉🎵
No, the tone pot is still fully functional. The bright cap is a bypass around the top half of the volume pot for high frequencies, effectively providing a treble boost at reduced volume settings. It's compensation for the way your ears perceive frequency vs. volume.
sluckey
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Re: Help w/2000 Fender Pro Jr Tweed Amp...

Post by sluckey »

zozoe wrote: Fri Jul 01, 2022 4:51 pm Lastly, what would clipping the bright cap do? I'm assuming it would just open up the treble tap, giving me all the high end on the amps got, as if the Tone control was on 10...? Thnx
The pro jr. does not have a typical bright cap on the volume pot. Using this schematic for a reference, please tell us which cap you are calling the bright cap.
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martin manning
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Re: Help w/2000 Fender Pro Jr Tweed Amp...

Post by martin manning »

Ah, you are right Steve. Of course I described what a bright cap usually does :^)
C2 functions like a bright cap, as does C3 when the tone control is rotated CW. As a first cut, I would get rid of C2 (22p), and reduce C3 to 1n or 500p. The pots are fine as they are.
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