I was given a SAE XXX preamp that for some reason had the balance slider pot removed and then put the unit back together. I would have been happier If they had at least bypassed the pot entirely. But no they just pulled it as shown in photo. I did locate a 100k ohm MN taper from surplusdealusa with the correct number of pins. No way to identify the pins on the new one even though the pin out configuration on the new matched the schematic and circuit board. The top two pins on the pot are identified as "3" and second row (staggard) of two pins are identified as "1" and the bottom two say "2". No mention of any ground. Any ideas how I can install the pot correctly. Have attached photos of schematic, new pot and the actual circuit board showing the holes were it was. Is this a straight plug-in or are modifications required? If this pot is a no go any ideas how to bypass the pot completely? Help appreciated.
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The balance pot is just after the volume pot, and is connected the same way.
Top = in, wiper = out. Looks like it is the exact same part as the volume control.
If your new part mechanically fits the board, it should work ok.
To bypass it, in each channel, add a wire jumper from balance in to balance out.
The 3rd terminal is grounded. If the balance control is just removed, there will be no sound.
Top = in, wiper = out. Looks like it is the exact same part as the volume control.
If your new part mechanically fits the board, it should work ok.
To bypass it, in each channel, add a wire jumper from balance in to balance out.
The 3rd terminal is grounded. If the balance control is just removed, there will be no sound.
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Yes the pins on the volume and balance pots look identical. SAE identifies the two with different part numbers. I also purchased a new volume pot from the same folks at surplusdealusa and it worked great. I have spoken to them and the two pots are different. The volume pot is an audio taper while the one I am working with is an MN Taper. What pins on the board should I attach jumpers to buy pass balance? If I do this will I end up with the balance at the 50/50 position which is what I would like to have as I never adjust balance anyway. Photo shows hand drawing of circuit board.
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Use a DVM and the schematic to determine which pins are which.
To bypass the balance control, for each channel, jumper the balance input pin to the balance output pin.
This will probably give you more gain as well.
To bypass the balance control, for each channel, jumper the balance input pin to the balance output pin.
This will probably give you more gain as well.
Aren't there two pins on one end and four on the other? It can only be installed one way. I get my SAE sliders from the same place, usually just plug and play.
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I too have ordered from Surplusealusa before for SAE products but this is the first balance slider I have ordered. The volume and tone sliders are plug and play but this balance slider, even though the pinouts match, does not work in the XXX.
The pin layout on the one from surplusdealusa is the same as the SAE but the pinouts must be different. I have tried two of them and no sound at all. Rayma says I can bypass with jumpers but I do not know which points to jump. I included A photo in my original post of the actual board where the pot should go but I am confused as to the jump points to bypass.
The schematic does not have the identifying pin numbers like the pcb has, so you'd have to trace things out.
All those connectors, etc. are very confusing.
All those connectors, etc. are very confusing.
Without the balance pot installed, I believe connect the V2A to B2A, and connect V2B to B2B via jumper wires will bypass the balance control.
Thank you, I will give it try. I had never considered using jumpers between the balance slider and the main volume slider to bypass the balance pot.
It seems that the MN taper pot from surplusdealusa reverses the L and R channel hence no sound.
Wonder is there is a way to jump it? Is your diagram showing how the Surplususa pot is set up or how the pot should work?
That is how a standard MN taper potentiometer is constructed.
From the image below, if the slider is in the middle position, the highest resistance end must be grounded, you can use a ohm meter to measure and determine which pins are which. I think the left and right channels of the SAE balance pot are reversed, so there is no sound output.
My suggestion is not to solder the pot directly to the PCB, but swap the L and R channels by connecting the pot via wires to the PCB, then test and see if this works.
If confirmed the pot L and R channels are reversed, you can cut all pin trace on the PCB and use jumper wires to swap channels.
From the image below, if the slider is in the middle position, the highest resistance end must be grounded, you can use a ohm meter to measure and determine which pins are which. I think the left and right channels of the SAE balance pot are reversed, so there is no sound output.
My suggestion is not to solder the pot directly to the PCB, but swap the L and R channels by connecting the pot via wires to the PCB, then test and see if this works.
If confirmed the pot L and R channels are reversed, you can cut all pin trace on the PCB and use jumper wires to swap channels.
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