moved to parts.
The schematic in the service manual does not describe the type or brand of pot. It simply specifies VR201 as two wafers, one is 50K B (audio) taper, the other 50K XH. I'm guessing that means the second wafer is just a reverse mounted version of the first, in order to have a mirrored response from either channel, like most stereo amplifiers.
However, I don't think it will be easy to buy an equivalent dual pot. with reversed log. tapers unless it is specifically described as a balance pot. You may find one in other amplifiers from that period that you can adapt but it's also easier to substitute a common, dual 50K linear pot with similar dimensions.
Note that a linear taper pot will not respond evenly across the range of rotation like the original audio (logarithmic) taper type but it likely never needs adjustment and this may not really matter to you unless you want to sell it.
However, I don't think it will be easy to buy an equivalent dual pot. with reversed log. tapers unless it is specifically described as a balance pot. You may find one in other amplifiers from that period that you can adapt but it's also easier to substitute a common, dual 50K linear pot with similar dimensions.
Note that a linear taper pot will not respond evenly across the range of rotation like the original audio (logarithmic) taper type but it likely never needs adjustment and this may not really matter to you unless you want to sell it.
I must correct an error in my reply above. In Asia, including Taiwan where the amplifier was made, B taper means linear taper so it seems you just need the dual linear 50K pot. type referred to, which you can buy from most major electronic parts distributors and maybe hobby electronics stores.
Check the dimensions from the datasheet so that it will fit the PCB and make certain the shaft is the correct type i.e. fluted to suit the same knob as used for other minor front panel controls. Modern pots are smaller than the old types and have smaller shafts too (6mm V 6.3mm) but you can often extend the pins with short pieces of wire if necessary, in order to locate the pot in the correct position and also in the front panel hole.
It may seem difficult but this is DIY and that's what we often need to do when the old style gear fails.
Check the dimensions from the datasheet so that it will fit the PCB and make certain the shaft is the correct type i.e. fluted to suit the same knob as used for other minor front panel controls. Modern pots are smaller than the old types and have smaller shafts too (6mm V 6.3mm) but you can often extend the pins with short pieces of wire if necessary, in order to locate the pot in the correct position and also in the front panel hole.
It may seem difficult but this is DIY and that's what we often need to do when the old style gear fails.
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Its solved.
I found my happiness on the internet.
Original potentiometer from NAD 3130.
Thank you.
I found my happiness on the internet.
Original potentiometer from NAD 3130.
Thank you.
Please tell us how it went when you fit the replacement. Assuming it is not a new component, you may not know its condition. Anyway, good luck and I trust it will work just fine for you.
Its original used potentiometer but in good working order.
I haven't received it yet I keep you informed after reception and assembly
I haven't received it yet I keep you informed after reception and assembly