Please can anyone recommend the best (and best quality?) replacement for the volume pot on the NAD 3020A ?
The original one isn't scratchy, but the volume output through the channels is uneven and accentuated when turned to a low level. Have tried contact cleaner and lots of turns already..
The original one isn't scratchy, but the volume output through the channels is uneven and accentuated when turned to a low level. Have tried contact cleaner and lots of turns already..
Attachments
This is a tapped pot. Note the upper connection. You can't find it, unless it comes from NAD or You search the web for used parts. But You could give up the loudness switch and fit in a standard pot.
Thanks Maaco, appreciated.
This was recommended.. would it work?
DACT Type 21 Stepped Attenuator / Potentiometer 20K * D Shape Shaft * HiFi grade | eBay
This was recommended.. would it work?
DACT Type 21 Stepped Attenuator / Potentiometer 20K * D Shape Shaft * HiFi grade | eBay
These are quite small pots and have loudness control taps (the red and white leads) on them. The type is rarely seen as a new part now and you'd have to ditch the feature to fit standard, available volume controls that would fit the board and the available space. Unfortunately, the best available pot types (copies of ALPS blue velvet RK27 style) are too large and won't fit the PCB. I would check out a local agent for Alpha brand pots if that's possible. They are dual gang, 10K log. taper pots (i.e. 10K audio taper type and everything has to match for it to be a simple replacement without needing to bodge the job. Try these folk in the UK- Alpha 16mm Short Split Shaft Potentiometers | Hifi Collective
Before ripping the pots out though, since they aren't noisy and probably aren't going to be directly replaceable, I'd look at the components connected to the loudness leads and see if the uneven low level problem isn't caused there. Start by checking what the loudness control switch function does and if that affects the balance problem.
If you can't find a schematic, it's because the 3020A doesn't have one but electrically, it's almost the same as 3020 inside.
Before ripping the pots out though, since they aren't noisy and probably aren't going to be directly replaceable, I'd look at the components connected to the loudness leads and see if the uneven low level problem isn't caused there. Start by checking what the loudness control switch function does and if that affects the balance problem.
If you can't find a schematic, it's because the 3020A doesn't have one but electrically, it's almost the same as 3020 inside.
Hi Ian,
Super helpful, as ever, thank you.
Waiting to hear back from Hi Fi Collective. Such a shame that the most likely outcome is that one has to lose the loudness function if one chooses to fit a high quality pot.
Measured resistance from loudness to ground which is 14.5 Kohms.
Got another question. The power switch broke as I attempted to disassemble and clean the carbonised contacts..., is this switch a suitable replacement?
https://uk.farnell.com/c-k-componen...5a-250vac-pcb/dp/3263285?MER=NULLSEARCH_VB_PD
NE1848EE
Industrial Pushbutton Switch, NE-18 Series, DPDT, On-On, Plunger for Cap
Super helpful, as ever, thank you.
Waiting to hear back from Hi Fi Collective. Such a shame that the most likely outcome is that one has to lose the loudness function if one chooses to fit a high quality pot.
Measured resistance from loudness to ground which is 14.5 Kohms.
Got another question. The power switch broke as I attempted to disassemble and clean the carbonised contacts..., is this switch a suitable replacement?
https://uk.farnell.com/c-k-componen...5a-250vac-pcb/dp/3263285?MER=NULLSEARCH_VB_PD
NE1848EE
Industrial Pushbutton Switch, NE-18 Series, DPDT, On-On, Plunger for Cap
Looks like a regular Alps volume control pot. Here's a similar one with solder lugs, but only 100k is stocked.
RadioShack 100KΩ Dual-Ganged Stereo Audio Potentiometer
RadioShack 100KΩ Dual-Ganged Stereo Audio Potentiometer
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You may be able to reuse that, but it is a 4700pF X capacitor. Keep the boot.
https://www.mouser.com/ProductDetai...n1630gtDLckf1QiWoCGT7htjPtgaQGJxoCN9wQAvD_BwE
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Thanks gentlemen!
Yes, looks ideal... but 100K...
Also, I'm in the UK and Radio Shack don't offer shipping I think
Yes, looks ideal... but 100K...
Also, I'm in the UK and Radio Shack don't offer shipping I think
Fully appreciate everyone’s very helpful earlier advice that the ideal replacement volume pot isn’t available on the market, but am trying to see how close I can get..
Anyone have an opinion on this pot as a replacement in the 3020A?
As a 50K pot, what would be the likely consequences of installing it?
Less volume output? Stress on other components?
Is there anything that could be done to or around this pot to mitigate things if it were to be installed?
https://www.ebay.com/itm/192823330491
Anyone have an opinion on this pot as a replacement in the 3020A?
As a 50K pot, what would be the likely consequences of installing it?
Less volume output? Stress on other components?
Is there anything that could be done to or around this pot to mitigate things if it were to be installed?
https://www.ebay.com/itm/192823330491