Could My Broken Off Pot Be Soldered Back On?

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Mark7

Well-known member
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Use light activated super glue developed by dentist. So it will take being twisted.

Yes, it could be mounted on a hobby lathe. It would be perfect.

Dude, a dremel tool could do that job too.

Would iit fit the knob? look at the shafts.
 
Clean break?

Probably. I don't know how damaged it is by the hit. Is there any stub you can twist with a finger to see if the base works.

Show me.
 
I think "A taper" means different things depending where you are but whether log or linear, 15mm 10k pots shouldn't be hard to find.
To remove doubt I'd measure the pot yourself, as you turn it, and determine if it's linear, log, or rev-log,
then buy from someone who uses those words...Take a/b/c out of the equation.
 
How can I tell if it's linear, log or rev-log if it's not wired up to anything? I assume rev-log is reverse logarithmic. I'm pretty sure it's not that.
 
Its easy to determine if you have linear or log/audio taper. Simply measure the resistance at 50% of rotation. A 10K linear taper pot should measure around 5K. A 30% taper should be around 3K. Most audio taper pots are in the 10% range.

This represents the typical taper curves for CTS pots.

Potentiometer curves.jpg
 
Mark7 said:
How can I tell if it's linear, log or rev-log if it's not wired up to anything? I assume rev-log is reverse logarithmic. I'm pretty sure it's not that.
Click to expand...
Are there any numbers/letters on the pot (stamped or ink) which maybe a manufacturers part number which could be used to identify or cross reference what it is?
 
The 'A' specifies a Log taper. The link below explains tapers a bit including the reverse log.

Potentiometer Resistance Taper

How to determine the Resistance Taper of a Potentiometer
www.potentiometers.com www.potentiometers.com

The '551F' is going to take some more digging.
 
Oh. I've been looking at linear taper pots on the advice of another forum member (no names).
 
Correct. It’s an audio taper pot, which is what I advised the OP some months ago.

he can get the exact pot, just with a 20mm shaft instead of 15mm. If it was me I’d get the 20mm pot and grind down the shaft with a dremel tool.

that way it’s the same as the pots already in the unit, guaranteed fit to the PCB, knob will fit, etc.
 
If it’s a plastic shaft, find a bit of 15mm metal tube. Heat it up and melt it on. Less vibration and residue. However if it’s a pot where the shaft it too long, stick it in a power drill, and spin it and use a file.
 
sweetbeats said:
Correct. It’s an audio taper pot, which is what I advised the OP some months ago.

he can get the exact pot, just with a 20mm shaft instead of 15mm. If it was me I’d get the 20mm pot and grind down the shaft with a dremel tool.

that way it’s the same as the pots already in the unit, guaranteed fit to the PCB, knob will fit, etc.
Click to expand...
Nothing beats first hand info. :) Thanks, Sweetbeats.
 
The packaging is different, but should fit. Pigtail leads would need to be soldered to the pins of one gang of the pot to connect to the PCB (may need to orient the pin side of the pot away from the PCB and loop the pigtails back down to the board). Otherwise it has the 15mm shaft length, is flatted for the knob, audio log taper is standard 15A, and the mount thread is the same as the ALPS you had linked. May not look like OEM, but who's going to see it?
The PDF 'Tech Sheet' in link shows ordering details.
 
This has all been covered in the OP’s original thread on this issue from back in October of last year. See this thread starting on about post 33 or 34:

https://homerecording.com/bbs/threads/388-aux-buss-not-working.405770/page-2

The OP has readily available and affordable ALPS part options on his side of the pond, but the catch is it’s either a pot that is a perfect drop-in physically but electronically it’s linear taper pot, or he gets the audio taper pot with the 20mm shaft and he grinds it down. Its that simple.

I advised him in the case of his application it may really not make a difference at all if it’s linear or audio taper...it’s the level pot for one of the mono effect returns on his 388. In my experience I’m not often actively fading or boosting an effect return during mixdown...I may be making level tweaks, but honestly, IMO it’s splitting hairs whether that function is linear or audio taper. In some ways I think linear taper makes more sense there, but Teac likely put audio taper pots in there because that’s what was on the shelf as a result of cost saving bulk purchasing from ALPS. And you know, anybody can approximate the behavior of an audio taper pot with a linear taper pot...just accelerate or decelerate the rate of rotation (depending on whether you’re fading in or out). The OP, if he wanted the behavior of the EFF 1 and EFF 2 RETURN level controls to match, he could buy a pair of the linear taper pots that are a drop-in fit and be done with it.

Anyway, point is he has options, he just needs to pick something and move forward.
 
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Wait. I can use an audio taper pot?

Also. It's Effect and Auxilliary. The Aux buss is meant to send an independent mono mix of the program material recorded thus far to the talent's headphones. Seems to me that for something like that you don't really need the ability to fade the signal out smoothly.
 
Good deal...and right...right...aux pot. I got myself confused with EFF 1 and EFF 2 RETURN pots...those are the ones you could rob from an M-300 series console that are the same. Okay. But honestly I would consider audio taper even LESS critical on an AUX send level pot. Those pre-fade busses are typically used as a monitor or cue feed for the talent during tracking or overdubs, and usually you are setting the level to what the talent wants and leaving it there, not doing fades. So linear taper would be fine there also IMO. Now if it was me yes it would bug me to have 7 audio taper sends and the 8th be linear...or for my AUX MASTER to be linear and my EFF MASTER to be audio...that’s the way I’m wired, so there’s that if you’re wired that way too.

Anyway, yes, glad the link to your old thread refreshed the information that the part is an audio taper part (that’s what the “A” in 10KA stands for), and glad you found one.
 
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