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Lexicon Alex Broken Input Pot replacement & knob (Read 12572 times)

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Great to hear, good job, can you share a part number with us?
Mapex Pro M Maple standard, Pearl 800 series cymbal stands, Vex hi hat stand, Pearl P201P double bass pedals, Tama mid level throne, All Zildjian A cymbals, 21" Rock Ride, 18" med thin crash, 16" med thin crash, 10" splash, 14" new beat hi hats.

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Problem solved. Replacement pot 50 ohm from mouser did the job. Old pot was extremely difficult to remove.

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Good deal, let us know how you make out.
Mapex Pro M Maple standard, Pearl 800 series cymbal stands, Vex hi hat stand, Pearl P201P double bass pedals, Tama mid level throne, All Zildjian A cymbals, 21" Rock Ride, 18" med thin crash, 16" med thin crash, 10" splash, 14" new beat hi hats.

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I actually bought a single item from Mouser Electronics which carried the ALPS P/N. Standard part in ALPS inventory. I will let you know after I disassemble and compare the resistances if it will work out.

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I went over to have a look at ALPS, did you notice you have to order at least 600 pieces? This is what I was telling you about when trying to order parts, most electronic supply companies will only sell in large quantities. So it's not just a matter of finding the right part, but also finding the part where you don't have to buy a truck load to order it. I will send an email or call a couple of vendors I usually deal with to see what they can come up with.
Mapex Pro M Maple standard, Pearl 800 series cymbal stands, Vex hi hat stand, Pearl P201P double bass pedals, Tama mid level throne, All Zildjian A cymbals, 21" Rock Ride, 18" med thin crash, 16" med thin crash, 10" splash, 14" new beat hi hats.

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To get true ohm's it should be taken out. Your going to have to take it out to replace anyway. If you find something before I do please keep us posted here. Thanks. I'm going to be meeting with Bob Sellon hopefully in a few weeks, he has allot of info he has to dig through he is going to get to me. As you may know he was an engineer for Lexicon and had a huge part in the development of Jamman and the MPX G2. But I will defiantly have some time during next week to help you if you have not found anything by then.
Mapex Pro M Maple standard, Pearl 800 series cymbal stands, Vex hi hat stand, Pearl P201P double bass pedals, Tama mid level throne, All Zildjian A cymbals, 21" Rock Ride, 18" med thin crash, 16" med thin crash, 10" splash, 14" new beat hi hats.

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Hi Keith,

Thanks for the help so far. I did call Lexicon and they were only able to tell me that the Input (first knob), mix and output (second and third knobs) used the following pots 1 - 10KBX2 and
2 -  50KAX2 but could not tell me which one was the input knob. I am leaning towards the 50KAX2 as the number on the pot is 15A50KX2. I found a 50K 16mm single shaft, dual unit from ALPS that looks like it might work P/N RK16312A0BKH. How Can I measure the resistance if the pot is soldered to the board or do I have to de-solder it first? Any thoughts are welcomed.

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I talked to Bob about it and it is the same one used in Jamman, that part number may not be of any use if the part was custom ordered for Lexicon. I did a search with the part number you gave, it comes up as a cap. You have to find the right pot, it's not as simple as 6 pins and travel of knob. You need to know voltage and resistance range for the pot. I have a Jamman here that I'll check out also I will do some inquiries. To see if something is available that will come close to do the job. If it is a custom part the only way to get an exact replacement you would need to go to a manufacturer and order like 1000 units. I am a bit tied up this week with a huge project, but will have some free time next week to get into this for you. 
Mapex Pro M Maple standard, Pearl 800 series cymbal stands, Vex hi hat stand, Pearl P201P double bass pedals, Tama mid level throne, All Zildjian A cymbals, 21" Rock Ride, 18" med thin crash, 16" med thin crash, 10" splash, 14" new beat hi hats.

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Hi Keith,
I opened the unit and the pot is marked 15A50KX2. It is a six pin (2 3-row) through hole with approximatley 3/16" pitch both directions. Any help identinfying a replacement would be greatly appreciated. Thanks

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Will need to find the specs for that pot. Lexicon does not carry parts for the discontinued line of their products so substitute parts have to be found using the specs of the original part. Most times you can not find exact part and may need to be modified a bit to get it to work with the unit. Most times pots do not come with the knob, but knobs can be found at Radio Shack.
Mapex Pro M Maple standard, Pearl 800 series cymbal stands, Vex hi hat stand, Pearl P201P double bass pedals, Tama mid level throne, All Zildjian A cymbals, 21" Rock Ride, 18" med thin crash, 16" med thin crash, 10" splash, 14" new beat hi hats.

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Thats correct. It is the first knob from the left side of the unit. Not a switch but a rotary input knob.

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When you say input switch, you mean the control knob next to the mix knob right?
« Last Edit: August 11, 2010, 07:17:17 PM by Keith »
Mapex Pro M Maple standard, Pearl 800 series cymbal stands, Vex hi hat stand, Pearl P201P double bass pedals, Tama mid level throne, All Zildjian A cymbals, 21" Rock Ride, 18" med thin crash, 16" med thin crash, 10" splash, 14" new beat hi hats.

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Hi All,

I recently became the owner of a Lexicon Alex Effects unit with a broken Input Pot. Can any one help identify the replacement pot to use and where to locate one. Also the knob for the pot. The knob and the shaft were sheared of.
Thanks.