felixq78
Rookie Solder Flinger
Posts: 2
Likes: 0
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Post by felixq78 on Dec 18, 2020 8:06:18 GMT -5
No one ever speaks about that pot under the bridge cover on the Aria Lapsteel. Finally someone who knows speaks about it. Thanks.
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Post by David Mitchell on Sept 16, 2021 12:48:11 GMT -5
It's taken me about three ganders at this thread, but I think I'm starting to grasp why I would want a blend, rather than pan, pot for combining pickups.
If one replaced a three-way pickup selector with a blend pot, you'd end up with the same sound options at the middle and at either extreme as with the three switch positions, correct? (Except that the additional resistance has to be compensated for?) Plus you'd have all the in-between variations.
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Post by newey on Sept 16, 2021 13:34:19 GMT -5
If one replaced a three-way pickup selector with a blend pot, you'd end up with the same sound options at the middle and at either extreme as with the three switch positions, correct? (Except that the additional resistance has to be compensated for?) Plus you'd have all the in-between variations. Yes, exactly |
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Post by Jack TriPpEr on Sept 16, 2021 13:54:19 GMT -5
BTW, i looked at the graph for the "500K knurled shaft" pot that member Ashcatl provided a link to back in Reply #17, and I don't concur with his assessment that it matches the response curves that Chris K posted that show how a true Blend pot behaves. [Edit: just noticed that Ashcatl's reply is #17 when viewing this thread in the Tapatalk app, but is #18 when viewing this thread using Chrome Browser For Anrdroid. Weird!] Chris K's graph shows a true Blend pot should feature a range in the pot sweep where one pup is dropping in output while at the same time the other pup is increasing in output. In Chris K's graph that range is from -120 to -20. While the response graph for the product that Ashcatl linked to, incidates such an interplay never occurs. Instead, one pup remains fixed at 100% output while the other increases in output from 0% to 100% in one half of the pot sweep, and then in the other half of the pot sweep, the 2nd pup that raised to 100% output stays fixed at 100% output while the 1st pup now begins to drop in output. So at no time are BOTH pups changing in output at the aame time as described per Chris K for a true blend pot. The response graph of that product referened in Reply #17 is attached here for convenience.  |
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Post by Jack TriPpEr on Sept 16, 2021 14:37:54 GMT -5
I happen to be planning to wire up one of my guitars soon with what I understand to be a Pan pot and not a Blend pot, based on Chris K's description of each earlier in this thread. The pot I will be using will be a dual gang pot, where each of those pots has an audio taper. Each pup will be wired to its respective pot in Independent fashion (i.e. pup hot wire goes to pot middle lug instead of left lug). That should alleviate the infamous Les Paul problem where turning down either pup's volume pot fully kills all output in middle position of the 3 way switch. I will also have the output wire from one pot coming off its left lug and the output wire for the other pot coming off its right lug. This reversal of one pot's output should give me the wanted behavior where one pup's output is decreasing at the same time that the other pup's output is increasing, as the the pot shaft is turned. I'll also be running the output of this pan pot to a Master Volume pot, so that will serve as the basis for the normal loading of each humbucker pup w 500K resistance, since the pan pot won't be able to provide that loading. ** I will also be incorporating an added feature that I believe will alleviate Chris K's concern about the tone when the the pot shaft is set to the middle of the pot sweep range. I plan to use a 2pdt switc to be able to bypass this pan pot at any time, and have full output from both pups simultaneously (going to the MV pot). I would use that bypass feature, instead of ever setting the pan pot shaft at the middle of the sweep range. So problem avoided. So really the pan pot would be used to get either Neck pup only, Bridge pup only, or a mix of the two.... but never setting the pan pot shaft at center. Instead use the bypass switch to get both pups at full output. I do have a concern that the taper for the one pup that will have its output wired in reverse on the dual gang, will provide an odd response/feel as the pot shaft is turned. Since ideally i would want anti-log taper instead. I'll just have to see how bad it really it is. I'll post about the results some time next week after I've done the deed and had time to review it. Attached here is the StewMac diagram that i used as the basis for this idea.  |
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Post by David Mitchell on Sept 16, 2021 16:13:49 GMT -5
Sweet. Really interested in this. BTW, i looked at the graph for the "500K knurled shaft" pot that member Ashcatl provided a link to back in Reply #17, and I don't concur with his assessment that it matches the response curves that Chris K posted that show how a true Blend pot behaves. I was looking at those Bourns pots, Bourns PDB182-GTRB, so I'm looking forward to the responses to your post. |
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Post by JohnH on Sept 16, 2021 16:17:36 GMT -5
Definitely a good idea to have the bypass switch, so you can get back to the full clear combo of a simple switched connection, without sparkle-reducing added load due to the extra pot .
But, personally I find most concepts for blending pickups in parallel using passive pots to be a bit of a disappointment. With one pickup at full, the other tends to fade out of the mix within a few k, a very small turn. I think the two volume pots, with toggle, on an LP is more versatile and simpler. I quite like blending in series though, particularly on an SSS guitar.
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Post by David Mitchell on Sept 17, 2021 9:41:56 GMT -5
Definitely a good idea to have the bypass switch, so you can get back to the full clear combo of a simple switched connection, without sparkle-reducing added load due to the extra pot . In case of an HH guitar, couldn't you get the right load by using 500k blend and volume pots and a no-load tone pot (probably the TBX mod I was asking about the other day, specifically), as I'm considering? Or would that still not work well? Oh, darn. I'm still tempted to try it, though.... |
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Post by David Mitchell on Sept 20, 2021 16:42:30 GMT -5
Chris K's graph shows a true Blend pot should feature a range in the pot sweep where one pup is dropping in output while at the same time the other pup is increasing in output. In Chris K's graph that range is from -120 to -20. While the response graph for the product that Ashcatl linked to, incidates such an interplay never occurs. Instead, one pup remains fixed at 100% output while the other increases in output from 0% to 100% in one half of the pot sweep, and then in the other half of the pot sweep, the 2nd pup that raised to 100% output stays fixed at 100% output while the 1st pup now begins to drop in output. So at no time are BOTH pups changing in output at the aame time as described per Chris K for a true blend pot. Can any of the resident experts comment on how the Bourns pot appears likely to behave?   |
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