Will 9mm pots shorten the horizon of "vintage" effects?

[Mark Hammer]

One of the things I wonder about is the rampant use of teensy weensy 9mm pots.  I mean, it's great that we can now shove more and more pots into less and less space.  But my experience is that the smaller the pot form-factor, the shorter the likely lifespan.  Typically, pots get dirty and crackly from two sources: dirt that enters via openings to the innards of the pot, and residue from the resistive strip than has been scraped up by the pot wiper.  If there is an opening to the pot for dirt to get in, that also means that cleaner spray can as well, which is good.  But those 9mm pots are sealed, so you can't spray them.  That wouldn't necessarily be a bad thing, in and of itself, except that I find the smaller the pot diameter, the crappier and more abrasive the wipers are.  Take apart a "classic" 24mm (full-size) pot, and several smaller sizes, and you'll see that the wipers change from a lovely rounded contact in the largest size to something like a "cow catcher" in the smaller ones.  I can't imagine the 9mm pots are any better.

So, as wonderful as it is to have so many controls in a small enclosure pedal, as much as they reduce production and ultimately retail costs, and as good as the pedal might sound, is it going to be working 10 years from now?  So many players have something from long ago that they love, and is part of their signature sound.  But can contemporary pedals that use 9mm pots aspire to be usable in 40 years, the way that "classics" from the '80s and earlier do with their much larger 24mm pots?  Just as bad, use of surface-mount components/boards makes replacing a 9mm pot that has gone crackly a risky proposition.  Will desoldering a pot dislodge any parts that have been sweated into place?  Will we even have "vintage" pedals made after 2000 five or ten years from now?  Will the 40 year-old fuzz go the way of the dodo and passenger pigeon?

Should we start insisting on bigger pots, or avoidance of 9mm pots unless it is for a control one won't use very often?  Will we accept bigger enclosures, simply to accommodate larger pots?  Conversely, can small pots be made to have the same lifespan as "old school" 24mm Centralab types?  Am I making too big a deal out of it?  After all, we don't HAVE any 9mm pots that have crapped out after 25 years because they aren't that old yet.

To be sure, I like the perks they offer in the way of price and space-conservation.  But are we inviting risk?  Even if someone DOES start making high-end 9mm pots for double the price, what about all those currently existing pedals that use them?  Will they be functional, or too crackly to gig with in 5 years?  Will pedals that use them simply become consummables?

[soggybag]

With no scientific eveidence to back me up I'll say that I have a lot of of confidence in those sealed 9mm pots. Like this one:



I don't no what's inside these pots but nothing can get in there to contaminate. There is is also no play.

The other 9mm variety with the plastic shafts give me very little confidence. The shaft easily and has no support.

[Mark Hammer]

But, as noted, only SOME of what makes pots crackly comes from outside.  So sealed, schmealed, AFAIC.  We forget that pots operate by pressure of the wiper against the resistive strip, and pressure=friction.  Wipers scrape OR "ride" on the resistive strip, depending on the design and construction of the wiper, nd smaller-diameter pots allow for fewer "degrees of freedom" in wiper design.

I'm not denying that 9mmpots can work very well.  But how long will they work for?  Currently, a person can - if lucky - score a pedal from 1968, and with a schpritz of DeOxit and puff of compressed air, they have a serviceable working "vintage" pedal.  How long will mini-pedals, made in 2015, continue to work?  Not trying to be alarmist - well, maybe just a little - but WILL or even CAN there be any working 40 year-old pedals in 2050?  Or will the assumption be that analog is decidedly a relic from before 2000, since not much analog made after then can hold up electronically?

And this is not a diatribe against small pots.  I LIKE the convenience and savings they provide.  But are we painting ourselves into a longevity corner, here?

[stallik]

Interesting questions Mark and, like you, I don't have the answers though I reserve the right to an opinion.

I've long thought that modern pcb's populated with tiny smd components don't lend themselves easily to repair or modification and in most equipment are simply replaced with a new pcb. Not too sure if this is only to keep repair times short or if diagnostic skills are lacking or unprofitable. The 9mm pots are, to me, part of the smd world and, should one fail, commercially, it'd be fixed by replacing the whole board. And that's only if that was cheaper than buying a new unit.

I guess what I'm saying is that I think you're right about 'vintage' pedals in the future. We live in a disposable society.

If 9mm pots prove to be less long lived or if you worry that might be the case, flying leads might be a better bet than directly soldering them to the main board. Perhaps a tiny pcb under the pot with a socket for a little ribbon cable?

[Phend]

Ok, what's up with the need to make effects smaller and smaller, is it some kind of contest to try to get 10 pounds of effects into a 5 pound bag? In my opinion, taste, like, big is cool. Literally,  more space for heat dissapation. (Should I start ducking the bullets?.lol) though I do like old mechanical watches

[iainpunk]

yeah, i think its the modern day normalised greed that makes people want to have 100 pedals on a tiny board. i generally don't agree with this idea, as having that much pedals is to distracting form actually playing.

[rant]
i used to go to a big local jam session every sunday, and we'd see lots of musicians come and go, and of all the archetypes i get most annoyed by the guitarists with the big pedalboards filled with mini pedals that are the most arrogant and proceed to play like a broken robot, no dynamics, timing constantly off, can only play 5 riffs in pentatonic scales and claim to be able to play every song or style.
its either a big board of mini pedals or (sometimes multiple) big multi effect pedals with 100 presets that they all seem to have remembered by heart.
[/rant]

i personally dont think ill build pedals with such pots, no. i really like big pots, preferably not soldered directly to the board.

cheers

[Rob Strand]

And this is not a diatribe against small pots.  I LIKE the convenience and savings they provide.  But are we painting ourselves into a longevity corner, here?

I think soggybag and yourself make some good points.

There's basic design parameters which help longevity, for example size and sealing.    However there's a zillion fine details which can override those.   For example,
- play (as soggybag mentioned)
  If you think about 0.01mm tolerance on a 24mm pot it has less relative effect than on a 9mm pot.
- wear (like you mentioned)
  That covers many aspects: material choices,  homogeneity of the track,
  choice of spring force (high spring for is more robust but has more wear)
  lubricants (and longevity of them),
  resistance to oxidization
- consistency in the manufacturing processes
  (eg. how do build the device so the spring force varies 10% in production and not 500%, or the contact
         region is smooth and free of burrs and abrasive contaminants?)

If you *had to* you can make improvements in any one of those areas.     You could even give up size and still end-up with a good product.   The problem is the costs start to go up.  That's OK for say a high budget defense project but it can only go so far for consumer goods.    When you set the cost it certainly constrains the parameters.    That's where you end-up with brand (=quality level) + size + sealed end-up being the (observable) choices.

Unfortunately all the rest of the stuff that makes it work gets swept under the carpet.   The dumb consumer is unaware of the finer points and isn't told about it anyway.    That's why you buy a pair of scissors made in china for $1 and it breaks getting it out of the packaging.  The customer bought "scissors".   Why does he need $400 scissors?    Or Gold plated connectors:  I buy gold-plated connectors where they don't even connect when new because the oxide has penetrated through the thin gold layer vs  gold plated connectors that last for years.

There's no doubt the vintage pots were built with far more care and set the quality bar much higher than todays pots.  The proof is all the equipment out there that's lasted for  50 years.    Sometimes the new stuff only lasts two years.

An interesting problem showed up in the automotive industry.  As the connectors got smaller reliability of the connections got worst.   Apparently you need a minimum amount of spring force to fend-off oxidation (and micro-movements).  So basically the laws of physics meet reality.   To some degree that idea supports larger pots.

[Phend]

It's become a, when you are done with it,  throw it away mentality. Working in the machine tool business I saw automotive companies go from buying machines that would last forever and could be repurposed to them buying inexpensive China machines that would last long enough, for that, call it, short production run. Decommission it, toss it out and buy new. Equipment designed for the short term . If you want a tank buy a tank. Times they are a ...changed. All comes down to cost, best costs more than good. Hawg or zip splat. Geeze you can learn from DIY.

[ElectricDruid]

For what it's worth, Taiwan Alpha quote a lifespan of 15,000 cycles for their 9mm pots. And their 16mm pots. And their 24mm pots.

Alps don't seem to offer any figure for lifespan that I can see.

Alpha Products (US Alpha) don't offer even a datasheet unless you log in, and I get broken links all over a website that doesn't look like it has moved on much since 1995. So while their pots might not survive to achieve vintage status, I think their website already did.

[digi2t]

What exactly is the baseline for "vintage" anyway?

10 years? 25? 50? If I use our provincial auto license board's definition, it considers anything over 25 years old as vintage. Then again, my son considers underwear he wore last week as vintage.

At the end of the day, they will last according to use/abuse. Personally, I don't think parts produced today are produced to the same philosophy as ones made 40+ years ago. Back then, companies didn't want to see repairs (or pissed off customers), so making parts as robust as possible may have been an incentive. My father was a great example of this philosophy, as every vehicle he ever owned he drove the living daylights out of. When he was done with it, trust me, there was nothing left to salvage. Today, teams of lawyers and engineers are busy determining failure rate versus lifespan versus liability rates. Not to mention, nowadays heaven forbid we keep anything longer than 5 years. Also keep in mind that over the years, many of the raw materials used in the past have been phased out because of connections to documented health hazards.

Then again....

With the improvements made in manufacturing process, parts made today are made to much tighter tolerances than ones made 40 years ago. It's give and take I think, and ultimately, I think it will be future generations that will dictate what's good or bad.

Which leads me to ponder....

What is "vintage" when it's REALLY old? Archaic? Ancient? Heritage? Bygone?

[GGBB]

Maybe part of the problem is the vintage technology in most pots. That is, the carbon tracks.

I've been using TT Electronics P160 series https://www.ttelectronics.com/TTElectronics/media/ProductFiles/Datasheets/P160.pdf when I can get them which are conductive plastic (drop ins for Alpha 16s). They are rated for 100,000 cycles, feel smoother (better), and seem to hold up better based on having put them in a tube amp that I use frequently several years ago and not yet having ANY sign of wear yet (crackling).

I really wish the pedal parts suppliers would wake up to these and start offering them instead of (or in addition to) Alphas. I've only been able to get them at Mouser and Digikey with limited selection. At Mouser they are ~40% cheaper than Alphas too.

[amptramp]

With external controls, how often does a user move them?

I can imagine someone with a Fuzz Face or similar device setting the pots to where he wants them and not changing settings after that.  If he has to change a parameter once during a gig, it would be better to have two pedals, one with the first setting and one with the second because you don't really want to interrupt the flow to bend over and turn a knob to a precise location.  I can see the pots getting used when the musician first gets the pedal but I don't see it being used all the time like a volume control on a radio.

[Mark Hammer]

I'll differentiate here between "old" and my intended meaning of "vintage".

There are plenty of inexpensive also-rans - pedals that do the exact same thing as 100 other brands/copies - that people will treat as consummables.  There, the lifespan of pots is simply a nuisance and inconvenience.  And it's not that everything made X years ago is a real keeper.

My concern is with pedals that are unique in their function and features, that won't likely be made again, so you want them to LAST.  Maybe MXR, Boss, and EHX can keep on churning out Distortion+, DS-1, and Big Muff Pi pedals, but consider how may really interesting pedals from Chase Bliss or Robert Keeley and many others have come and gone, supplanted by newer catalog items.  Worth noting that even MXR, Boss, and EHX have catalog items that will come and go, not to be seen again.

Maybe those 40 year-old pedals that are still hanging in there are able to do so because they're only 2 pots?  Will something like the ZVex Seek-wah - that is unique and uses eight 9mm pots for its sequencer - still be usable in 20 years?  I'm not singling it out as any sort of weak link.  Rather, it is unique, something that some players love, and is unlikely to remain an in-production catalog item in 20 years.  BUT, it packs a lot of small pots into a small form-factor.  Will it be usable to the musician who loved it "back then".  It's not alone, AND it's not just guitar pedals.  Consider the mushrooming market of Eurorack modules, and all the economy re-issues of older synths.  So many are using 9mm enclosed pots and their price-point suggests they are not using the higher-quality plastic ones that Gord describes.

Will they be here for us when we're a little grayer, but still just as musically-inclined?  Are we simply spoiled by the quality of the first few generations of pedals, and the materials use to make them or make our own designs?

[ElectricDruid]

I've been using TT Electronics P160 series https://www.ttelectronics.com/TTElectronics/media/ProductFiles/Datasheets/P160.pdf when I can get them which are conductive plastic (drop ins for Alpha 16s). They are rated for 100,000 cycles, feel smoother (better), and seem to hold up better based on having put them in a tube amp that I use frequently several years ago and not yet having ANY sign of wear yet (crackling).

I really wish the pedal parts suppliers would wake up to these and start offering them instead of (or in addition to) Alphas. I've only been able to get them at Mouser and Digikey with limited selection. At Mouser they are ~40% cheaper than Alphas too.

Those look really good (and 100K cycles sounds excellent) but unfortunately they don't seem to clone this variant:

[GGBB]

Those look really good (and 100K cycles sounds excellent) but unfortunately they don't seem to clone this variant:

Ah - right - I always use lugs (or bend pins into lugs) anyway so that doesn't bother me, but I know those are popular. I should also mention that I think the build quality of the TTs is a little higher than Alphas as well - they somehow feel a bit more robust.

[bartimaeus]

i guess the issue is that even 16mm pots are too large for the density of features desired by today's guitarists? plus when you have microcontrollers on board, i wouldn't be surprised if you get an issue with that before the hardware?

that said, those 12mm alpha pots from Smallbear seem like a good compromise: https://smallbear-electronics.mybigcommerce.com/alpha-single-gang-12mm-solder-terms/

perhaps there's a PCB-mount version?

edit:
seems like the answer is RV120DF-40B1, but that's not commonly available unfortunately.

[POTL]

I don't think that 9mm potentiometers will be less reliable, they inspire more confidence (like all modern components) than 16mm dinosaurs;) Taking into account pressure from digital floor units (kemper, ax FX, quad Cortex etc.) we will come to a point where analog pedals will have to evolve or retire. We have already noticed that the new generation of manufacturers have almost completely abandoned the 3pdt bypass button. More and more analog effects appear with digital control and presets, I think that potentiometers will gradually become a thing of the past, being supplanted by digital components. Toggle switches are gradually being replaced by buttons. There are fewer and fewer mechanically moving components in the pedals.
I think that 6.3mm jacks will also be replaced by more compact analogues or unified technology that will not require a power and sound jack (Yerasov did this in Russia). Perhaps we will switch to wireless connections and abandon wires.
As for reliability and maintainability, look at MXR, they have long used 9mm potentiometers, which are installed on a separate board. Some companies make a separate board for the audio jacks and the power jack, if someone steps on the wire, you don't need to buy a new device, it will either stay intact or just an additional board will be broken. modular designs are another part of the future.

[soggybag]

I'll guess the two important features that affect the life of a pot are the mechanical construction and the life of the conductive element.

The conductive element seems to be the point of failure with old pots. I can't remember guitar pedal with a pot that failed. I do recall a volume pedal and wah that failed. I have a couple guitars with a bad volume pot.

You'd guess the reason for failure of the resistive element would be from friction. The only real difference between a small pot one a larger pot is the size of the resistive element. I'm going to go out on a limb a propose that the size of the element has little affect on the life.

Think about how the wear would be applied from the wiper. With a large pot you have a larger wiper. You'd still have the same amount of wear with each turn.

[bartimaeus]

I don't think that 9mm potentiometers will be less reliable, they inspire more confidence (like all modern components) than 16mm dinosaurs;) Taking into account pressure from digital floor units (kemper, ax FX, quad Cortex etc.) we will come to a point where analog pedals will have to evolve or retire. We have already noticed that the new generation of manufacturers have almost completely abandoned the 3pdt bypass button. More and more analog effects appear with digital control and presets, I think that potentiometers will gradually become a thing of the past, being supplanted by digital components. Toggle switches are gradually being replaced by buttons. There are fewer and fewer mechanically moving components in the pedals.
I think that 6.3mm jacks will also be replaced by more compact analogues or unified technology that will not require a power and sound jack (Yerasov did this in Russia). Perhaps we will switch to wireless connections and abandon wires.
As for reliability and maintainability, look at MXR, they have long used 9mm potentiometers, which are installed on a separate board. Some companies make a separate board for the audio jacks and the power jack, if someone steps on the wire, you don't need to buy a new device, it will either stay intact or just an additional board will be broken. modular designs are another part of the future.

i see where you're coming from, but i'm not sure i agree. encoders are both more complicated and much less robust than potentiometers, so i think pots will stick around on digital effects. and i remember dave smith's prophet '08 originally had encoders, no pots. but users kept demanding pots, so he eventually made a pots version, and now all of his synths use pots.

however, i'd love to see 3dpt switches disappear. especially on pedals with the 3pdt soldered directly to the main PCB. that's basically a guarantee your pedal will be a nightmare to repair.

using a separate board for connectors is great. that's my big gripe with a lot of modern boutique companies. all of of the jacks are soldered to the main board. i know broken jacks aren't too common, but i still prefer them off the main board.

[Phend]

Some effects with only two pots, like Vol and Tone, could be made without any pot and called Factory Preset.
Vol could be eliminated, set on what would be 10. A three or four position switch used for Tone.
But what fun is that, my friend had a five speed bike and I only had three.