Isostat and Dialistat switches: Neve and SSL desks

[Brian Roth]

I'm making a branch from this topic:

https://groupdiy.com/index.php?topic=76658.0

My initial "close encounters" with a Neve desk was an 8068 (originally from the Power Station in NY).  I did a variety of services to that desk from 1991 through approx. 2009.  I don't recall many problems with any of the switches, although the desk's owner (now RIP) was a talented tech and performed a lot of his own maintenance/repairs.

In more recent times, I fought battles with a Neve 5116, including many pushbutton switches that were glitchy, but more often would NOT stay "locked" in position when depressed.  A box of toothpicks sat on the desk to hold those in the "down" position after I depleted the (large-ish) supply of NOS switches and a batch of new ones from Stanler in the UK when Neve had no more replacement stock.

Thinking back through this and looking at the pix here (click on the "pushbutton" tab on the right and scroll down a bit):

http://www.pandpelectronics.co.uk/switches/switchframe.html

The blue plunger on the Dualistat reminds me of many of the switches on the 5116, but I recall others had a gray plunger.  I don't recall any blue plungers on the 8068 switches.

Dialistat vs. Isostat.  Clear that up for me....LOL  Seem very similar in appearance.  Same general dimensions but from different manufacturers? 

I also ran into Dialistat/Isostat switches in SSL 4K and 6K desks and one of our GroupDIY members here (jwhmca) concocted an ALPS switch retrofit for SSL desks.  Here's the six year-old thread, but unfortunately the pix are no longer attached:

http://forum.sslmixed.com/index.php/topic,521.0.html?PHPSESSID=ffa7dc99d24eb173feda27c5344cc386

Perhaps jwhmca will chime in?

Bri

 

[abbey road d enfer]

Dialistat vs. Isostat.  Clear that up for me....LOL  Seem very similar in appearance.  Same general dimensions but from different manufacturers? 

I've used Isostat extensively in the early 70's; I believe they were made in France, as were the original ITT/Jeanrenaud F types. Different companies, though.
Never used Dialistat. Just saw them in some products. They may have been from a different mfgr, taking advantage of the established "stat" name... just guessing.
Although very similar, Iso and Diali use a different grid. In the Isostat, pin rows are unconditionally 4mm apart. On the Dialistat, there is a larger space between sections.
Given the number of hits in Poland and Czech republic, there is a possibility the manufacturing may have been moved over there...again speculating.

 

[Brian Roth]

Branching again:

" original ITT/Jeanrenaud F types"

"ITT F types" to me means Schadow and other clones. In my world with a jillion MCI desks the "F" switches are an (aging) mainstay.

Abbey....you mentioned JeanRenaud.  With that 5116 I mentioned, those were rotary switches used for gain steps for mic and line input stages.  Those were failing BIG TIME and I never found a "drop in" solution.

Bri

 

[abbey road d enfer]

"ITT F types" to me means Schadow and other clones.

That's correct. Jeanrenaud (one word) was the original mfgr, in Dôle (Jura). Purchased by ITT in the 70's.

In my world with a jillion MCI desks the "F" switches are an (aging) mainstay.

Abbey....you mentioned JeanRenaud.  With that 5116 I mentioned, those were rotary switches used for gain steps for mic and line input stages.  Those were failing BIG TIME and I never found a "drop in" solution.

Unfortunately, some of their products were not that good...

 

[gyraf]

the Jeanrenaud/ITT/Dialistat switches were also widely used in the Calrec boards, as well in our SSL4040E - I still have a backup box of 2x-4x-8x types that we had made at the "last call" in 1999.. pic related

There is apparently something special about the lubrication compound that makes the locking pin work smoothly - it only takes one drop of misplaced contact cleaner, and the locking pin will most probably stick or break on next activation.

When the "last batch" was announced, there was talk about the discontinuation being because of running out of this special material. At the time I found it hard to believe.

For reviving spray-damaged switches, in which the pin had not yet broken, I've had limited luck with something iirc called "molycote" - a compound for some variation of ball bearings. No luck at all with any other material

/Jakob E.

 

[dunk91]

Oh well, nice to see this post. I'm also cursed by dialistat, as I own a small format ex bbc calrec mixer stuffed with them. No need to say that they should be mass-replaced, as 4 or 5 doesn't lock anymore and a few others became noise if I don't use the mixer for a few days.
Almost and year ago I've searched for a replacement, eventually found them at P&P electronics. But price is on the wild side, ideally they should be assembled in groups (usually they are binded in groups of 2\3\4 ones with a small metallic rail wich keep them in place) and so I've postponed the problem for a while.

I've also searched a replacement, but the pin spacing is pretty weird by today standards (alps & co.) and almost nothing fit their footprint.

If someone will ever find a modern solution or reissue production (lol) will have my eternal blessing

 

[gyraf]

afaik, there's nothing else with this footprint

it is sometimes possible to replace locking pin in non-locking switches

If switches gets noisy "by themself", there nearly always is a leaky electrolytic capacitor to blame..

/Jakob E.

 

[dunk91]

afaik, there's nothing else with this footprint

it is sometimes possible to replace locking pin in non-locking switches

If switches gets noisy "by themself", there nearly always is a leaky electrolytic capacitor to blame..

/Jakob E.

Yep, the footprint is sadly unique.
Regarding noisy switch, I've always blamed the contact coating, that according to various forum posts, is  prone to tarnish and became a sort of semiconductor, something like this.

So besided P&P electronics seems like there aren't any other solutions to the problem, but @ 12.95£ each they are pretty hard to digest  :'(

 

[gyraf]

perhaps googling the ref. number on above pictured box can find you some - seems like there may actually be a NATO part number for these switches, see e.g.:

https://natopart.com/en/switches/10745018-5930-14-483-6887.html
https://www.nsncenter.com/PartNumber/PMB104-44PP

If they're the right type, being mil parts, there's a good chance someone has stock still, perhaps try to get a quote from above places?

..and from those numbers, there are a couple of cross-reference numbers as well..

/Jakob E.

 

[dunk91]

perhaps googling the ref. number on above pictured box can find you some - seems like there may actually be a NATO part number for these switches, see e.g.:

https://natopart.com/en/switches/10745018-5930-14-483-6887.html
https://www.nsncenter.com/PartNumber/PMB104-44PP

If they're the right type, being mil parts, there's a good chance someone has stock still, perhaps try to get a quote from above places?

..and from those numbers, there are a couple of cross-reference numbers as well..

/Jakob E.

This is beautiful Jakob, kudos to you. I'll search again starting from those codes, from your photo the switches are different in plastic color but footprint seems on spot, so it could be a good road to try.
I've also contacted again P&P electronics and requested new quotes, for 4 poles version @ 50 pieces price is around 6.5£, unfortunately 2 poles are gone also from their stock, and I need 80 of them to restore my calrec

 

[Returnofthebatt]

As a caretaker of a Neve V1, it's been real fun managing the obsolescence of the dialistat and ITW/Licon 39 series switches. In regard to the dialistat, about five years ago I decided to take apart a DPDT and remodeled it in a CAD program. I did the entire switch minus the actuator (my CAD skills at the time were not up to par to branch too far from basic geometric shapes). Unfortunately, I've been meaning to go back to that project and remodel at least the latches/locking pins as both my CAD skills, CAD program, and manufacturing knowledge has increased vastly since my initial run.

Knowing that there are others out there feeling my pain, I will definitely revisit the latches soon. Unfortunately, I have been unable to contact CML Audio (their website has been down for months) in regard to purchasing their Solo and Cut replacement switches for our V1 after years of glancing at them (plus, I believe I tracked down the switches they used as replacements and they have been discontinued; I believe eSwitch makes the same switch but not in the configuration I need without a MOQ), so I've been forced to make replacements myself from off-the-shelf parts and that has been taking up a lot of my free time (still not done) when I am not doing other maintenance tasks at the studio.

Since there is obviously a need by others for the dialistat switches and/or their parts, injection moulding may finally be a possibility (it is extremely expensive and I originally started the dialistat project as an in house project and looked at other plastic manufacturing options to keep costs down). If you are interested, please let me know so I have an idea of the amount of demand that there is out there.

Jacob

Edit: Gareth from CML messaged me. CML is still active and still make their switches and provide their services. Hopefully this helps anyone else out there requiring them.

 

[Whoops]

The SSL 4K E-series in the studio I previously worked had huge problems with those switches, specially the ones in the top routing section. A lot of them were stuck

 

[porkyc]

These switches going missing killed a number of Harrison consoles dead at the factory.
To redo them back to Schadow switches was deemed prohibitive. So goodbye MR2/3/4 TV3.

 

[dunk91]

Actually I've been able to buy a NOS lot of 2 poles dialistat for a more than reasonable price trough ebay. Around 300 switches, I'll refurb my calrec desk and keep a good amount of them for future manteinance.
If someone needs a few of them (after manteinance and spares stock I should have maybe 80 more switches) hit me up. They are latching, so will cover both latching and momentary function (just remove the cursed pin).

Before installing I put a tiny (TINY) amount of ptfe grease in the latching mechanism, the action became really smoooth and it should help them lasting  a bit more maybe.

Also I've managed to find an old datasheet, I'll leave it here. Hope can help someone as I never encountered it in any discussion about dialistats.

@Returnofthebatt, if you will ever be able to reissue them, please do it. Many vintage equipment needs them, and I feel that NOS stock are pretty low (P&P electronics doesn't have any more 2 poles ones, just saying)

 

[gyraf]

I think you should really reconsider the additional lubrication - as mentioned above, the material used here seems to be mission critical..

(just my opinion anyway)

/Jakob E.

 

[dunk91]

This was also a mine concern at first, so I've only lubricated with extra grease a few switches and stress tested them for a few days, forcing them to work out of axis, in standard position ecc ecc and comparing the action with a standard lubricated ones.
Actually the only difference I've spotted is that the travel became a bit smoother, the ones factory lubricated are always a bit grainy when they go up and down.
Also being ptfe inert to almost any plastic material it shouldn't compromise nothing in the long run.
The original grease looks a kind of vaseline, wich tends to be solvent for a few plastic material (not that this is the case, of course)

I think you should really reconsider the additional lubrication - as mentioned above, the material used here seems to be mission critical..

(just my opinion anyway)

/Jakob E.

 

[Returnofthebatt]

Actually I've been able to buy a NOS lot of 2 poles dialistat for a more than reasonable price trough ebay. Around 300 switches, I'll refurb my calrec desk and keep a good amount of them for future manteinance.
If someone needs a few of them (after manteinance and spares stock I should have maybe 80 more switches) hit me up. They are latching, so will cover both latching and momentary function (just remove the cursed pin).

Before installing I put a tiny (TINY) amount of ptfe grease in the latching mechanism, the action became really smoooth and it should help them lasting  a bit more maybe.

Also I've managed to find an old datasheet, I'll leave it here. Hope can help someone as I never encountered it in any discussion about dialistats.

@Returnofthebatt, if you will ever be able to reissue them, please do it. Many vintage equipment needs them, and I feel that NOS stock are pretty low (P&P electronics doesn't have any more 2 poles ones, just saying)

Well, I have some good news. While I haven't finished the whole switch, I have managed to successfully remake the latch and they are functional. I am currently revising the latch design to improve on it and increase its structural integrity—but these latches currently look more promising than the original latches.

As for lubrication, I originally subscribed to the stories that a very special lubricant was used for these switches. I and another person, whom I have been in contact with for the past month, have experimented with only two lubricants that I have found during my research—but have talked about many others that I have found—and they have worked for us. My initial thought years ago before really researching into lubricants was to use Super-Lube with PTFE because of the inherent plastics compatibility. However, I have seen the base from Super-Lube start to separate over time and decided not to use it. I also found that datasheet you posted about a month ago, but I also found another one with a few more details. It's interesting that you mention vaseline because, "a light grease, or vaseline...", is actually mentioned as lubricant in the first page of the attached PDF. But, like you, I would avoid vaseline.

As for what lubricant(s) to use, well I looked to Electrolube. I originally decided on SPG as the lubricant of my choice (I actually used it yesterday on two latches and it works beautifully) as it is designed for lubricating thermoplastic switches. However, the person I have been in contact with desired a lubricant they could spray into the mechanism. I recommended Electrolube's DFL as I use it for P&G faders. They let me know a few days ago that the DFL has worked wonderfully for them; but, you will have to adapt the nozzle or it will spray everywhere. I, however, prefer a syringe based application of lubricant as I will have the retaining bracket off anyway to replace a latch (plus, I may be able squeeze the SPG into the latch area via the mounting holes of the retaining bracket). If anything, I would say that DFL should, theoretically, have a better plastics compatibility than SPG. If SPG does degrade the actuator in time, well I will just have to remanufacture that part as well.

One last thing on the lubricant. In my opinion, the original lubricant used was either horrible or not enough was placed into the switch. The two switches I repaired yesterday either had no lubricant or it dried up (it is a V1 after all with heat, etc. so I am leaning towards the heat; but NOS switches I have don't have too much lubricant either). Regardless, I believe that lubricants tried by many as a replacement were done with probably used latches. Well, the original latches easily develop microfractures—which can be seen under a microscope—that can both cause the switch to not operate correctly, even when it appears to have latched fully, and soon result in complete failure of the latch.

Now, onto the best part. I believe we are all in this together in the fight against dialistats. So, I am happy to share anything that I have learned about these switches and, once I have them fully manufactured, to sell the latches at an extremely fair price (I'm still shopping around with different manufacturers, so I haven't figured out an exact cost yet). Feel free to PM me with any question(s) you may have and I will gladly give you my contact info.

Also, apologies for the delayed response. I never got a notice of a response/mention regarding this thread.

All the best,

Jacob

 

[dunk91]

Well, I have some good news.
.
.
.

All the best,

Jacob

Thank you for your detailed post, this thread can really shed some light on these infamous switches. I've seen lots of help requests posted on various forums regarding dialistats, but never many sure answers or details about them, just a few speculation (more than comprensible, being them obsolete since 30 years already?).

I'm using a generic ptfe grease, it doesn't looks to separate easy and it's pretty adesive, so if you put it inside the cam mechanism it will remain there and not migrate outside\around. I'm applying it with a medical syringe when I'm assemling them, but the mounting holes in the brackets are just large enough to let pass a dermal needle, so I can also lubricated them from the outside without disassemble them.

The original grease smells a lot as vaseline, and is a bit more "liquid" than the one I'm using.
I second your thought about poor lubrication on NOS ones, every 4 or 5 of them I found at least one wich is almost not lubricated, and a few from the lot have grease migrated on the outside of the latching mechanism.

Also I've encountered two kind of latching pins. A transparent one wich I presume it's older and is really really fragile and a black one (actually the ones from P&P electronics comes with black pins, hence I think that those are newer) wich looks a bit more solid.

If I can be of any help with your reissue (detailed photos, measurements ecc) just drop a line here.

Emanuele.

 

[gyraf]

Thank you gentlemen, nice that things are moving

It's VERY interesting if an after-market locking pin gets possible - can potentially add many years of service to some of the classics. Did not believe a new pin could be done when we looked into it last century

As for some mechanisms appearing dried out completely when disassembled, this may very well be the result of being drenched in contact cleaner. It was in many cases by us at least..

the micro-crack explanation for some of the unexpected bad behavior is new to me. Do you have any guesses as to if there's something to be done in these cases?

/Jakob E.

 

[Returnofthebatt]

Thank you for your detailed post, this thread can really shed some light on these infamous switches. I've seen lots of help requests posted on various forums regarding dialistats, but never many sure answers or details about them, just a few speculation (more than comprensible, being them obsolete since 30 years already?).

I'm using a generic ptfe grease, it doesn't looks to separate easy and it's pretty adesive, so if you put it inside the cam mechanism it will remain there and not migrate outside\around. I'm applying it with a medical syringe when I'm assemling them, but the mounting holes in the brackets are just large enough to let pass a dermal needle, so I can also lubricated them from the outside without disassemble them.

The original grease smells a lot as vaseline, and is a bit more "liquid" than the one I'm using.
I second your thought about poor lubrication on NOS ones, every 4 or 5 of them I found at least one wich is almost not lubricated, and a few from the lot have grease migrated on the outside of the latching mechanism.

Also I've encountered two kind of latching pins. A transparent one wich I presume it's older and is really really fragile and a black one (actually the ones from P&P electronics comes with black pins, hence I think that those are newer) wich looks a bit more solid.

If I can be of any help with your reissue (detailed photos, measurements ecc) just drop a line here.

Emanuele.

Thanks for the offer. It is my belief that any lubricant, as long as it is not too viscous and doesn't detrimentally affect the plastics used, should be good. If the generic PTFE grease is working for you, then that's a lubricant that works. Whether or not it will last long term, only testing will reveal that. Also, I believe the lubricant is also found on the contact springs of the switch itself (it certainly is present inside the u-shaped cavity of the spring contact). This was probably simply to aid in contact lubrication and maybe aid in preventing tarnish, which there are many other products out there that can do these jobs.

As for the differences in the clear and black latches. A lot of the original switches in our console still have the clear latches. We do have a small stockpile of NOS switches some from '98 (I think) and others undated. The undated switches have the transparent latches (which I guess to be polycarbonate, but I could be wrong) and the latches stamped with the production date have the black latches. I'm going to agree with you that the black latches are a little stronger based on my handling of NOS latches of both types. However, the black latches were not well finished from the factory. Many of the black latches, if not nearly all of them, have evidence of the gate from the injection molding process. It doesn't really matter as it was finished enough to function in the switch.

On another note, it is both kind of amazing and shocking that the switch relies on such a small part to begin with. At least the switches are somewhat modular allowing a degree of serviceability.

Thank you gentlemen, nice that things are moving

It's VERY interesting if an after-market locking pin gets possible - can potentially add many years of service to some of the classics. Did not believe a new pin could be done when we looked into it last century

As for some mechanisms appearing dried out completely when disassembled, this may very well be the result of being drenched in contact cleaner. It was in many cases by us at least..

the micro-crack explanation for some of the unexpected bad behavior is new to me. Do you have any guesses as to if there's something to be done in these cases?

/Jakob E.

Normally I would agree about the contact cleaner, but in one of the switches I went to replace the latch in yesterday was a NOS switch that I installed a few years ago and never touched with contact cleaner. I'll chalk the lack of lubricant up to possibly a factory error. But, the best way if contact cleaner is needed is to drip it into the switch via the pins if you can access them. Prevents overspray from getting into the latch area. I use EML from Electrolube (both cleans and lubricates the contacts) which can be bought in an aerosol form and in bulk where you can fill a small a squeeze bottle with a needle applicator. Also, this reminds me, the metal bracket is integral for the latching of the switch. The same switch as the aforementioned actually had the metal bracket on the bottom of the switch not fully seated onto the circular tabs and, as a result, wasn't compressing against the housing enough. The latch gets pushed against this bracket as it moves through the track in the actuator; if there is nothing for it to solidly push against the latch will pop out of the track. So, if you start replacing latches make sure that the bracket fits tightly.

The other person and I have theorized the microfractures being a combination of insufficient lubricant and/or general misuse of the switches, i.e. hitting them extremely hard. Hitting the switches hard causes the follower pin of the latch and/or, what I call, the trapezoidal shelf the follower pin is part of to start developing these cracks. More than often, a broken latch broke at the trapezoidal shelf. Isostats had a metal component doing the latching and many other switches before dialistats were introduced (I think it was around the late '70s) had a metal latch including the very used ITT Schadow switches and many of their modern clones (a beefy latch at that). An intermittent schadow switch could be temporarily restored, until properly dealt with, by burnishing the contacts with a few quick, successive hits of the switch letting the momentum help the contacts scratch through any oxides or containments on the pins. Well, if you do that with a NOS dialistat, it will probably still latch and function correctly. However, the latch would have been extremely stressed and then general use would eventually result in its failure. This is what we believe to be the primary cause of latch failures.  Plus, we think heat negatively affects the factory lubricant and the the latch further contributing to the latch's weakening. Many of the almost 40 year old dialistats in my V1 haven't been replaced and mostly work fine; I say mostly because I believe some of the switches suffer from the latch microfractures and aren't making good electrical contact.

Jacob