Tascam 246 Left / Right PGM Master faders question

[cjacek]

I'm still in the process of servicing my Tascam 246 and noticed something interesting while looking into the faders / sliders from the top of the unit with a good light (faders have not been disassembled). The LEFT / RIGHT PGM MASTER FADERS seem to be built different than the typical faders inside, meaning that each one (Left and Right, which are separate) actually seems to have a metal railing of some sort in the middle (of each fader - that the slider slides on) and the conductive plate / surface on the opposing sides, rather than just one flat conductive surface as the typical low profile ALPS have, with the sliders attached to the sides. I don't know if I'm explaining this right. But I'm just curious if anyone has disassembled these or knows more about how these specific ones are built inside.

 

[sweetbeats]

Interesting, Daniel…I’m not sure I can quite picture what you have by the description as far as connecting with other stuff I’ve seen. Any way to get any pictures of anything? It’s a “stereo” fader or rather two-channel fader with separate elements and wipers for each channel, so the wiper carriage may ride on a center divider between the two elements…?

 

[cjacek]

Hey Cory I have attached a few photos, very difficult to make, hopefully you can see what I'm talking about. I tried to compare the L + R faders with the normal channel faders. The two faders closest to each other are the PGM L + R and the other is the normal channel fader. The brown element is easy to see in the normal fader (2nd photo) but not in the PGM faders, there's a "track" right there. The reason I actually asked (and you're gonna hate this ) is because I wanted to clean the elements without disassembly (as one of these is slightly crackly and cuts out, although sliding it a few times seemed to "fix it"). I know it's heresy to be even considering that but I just don't have the mind-set right now to be even considering such a painful process. I'll leave that sort of thing to the restoration experts such as yourself Cory. So anyway, that's why the two above mentioned L + R sliders stumped me when I thought they were just the typical flat elements inside, that I could just do a once over with some D100 (on a small piece of thin lint free cloth carefully inserted into the slot to clean the element) and then follow up with F100 (same procedure) but then I said "Hey, what the hell is this down there?". I was just not seeing the carbon element as on the others, and knew I couldn't clean that as I had intended. I could see a tiny bit of element on each side of the railing or center divider of some sort but access would be difficult. I then thought of getting the spray version of the D100 for better access but cleaning it with cloth would not be possible. You might ask why not use the D5 with the flushing action. Well, it does use solvents which might be a problem and also over-spray is an issue and can't really clean up the excess fluid or dirt due to difficult access. That's why the D100 / F100 option. Is there any other solution (other than you know what)? Also wanted to add that initially (before I saw what's up) I carefully inserted a small piece of thin cloth in there (just dry) to see the logistics of doing it (gently wiping) but then felt something was off so I took out the cloth and it had two grease "tracks" on it close together, like seemingly what the wiper carriage rides on was greased up from factory? Makes sense?

 

[cjacek]

I think I found something interesting on the ALPS page. Apparently it's called a dual-unit: https://tech.alpsalpine.com/e/products/detail/RS60N1219A04/ but I'm unsure if this is the exact type in the 246 but looks legit. There's a 60 mm and 100 mm version.

 

[sweetbeats]

Hey, so, yeah…looking at the pictures what you are seeing I think is an internal divider of sorta between the two sides of the dual unit…one wiper carriage straddling two element sets. You could try and jet the cleaning agent to each side maybe?

 

[sweetbeats]

Hopefully the issue is just debris. I have had an issue in a 388, which of course have the 4-gang PGM MASTER faders, where the wipers needed gentle manipulation to restore proper contact with their elements. This required disassembly of the fader assembly.

 

[cjacek]

Thanks Cory, it's a little confusing on the ALPS page with the different styles but noticed that the ones with that "divider" can be either dual or single but are under the category of "Low-profile Master Type". I wonder why they did it like that, with that divider there?

 

[cjacek]

From what I've been able to find out, it's for "tactile" feel for a "smooth and precise operational feel".

 

[sweetbeats]

I think for me to know what that means I’d need to take one apart.

 

[cjacek]

They do travel a lot more smooth and precise than the others from what I can tell.

 

[cjacek]

I found a master channel strip from the 246 online and contacted the owner of the photo if they can provide me with a clear top down view of the sliders, to see if perhaps that can help to identify what's going on in there.

 

[cjacek]

I'm actually starting to question whether or not there's a centre divider or if the slider carriage just rides differently than the others, perhaps on a narrower gap but the element underneath is the same as on the others. I don't know. And BTW, that drawing of the ALPS slider I posted above from their website, I don't think that's a centre divider in the middle --- I think that's the opening.

 

[cjacek]

So I've been on the ALPS site studying the info and drawings, even downloaded a CAD drawing and opened that up to see if there is any clue as to their build but nothing so far that I can see. I also did another look inside my 246 and now I'm positive that's there's indeed a centre divider (as you said Cory) or a rail of some sort in the middle that the carriage rides on, which is absent from the other channel sliders. I'm hoping I can identify these inside without doing disassembly. Even sent a message to a guy on YouTube who does these disassembly videos (you linked me to one of these Cory when I couldn't remove the top cover, missed that one screw near the transport ). Anyway, will update again as I get (hopefully) more info. I just don't want to start spraying in there not knowing what and where I'm spraying.