Congrats on figuring this out. Glad this was a straight-forward fix. Wow, four bus mixer. That's impressive for a cassette multitracker. The only drawback seems to be no way to disable noise reduction on one of the tracks to use for sync, but maybe it works fine with dolby C? looks like the backlights on first two channel VU meters need replacement?
There are other 4-track cassette “portastudios” with 4 mix busses, but I’d say the AT-RMX64 is really the most straight-forward most fully-featured mixing console on a 4-track machine. Like with most others it would be kind of a challenge if not impossible to plop the machine into an environment to just use it as a mixer, like a small club or other venue, and on top of that would be the sound quality. I’d have no qualms doing that with the AT-RMX64…well-built, well-featured and nice sounding. That’s an interesting question about the dbx vs Dolby noise reduction and synchronization. I’m actually not sure about that. It’s possible a sync track with timecode will work just fine with Dolby where it doesn’t with dbx because they work completely differently. Maybe somebody else has tried this and can chime in. If I had things more setup here I could test this, but can’t at the moment. And yeah I’ve still got two meter lamps to replace…will do all of them actually. Thanks for the comment!
What have you done to resolve the issue? I have two AT-RMX64s. The first one only two I put channels worked. The second only three worked. In 100% of the cases all it took was exercising the card edge connectors and treating with DeoxIT D5. Have you done anything like that?
@@SweetbeatsTechStop Yeah, I pulled and re-seated the strips to isolate the bad ones. Of the two in question, one is dead-dead, and the other works, but then brown's out..I'll get to it again. (not a tech, just an enthusiast!) I'll try some De-Oxit.
I’m not a tech either…”bloated hobbyist” is probably appropriate. Honestly I think applying the contact cleaner is critical, if for nothing else than to rule out contact issues. I’m not a real fan of the edge connectors used on the AT-RMX64. Clearly they are prone to issues at this age because it is so common to have connectivity issues that are resolved with exercising the connections and applying contact cleaner. The pins and sockets are tin plated, which is common, but doesn’t last at all like gold plated. My Studer console uses gold plated DIN “euro card” connectors with lower insertion force and zero oxidation/connectivity issues…it’s only about 25 years old, but with 128 to 194 pins per module you’d think *something* might be awry at this point but nada. Anyway, I think it takes very little oxidation or debris to disrupt continuity with the AT-RMX64 connectors…so you can exercise them, but without jetting some DeoxIT in there you won’t flush the debris. So my treatment is remove the card, apply the cleaner to the sockets, insert and remove 5-10 times, then spray more cleaner in the sockets and spray off the pins on the card. It’s messy. Have rags handy to mop up the excess, and leave the unit sitting in its normal horizontal position overnight so the excess drains down to the motherboard along with debris and it can dry. The DeoxIT provides the additional benefits of guarding against future oxidation and improving continuity.
Yeah, Ben, do that, but maybe we need to dig in a little bit and be a little more strategic and focused rather than shotgunning reflowing solder joints. Not that it’s a bad idea, but can you refresh me on what’s happening with your machine? Is it just like my situation where 1 or more tracks are not recording, but you can flip the tape over or play a known good tape and verify the playback is working? And do all tracks erase? Remind me which track(s) is/are affected and if it erases correctly and plays back fine across all tracks.
@@SweetbeatsTechStop Good advice! When that run and gun method works it's great but taking a more strategic approach is a very good reminder that I needed for this project, so thanks for that. My issue is that I can play back recorded material on track two, but I cannot record on track two. All other channels are good. I hadn’t thought to check erase on my problem channel, but that's a good idea and I will. Any thoughts or advice on a stepped approach are most appreciated. Many thanks!
So step 1 is let me know if it erases on track two. And then if it does, get out your tone generator, DMM, flip it on its side and remove the bottom panel. I want you to get setup to inject tone, like 1K is fine, to one of the input channels, assign it to all 4 SUB busses, load a cassette, arm all the tracks, set your meters to monitor “TAPE”, put the transport in RECORD/PAUSE mode, and adjust your record level pots so you have good signal on all 4 meters. That condition brings tone through the record amp PCB. So if it erases, get ready to get it setup as above and I’ll start telling you where to probe. I don’t know if you’re a member at homerecording.com, but if not I’m going to ask you to consider registering so we can continue over there. It’s just easier to post pics and links and things and that would really help me tell you where to probe. I can tell you “probe pin X of connector X, but it would be easier to post a pic of the subject motherboard with an arrow pointing to the pin to probe. I have a thread on the AT-RMX64 going there and you could just join the conversation: homerecording.com/bbs/threads/audio-technica-at-rmx64-story….419129/
@@SweetbeatsTechStop Excellent! Okay, I’m going to get my AT out of storage and lay it out this week. I’m Home Recording member “MonolithGardens” - I will touch base with the thread this week! Thank you for your help!
No way you can get it out the bottom without totally disassembling the chassis. It’s designed to come out the top. 1. Remove the transport section dress panel (screws on the face of the panel). 2. On the underside of the transport section dress panel remove the two screws that fasten the record arm LED PCB strip to the dress panel. This is just for convenience…allows you to completely set the dress panel aside. 3. You’ll see two screws on each side of the transport assembly that fasten it to the main chassis, two on each side…remove those and the transport assembly is free except for… 4. Wire harness connections…I don’t have either of mine in front of me at the moment, but there are multiple connections IIRC below the transport (toward the front of the machine) that connect to the logic PCB assembly that’s underneath the transport assembly…they are not hard to get to…in fact I think they are all different sizes, but take pics and label with blue painters tape or similar to make reassembly easier…and then the head connectors go to one of the amplifier PCB assemblies above the transport assembly (to the rear of the machine) and you have to remove that one amp card assembly to unplug the head wiring connectors from the PCB. The amp cards are held in by two obvious screws each, and they are plugin cards. Be gentle with removal, they may be stubborn after all these years and the motherboard is phenolic resin type, so not as sturdy as a glass fiber board…gentle rocking side to side and it’ll pop free. Post any questions. I’ll help.
I have another question for you, I hope you don't mind. I have a cassette MTR that needs work, including rehabbing the faders. I know the Caig Fader Grease is considered the go-to for greasing them once you've cleaned them, but it is costly per oz. I found something at my local Harbor Freight called SuperLube that is clear and states it is dielectric, which to my mind would be the number one requirement for a grease used in faders. Would this possibly be an acceptable substitute or is it best to trust the known brand? Thanks
I would never, ever, ever, ever, ever use any kind of general “grease” or “lube” or “lubricant”, dialectic or not, on any rotary or linear audio potentiometer. Ever. Understand this: the Caig product I think you are referring to is not a “grease.” DeoxIT F5 FaderLube is a “lubricant”, yes, but, according to the information on the can itself, only provides for “slight lubrication.” Mostly what it is and does is a cleaner to flush debris off of and out of the internal structures of the potentiometer, and it leaves behind elements to provide for the slight lubrication. Caig does make a FaderGrease product. I’ve never used it. It is not cleaner. It is intended for spot application at specific mechanical points for better mechanical operation, but it is not for cleaning and treatment of the conductive elements of the potentiometer, which is usually what needs addressed; cleaning. So I use the F5 because it is a cleaner. You’re welcome to use whatever you want, but the above is what I use for cleaning potentiometers and some reasons why. Hope that helps.
@ So I actually own and use F5 and it's an excellent product, I use it on pots and faders. I'm referring to a different product, which is their "Fader Grease, DFG-213" product. You can either buy it in a syringe or a small tub. Again, quite expensive. From the sounds of it you don't have experience with it, that's ok. I was just curious what properties it might have so as not to interfere with signal transmission. Thanks, tho.
Gotcha…so here’s my take on that…I don’t know what’s special about FaderGrease…when I’m servicing a fader, which involves complete disassembly and cleaning, if there are mechanicals to lubricate, I use Lubriplate 105 generally, unless it’s a P&G fader and then I use the correct silicon fluid for that procedure. The Lubriplate doesn’t go anywhere near conductive facets of the assembly…it’s on the carriage or rails…not the element or wipers…so I don’t really concern myself with dialectic properties and such because the grease shouldn’t be in contact with conductive pathways, and if it does I’m using too much.
@@SweetbeatsTechStop that is helpful, thank you 🙏🏻. I wish all of my analog mixing equipment came with high quality faders with rails, but in lieu of that I know folks use grease to protect from dust on the conductive surfaces and add a pleasing amount of resistance to the fader throw. I definitely enjoy the latter myself, but have always been a bit confused how it didn't interfere with the signal path.
So with that I’m going to clarify something…and I think this is why I responded the way I did in my first response…FaderGrease is NOT for application to the conductive surfaces. I have never encountered anybody who applies or uses grease to “…protect from dust on the conductive surfaces and add a pleasing amount of resistance to the fader throw.” The conductive element is contacted by the wipers, which are a relatively delicate (depending on the fader) set of conductive filaments. Anything with viscosity like grease applied to the element will either interfere with the wipers’ ability to reliably stay in contact with the element, or actually trap or retain debris adding to the problem, and probably both. It’s a horrible idea to apply grease to the element. The element and wipers should be clean and dry. Furthermore, because the wipers are small and delicate, adding grease to the mating of the element and wipers is not going to add any appreciable resistance to the fader throw. Good quality professional faders, IMO, actually have low throw resistance in my experience. So that’s part of my goal when servicing faders, whether professional assemblies or more “budget-grade” short-throw low-profile ALPS-type PCB or chassis-mount faders we find in machines like cassette “portastudios.” Because of the mechanical design of the more “budget-grade” faders described above, there is absolutely no way to apply grease-type lubricant to the relevant bearing surfaces without removing the fader and disassembling it. And bear in mind these types of faders were not designed to be disassembled and serviced. So it takes some knowledge, care and skill to do it, including (usually) desoldering the fader from its PCB. So unless that’s what you are planning on doing, there is no reason for you to purchase any grease because you should not be just blindly packing that down into the fader, which is the only thing you’d be able to do without removing and disassembling it.
Congrats on figuring this out. Glad this was a straight-forward fix.
Wow, four bus mixer. That's impressive for a cassette multitracker. The only drawback seems to be no way to disable noise reduction on one of the tracks to use for sync, but maybe it works fine with dolby C?
looks like the backlights on first two channel VU meters need replacement?
There are other 4-track cassette “portastudios” with 4 mix busses, but I’d say the AT-RMX64 is really the most straight-forward most fully-featured mixing console on a 4-track machine. Like with most others it would be kind of a challenge if not impossible to plop the machine into an environment to just use it as a mixer, like a small club or other venue, and on top of that would be the sound quality. I’d have no qualms doing that with the AT-RMX64…well-built, well-featured and nice sounding.
That’s an interesting question about the dbx vs Dolby noise reduction and synchronization. I’m actually not sure about that. It’s possible a sync track with timecode will work just fine with Dolby where it doesn’t with dbx because they work completely differently. Maybe somebody else has tried this and can chime in. If I had things more setup here I could test this, but can’t at the moment.
And yeah I’ve still got two meter lamps to replace…will do all of them actually.
Thanks for the comment!
I’ve got one with a pair of spotty input cards.. 4 work, but … sigh. Glad you solved the issue!(Ridiculous V-Ger 4-track!)
What have you done to resolve the issue? I have two AT-RMX64s. The first one only two I put channels worked. The second only three worked. In 100% of the cases all it took was exercising the card edge connectors and treating with DeoxIT D5. Have you done anything like that?
@@SweetbeatsTechStop Yeah, I pulled and re-seated the strips to isolate the bad ones. Of the two in question, one is dead-dead, and the other works, but then brown's out..I'll get to it again. (not a tech, just an enthusiast!) I'll try some De-Oxit.
I’m not a tech either…”bloated hobbyist” is probably appropriate.
Honestly I think applying the contact cleaner is critical, if for nothing else than to rule out contact issues. I’m not a real fan of the edge connectors used on the AT-RMX64. Clearly they are prone to issues at this age because it is so common to have connectivity issues that are resolved with exercising the connections and applying contact cleaner. The pins and sockets are tin plated, which is common, but doesn’t last at all like gold plated. My Studer console uses gold plated DIN “euro card” connectors with lower insertion force and zero oxidation/connectivity issues…it’s only about 25 years old, but with 128 to 194 pins per module you’d think *something* might be awry at this point but nada. Anyway, I think it takes very little oxidation or debris to disrupt continuity with the AT-RMX64 connectors…so you can exercise them, but without jetting some DeoxIT in there you won’t flush the debris. So my treatment is remove the card, apply the cleaner to the sockets, insert and remove 5-10 times, then spray more cleaner in the sockets and spray off the pins on the card. It’s messy. Have rags handy to mop up the excess, and leave the unit sitting in its normal horizontal position overnight so the excess drains down to the motherboard along with debris and it can dry. The DeoxIT provides the additional benefits of guarding against future oxidation and improving continuity.
Duuuude! You got it! Congrats. I’ll have to double back and do more reflow… tracing from those buss boards up to the cards. Thanks!
Yeah, Ben, do that, but maybe we need to dig in a little bit and be a little more strategic and focused rather than shotgunning reflowing solder joints. Not that it’s a bad idea, but can you refresh me on what’s happening with your machine? Is it just like my situation where 1 or more tracks are not recording, but you can flip the tape over or play a known good tape and verify the playback is working? And do all tracks erase? Remind me which track(s) is/are affected and if it erases correctly and plays back fine across all tracks.
@@SweetbeatsTechStop Good advice! When that run and gun method works it's great but taking a more strategic approach is a very good reminder that I needed for this project, so thanks for that.
My issue is that I can play back recorded material on track two, but I cannot record on track two. All other channels are good. I hadn’t thought to check erase on my problem channel, but that's a good idea and I will.
Any thoughts or advice on a stepped approach are most appreciated. Many thanks!
So step 1 is let me know if it erases on track two. And then if it does, get out your tone generator, DMM, flip it on its side and remove the bottom panel. I want you to get setup to inject tone, like 1K is fine, to one of the input channels, assign it to all 4 SUB busses, load a cassette, arm all the tracks, set your meters to monitor “TAPE”, put the transport in RECORD/PAUSE mode, and adjust your record level pots so you have good signal on all 4 meters. That condition brings tone through the record amp PCB. So if it erases, get ready to get it setup as above and I’ll start telling you where to probe. I don’t know if you’re a member at homerecording.com, but if not I’m going to ask you to consider registering so we can continue over there. It’s just easier to post pics and links and things and that would really help me tell you where to probe. I can tell you “probe pin X of connector X, but it would be easier to post a pic of the subject motherboard with an arrow pointing to the pin to probe. I have a thread on the AT-RMX64 going there and you could just join the conversation: homerecording.com/bbs/threads/audio-technica-at-rmx64-story….419129/
@@SweetbeatsTechStop Excellent! Okay, I’m going to get my AT out of storage and lay it out this week. I’m Home Recording member “MonolithGardens” - I will touch base with the thread this week! Thank you for your help!
Sounds good. I’ll see you there!
Hi there! Working on my machine right now, how did you take the transport completely out? From the back or top, which is easiest?
No way you can get it out the bottom without totally disassembling the chassis. It’s designed to come out the top.
1. Remove the transport section dress panel (screws on the face of the panel).
2. On the underside of the transport section dress panel remove the two screws that fasten the record arm LED PCB strip to the dress panel. This is just for convenience…allows you to completely set the dress panel aside.
3. You’ll see two screws on each side of the transport assembly that fasten it to the main chassis, two on each side…remove those and the transport assembly is free except for…
4. Wire harness connections…I don’t have either of mine in front of me at the moment, but there are multiple connections IIRC below the transport (toward the front of the machine) that connect to the logic PCB assembly that’s underneath the transport assembly…they are not hard to get to…in fact I think they are all different sizes, but take pics and label with blue painters tape or similar to make reassembly easier…and then the head connectors go to one of the amplifier PCB assemblies above the transport assembly (to the rear of the machine) and you have to remove that one amp card assembly to unplug the head wiring connectors from the PCB. The amp cards are held in by two obvious screws each, and they are plugin cards. Be gentle with removal, they may be stubborn after all these years and the motherboard is phenolic resin type, so not as sturdy as a glass fiber board…gentle rocking side to side and it’ll pop free.
Post any questions. I’ll help.
I have another question for you, I hope you don't mind. I have a cassette MTR that needs work, including rehabbing the faders. I know the Caig Fader Grease is considered the go-to for greasing them once you've cleaned them, but it is costly per oz. I found something at my local Harbor Freight called SuperLube that is clear and states it is dielectric, which to my mind would be the number one requirement for a grease used in faders. Would this possibly be an acceptable substitute or is it best to trust the known brand? Thanks
I would never, ever, ever, ever, ever use any kind of general “grease” or “lube” or “lubricant”, dialectic or not, on any rotary or linear audio potentiometer. Ever. Understand this: the Caig product I think you are referring to is not a “grease.” DeoxIT F5 FaderLube is a “lubricant”, yes, but, according to the information on the can itself, only provides for “slight lubrication.” Mostly what it is and does is a cleaner to flush debris off of and out of the internal structures of the potentiometer, and it leaves behind elements to provide for the slight lubrication. Caig does make a FaderGrease product. I’ve never used it. It is not cleaner. It is intended for spot application at specific mechanical points for better mechanical operation, but it is not for cleaning and treatment of the conductive elements of the potentiometer, which is usually what needs addressed; cleaning. So I use the F5 because it is a cleaner. You’re welcome to use whatever you want, but the above is what I use for cleaning potentiometers and some reasons why. Hope that helps.
@ So I actually own and use F5 and it's an excellent product, I use it on pots and faders. I'm referring to a different product, which is their "Fader Grease, DFG-213" product. You can either buy it in a syringe or a small tub. Again, quite expensive. From the sounds of it you don't have experience with it, that's ok. I was just curious what properties it might have so as not to interfere with signal transmission. Thanks, tho.
Gotcha…so here’s my take on that…I don’t know what’s special about FaderGrease…when I’m servicing a fader, which involves complete disassembly and cleaning, if there are mechanicals to lubricate, I use Lubriplate 105 generally, unless it’s a P&G fader and then I use the correct silicon fluid for that procedure. The Lubriplate doesn’t go anywhere near conductive facets of the assembly…it’s on the carriage or rails…not the element or wipers…so I don’t really concern myself with dialectic properties and such because the grease shouldn’t be in contact with conductive pathways, and if it does I’m using too much.
@@SweetbeatsTechStop that is helpful, thank you 🙏🏻. I wish all of my analog mixing equipment came with high quality faders with rails, but in lieu of that I know folks use grease to protect from dust on the conductive surfaces and add a pleasing amount of resistance to the fader throw. I definitely enjoy the latter myself, but have always been a bit confused how it didn't interfere with the signal path.
So with that I’m going to clarify something…and I think this is why I responded the way I did in my first response…FaderGrease is NOT for application to the conductive surfaces. I have never encountered anybody who applies or uses grease to “…protect from dust on the conductive surfaces and add a pleasing amount of resistance to the fader throw.” The conductive element is contacted by the wipers, which are a relatively delicate (depending on the fader) set of conductive filaments. Anything with viscosity like grease applied to the element will either interfere with the wipers’ ability to reliably stay in contact with the element, or actually trap or retain debris adding to the problem, and probably both. It’s a horrible idea to apply grease to the element. The element and wipers should be clean and dry. Furthermore, because the wipers are small and delicate, adding grease to the mating of the element and wipers is not going to add any appreciable resistance to the fader throw. Good quality professional faders, IMO, actually have low throw resistance in my experience. So that’s part of my goal when servicing faders, whether professional assemblies or more “budget-grade” short-throw low-profile ALPS-type PCB or chassis-mount faders we find in machines like cassette “portastudios.” Because of the mechanical design of the more “budget-grade” faders described above, there is absolutely no way to apply grease-type lubricant to the relevant bearing surfaces without removing the fader and disassembling it. And bear in mind these types of faders were not designed to be disassembled and serviced. So it takes some knowledge, care and skill to do it, including (usually) desoldering the fader from its PCB. So unless that’s what you are planning on doing, there is no reason for you to purchase any grease because you should not be just blindly packing that down into the fader, which is the only thing you’d be able to do without removing and disassembling it.