That was awesome, like a surgeon you replaced those op-amps! I dabble myself and loved the heat gun use for their removal. I just purchased an MPX 1 and was looking for videos and yours just blew me away! Keep them coming.
great video, im teaching myself electronic music equipment repair ...thank you, this was very informative, i have this unit as well as the g2...both work fine...fortunately but awesome idea on the listening probe ...will make one asap ..more repair videos please
Hi .could you tell me please what fuse for the cpu shall i have ?? Yesterday when i turn the unit i heard a click and it did not turn on . So i have another unit and take its fuse and put it in the damage unit and it worhs again.the problem i cant see any thing written on that fuse .which one please should i buy .many thank's from Germany
Awesome vid, thanks and subscribed! There's a bit of confusion about connecting the MPX-1 that's never been really described or clear in the manual...since this video centers on the in/out circuitry......In the MPX-1 manual it states if you are going to unbalance the unit from the balanced ins/outs you connect pin 2(hot) to tip, leave pin 3 floating....and pin 1 to sleeve.......looking at the schematic....would this be correct for the inputs AND outputs(going from xlrs on the MPX-1 to unbalanced TS. I appreciate it....I'm having to move my MPX-1 to an unbalanced mixer and want to be sure to do it correctly(MPX-1 manual page 1-3 states: "When connecting MPX 1 outputs to single-ended, unbalanced devices, leave the low side floating and connect the grounds between the units"
Excellent and insightful video! Thank you! I have one of these and the in/out pots both do crackle quite a lot. I need to see if I can fix it by cleaning the pots. Or might there be DC in the audio?
Wow how Timely I have this unit and just took it out to play with and both knobs (input and output level) make noise and the output knob makes terrifyingly loud exploding sounds when turned. Left alone snd set to the level you want all seems to be ok. The pots are both sealed as far as I can tell no way to get deoxit spray into the wiper that I can see.
@@mKreifeldt : that is the exact same problem I have: explosive crackle sounds when either turning the Input or the Output control and all get once levels are set. If there is no way to clean the pots, then one might need to change them. Or maybe it is something else than being dirty. Maybe DC over the pots? i need to open up the unit and see what is going on.
@@electronavalanche Both pots being bad seems sort of unlikely to me. This unit is old but not that old and usually rapid twisting can temporarily help an ailing pot getting carbon build up off but it’s not. Dc on the pots seems like a more likely culprit. I wasn’t expecting to see surface mount technology in this thing! If you get any ideas I’ll be grateful if you can let me know. A blocking cap somewhere there hopefully easy to replace…
Hi all, today I fixed the crackle sounds. I removed the pot pcb and sprayed a very good amount of Deoxit into the pots which are not potted btw. Turn the pots a couple of times and repeat. This fixed the crackle for good.
Hello. There is no positive or negative. The capacitor is not polarized. It is a 630 Volt 10nF axial capacitor. It is there in case you accidentally probe a DC voltage so it can block the DC. I soldered one capacitor lead to a finish nail (that's the probe) and the other capacitor lead goes to a wire connected to the tip of the jack. The the negative alligator clip connects directly to the sleeve of the jack. Then I put the entire thing in an old ball point pen case and wrapped heat shrink around it. It works great I always use it.
@@signalsandbits Great stuff although i've not had time to make probe but I've got adjacent question. I've got burned 33078 ic op amp U11 on my board. Unit doesn't show on signs but this part is visibly burned out. Which one did you buy from digikey as there is few options there? Regards Adrian
@@signalsandbits Thanks so much for sharing. A definite project in my future. Showing how you did the surface mount soldering was very helpful. I'm fine with through-hole, but have yet to tackle surface mount.
Fantastic video !
That was awesome, like a surgeon you replaced those op-amps! I dabble myself and loved the heat gun use for their removal. I just purchased an MPX 1 and was looking for videos and yours just blew me away! Keep them coming.
great video, im teaching myself electronic music equipment repair ...thank you, this was very informative, i have this unit as well as the g2...both work fine...fortunately but awesome idea on the listening probe ...will make one asap ..more repair videos please
Hi .could you tell me please what fuse for the cpu shall i have ?? Yesterday when i turn the unit i heard a click and it did not turn on . So i have another unit and take its fuse and put it in the damage unit and it worhs again.the problem i cant see any thing written on that fuse .which one please should i buy .many thank's from Germany
Thanks for the video ! - Can you do a video on a battery replacement ?
Thanks for all your hard work. And technical knowledge PEACE!!!
Awesome vid, thanks and subscribed! There's a bit of confusion about connecting the MPX-1 that's never been really described or clear in the manual...since this video centers on the in/out circuitry......In the MPX-1 manual it states if you are going to unbalance the unit from the balanced ins/outs you connect pin 2(hot) to tip, leave pin 3 floating....and pin 1 to sleeve.......looking at the schematic....would this be correct for the inputs AND outputs(going from xlrs on the MPX-1 to unbalanced TS. I appreciate it....I'm having to move my MPX-1 to an unbalanced mixer and want to be sure to do it correctly(MPX-1 manual page 1-3 states: "When connecting MPX 1 outputs to single-ended, unbalanced devices, leave the low side floating and connect the grounds between the units"
That sounds right. Pin 1 of XLR is ground so that would be going to the sleeve of the TS.
Excellent and insightful video! Thank you! I have one of these and the in/out pots both do crackle quite a lot. I need to see if I can fix it by cleaning the pots. Or might there be DC in the audio?
Thanks! I would suspect the pots. Try using some electronics cleaner if the doesn't help then it could be something else.
Wow how Timely I have this unit and just took it out to play with and both knobs (input and output level) make noise and the output knob makes terrifyingly loud exploding sounds when turned. Left alone snd set to the level you want all seems to be ok. The pots are both sealed as far as I can tell no way to get deoxit spray into the wiper that I can see.
@@mKreifeldt : that is the exact same problem I have: explosive crackle sounds when either turning the Input or the Output control and all get once levels are set. If there is no way to clean the pots, then one might need to change them. Or maybe it is something else than being dirty. Maybe DC over the pots? i need to open up the unit and see what is going on.
@@electronavalanche
Both pots being bad seems sort of unlikely to me. This unit is old but not that old and usually rapid twisting can temporarily help an ailing pot getting carbon build up off but it’s not. Dc on the pots seems like a more likely culprit. I wasn’t expecting to see surface mount technology in this thing! If you get any ideas I’ll be grateful if you can let me know. A blocking cap somewhere there hopefully easy to replace…
Hi all, today I fixed the crackle sounds. I removed the pot pcb and sprayed a very good amount of Deoxit into the pots which are not potted btw. Turn the pots a couple of times and repeat. This fixed the crackle for good.
Great video!!
I’m interested in your testing tool. Is positive capacitor leg connected to tip?? And I assume it’s in series?
Regards
Adrian
Hello. There is no positive or negative. The capacitor is not polarized. It is a 630 Volt 10nF axial capacitor. It is there in case you accidentally probe a DC voltage so it can block the DC.
I soldered one capacitor lead to a finish nail (that's the probe) and the other capacitor lead goes to a wire connected to the tip of the jack. The the negative alligator clip connects directly to the sleeve of the jack. Then I put the entire thing in an old ball point pen case and wrapped heat shrink around it. It works great I always use it.
@@signalsandbits Great stuff although i've not had time to make probe but I've got adjacent question. I've got burned 33078 ic op amp U11 on my board. Unit doesn't show on signs but this part is visibly burned out.
Which one did you buy from digikey as there is few options there?
Regards
Adrian
@@Sickindian5 This one: MC33078DR2G - it looks like they are out of stock on Digikey and Mouser but Newark still has 25 in stock.
@@signalsandbits Thanks so much for sharing. A definite project in my future. Showing how you did the surface mount soldering was very helpful. I'm fine with through-hole, but have yet to tackle surface mount.
Hey brother, are you in Canada?
No in US
@@signalsandbits Oh nice! Was just curious because I need a tech. It's pretty hard to find good tech's in Canada these days hah.
Dave from 12VoltVids here on youtube is from Canada. He can fix just about anything.