Tascam M520 Story...

  • Thread starter Thread starter sweetbeats
  • Start date Start date
Tascam still sells these so I can't legally distribute the manual and certainly can't sell a copy. I'm happy to help out with sections though and/or questions regarding the operation...several of us here know the operational features and functions right off the top of our heads so its no trouble.

How can I help?

BTW, it really is worthwhile to have the full manual and as I said you can get them from Teac in California (323) 727-4840. I would recommend getting it from them rather than eBay or somewhere because you never know what you are going to get...got an eBay manual for a Tascam 48 I used to have and whole pages were missing and parts lists and schematics were unreadable...total waste of $20. If you DO go to eBay looking make sure it is an original and not a copy or scan...too risky.

So tell us the story...what's your setup? How did you come into possession of your M-520?
 
sweetbeats said:
Do you have full service manual for your M-520?

That would help the troubleshooting dialogue. Keep in mind you are going to need to access your master section so be prepared to:

  1. remove the buss faders
  2. remove the master dress panels
  3. remove the armrest trim strip
  4. remove the 6 screws on the top rear panel under the meter bridge and tip the meter bridge and panel back
  5. remove the 4 screws holding the master section to the frame and tip it up
Click to expand...

Yes, I do have the manual, and have popped open the machine once to get my self acquainted with the process. I'm ready!
 
Okay...rather than reinventing the wheel, look back to post #357. onesong321 put up a post there as he was having trouble with the output of the monitor mixer.

What happens when you connect a measurable source to the MON SUB IN L and R jacks? Like the TEST TONE generator OSC OUT jack to each L and R SUB IN jack one at time? You still got one channel that is quieter than the other in the STEREO A/B busses?

onesong321 had one dead channel, but I suggest that the troubleshooting steps would be the same if you are still having the level discrepancy using a known source and the MON SUB IN jacks. So if so, get out your multimeter, open up the mixer and read starting at post #357. The idea is that we are going to make sure the monitor mixer is outputting evenly on both R and L channels from each monitor mixer channel, and then trace it through to the STEREO A/B busses and see if we find anything. Your case is a little different because you haven't got a completely dead channel, just a channel outputting lower. What I would do FWIW:


Connect the TEST TONE generator of your M-520 to each of the PGM BUSS IN jacks one at a time and test each of the pairs of monitor mixer channels (i.e. you'll test monitor mixer channels 1 and 9 when the OSC OUT jack is connected to the PGM BUSS 1 IN jack, test monitor mixer channels 2 and 10 when the OSC OUT jack is connected to the PGM BUSS 2 IN jack, etc.) To do this (for example):

  1. set the TEST TONE generator to 1kHz
  2. set the TEST TONE/SLATE switch to TEST TONE
  3. connect the OSC OUT jack to the PGM BUSS 1 IN jack
  4. raise the PGM BUSS 1 fader to unity gain
  5. raise the monitor channels 1 & 9 LEVEL knobs to about 12 o'clock
  6. source monitor channel 1 to BUSS
  7. make sure all other monitor mixer source switches are set to the middle off position
  8. sweep monitor mixer channel 1 hard left
  9. measure the DC voltage at the appropriate pin of the output of the monitor mixer channels 1/9 Monitor A PCB (the monitor mixer PCB where the monitor mixer summed output actually connects to the Monitor B PCB...watch the video I linked about 24 posts ago as it will give you visual pointers as to where I'm talking about...I don't have a manual or schematic with me at the moment so you'll have to look in your manual or watch the video or look at other posts above to know which pin of the 3-pin connector that goes from the channel 1/9 Monitor A PCB on to the Monitor B PCB goes to the right channel and which goes to the left)
  10. make a note of the DC voltage, then sweep the monitor mixer channel 1 PAN hard right and measure the voltage on the appropriate pin.
  11. now switch channel 1 source select to the middle off position and flip channel 9 source select to BUSS and do the same thing (sweep hard left, measure voltage, sweep hard right, measure voltage, blahblahblah)
  12. Now move the cable from the OSC OUT jack from PGM BUSS 1 IN to PGM BUSS 2 IN and do the same thing with monitor mixer channels 2 and 10...
  13. repeat all the way to channels 8 and 16.
  14. Sound tedious? Yeah, but we'll know if the monitor mixer is the problem or if it is in the second stages on the Monitor B PCB.
  15. Just for poops and giggles connect the OSC OUT jack to any mixer channel strip LINE IN, source the channel to that input, raise the TRIM, route the channel to PGM 1, raise the channel fader to unity gain, raise the PGM 1 fader to unity gain and run the same tedious test with just one monitor mixer channel (sweep left, measure, sweep right, measure). This will tell us that it isn't something wierd upstream. Can't imagine it is, but...

You don't need a fancier True RMS meter to do this...even a cheapy basic DMM will work because we are just wanting to see if the left and right outputs from each monitor mixer channel are the same. Don't worry if the level is different from monitor mixer channel to channel because remember each channel has its own LEVEL pot and and each pair of monitor mixer channels (i.e. 1/9, 2/10, etc.) is post PGM fader so they're bound to be a little different from monitor mixer channel to monitor mixer channel. what we care about is whether or not each monitor mixer channel's left output is pretty stinkin' close to the right output.

That's a lot. Let me know what questions you have.
 
sweetbeats said:
Okay...rather than reinventing the wheel, look back to post #357. onesong321 put up a post there as he was having trouble with the output of the monitor mixer.

What happens when you connect a measurable source to the MON SUB IN L and R jacks? Like the TEST TONE generator OSC OUT jack to each L and R SUB IN jack one at time? You still got one channel that is quieter than the other in the STEREO A/B busses?

onesong321 had one dead channel, but I suggest that the troubleshooting steps would be the same if you are still having the level discrepancy using a known source and the MON SUB IN jacks. So if so, get out your multimeter, open up the mixer and read starting at post #357. The idea is that we are going to make sure the monitor mixer is outputting evenly on both R and L channels from each monitor mixer channel, and then trace it through to the STEREO A/B busses and see if we find anything. Your case is a little different because you haven't got a completely dead channel, just a channel outputting lower. What I would do FWIW:


Connect the TEST TONE generator of your M-520 to each of the PGM BUSS IN jacks one at a time and test each of the pairs of monitor mixer channels (i.e. you'll test monitor mixer channels 1 and 9 when the OSC OUT jack is connected to the PGM BUSS 1 IN jack, test monitor mixer channels 2 and 10 when the OSC OUT jack is connected to the PGM BUSS 2 IN jack, etc.) To do this (for example):

  1. set the TEST TONE generator to 1kHz
  2. set the TEST TONE/SLATE switch to TEST TONE
  3. connect the OSC OUT jack to the PGM BUSS 1 IN jack
  4. raise the PGM BUSS 1 fader to unity gain
  5. raise the monitor channels 1 & 9 LEVEL knobs to about 12 o'clock
  6. source monitor channel 1 to BUSS
  7. make sure all other monitor mixer source switches are set to the middle off position
  8. sweep monitor mixer channel 1 hard left
  9. measure the DC voltage at the appropriate pin of the output of the monitor mixer channels 1/9 Monitor A PCB (the monitor mixer PCB where the monitor mixer summed output actually connects to the Monitor B PCB...watch the video I linked about 24 posts ago as it will give you visual pointers as to where I'm talking about...I don't have a manual or schematic with me at the moment so you'll have to look in your manual or watch the video or look at other posts above to know which pin of the 3-pin connector that goes from the channel 1/9 Monitor A PCB on to the Monitor B PCB goes to the right channel and which goes to the left)
  10. make a note of the DC voltage, then sweep the monitor mixer channel 1 PAN hard right and measure the voltage on the appropriate pin.
  11. now switch channel 1 source select to the middle off position and flip channel 9 source select to BUSS and do the same thing (sweep hard left, measure voltage, sweep hard right, measure voltage, blahblahblah)
  12. Now move the cable from the OSC OUT jack from PGM BUSS 1 IN to PGM BUSS 2 IN and do the same thing with monitor mixer channels 2 and 10...
  13. repeat all the way to channels 8 and 16.
  14. Sound tedious? Yeah, but we'll know if the monitor mixer is the problem or if it is in the second stages on the Monitor B PCB.
  15. Just for poops and giggles connect the OSC OUT jack to any mixer channel strip LINE IN, source the channel to that input, raise the TRIM, route the channel to PGM 1, raise the channel fader to unity gain, raise the PGM 1 fader to unity gain and run the same tedious test with just one monitor mixer channel (sweep left, measure, sweep right, measure). This will tell us that it isn't something wierd upstream. Can't imagine it is, but...

You don't need a fancier True RMS meter to do this...even a cheapy basic DMM will work because we are just wanting to see if the left and right outputs from each monitor mixer channel are the same. Don't worry if the level is different from monitor mixer channel to channel because remember each channel has its own LEVEL pot and and each pair of monitor mixer channels (i.e. 1/9, 2/10, etc.) is post PGM fader so they're bound to be a little different from monitor mixer channel to monitor mixer channel. what we care about is whether or not each monitor mixer channel's left output is pretty stinkin' close to the right output.

That's a lot. Let me know what questions you have.
Click to expand...

whew! i will give this a try next week. i really appreciate all the help!!!!!
 
For sure, just start by testing the output level at the STEREO A/B jacks with a known level tone (i.e. from the OSC OUT jacks) at the MON SUB IN jacks and post back if there is the level discrepancy or not. That may side-step all the testing of each monitor channel.
 
A Swift deal...

Well my AO friends, the last chapter has been written in this "Story"...I watched the M-520 head down the road today.

Its been for sale for a number of weeks and no solid bites, some I don't want biting, and finally a Richard Swift contacted me. We made arrangements to meet this afternoon. He came with his technician. Both really great guys. We had a nice time talking "shop". Were it not for the good conversation it would have been a very swift deal because I think they were about ready to plunk down the money when I pulled the cover off...I sort of had to encourage them to do a functionality test but it was sort of a formaility and maybe an excuse to buy time to talk about gear.

Check out Richard's myspace page linked above. He's got some cool sounds happening. He's an analog enthusiast for sure. He's done some recording at Fairfax Recordings in Hollywood, and has worked with the Daptone folks. He has a Studer A80 with 24 and 16 track headstacks from Sunset Sound. He's going to use the M-520 primarily as a summing and monitor mixer for the Studer. I think its neat that even with their experience with mojo-infested gear they were jazzed about the condition and features of the M-520. They were impressed with the routing fefatures and all the I/O...the Balance Amp section, EXT meter sourcing...all those innovations.

So they paid full price of $690 and we carefully loaded it into the truck and off they went. He says he'll send pics when they get it setup. I'm glad it went to people who appreciate it and will care for it. I think its found a good home.

I'm ALSO glad to have some more table space to work on the 58, 388 and 440-8. :D

P.S. They were both really interested in the M-___ mixer. The technician said that, in looking at the channel strip guts, he'd have never guessed it was Teac unless I told him. He was saying it looked very MCI-ish and/or something else, can't recall what he said. Teac did indeed know their stuff when they designed these products.

That's my Story. Leaving this thread open for future discussion and support needs on M-500 mixers. ;)
 
Hey Sweetbeats...

I've really been enjoying your M250, M___ and 388 threads, and wanted say thanks for all the great info you've been sharing, about these old Tascam mixers/recorders. I picked up a M520 last winter from a really nice guy in Detroit, and your posts have been a big help for me, as i go about cleaning it up and learning to use it. You did a beautiful job bringing your 520 back to life... It's good to see it go to a good home.

So to keep the thread rolling... Here's my M520:

tascam_m520.jpg


Over-all the board is in great shape, most of the channels sound pretty good as-is, it's not missing any of the little jumpers and it even came with the Tascam stand/rack that it sits on. The mic inputs on channels 13-14 are a bit noisier than the others, and the tape input on 13 has a waterfall-sound-of-static that gets louder as i move the channel fader up. Since 13-16 are lesser-used channels, i figured that is where i'd start learning how to re-cap this thing. Which leads me to a question i have...

I remember in another thread you were looking for a suitable replacement for C12 on the Input PCB. It's a 22uF/25V cap with a 5% tolerance. Did you you ever end up finding a 5% cap for this, or did you use a 20%? I've looked at mouser and some other sites and all i see are 20% caps. I've been able to pick out replacements for all the other sizes on the channel PCB, but this one with the 5% has me stumped. Any advice you have would be great!

Here's my channel 13... I pulled it out so that i could compare it to the schematics. Pretty cool, but a few of those white plugs were a pain to get disconnected. I tried to be real careful, and got them all unplugged eventually, without any disasters. :)

tascam_m520_channel13.jpg


Thanks again for the great thread!

-Tom.
 
Sad to see the "Story..." end but at the same time it's really cool to know that the M520 finally found a good home. :)
 
Hey, Tom, Welcome! :)

Very glad you have been enjoying the threads and that they are of some help. ;)

Your M-520 looks fantastic! Wow. And with the stand too that is great.

Hey, seriously, the first thing I would recap is the PS-520. That is the top of the electronic "food-chain" and I really noticed a difference in self-noise on my M-520 after the recap. It does sound like there is something else going on with the channel 13 TAPE input, but the PSU feeds the rest of the board and new caps help that food to be clean...food for thought.

Plus, my understanding is that bad caps won't typically produce "hiss" type noise but pops and crackles. Not trying to discourage you from recapping the card, but just preparing you that that may not be the silver bullet.

Okay. C12, 5%. I took Ethan and dementedchord's advisement actually with a cap replacement on the Control PCB on my Tascam 58...the spec was, again, for 5% and I couldn't find one in 5% in the value and voltage spec'ed for that cap...I bought, like, 20 20% caps and you know what I found? Almost all of them were well under 10% (like around 7%), and some were below 5%. Nichicon PW's I believe. Those are good quality caps and they are very affordable. I like those and KT's which are an "audio-grade" cap FWIW. In either case I think you'll find that if its a new good quality cap spec'ed at 20% the actual tolerance will be way below that. Get a few and pick on that is close to 5%, and remember that for C12 it looks as though Teac spec'ed a 5% cap so that there was less variance between the channels...all the C12's for all the strips could be 20% off rated value and the cap would still get the job done and all the strips would have the same performance with respect to C12 because they'd all be the same. I ended up getting KT caps for C12 and just putting them in because they were all at or less than 10% and very close/consistent.

I hope that helps.

Again, welcome!

Sad to see the "Story..." end but at the same time it's really cool to know that the M520 finally found a good home.
Click to expand...

Yeah, I know Daniel, BUT...this means there is more room on the table to continue the 58, 440-8, M-___, 388, and BR-20T stories...M-308B too but I'm not sure what's going to happen there...OH! The 234 Story too...ugh...okay...that all makes me tired. :rolleyes::o:D
 
I've seen Cory's (sweetbeats) posts for awhile since joining and they are always informative and great reads. Well tonight I decided to dig in to one of his inimitable "Story" threads and read this entire 17-pager tonight.

What a wonderfully informative and drool inducing masterpiece! I learned so much in these two hours it's unreal! Cory is a true analog junkie and his wisdom and kind encouragement to anybody's questions are way beyond cool. Kudos as well to all the guys who contributed and helped Cory get this M520 from radio station reject to a clean, mean, better than new machine!

I almost got choked up when I hit page 16 and Cory announced it was up for sale!:eek: But I get where he's coming from with the "too much stuff, too little room" dilemma and no one can ever take away the knowledge and joy he got from resurrecting this bad boy. Glad to see it went to a good home...

Thanks again Cory; I'm looking forward to going back through some of the other threads whenever "analog gear induced insomniatic psychosis" hits me again...John
 
John, hey...really: thanks for the words. Really glad you enjoyed it. Trying to become less of a "junkie" but, yes, I'm learning MUCH in the process and a big part of that is:

  1. what do I really need
  2. what do I want
  3. what actually works for me

Its easy to get lost in all the stuff in the process and letting go of the M-520 is part of digging out and actually it feels really great to have it gone...not a moment's regret over it...got cash in my pocket, space (physically and mentally) to continue on other projects, and the biggest prize (and you hit right on it) is the knowledge I gained in the process and fun that was had...and, yes, it does help that it went to a good home.

So, kudos to all you viewers and contirbutors and consultants. A community project. Can't believe this little story has had over 14K views. So if it is helping others keep their gear going and inspiring others that they can keep their gear going it is well worth it, and its been a great place to document the journey which is fun for me to go back through at times too.
 
hey sweetbeats awesome thread! i can't believe what an incredible job you did on this board and I can't thank you enough for not only the insight it has provided to me but that it also introduced me to this forum which i was completely unaware of previously. I think this should be made the official m-520 thread for the entire internet as there is almost no good information available anywhere else. And sad as i am to have seen the conclusion of this with you parting with your board at least it went to a good home.

I just picked up an m-520 a couple of weeks ago for a hundred bucks with power supply a ton of cables and a thousand watt power amp, i may have gotten the deal of a lifetime:). And although slightly dirty and dusty from sitting in a garage for a few years ended up being a rather pristine specimen electronically, im thinking it must have been recapped at some point within the last ten years or so as i have no noise from any switches, knobs, or faders, and i can crank the masters and have essentially no hissing or any other noise.

This thread has been invaluable to me in terms of figuring out the internal routing of sound and use of the masters and monitor sections and busses which never having had a big board before gave me a slight headache when i first attempted to figure out.

Does anyone know what tascam is currently charging for a manual? I'd like to be prepared to hand out the dough before i call them up and start bothering them about an obsolete piece of equipment;), also if anyone is aware of the part number or knows if tascam still stocks the orange caps for the eq section i would appreciate that information as well, as im missing three of them, which isnt so bad after reading some of your guys other posts if thats my only problem.

so again congrats on a job well done, and lets keep filling this thread with m-520 info!
 
lets keep filling this thread with m-520 info!
Click to expand...

Yep! That's my hope.

Hey, welcome and congrats on your purchase. That was a good deal! ;)

The folks at Teac are great. If you don't want to call then just send an email to parts@teac.com. They'll get back to you in 1 ~ 2 business days. Believe me...I've badgered them about all kinds of wierd stuff.

My guess is that the manual is only available in a reprint. You'll still have schematics in foldout pages but the manual is a photocopy of their master and on normal stock paper. Still worth every penny IMHO and I've purchased a number of reprint manuals from them. I recently got a reprint of the 388 Studio 8 manual...170 pages for $23. That is a newer model and possibly in greater demand so the M-500 series manual may be more. Quite possibly in excess of $40 but give them a holler and see.

Orange caps are unobtanium from Teac. Best bet is finding used spares.

Put up some pics of your M-520 if you have a chance.

You can probably tell if the PSU was recapped just by removing the 4 screws in the top vented panel of the PS-520...all the big caps in there were fixed to the main PCB with cement and you'll be able to see if the caps in there are glued in with the stock cement or not.

The M-520 is a bit daunting at first with all of its routing options, and there were some things (not having used the board frequently enough) that I'd have to refresh via the manual. Its a sleeper...underrated as are the M-300 mixers, but there I go pimping Tascam's vintage stuff again...! :eek::rolleyes::D
 
Re-capping the PS-520

Speaking of re-capping the power supply... I took Cory's advice and changed my priorities to re-capping the power supply first, before getting all into working on specific channels and stuff. I was kinda reluctant to pull it apart at first, since this would be my first re-cap job, and there's only one power supply - so i didn't want to mess it up. Thankfully, it all went well, and i learned a bunch of stuff in the process...

Opening up the PS-520 is easy, just make sure everything is disconnected and remove the 4 screws to get the top panel off.

ps520_opened_up.jpg


With the PS opened up you'll see the main PCB just staring at ya'. Mine was pretty dusty and due for a cleaning. The pcb is held in place by 2 screws in the corners on the left and 2 plastic pins on the right.

ps520_before.jpg


I tried tugging the board a bit to see if it would come up from the pins, then realized, you need to squeeze each pin a bit with some needle-nose pliers, while lifting the board.

ps520_squeeze_pins.jpg


With the PCB unmounted, the wires had enough slack to lift the board out of the unit, flip it around gently, and set it on top, without having to disconnect anything from the transformer or heat sinks. I used the lid from the PS and a towel, sitting on top of the unit, as my work bench.

All the caps in my power supply were spec'd as the manual said they were, except for one. C005 was supposed to be a 1uF/50V cap, according to the user manual. I pulled it out and did a double take when i saw that it was a 10uF/35V - i didn't order any of those. :/ I looked through the bags of capacitors i had ordered, and by some stroke of luck, i had ordered 1 extra 10uF/50V! Phew... I put that extra 10uF/50V in for C005. :D

ps520_pcb_on_towel.jpg


Once i had all of the small caps in, i moved onto doing the big ones. They have that glue that holds them in place, as well as 3 leads, so they are a bit harder to get out. I wasn't sure what to think of the third lead at first, all the new caps only had 2 leads. I looked a bit closer at the traces on the board and determined that the 3rd lead wasn't part of the circuit and appeared to be there just for stability. Here's a photo of the PCB showing a vacant 3rd hole and a bit of a rough soldering job...

ps520_soldering_bigcaps.jpg


I learned real quick that you need to be careful to not get the board too hot with the iron or else the little traces can melt and peel up. The blobs of solder above are from trying to repair a spot where that had happened. After doing a couple of the big caps, things started going much smoother. Here's the "after" photo with all the new caps installed and the board cleaned and dusted.

ps520_after.jpg


With everything back together, i tested out the mixer, and everything works fine. No smoke, no strange noises. The mixer sounds good, maybe a bit better than before, though it's subtle. The biggest change i think i've noticed, is when playing a mix back through the board. It seems to have a bit more range now, the sound has a bit more "authority", it's kinda hard to describe, but it sounds good. :)

Cory... Thanks again, for the advice and help! I've moved on to re-capping the channels and it's going well, but i'll save that for a later post. :)
 
Hey nice work! ;):)

One problem of such a big thread is that info gets spread out and buried. Your tutorial is awesome and covers some sticky bits about getting that main board out. Thank you so much for taking the time to document and put it here! :D

I do the exact same thing when accessing the main board with removing the two screws and squeezing the two pins with the pliers and then flipping it over and resting it on top of the front panel...I used a towel at first but found that using some of that grippy rubber mesh shelf-liner that you can get in pretty much any kitchenware store or department helps to protect both the dress panel and the PCB, as well as helping things to stay put while removing solder or burning new components in.

I learned real quick that you need to be careful to not get the board too hot with the iron or else the little traces can melt and peel up.
Click to expand...

YES. This goes for any of the PCB's that are made from the phenolic resin...having a clean tip on your iron is key and a good tip temp. My pencil iron I use has a fixed temp of about 650 and it has worked great for all the work I have done. I keep a small break-away box-knife handy to scrape the coke off the tip as well as a wet piece of cotton cloth. I wipe frequently. If the tip is dirty the heat conduction is greatly reduced and the heat from the tip won't be enough to quickly melt the solder, but hot enough to cook the adhesive that binds the pads and traces to the board. :mad: With the tip clean and with a good vacuum solder sucker you can get in and out very quickly. My vacuum solder sucker gets nearly all the solder off and then I can gently pop the tails off the solder pad on those big caps or on devices with more terminals like pots or opamps...the point that you highlight though is that you do need to be careful with those pads and traces on these boards. Once you the hang of it it is fine. Anybody wanting to get into this should go to a local electronics shop...a lot of times they've got grab bags or bins of surplus parts. You can pick up a PCB assembly or two for a song and practice on it...if you don't have such a shop go to a garage sale and spend a couple bucks on a transistorized electronic device, crack it open and practice away.

On that 10uF/35V cap...I may not have put that info up in the thread...evm1024 and I ran into that when recapping the modded PS-520 for my Tascam M-___ prototype mixer. Yes, the schematic shows 1uF/50V but sure enough its 10uF/35V on the board. This is where I learned that it is valuable to cross-reference the actual components with the parts list and the schematic before making shopping lists. The 388 is really bad...the schematics for the dbx boards and bias boards in particular are loaded with errors and omissions compared to the actual assembly. Not pointing a finger at Teac there...I think it is pretty common for there to be differences in what was spec'ed and what went out the door. Sometimes they run out of a part and put an equivalent part in. Ethan and I figured that may be what happened with that 10uF/35V cap, although it is the same in his PS-520, and obviously in yours and I ran into that with the PS-520 for the M-520 that is the subject of this thread. Ethan felt it would be fine to put the spec'ed 1uF/50V cap in instead of the 10uF/35V cap...they may have run into issues when testing the board at extremes. BUT, of course if the actual part is a higher spec then the best thing is to go with that. That's why I go through the actual assembly with the parts list and the schematic when making shopping lists and I have come accross situations where the schematic calls for a higher spec part than is on the assembly. It those cases I have to analyze what the purpose of the cap is, and depending on the purpose (which of course half the time I have to ask somebody :)) then I may go with the higher value in the schematic. If it is a higher voltage part on the schematic I will just do that regardless of the purpose of the cap. Bottom line: at least on the Teac stuff, which, according to opinions I have run accross and my own personal opinion is well engineered, you can play it safe and just replace caps with like parts and it'll be good. No need to go spending eons questioning whether or not Teac cut corners on a certain spec for a part. Putting in contemporary 105 degree caps of a reputable brand will git 'er dun! What caps did you use? Panasonics are well-reputed but so are the Nichicons and they are cheaper and available in more flavors.

BTW, I'm pretty sure something was nearing end-of-life in my PS-520 when I recapped it because of the very noticeable change in the noise floor after recapping. Yours may have been in better shape, but I've arrived at the conviction (secondary to much advisement and reading) that having a healthy PSU effects so many things. Noise and ripple in the rails will reduce the life of everything downstream on top of being audible. That big 10,000uF/25V cap is, IIRC, the filter cap for the audio rails and having a new better quality cap in that location could certainly improve the performance of the audio path even if it is only barely noticeable...so much of what goes on is under the radar so to speak, but you put it all together and sometimes that's where you can hear that "something".

The PS-520 seems to be a good supply. In testing that Ethan did to check the output of the good-sized transformer in there it looks like the PSU can output 3 ~ 4 times the theoretical draw of the M-520.

Keep up the good work and don't hesistate to ask any questions along the way too. I went round and round on a couple things decision-wise when recapping input boards and of course I'm happy to share where I landed on those decisions.
 
golden nuggets

Perhaps what you should do is extract the golden nuggets and post them in a tascam M520 golden nuggets thread. This is a resource we shold keep.

--Ethan
 
Better late than never.

This is kind of a belated follow-up post to my post about re-capping the PS-520...

I forgot that i hadn't included what caps i used in the power supply... I pretty much followed Cory's selections that he posted in this post. The smaller sized caps are Nichicon PW series and the larger ones are Panasonic NHG series or Nichicon VZ for the 10000uF/35v cap. The only caps that i used that differed from the original specs were the previously mentioned C005, where i used a 10uF/50V and then the big 10000uF/25V where i used a 35V instead. I'm pretty green when it comes to electronics stuff, so it was great to have Cory's selections to work from. Thanks again for sharing... :)

Ethan... Golden Nuggets... That's a great idea. It seems that there's a bunch of us M520/512 owners around here that could benefit or contribute... When i was looking for info on choosing capacitors i did a lot of jumping around from thread to thread, following the conversations about recapping, the 520 story and the 520 mods. There's a ton of golden nuggets spread around in those threads... It would be allot to consolidate, but when combined, could make an awesome supplement to the owners manual. :)

-Tom.
 
Hmm, in my "downtime" (which is rare at the moment), I might try tackling the documentation side of this project. I can't make any promises, but it would tickle me to actually get all of this put together in a "how-to" type pdf file or web page. Once I get into the new house, it should be much easier to tackle all of my little "projects" like this.;)

Man, I'd love to get my hands on a 520. I don't think I'll really have the room for it, but it is a beautiful piece of equipment.:D
 
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