Nick Danger's Yamaha M80 Amplifier Repair/ Restoration

[laatsch55]

So is this amp in working or non-working status? I have one here thats going to get 99.9% of all the components on the main board replaced due to heavy corrosion on just about every component. C162 and C163 are going to get a pair of Mundorf M-Lytics 1000µf/100v. All the old blackgates will get replaced with Blackgates from my private stock.

So, how private is that private stock?? I have some 100uf/100volt, and some 33uf/160 volt I'll trade for some 470 at 25 or 50 volr, or 220 at 50volt....

 

[Nick Danger]

You are going to replace all electo's ....right?? Acetone will do the rest ..maybe... Buss Bars...Tarnx

Seems to be the thing to do since I have her in pieces right now. Don't know about doing the big ones if they are good as I am having a hard time tracking them down.

I have acetone and copper cleaner here(may have some tarnx, too). Seems like it may thake a while to get the boards cleaned of flux- on there like pudding!!

 

[laatsch55]

Did a bit of beggin' for help, Lee. Couple of folks names kept popping in regards to this line of amps and thought it best to ask those who know, ya know?

Absolutely, Dave needed to put some posts in anyway, was fixin to send him a PM in ALL CAPS.....

 

[laatsch55]

Seems to be the thing to do since I have her in pieces right now. Don't know about doing the big ones if they are good as I am having a hard time tracking them down.

I have acetone and copper cleaner here(may have some tarnx, too). Seems like it may thake a while to get the boards cleaned of flux- on there like pudding!!

I don't think you'll find those for less than the mortgage on your house, but Dave has a sub I believe, if not HE"S SLACKIN!!

 

[Nick Danger]

Keep track of where those Blackgates came out of , you could probably go with Nichicon KZ's in place of those...if not the right value in KZ's, Elna Silmic II's...

Will do, Lee. Only pulled a handleful of components until I get her cleaned and figure out what needs to be replaced. I will remove and replace one or two pieces at a time after I have everything I need in hand to finish the boards. Slow and steady for me, my friend.

 

[Nick Danger]

I don't think you'll find those for less than the mortgage on your house, but Dave has a sub I believe, if not HE"S SLACKIN!!

Yeah, imagine that, something unobtanium for the amp. I am not averse to a mod if needed and understood that this may be something I would need to do.

 

[laatsch55]

Please mark the polarity on the board as you remove them. It happens that the silksceening is wrong, just to be sure Bud...

 

[Nick Danger]

I´m here periodically. Got a personal invite to this thread.

Thank you, thank you, thank you!

 

[laatsch55]

A good leakage test for those PS caps is in the WOPL archives in "Forming PS caps "

 

[Nick Danger]

Did you find these at the Yamaha forum "Yamaha Literature" sticky link (or links inside the sticky) over at AK?

IMHO, avoid that guy like the plague. He didn't even address the DSBG issue that we have discussed and remediated for years until questioned about it through e-bay. He was happy to sell many Yamaha amps without ever repairing the DSBG. Just throw on some binding posts, clean it up, cover up the transformers with black vinyl and call it a rebuild. I seriously doubt he's doing a full recap or replacing the filter caps. READ this and tell me what you see. $400 to clean it and put on binding posts! $26 PER PART for repairs. I should quit IT consulting and scrub M-80's.

Gotta give him credit for building an empire based solely on the legend in his mind.

Not disparaging the amps as I'm a HUGE Yamaha fan, but besting the best from McIntosh and Carver? I mean, c'mon guys.

FWIW, The M-80 is a fine amp and worthy of a build, and I ran a couple for YEARS and was very happy with them, but give me a PC2002M any day of the week.

Thanks for the heads up re: Legendary. I did try and contact them in the hopes of scoring some of the big caps but I was told they do not sell repair parts.

 

[Nick Danger]

A good leakage test for those PS caps is in the WOPL archives in "Forming PS caps "

Thanks. I was gonna PM you later and ask how to go about doing that. see if I can't find that thread......

 

[Nick Danger]

So is this amp in working or non-working status? I have one here thats going to get 99.9% of all the components on the main board replaced due to heavy corrosion on just about every component. C162 and C163 are going to get a pair of Mundorf M-Lytics 1000µf/100v. All the old blackgates will get replaced with Blackgates from my private stock.

Pretty sure amp was working, avionic, but only checked speaker connections A at 8ohms when I auditioned it. Sounded good, looked good, but knew that if this issue wasn't addressed(it wasn't) that I was going to try my own hand at the repair as I did not want to put it in the system and have it poop out on me(Murphy's Law).

Amp was purchased from the original owner who said it was only in for repairs once since he had it. Not sure what he had done as he could not remember and did not have the receipt.

 

[Nick Danger]

Did you find these at the Yamaha forum "Yamaha Literature" sticky link (or links inside the sticky) over at AK?

Cheers for the link, brutal. Looks like I am going to have a bit more to tackle after the main board is finished.

 

[Nick Danger]

A good leakage test for those PS caps is in the WOPL archives in "Forming PS caps "

Forming PS caps thread.

 

[brutal]

MEK to clean that glue and the PCB slime. Wash it with a stiff flux past brush. I use a pair of brushes, one with the bristles cut short to scrub, one to wipe on the MEK.

Please use at your own risk and in a well ventilated area. I only saw the fake stuff at HD, but saw some real MEK at Lowes and I'm kicking myself for not grabbing some but it was only in a gallon jug and it takes me years to go through a pint.

DeOxit on the copper bars, and then I polish them with a dremel and spray coat them with lacquer. Yes, I'm that anal.

 

[Nick Danger]

MEK to clean that glue and the PCB slime. Wash it with a stiff flux past brush. I use a pair of brushes, one with the bristles cut short to scrub, one to wipe on the MEK.

Please use at your own risk and in a well ventilated area. I only saw the fake stuff at HD, but saw some real MEK at Lowes and I'm kicking myself for not grabbing some but it was only in a gallon jug and it takes me years to go through a pint.

DeOxit on the copper bars, and then I polish them with a dremel and spray coat them with lacquer. Yes, I'm that anal.

Is MEK dangerous to the boards/ components or just to me?

 

[laatsch55]

Pretty handy if you want fiberglass resin cured....

 

[brutal]

Is MEK dangerous to the boards/ components or just to me?

If you review our DSBG threads, you may find mention of it and discussion of not only its merits, but cautions as well.

MEK is sort of a slower evaporating version of acetone so treat it as such. Better for dissolving glues and resins like baked on Sony Bond, and crusty flux. It's also better IMHO to reflow a little board lacquer than acetone and looks neater in the end. That means it will also dissolve/weld most plastics so be careful with the stuff. It's not inherently any worse than acetone on the silkscreen if you're careful and avoid excess scrubbing. Pick/scrape off what you can without damaging the silk-screening on the pcb component side and cleanup with MEK.

I also use MEK to disolve the glue from speaker cone foam surrounds. http://www.audioheritage.org/vbulle...d-Step-by-step&p=197788&viewfull=1#post197788

( This one is supposed to be on the front)

 

[laatsch55]

Neat job on the foam...

 

[avionic]

Pretty sure amp was working, avionic, but only checked speaker connections A at 8ohms when I auditioned it. Sounded good, looked good, but knew that if this issue wasn't addressed(it wasn't) that I was going to try my own hand at the repair as I did not want to put it in the system and have it poop out on me(Murphy's Law).

Amp was purchased from the original owner who said it was only in for repairs once since he had it. Not sure what he had done as he could not remember and did not have the receipt.

I did try and contact them in the hopes of scoring some of the big caps but I was told they do not sell repair parts.

Thats because they don't have any parts.Especially those large filter caps.Maybe used ones out of parts units.