MA-6100 cage
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clinic-audio
all on YAMAHA untill 1990
MA6100 cage
Hello
1) To remove the cage you have to turn the unit upside down
2) remove bottom cover all the screws on it + 3 on the left and 3 on the right
3) once the unit is open , watch the fixing screw on the left closer to the swich and the other one on the right . Once these both screws are removed pull the unit to the top and the cage will stay down on your "table" !
regarding the bulbs :
A) the front panel off (once you remove all the knobs) , you can see them easely, but regarding the bulbs in connection with the keyboard , it is a little bit more complicate . You have to try with your finger 1/4 turn on the left and the banana will be no more locked and the bulb is " free " but if you have "slipping" finger , you have to delete the fixing screxs holding the lamp holder no other way , sorry
Hello
1) To remove the cage you have to turn the unit upside down
2) remove bottom cover all the screws on it + 3 on the left and 3 on the right
3) once the unit is open , watch the fixing screw on the left closer to the swich and the other one on the right . Once these both screws are removed pull the unit to the top and the cage will stay down on your "table" !
regarding the bulbs :
A) the front panel off (once you remove all the knobs) , you can see them easely, but regarding the bulbs in connection with the keyboard , it is a little bit more complicate . You have to try with your finger 1/4 turn on the left and the banana will be no more locked and the bulb is " free " but if you have "slipping" finger , you have to delete the fixing screxs holding the lamp holder no other way , sorry
Hi,
You can remove the entire front glass assembly by taking out the three screws on each side of the amp that are about 1 inch from the front. Unless you're changing the glass, you shouldn't need to take out the small screws on the shiny end caps.
As for the knobs, they're pressure fit. It's really hard to pull them off, but they do pull off. I thought I was going to break mine.
The lamps are bayonet base, so they theoretically press in and rotate 30-45 degrees. On mine, the main illumination bulbs came out fairly easily, while the indicator bulbs were virtually impossible. I broke the glass on a couple of them and used needle nosed pliers to get the bases out. Fortunately, putting them back in was much easier. Hopefully someone with a better experience can say what I did wrong.
One other thing to note. I noticed that the two outside main bulbs had some play in depth after they were seated properly. Pulling them as far out of the front as possible before installing the glass made the glass brighter. I haven't taken pictures yet, but I can see where the socket has a spring clip and can move in and out about 1/8".
You can remove the entire front glass assembly by taking out the three screws on each side of the amp that are about 1 inch from the front. Unless you're changing the glass, you shouldn't need to take out the small screws on the shiny end caps.
As for the knobs, they're pressure fit. It's really hard to pull them off, but they do pull off. I thought I was going to break mine.
The lamps are bayonet base, so they theoretically press in and rotate 30-45 degrees. On mine, the main illumination bulbs came out fairly easily, while the indicator bulbs were virtually impossible. I broke the glass on a couple of them and used needle nosed pliers to get the bases out. Fortunately, putting them back in was much easier. Hopefully someone with a better experience can say what I did wrong.
One other thing to note. I noticed that the two outside main bulbs had some play in depth after they were seated properly. Pulling them as far out of the front as possible before installing the glass made the glass brighter. I haven't taken pictures yet, but I can see where the socket has a spring clip and can move in and out about 1/8".
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2string1
Super Member
All lamps on the push button controls where burnt out and two of the others.I had a big pen with a rubber grip that I took the insides out.It was tapered so I cut it to size and used that to get the control panel lights out. Why couldn't they just keep then out like others. There are these cardboard tubes that go around the bulbs but they don't seem to go back in very easy. I talked to someone at Audio Classics and he said don't worry about putting them back. Does anyone know if it makes a big difference? Also the foam around the control panel turned to dust just by touching it lightly. Had to replace that too. Now I'm just waiting for the new lamps to get here.
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Gregory
Soundco Kid
Hey nice photos!!
One way to get the knobs off is using yellow latex and neoprene gloves like the Mrs. has under the sink. You can get sufficient grip on the knobs with that method.. Same with the lamps. It takes a bit of force inward to disengage the bayonets from the socket. As someone suggested recently.. brush on some Deoxit before reattaching the knobs.
Looks like a good re-foam job atop the switches. My C26 recently had a lot of corrosion under the foam tape but it came out ok. I haven't applied any new tape yet. Will let the paint dry underneath for a good long while first. Check the warranty on the new FOAM (5yr, 10yr.) That's about the time, maybe +50 to 100% when it will begin to "det-tree-ate" and need replacing again.
Oh.. and nice photos BTW. :yes:
-Gregory
One way to get the knobs off is using yellow latex and neoprene gloves like the Mrs. has under the sink. You can get sufficient grip on the knobs with that method.. Same with the lamps. It takes a bit of force inward to disengage the bayonets from the socket. As someone suggested recently.. brush on some Deoxit before reattaching the knobs.
Looks like a good re-foam job atop the switches. My C26 recently had a lot of corrosion under the foam tape but it came out ok. I haven't applied any new tape yet. Will let the paint dry underneath for a good long while first. Check the warranty on the new FOAM (5yr, 10yr.) That's about the time, maybe +50 to 100% when it will begin to "det-tree-ate" and need replacing again.
Oh.. and nice photos BTW. :yes:
-Gregory
Gregory
Soundco Kid
As Patrice says above, the cage is held on by threaded lugs through the chassis with washers and nuts underneath.
You will then be looking at something like the photo below.
Might as well, if so inclined lift the heat sinks slightly and polish the chassis underneath them.
When complete, it will be like the following: comcast.net/~mc_audio/MC2505_polished.jpg
Very good idea to pull the cage and remove any crud or film from the chassis and heat sinks, even polish the chassis to help keep if from oxidation.
-Gregory
Gregory
Soundco Kid
Wow!! beautiful photos, and the unit is in GREAT shape. :thmbsp:
You have a fun and rewarding project there.. with original caps in view.
-Gregory
2string1
Super Member
Yes this is a fun hobby working on vintage gear if you have the time and a little money to play with...and you know what,the vintage sound is very rewarding too... I'll probably pick up a modern intergraded some day just to satisfy my curiosity,but it's got to have tone controls.
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smartin53
Well-Known Member
I'd recommend a recap using Nichicon Muse types for the radials and Vishay's for the Axials. You can also order new 9300uf caps from McIntosh for about $40 for the pair. I did this and it made a world of difference in how the unit sounded. Also added the security knowing that all the electrolytics are now new and fresh.
The only thing I did not change out was the multicap since there is no direct replacement for that one on the market. You could always restuff it with new caps, but mine tested OK so I left it in. Restuffing is a pain.
The only thing I did not change out was the multicap since there is no direct replacement for that one on the market. You could always restuff it with new caps, but mine tested OK so I left it in. Restuffing is a pain.
I did restuff the multicap on mine, it did make an improvement to the sound, and it was a pain.
I would certainly replace electrolytics as they will dry out and do bad things, either to the sound or short and burn up electronics.
Also, there are four pots on the tone board in the front. Those are likely out of adjustment. I realigned mine by using a software-based pink noise generator and spectrum analyzer. When properly adjusted, the preamp should have a flat frequency response with the tone controls at 12:00.
I would certainly replace electrolytics as they will dry out and do bad things, either to the sound or short and burn up electronics.
Also, there are four pots on the tone board in the front. Those are likely out of adjustment. I realigned mine by using a software-based pink noise generator and spectrum analyzer. When properly adjusted, the preamp should have a flat frequency response with the tone controls at 12:00.
2string1
Super Member
Thanks... today is my first day to really get to listen to it and I must say it's very nice. It almost sounds darker then my tube Fisher,but I'm hearing a difference in the bass ,it a a little tighter and faster. I need to have patience and listen to it for a couple of weeks before I go back to the Fisher and hear the difference. All controls are quiet. Does take a while to warm up. Terry's going on vacation so I may wait a while and send it to him. I don't know there's something about a virgin piece 
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2string1
Super Member
New bulbs don't light up all the printing. I noticed when I had the faceplate off, if I held it up to the sun light some of the printing was sort of grayed out and not bright green. I think it's just do to age. It's never been taken apart so everything should be lined up. Here 2 shots taken at different shutter speeds hand held.
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