m-45 power meter

[bmanone]

My Yamaha M-45 amplifier had the glue...:sigh:

 

[bmanone]

I stuttered......

My Yamaha M-45 amplifier had the glue...:sigh:

 

[avionic]

I stuttered......

My Yamaha M-45 amplifier had the glue...:sigh:

Well. There you go. At least one M-45 had the glue.



Did you see the blackgate caps.:yes:

 

[Ndirish147]

I just ordered the new lights so once they come in I will look more closely for the glue. One thing i did notice was the meters seem to show an unbalanced output signal. Is there anyway to test this? I sent a mono signal to the amp but the left meter was still showing more output than the right channel.

 

[Ndirish147]

First want to thank avionic for recommending dave at dgwojo excellent service ordered Sunday and got the lights Wednesday. Have a few more questions. Where do i adjust the dc offset? I checked the idle current and both channels are running at - 5mv pretty sure that is within spec? Other thing is i do have the glue on the board what is the best way to go about cleaning it? Thanks for all the help

 

[avionic]

Other thing is i do have the glue on the board what is the best way to go about cleaning it?

I remove the contaminated parts and chip and scrape with a square, chisel bladed exacto knife. Parts get replaced if leads have any signs of corrosion.Usually comes off the boards rather easily in big chunks.

 

[avionic]

Where do i adjust the dc offset?

I give up. Where ?
There is no provisions for offset adjustment. How much DC offset are you looking at , at the speaker binding posts ?

 

[avionic]

I just ordered the new lights so once they come in I will look more closely for the glue. One thing i did notice was the meters seem to show an unbalanced output signal. Is there anyway to test this? I sent a mono signal to the amp but the left meter was still showing more output than the right channel.

Verify the your input attenuator controls are both set to the same level. Then follow the meter adjustment procedure in the service manual.
http://www.hifiengine.com/library/yamaha/m-45.shtml

 

[avionic]

Yes , you need and True RMS AC voltmeter ( that's accurate at 1khz * ) and a 1khz audio signal source. (generator , etc.) No speaker load required.

* Some Flukes are. You will need to review your meter,s owners manual. I know " read the owners manual" WTF..

 

[Ndirish147]

I gave up on the bias adjustment too my left is 24mv and the right is at 5mv so they arent bad i was just going to get them closer. If i pull the caps with glue on them out is it worth it to just replace them along with all of the other caps? I just have a cheap meter so i doubt it will do 1khz but i will check.

other than all of that the amp sounds very good, i am shocked at how clean and tight it is. looking forward to many years of use with it.

 

[avionic]

I gave up on the bias adjustment too my left is 24mv and the right is at 5mv so they arent bad i was just going to get them closer. If i pull the caps with glue on them out is it worth it to just replace them along with all of the other caps? I just have a cheap meter so i doubt it will do 1khz but i will check.

other than all of that the amp sounds very good, i am shocked at how clean and tight it is. looking forward to many years of use with it.

The left is going to run pretty hot at 24mv.

 

[Grooverider]

My Yamaha M-45 amplifier had the glue...:sigh:

As did mine.

This thread showing the DSBG in a M-45 might help.
http://www.audiokarma.org/forums/showpost.php?p=5423046&postcount=11