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Yamaha M-45 - Help needed

Thanks a lot for the suggestion DeltaB. I really didn't give much of a thought and as soon as I got in the suggestion from Avionic, ordered that part 10A / 400V. Checking even Mouser had a 6A / 200V, but I trusted Avionic suggestion and went for the part he suggested.

Placed the order yesterday afternoon, USPS express... which is about standard time to Canada. Once the part is here and soldered in place I will post updates guys.

In the meantime, a Yamaha CA-810 has been plugged to the Tannoys to keep the music flowing and it will be a mellow week or two until it arrives.
 
Bastian said:
Thanks a lot for the suggestion DeltaB. I really didn't give much of a thought and as soon as I got in the suggestion from Avionic, ordered that part 10A / 400V. Checking even Mouser had a 6A / 200V, but I trusted Avionic suggestion and went for the part he suggested.

Placed the order yesterday afternoon, USPS express... which is about standard time to Canada. Once the part is here and soldered in place I will post updates guys.

In the meantime, a Yamaha CA-810 has been plugged to the Tannoys to keep the music flowing and it will be a mellow week or two until it arrives.
Click to expand...
Good luck getting it up and back in service!
 
Hi Blue shadow. I should have ordered all that stuff from mouser while I was at it. Dang. I should be able to get what I need though from a nearby store.

However, have not started. I have to take care of home chores and dedicate some time to the wife these coming days. She's getting worried (tense) by now haha.

I'll update on that hopefully next week. I'll look for some schematics around.
 
Hardware store should have all you need for a DBT. Lots of how tos on the web with pictures and such. This keeps high voltage and high current from coursing through the amp looking for weak spots as you sort out issues. Once all is good then the amp can see mains power, full 120V and up to 15 amps from a standard socket in NA. Don't want that popping things after you put some new parts in the amp and it still has a couple things needing attention.
 
Ok guys,

I'm not sure if I'll be able to move further tonight, but... I'll let you know guys know soon enough how this went down.

20181011_213116.jpg greceived_2361299647219497.jpeg
 
You'd laugh at my Dim bulb setup.
1 each 6" piece of 2" X 6"
1 each ceramic bulb socket
1 each 6' extension cord
and a 100-watt incandescent bulb
Low budget--
 
Haha! Sounds fun. Mine turned to be pretty inexpensive, around 13 bucks total. Fun fact is that it's way cheaper to buy a dollar store extension cord, cut the outlets side, and cut all wire you need, and use the cord that is left to run it to the tester to the wall. I checked and doing the cord from scratch was about 6 times more expensive.

Anyhow!! I cannot thank you enough. It is fixed and working flawlessly!! I used it with the bulb. Bulb was pretty much off, so it looked fine. Then I plug it straight on its own, left it on for about 3 min, set bias on both channels at 1.3 mV. Then plug it to the speakers and it sounds fantastic!

I placed as definitive fuse an average audio grade fuse (never tried one before), and I'm listening to new caps. These will be breaking in for the next month pretty much. However, the bass is more powerful and controlled than before to me. Voice is so lively now, and trumpets and saxophones are warm and inviting. I'm very happy, thank you so much.

I know recordings are silly, but I might just post a link later.

received_242649449762810.jpeg
 
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Bastian said:
, set bias on both channels at 1.3 mV
Click to expand...
That's a pretty low bias setting (idle adjustment). Service manual states 5mv +/- 1mv .May experience distorted sound at higher listening levels.
 
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avionic said:
That's a pretty low bias setting (idle adjustment). Service manual states 5mv +/- 1mv .May experience distorted sound at higher listening levels.
Click to expand...

Ohh!! Ok. So might be better to set it up to say 2.3 mV? Or 3.3 perhaps?
 
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Another one saved by Avionic. Well done, Bastian.

When I had an M-45, I did not like the sound of the amp in the normal setting, much preferring the Class A operation. Sure the amp idled much warmer but still well within its designed temp range. For this reason, I would not bias that amp lower than spec because the Class A operation basically boosted the bias level.

But of course, that was on my rig and using my hearing. YMMV, but it would be interesting to see what you find out if you do make the change.
 
4.8 in the left ch., and 5.0 in the right ch.. It's a bit more detailed maybe, like it has more nuances when loud, and voices feel a bit more lively. I'm playing same tunes I listened yesterday, but there was not a massive change per se. Although I made it to have it up to proper spec :biggrin:
. In class A readings are about 45mv.

Thank you all for the support and guidance. I have read many times from people that they set bias low to reduce impact on the parts. Didn't know that it could cause actually distortion and was not good practice.

As for the sound of the M-45, I have to say that 1, I use a tube buffer between the pre and the amps. It does make the amp sound a bit mellow and timbre is quite natural with it. And 2, I find that after recap the highs are not as harsh. I found them to be not very pleasant before, but I will try again in couple months after breaking in the new parts.

However, I don't use the M-45 for the highs. The M-45 deals with the woofers only. Then I match the amplifiers, and well, I wouldn't change the current set up. Specially because I used to have one that pleased me, decided to make an unnecessary "upgrade" and natural sound went away. I have been changing this and that in the persuit of returning to a natural, cozy, not fatiguing sound. I remembered that the M-35 I heard in a friend's house had a very sweet voice tone and decided to try the m-45. Whether it's in class A for average listening levels, or A class off when I want to crack it up (for the sake of dynamics), it sounds very pleasant over here. Voices are right in size, and tone is very inviting. It has a good sinergy with the speakers. I bought tannoy because they are very sought after in japan, figured they will get along with Japanese gear (plus they go as low as 3.2 Ohm as per my understanding. I needed something to cope with that!) I am very happy with what I have right now :beerchug:

Cheers guys! I'm off to play some tunes :music:
 
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