Needing a 1970's Yamaha Engineer (employed by Yamaha)

[Want to be]

You're putting too much thought into the documents. Plenty of times changes are made during production because of cost or availability. The best way is visually see what the board has. Metal film resistors for everything until you get above 1 watt then it's usually the white coffin cement kind. Metal film resistors are cheap and pretty standard. Spend $3 and get yourself a bag of 100. Ceramic caps are usually for bypass reasons but I have seen them used in coupling applications. Again nothing here is critical or stressing the caps in any way. Buy whatever is cheapest. Low ESR or FC caps are best used in switching power supplies. You won't see any advantages in audio applications. Lately I've been splurging and buying Nichicon audio grade caps because they are gold colored. Polystyrene and film caps last forever. I'd leave them alone. One time I did see a green dipped film cap with it's guts exploded outward. Someone was pushing their PA amp too hard in church.

THANK YOU SO VERY MUCH, THIS IS THE TYPE OF ANSWERS THAT I HAVE BEEN SEEKING!

 

[Want to be]

Metal film resistors for everything

I have been told in the past that Yamaha didn't use Metal Film as a everything and that I should use Carbon Film, thus the reason for the REX.

 

[Want to be]

Low ESR or FC caps

Not to question anything that you have stated
I have been told in the past to use this type in the Power Supply board.

 

[Want to be]

Here is a specific parts replacement request:

 

[astouffer]

Here is a specific parts replacement request:

Ok that is the one type of critical component because it's an AC line capacitor. Those have been known to fail (in a spectacular way) from a certain vintage and manufacturer. You want to replace it with an X or Y capacitor depending on the circuit. See https://www.allaboutcircuits.com/technical-articles/safety-capacitor-class-x-and-class-y-capacitors/

 

[Want to be]

Ok that is the one type of critical component because it's an AC line capacitor. Those have been known to fail (in a spectacular way) from a certain vintage and manufacturer. You want to replace it with an X or Y capacitor depending on the circuit. See https://www.allaboutcircuits.com/technical-articles/safety-capacitor-class-x-and-class-y-capacitors/

Because Class-X and Class-Y capacitors must be connected directly to AC lines (line-to-neutral or line-to-ground)

 

[JMFahey]

So much judgement being handed out here, that is not at all what I was hoping for. I thought I had asked some very simple questions with hopes of simple answers. My big mistake in thinking, has become more of a delusion. I did receive some okay information and I am most appreciative of the assistance.

Saying you see problems where there are none is not judgement but stating reality.

Since we are again at it, I´ll add: you have NO CLUE about 70´s Japanese Electronics.

You were given simple and detailed answers, but you fail to acknowledge them.

What you call thinking, somebody else might call obsession.

Pulling all components from a working amplifier? .... gimme a break!!!!

Delusion? .... you mentioned it, not us.

 

[Want to be]

This is what I am finding, I was reading a Tech Note on Snubbers the other day and it's effect upon transformer ringing. Therefor it appeared to be critical to use the correct values. I don't see the values here.

I also saw an article on using a MICA cap and Carbon Composition Resistor. When I looked at MICA the price was over $40.00, that is a surprise and other ideas?

 

[astouffer]

This is what I am finding, I was reading a Tech Note on Snubbers the other day and it's effect upon transformer ringing. Therefor it appeared to be critical to use the correct values. I don't see the values here.

I also saw an article on using a MICA cap and Carbon Composition Resistor. When I looked at MICA the price was over $40.00, that is a surprise and other ideas?

This part in question has nothing to do with transformer ringing. It's to quench the small arc when the switch is opened and slow down wear on the contacts. Where did you see the article about mica? Here's all you need.

https://www.digikey.com/en/products/detail/würth-elektronik/890324025006CS/5038917

$0.39

https://www.digikey.com/en/products/detail/ohmite/OF121KE/15294014

$0.95

Honestly you could leave it out of the circuit and never notice a difference. There's probably a dozen devices in your home right now with a switch and no snubber across it.

 

[Want to be]

This part in question has nothing to do with transformer ringing. It's to quench the small arc when the switch is opened and slow down wear on the contacts. Where did you see the article about mica? Here's all you need.

https://www.digikey.com/en/products/detail/würth-elektronik/890324025006CS/5038917

$0.39

https://www.digikey.com/en/products/detail/ohmite/OF121KE/15294014

$0.95

Honestly you could leave it out of the circuit and never notice a difference. There's probably a dozen devices in your home right now with a switch and no snubber across it.

This is the only 0.1uf ceramic cap that I can locate, unless I can use a film. This for the Main board.

 

[astouffer]

This is the only 0.1uf ceramic cap that I can locate, unless I can use a film. This for the Main board.

View attachment 1091143

Where is it located in the circuit?

 

[Want to be]

Where is it located in the circuit?

Please see post 11

 

[Want to be]

Where is it located in the circuit?

See also post 44

 

[astouffer]

Ceramic disc caps are ancient now and that's why Digikey carries ONE in that value. Pick a regular ceramic capacitor and you'll have hundreds to choose from. I don't know of the voltage rating you require but here is 0.1uf at 100VDC.

https://www.digikey.com/en/products/detail/kyocera-avx/SR291C104KARTR1/3066849

 

[Want to be]

TO-3P transistors were originally intended to drop into a TO-3 outline, though they might need a rectangular insulator rather than the diamond-shaped TO-3 insulators. There are a couple of TO-3P devices available at Digi-key that might be suitable as replacements for the original TO-3 devices used in this appliance.One is from Sanken, and one is from On Semi.Both appear to be as zippy as the original TO-3 devices used here.

Help me out here, I thought you were referring to these?

 

[Want to be]

Help me out here, I thought you were referring to these?

View attachment 1091275

TR609,
TR610,
TR611
TR612

 

[astouffer]

Every one of those transistors can't possibly be bad unless it was maybe struck by lightning.

Have you considered that your meter is bad since you claim every part is measuring out of spec?

 

[Want to be]

Every one of those transistors can't possibly be bad unless it was maybe struck by lightning.

Have you considered that your meter is bad since you claim every part is measuring out of spec?

Part number inconsistent
I don't find anywhere a cross-reference from original to these

 

[Want to be]

Part number inconsistent
I don't find anywhere a cross-reference from original to these

 

[Want to be]

I hope you can see this