Yamaha M4/C4

[ferninando]

Will soon be acquiring a nice Yamaha matched set.
M4 amp and C4 preamp.

Any thoughts or comments welcome.
thanks

 

[avionic]

A real nice pair of Yamaha's.

 

[mgkfifty]

Like my M4 C6 combo a lot, both needed a little smoothing, voltage transistors, caps and switch cleaning in the C6 and general cleaning and power supply caps in the M4. Well worth the effort, will never part with them. The above poster helped me work thru the issues.

 

[ferninando]

I am expert at recapping so no worries there.
U think the c4 will need V-trs addressed and how will I know?
Probably will have more quests. later on.
So are U the expert on these amps avionic?
Thanks for replying.

 

[avionic]

U think the c4 will need V-trs addressed and how will I know?

Have to remove the top cover and look..


On some C-4's the heatsinked pass transistors were glued in place. But most were screwed in place. If yours was glued. No sweat. There are provisions to secure them to the PCB with screws like the rest.

 

[avionic]

So are U the expert on these amps

I know my way around them.

 

[Blue Shadow]

When you open that C4, removing the top as Avionic says, you will be looking at the circuit board right there. All the guts are underneath, built upside down compared to lots of gear. You are looking at the two TO-220 devices that have the large heat sinks attached, checking for the quality of the solder connections and traces for those connections.

Fun to work on, but I keep forgetting to pull the bottom if all I need to do is look inside.

There is plenty of C4 rebuild information if you search. Everything needed to make a working unit like new is discussed, already. Thanks to Avionic in most cases.

 

[Blue Shadow]

So are U the expert on these amps avionic?
Thanks for replying.

I know my way around them.

That is a Yes, he helped me with my C4.

 

[mgkfifty]

My advice, get a service manual.

 

[avionic]

Needless to say the solder side up build.Allows the circuit board to get real filthy with dust and what not.

 

[ferninando]

I love opening thes things up and house cleaning.
somewhere I read that LEDs can be used for the lights. TRUE?
I am also good doing that on my refurb/rebuilds on tube amps or just installing one where none was before.
Got the M4 usr and svc mnl and C4 user mnl . but not yet the C4 svc mnl.

 

[avionic]

My advice, get a service manual.

HQ pdf available at analogalley.com Just e-mail Norman and tell him what you want.

 

[avionic]

TRUE

 

[ferninando]

I just downloaded the c4 svc mnl from hifiengine free so now am good for all mnls.
makes me feel all fuzzy inside.
I will do a led for out lite.
thanks guys. Really like the quik replys

 

[Blue Shadow]

I put white 10V LEDs in for the muting and tone controls. Gives a bit more aqua color but looks good. I didn't like the look in the power switch position as it washed out the color. maybe darkening the led would work but I had a bulb. Good to go.

 

[ferninando]

I have red, org, grn, blu, yel, wht LEDs to play with and can pik the one that looks best.
I like the blu and org but thats just me.

Just have to wait and see.

 

[avionic]

Personally I'd stick with the incandescents if the colored grommets are still intact.

 

[ferninando]

new inc. replacements are $10 plus shipping for 3.
gotta think on that.
I can go either way.
I like leds tho so we'll see.

 

[avionic]

I'm a romantic. Fell in love with that orange and green surrounded by black , back in 1980-81. Bought a new M-4,C-6 & T-1 combo in Germany.So the incandescent is first choice for me.

 

[ferninando]

i hear ya avionic. hard to dismis favorits of things you have long held feelings for.