WOPL a Carver C-500 Amp.

[gary33030]

Control board completed.
Front and back.

 

[mlucitt]

Nice work on that Control Board. Your soldering skills are commendable.

 

[gary33030]

Nice work on that Control Board. Your soldering skills are commendable.

I have to take that as a complement. This is board #3 for me. Thank you!

 

[gary33030]

I'm on a small pause. Have transistor sockets on order.

 

[gary33030]

Is a Film Capacitor and a Metallized Polypropylene Film Capacitor interchangeable?
OfCourse all the spec matches.

 

[Gepetto]

Is a Film Capacitor and a Metallized Polypropylene Film Capacitor interchangeable?
OfCourse all the spec matches.

In a word, yes

 

[gary33030]

In a word, yes

Thank you..

 

[gary33030]

All the transistors are mounted in the back panel in a new TO-3 socket. Each one was tested to ground before proceeding to the next.

 

[wattsabundant]

What was the test criteria for checking the TO3’s to ground? Resistance readings will only find gross errors. A hipot would require all 3 pins of all of the transistors tied together with a minimum test voltage of about 500V. That’s not very practical.

 

[gary33030]

The criteria I use was from Joes instructions to "test for no shorts to the chassis." You are right, I don't have all the tools you do. I'm just a hobbyist enjoining my amp. More pictures showing my progress.

 

[gary33030]

Left back plane of my Carver C-500 almost done. Thats all for tonight.

 

[grapplesaw]

Left back plane of my Carver C-500 almost done. Thats all for tonight.

Hello
interesting layout. Your Mylar .33uf cap need to go from rail to ground . In the photos it appears to me they go from rail to output, but I may not see it correctly. Also you would be happy to add a 1.5uf metal film caps along wi these .33uf caps. I use 2 1.5 on each rail along with a .33 or .15 cap in this size amp.

 

[gary33030]

Hello
interesting layout. Your Mylar .33uf cap need to go from rail to ground . In the photos it appears to me they go from rail to output, but I may not see it correctly. Also you would be happy to add a 1.5uf metal film caps along wi these .33uf caps. I use 2 1.5 on each rail along with a .33 or .15 cap in this size amp.

You sir are 100% correct. I did rail to output not rail to ground. I will correct this, this evening before I do anything else. Thank you. When you say to add 2 1.5UF metal capacitor, do you mean from rail to ground also? Both capacitors wired in parallel?

 

[grapplesaw]

You sir are 100% correct. I did rail to output not rail to ground. I will correct this, this evening before I do anything else. Thank you. When you say to add 2 1.5UF metal capacitor, do you mean from rail to ground also? Both capacitors wired in parallel?

Yes in parallel and space them apart

 

[gary33030]

Yes in parallel and space them apart

Does this look any better? (250v 1.5uf 5% film capacitors) It definitely much easier working with Joe's Back plane boards.

 

[Hexis22]

Highly recommend you place the bridge rectifier closer to the transformer and away from the control board.

 

[wattsabundant]

What's the purpose of all of the paralleled film caps? It is preferable that the common connection of the film caps be isolated from the chassis ground and connect directly to the ground bus bar. Likely won't make a difference, but that is best practice.

 

[gary33030]

What's the purpose of all of the paralleled film caps? It is preferable that the common connection of the film caps be isolated from the chassis ground and connect directly to the ground bus bar. Likely won't make a difference, but that is best practice.

Don,
I'm sure I will not be able to explain the parallel capacitors to your satisfaction. Your skill and knowledge are way above me. Remember, I'm just your everyday electronics hobbyists. I'm trying to follow a semantics plan. I do something and then display it here for all to say yes or no. Glen, (grapplesaw) has a couple of Carver c-500 amps under his belt. In post 32 above, he explains adding the paralleled film capacitors. 2 on each side per channel. My attached file picture was to get approval from him and everyone. Glen also commented: "interesting layout". (I hope that's good) I know from my two Phase linear 400 amps under my belt, that's what Joe suggest with one point grounding on the bus bar. For the life of me could not figure a way to ground my capacitors to the bus bar without it looking more like a bowl of spaghetti. I just hope what you said above "likely won't make a difference." Please keep me on my toes and let's get another amp up and running.
Gary

 

[grapplesaw]

the film caps Make a difference.
They are there to deal with any inductance in the rail supply wires. The closer to the collector of the outputs the better they work. Spread evenly between the four outputs is best.

 

[gary33030]

the film caps Make a difference.
They are there to deal with any inductance in the rail supply wires. The closer to the collector of the outputs the better they work. Spread evenly between the four outputs is best.

Thank you for the explanation. Hopefully Don will see the response....