• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Continuing on with my good fortune recapping my 500B help identify these caps? Pic

chadbang

chadbang

Well-Known Member
Hi, I had good luck putting in my new coupling caps and I thought I do some other things. I am terrible at reading schematics because I'm lost looking at the pictures and unable to orient things (lousy eyes don't help), I know I'm supposed to do the "bias filter cap" But where is that? Is it one of the labeled caps in this picture? Does anyone know the Fisher identification? (C25, C26, etc.) Similar question about the 50uf 35V electrolytics in the "phase inverter stage." Thanks for your help. Hopefully these are the caps I labeled A, B C&D.

500b-recap_zps60015fce.jpg
 
Register to hide this ad
The bias filter cap is part of the DC heater/bias supply, which is all located in the upper left corner in your pic of the underside. There has been significant work done in that area, so by all appearances, no further work is needed with the bias supply.

The phase inverter electrolytic caps are located under your caption "Did these 4", so I cannot tell if they have already been replaced or not. Based on the extensive amount of work on this unit however, there is a very good chance that they have.

Good luck with it!

Dave
 
dcgillespie said:
The bias filter cap is part of the DC heater/bias supply, which is all located in the upper left corner in your pic of the underside. There has been significant work done in that area, so by all appearances, no further work is needed with the bias supply.
Click to expand...

Sadly this is not my receiver, I wish it was! I just borrowed this get get a shot of the areas of the receiver. So bias filter cap in in the upper left had corner? Would it be one of the two white'beige ones or one of the two large black ones, this is finally zeroing me in so I can find it on the schematic.
 
Take a picture of yours and post it, without notes. That way we can help you ID everything on yours.
 
Here's how mine looks now. All current parts marked and ready for Jim McShane replacements. These labels may help with yours.
14f1171170615d46b4937e1d05181a15.jpg


Rob
 
If Rockyhill's unit is in fact a 500 "B", then based on his unit, there are no electrolytic caps associated with the phase inverter stage. I know there are with the 800C, of which the 500C's power amp section is identical. But apparently in the B version the caps were not used -- again, based on Rock's pic.

Dave
 
dcgillespie said:
If Rockyhill's unit is in fact a 500 "B", then based on his unit, there are no electrolytic caps associated with the phase inverter stage. I know there are with the 800C, of which the 500C's power amp section is identical. But apparently in the B version the caps were not used -- again, based on Rock's pic.

Dave
Click to expand...

Yup, it's a "B".

This is my first refurb so I'm teaching myself how to read a schematic and translate with the hardware. They are logical representations of a circuit. As I've observed the physical location of components can be different, i.e., a cap drawn right next to a resistor in the schematic may be located many inches away in the receiver.
 
Very helpful, Rocky! Thank you! Yes, that is a quick and efficient way to pair components with the Fisher data sheets, an excellent idea! When I flip my unit back over and discharge it I will take some photos of my own, Dr.G.
 
You must log in or register to reply here.
Back
Top Bottom