PL3000 resurrection project

[MarkWComer]

I bought a PL3000 preamp at the same time as my PL400 amp thinking I got a sweet deal on a whole functioning combo. The preamp was listed on the bay as "functioning", but it turns out that it's FUCKtioning instead. The selection latch and flip/flop ICs are (I suspect) faulty.

So- got my list together, found my chips, found replacements for all the electrolytics on Mouser, put my order in. BUT- I'm left with a question about two ceramic disc caps connected to the power switch. They're marked .0047, and they're 17mm (5/8") diameter. So- these are 47 picofarad? What should the voltage value be so I don't make ceramic popcorn from my replacements?

EDIT: Sorry, stupidity sometimes reigns. .0047 µf = 4700pf. Still need to figure out what voltage it can handle...

(Photo: You can see that these goobers have been subjected to some considerable amount of heat...)

 

[Gepetto]

Those are 4700 pF Mark. Should be 1KV if you can get them.

 

[NavLinear]

Here's a link to a PL 3000 Series II power switch repair.

http://forums.phxaudiotape.com/show...-Series-II-Preamplifier-Repair?highlight=3000

 

[MarkWComer]

Here's a link to a PL 3000 Series II power switch repair.

http://forums.phxaudiotape.com/show...-Series-II-Preamplifier-Repair?highlight=3000

Thanks- power switch is fine, but there is some blackening of the wires and those disc caps, so there may have been some arcing in the past. Will keep an eye on that.

Those are 4700 pF Mark. Should be 1KV if you can get them.

Haven't looked for the replacement disc caps yet, but my logic chips did come today. Chips replaced now, input selection works again! Will attempt a signal source to verify that all the inputs are working (except for the MC phono input- I don't have an MC cart to test that one) and then it's on to ALL the other electrolytics on the board. Yes, I did buy replacements for the electrolytics in the power supply, and I found a disconnected wire in the PS that I temporarily fixed to check the logic chips.

I think I understand why this forum is named "Phoenix" now...​

 

[MarkWComer]

Are these caps OK to use?

These suckers look too small to me...

<iframe width="560" height="315" src="https://www.youtube.com/embed/tWNRoG5tdaA" frameborder="0" allowfullscreen></iframe>

 

[Gepetto]

These suckers look too small to me...

<iframe width="560" height="315" src="https://www.youtube.com/embed/tWNRoG5tdaA" frameborder="0" allowfullscreen=""></iframe>

Who is the manufacturer Mark?

 

[MarkWComer]

Who is the manufacturer Mark?

Vishay printed on envelope. Sprague pressed into the cap itself. (are they the same?)

 

[Gepetto]

Vishay printed on envelope. Sprague pressed into the cap itself. (are they the same?)

Yeah Vishay purchased Sprague. Same company now. Hard to find many axial caps these days, selection is slim. Everything has converted to radials.

 

[MarkWComer]

Yeah Vishay purchased Sprague. Same company now. Hard to find many axial caps these days, selection is slim. Everything has converted to radials.

So... use 'em? They're good?

 

[Gepetto]

So... use 'em? They're good?

Sprague is a known quantity. I am not much of a Vishay fan but they keep gobbling up companies so it makes it hard to stay clear of them. Sure use them. Not much downside.

 

[MarkWComer]

Sprague is a known quantity. I am not much of a Vishay fan but they keep gobbling up companies so it makes it hard to stay clear of them. Sure use them. Not much downside.

THANKS! Will do!

 

[laatsch55]

Sprague is a known quantity. I am not much of a Vishay fan but they keep gobbling up companies so it makes it hard to stay clear of them. Sure use them. Not much downside.

Why are you not a fan??

 

[laatsch55]

Somebody needs to gobble up Blackgate and get on with it.....