George Wright WPL-20

[Paul Birkeland]

Straight forward directions. Unfortunate hum pot in chassis there is just no room to mount I understand that.  What hum pots do you recommend? 
Since I have the mono blocks open, see anything I should upgrade?

What I recommend... not buying 10 turn pots!!!

These are OK:https://www.mouser.com/ProductDetail/CTS-Electronic-Components/026TB32R500B1A1?qs=%2Fha2pyFaduj4XvYIjXDDp0se3jA0cGcd9%2FjCnKWc9EhzbKyEB7d6lQ%3D%3D

I think you have enough space to drill a hole in the side of each chassis and add them there.  That also makes them more accessible.

You definitely have Magnequest output transformers, so it's worth keeping these going as they are worth some good money and should sound quite nice.  The things that I see are:

• There's no ventilation (we had this conversation about your preamp already didn't we!).  I would space up the bottom plate with some washers to get some air moving through there. You could also just run them with no bottom plates and put some rubber feet around the edge.
• The 100uF/100V cap by the cathode resistor has likely lived a rough life.  I would favor these as replacements:
  https://www.mouser.com/ProductDetail/KEMET/PEG124PF310VQL1?qs=DqLQsTv2bi4z4%2FmyDhxewA%3D%3D
• The blue coupling cap is probably an inexpensive mylar type, you could replace it with whatever makes you happy.
• The Nichicon VX power supply caps are definitely not bad, but depending on their age you may want to toss them while you are in there.  These are what I would replace them with:
  https://www.mouser.com/ProductDetail/KEMET/PEG124YH2220QL1?qs=DqLQsTv2bi6qw6e9LF%2Fn1Q%3D%3D
• The 100K 2-3W resistor that goes to pins 1/5 on the octal driver socket looks like an inexpensive metal oxide.  I'm sure you could find a nice replacement at Parts Connexion.  The same goes for the 30K cathode resistor going to pin 3.

[robertod]

1)  I agree on mounting on the side.

2)  Ok

3)  Blue coupling cap?  Is it solid blue no lettering on it? I would like a recommendation not familiar with a replacement.

4)  Ok

5)  100k 2-3w resistor center bottom. Parts connexion, Holco resistor brand? Not sure where 30k cathode resistor pin 3 is.(is this resistor under blue cap(no lettering) in photo.

Thanks

[Paul Birkeland]

On the 4 pin side of the blue cap, there will be a resistor to ground.  I can't see it in the photo, but if you provide the value I could give an educated guess as to what value it might be.

Yes, the 30K resistor goes to pin 3.

Holco would do just fine.  If you're ordering from Mouser, you could also just get Vishay PR-03 metal films while you are there.

[robertod]

Attached a few more pics including blue cap.
The Vishay PR-3 metal films would be the other resistor I need to purchase.  Under #5 item.

[Paul Birkeland]

That's a 1uF 250V cap.

[robertod]

To summarize;
Items;
1. More ventilation,
2. Cap from Mouser(link sent)
3. Blue coupling cap 1uf 250v cap.(I could get from Mouser?)
4. Cap from Mouser(link sent)
5. Two resistors 1) 100k resistor Vishay PR-3 Metal films. 2) 30k resistor (I could also get from Mouser the type would be my choice, right?

I have summarized your recommendations is it fair to say I can go ahead with the upgrades.

Thanks PB

[Paul Birkeland]

Yeah, that's what I would do! You also have heatshrink right?  If you wanted to get some from Mouser, I would get this:
https://www.mouser.com/ProductDetail/TE-Connectivity-Raychem/SCL-3-16-0-STK?qs=pUKx8fyJudD1JeC4dGRpiw%3D%3D

[robertod]

Any recommendations;
Replacement on blue coupling cap
And 30k resistor.
I will get everything from mouser.
Thanks

[Paul Birkeland]

I'm sure there's a 30K PR-03.

[robertod]

P.B.
Thanks for your help.

[robertod]

Having trouble locating 16-18 AWG buss wire.  I've checked with local audio dealers, and electrical distributors. Any suggestions, recommendations.

[Paul Birkeland]

If you e-mail me your address I can mail you some in a postal envelope.  pb(at)bottlehead(dot)com

[robertod]

PB,
Thank you.

[robertod]

PB,
Thanks for all your help and patience's on all my questions!

 

[robertod]

PB

I'm getting ready to install hum pots and upgrades ( caps and resistors) I have a few questions;

I received the buss wire, I don't know if it is enough.  (could I use 16-19awg stranded and tin the ends, or solid 18 gauge copper wire?

The caps have neg-pos symbols, these caps are directional do they flow from pos---neg--> ?,

The 250v 1uf film cap does not have a - or + , is it safe to say this is not directional?

The resistors are they directional?
RESISTORS ( added pic to verify location)
Resistor- 3watts 30kohms

Resistor- 3wats 100kohms