I'm Buying a "Mule" PL400

[WOPL Sniffer]

RIP James

 

[laatsch55]

Yeah, f%*^%$# overkill Glen....

 

[mlucitt]

You guys have the best stuff.

 

[laatsch55]

Of course....we're renissaunce men...

 

[WOPL Sniffer]

reconnaissance what????

 

[laatsch55]

I have trouble spelling today I guess..lol..

 

[WOPL Sniffer]

I had to use spell check, I couldn't spell either one.

 

[laatsch55]

Thank God for spell check..

 

[mlucitt]

Is this a pretty picture or what??? Outputs torqued to 12 inch-pounds with new screws, and no shorts to ground, all transistor pins measure zero ohms to sockets. First time using Sil-Pads, they are great! I remember someone saying to check the torque of the screws after the first heat cycle.

 

[laatsch55]

That would be.blasphemy..

 

[mlucitt]

Hookay

 

[mlucitt]

Lee, I believe you have done at least one of the WOA Backplane mods. I was stubborn and wanted to do the new emitter resistors the old-fashioned way, and now I am paying for it. Never had these problems before... I have joined the WOA Backplane team, for the next amp rebuild.

Can you send me two of your old output transistor mounting fixtures? I have one that is missing a head and a leg! How does this stuff happen?



Thanks!

 

[laatsch55]

I have some brand new ones I can send.

 

[mlucitt]

I have some brand new ones I can send.

The old ones are gonna be so jealous. The big caps are dated 7351, so I'm thinking it was a 1974 amplifier. Sheesh, that makes this amp 45 years old.

 

[mlucitt]

I installed a 3-wire power jack a few days ago. It just barely fits, but that is OK because only a small bit of aluminum needs to be cut around the old 2-wire cord strain relief bushing hole. I do it with a Dremel in about five minutes. The solder lugs on the back also make it easy to install a couple of EMI Type X2 .022uf 250 VAC capacitors between the AC lines.

 

[mlucitt]

Any thoughts on using different bias transistors (Q6)? The "Mule" had one 2N3403 (probably stock) and one NTE 192A. On both of these the numbers were printed on the metal strap. I am considering matched 2N5088 as Joe recommends. Any easy source or should I buy 100 and match them myself?

 

[Gepetto]

Any thoughts on using different bias transistors (Q6)? The "Mule" had one 2N3403 (probably stock) and one NTE 192A. On both of these the numbers were printed on the metal strap. I am considering matched 2N5088 as Joe recommends. Any easy source or should I buy 100 and match them myself?

No matching required Mark.

 

[mlucitt]

I have not shared any progress pictures of the Mule WOPL 400 lately, so here is one showing my attempt at nylon lacing instead of the venerable ty-wraps:

 

[laatsch55]

Pretty work on the backwall.....

 

[VSAT88]

Like the way you put the WIMA's across the posts on the filters. That is a great idea.