Testing of a stock, and a WOPL 400

[mlucitt]

I looked at the Series I, it seems pretty original and the serial number is very low. I'm bidding on the PL 700B Series II, currently at $107. It might be fun to install a WOA Rev C board into that amp.

Mark

 

[laatsch55]

I would think so.

 

[ksrigg]

Let me get this right....a 400 Series I with stock PCB (other than some new electrolytics), stock storage caps, old 1973 production MJ2741 and XPL909 in the driver and output positions...and you are getting numbers and graphs like that from a REV A White Oak PCB? Absolutely amazing...maybe we need to rethink replacing all the driver and outputs....and storage caps...but the caps have got to be introducing what little distortion is there..

What would this baby do if everything was replaced.....the full meal deal? It's almost scary....Way to go Joe........Your board is nothing short of amazing...an extra 100 watts to boot...

What would be possible if you used the Phase Linear chassis, and did basically everything else new...new TO-3 sockets, new resistors, diodes, everything..and would you go with metal oxide or wire would resistors? Would you stay with the Phase Linear transformer, or go with a torid? Anyone ever give this any thought?

 

[laatsch55]

Yep, cookling up a monster--remember. A toroid to boost B+,B- to 115-120 volts, New chassis, monster heatsinks, etc...

Joe has a little tweaking to do to some components on the board but it will basically be a stock White Oak board driving it.

 

[orange]

2.5KW

My toaster has a prostate condition vs that stud.

I'm surprised it gives it back for me to butter. Page 2 or so but it still hits me.

 

[ksrigg]

Lee,

I know you were cooking something up with the big Toriods, but I'm just taklking about staying inside the PL 400 chassis, and doing what one could to get the most out of the origanal design.....(forgetting the trannie for a sentence or two) ...I ordered some TO-3 sockets....most of which were backordered, but just new sockets, new resistors, new diodes, and new everything, with Joe's board, caps, leds, and Mark's DC protection scheme, I wonder how much good clean power (with low distortion numbers).might not be any more than the older stuff........just didn't know...if you could match all the resistors, etc...to get it as close to the perfect PL 400....how much could she produce? I guess that is where the limitations of the transformer came in. I know they vary from the high 70's to the low 80's in DC voltage output....guess that is where I wondered if a toriod with high 80's or low 90's...or even higher, if the components in the amp could handle the added voltage...I think the driver and output transistors are rated to handle more. Where would the ouput be? Pushed to a realistic operating range, of course...or are we back to the ......... just get a 700 instead of a 400 concept.....but just how much can the drivers and outputs in a 400 deliver....on a continuous basis?

 

[laatsch55]

As much as the 700's can.


it's just a matter of rail voltage. We are using the same board with the same components, same drivers and same outputs, just higher voltage with the 700's.