Phase Linear Newbie

[kwingylee]

You don’t really need the new chassis or heatsinks, not completely necessary, but they’re very nicely made and enhance the appearance- looks like it’s fresh from the factory!

The backplanes make use of better components, and a full- comp circuit gives a good boost to the power. Residual noise is subterranean, DC offset zero, damping factor of 1000. FAR superior to the original quasi config. The transistors used are made for audio application, not the electronic ignition from a 1979 Buick.

There’s some debate in these threads about the transistor covers regarding heat dissipation vs. getting a fatal DC shock if you touch the collector cans. Some of us keep ‘em, others toss ‘em. So far, I haven’t heard of anyone experiencing any thermal shutdowns with the covers in place, but a few comments about nasty DC shocks. Just don’t touch one transistor bank with your left hand and the alternate bank with the right. If anything, they’re a safety feature and prevented PL from some law suits.

It’s already been mentioned that you can consider this an investment, an excellent point to consider. Also think of this: these days you don’t see many superamps! Look through some websites or catalogs at what’s available now- how many do you see above 70w/channel? How much dynamic headroom ya gonna get with those “Fisher-Price” contraptions?

It’s well worth the bucks and hours to rebuild, don’t cheap out on it!

Thanks Mark. Your youtube videos are awesome.

 

[MarkWComer]

Thanks Mark. Your youtube videos are awesome.

Wow… Thank you!

 

[marcok]

Welcome aboard !
Ciao
Marco

 

[laatsch55]

All 4 columns have 5 Motorola TP9054's from top to bottom and one RCA 66546 output transistor at the very bottom. 20 Motorolas and 4 RCAs. I assume that is Quasi complementary and I need the back plane upgrade? Everything looks original to me..

The 66456's are rebranded RCA 410's
The TP 9054's are rebranded On-Semi MJ 15024's

 

[kwingylee]

Thanks Mark. Your youtube videos are awesome.

Hey Mark and guys.
I just order a replacement power switch off ebay to make it into close to mint.
So I will plan to do the full WO mod but using the original chassis and heat sinks. Is there a way to test each change one stage at a time to make sure I did not screw up? For example, I do the cap and control board (in Quasi Comp operation) change before tackling the backplane and transistor changes?? How easy is it to go from quasi comp to full comp?

 

[MarkWComer]

Hey Mark and guys.
I just order a replacement power switch off ebay to make it into close to mint.
So I will plan to do the full WO mod but using the original chassis and heat sinks. Is there a way to test each change one stage at a time to make sure I did not screw up? For example, I do the cap and control board (in Quasi Comp operation) change before tackling the backplane and transistor changes?? How easy is it to go from quasi comp to full comp?

That’s the route I took when rebuilding my 400. Changing the driver board from quasi- to full- was simple.

 

[kwingylee]

Thanks for affirming... I noticed little is said about power supply upgrades such as changing the FWB, swapping smaller lytics, adding polyprop caps to by pass the big filter caps, etc., is it because they do not yield any appreciable benefits? I plan to do that to mine...

 

[Gepetto]

Thanks for affirming... I noticed little is said about power supply upgrades such as changing the FWB, swapping smaller lytics, adding polyprop caps to by pass the big filter caps, etc., is it because they do not yield any appreciable benefits? I plan to do that to mine...

Bypassing the big bulk caps at the big bulk caps won't do zilch. The bypass needs to occur close to the use case. That is why the backplanes bypass right on the backplane.

 

[WOPL Sniffer]

Bypassing the big bulk caps at the big bulk caps won't do zilch. The bypass needs to occur close to the use case. That is why the backplanes bypass right on the backplane.

I prefer the adamantine transformer bolts

 

[George S.]

I prefer the adamantine transformer bolts

I just had to look that up!