Phase Linear Newbie

[kwingylee]

Hey guys I just joined the forum this morning...its been dizzying to say the least.
I recently bought a system consisting of the PL 700 S2 amp, 5000 tuner and Carver C400t preamp.
They are pretty.
Looking into the list of WOPL options. I am interested in upgrading the sonics but leaving the cosmetics alone.
I am notably interested in the control board, capacitor and transistor upgrades.
Why do I need new chasis, heatsink and "backplane"? Seems like a lot of work for no gain. Point to point wiring is good and unless the heat sinks offer larger surface area, why would I change them? and lose the transistor covers?

Appreciate some advice on sourcing a new power switch...
Also interested in hearing everyone's though the the post mod sonic improvements.

Thanks in advance

 

[George S.]

Regarding the backplane kit versus original point to point. Research complementary outputs and quasi-complementary output transistor configurations. The backplane wiring dictates the output transistor configuration. Some of the last built amps had complementary outputs, most do not, and are quasi-complementary.
Research and read up on this, and see what configuration your amp has.
Most of us install the backplane kits with all new complementary configured output transistors.
It gets complicated! Feel free to post any questions, lots of friendly folks here will answer any questions, but do some research. Welcome aboard. Note a full WOPL 400 or 700 is amazing.

 

[kwingylee]

Thank you George: After I had read through some posts, I ascertained that the new back plane enables the full complementary operation. My unit is serial number 7A8917, would that be enough to tell what I have? Or I need to post photos?

 

[laatsch55]

Check the outputs. If you have 2 different numbers on alternating columns, that's complementary. Remove the covers and post some pics..

 

[George S.]

Post a close up photo of the two vertical rows closest to the transformer or the two furthest away. Need to see the numbers.

 

[George S.]

Oh, and chances are it's been "blown up" sometime in the past so it probably has mixed replacement outputs. Good photos of all vertical rows. I'm outta here for rest of day working.

 

[kwingylee]

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..

 

[WOPL Sniffer]

Hey guys I just joined the forum this morning...its been dizzying to say the least.
I recently bought a system consisting of the PL 700 S2 amp, 5000 tuner and Carver C400t preamp.
They are pretty.
Looking into the list of WOPL options. I am interested in upgrading the sonics but leaving the cosmetics alone.
I am notably interested in the control board, capacitor and transistor upgrades.
Why do I need new chasis, heatsink and "backplane"? Seems like a lot of work for no gain. Point to point wiring is good and unless the heat sinks offer larger surface area, why would I change them? and lose the transistor covers?

Appreciate some advice on sourcing a new power switch...
Also interested in hearing everyone's though the the post mod sonic improvements.

Thanks in advance

A lot of work for NO GAIN????? HUH? A WOPL'd 400 will smoke a Stocker full comp or otherwise. I assume by your first post that you either have a Carver C4000 Preamp, or a Carver 4000T..... They didn't make a C4000t. The 4000t responds VERY WELL to upgrades. There are several threads on this site. Welcome aboard....

 

[George S.]

Yup, quasi. You don't necessarily "need" the back plane kit and new On Semi transistors MJ21195G and MJ21196G, but it would be worthwhile in the long run.
This gets expensive, so most of us, including me, look at it as a long term investment.
I've built two full WOPL 400s, and have one of the last 700s, and it was actually built complementary from the factory. It was on its second set of output transistors when I got it. It's now sitting torn down prepped to be a winter project once the weather turns in OH. It will get the full WOPL treatment, including backplanes and new output transistors. I'll fully rebuild it with Joe's (Geppetto here on the forum) WOAD parts and it should be trouble free and bullet proof for 30-40 years. I'll hand it off to one of my sons eventually. That's the investment I'm talking about. But it gets expensive, and probably takes 40 hrs or more to build one, provided you have the skill, tools, and place to work undisturbed.
If you don't want to build it yourself, there are techs who frequent the forum who can do it for you. I think the price is appx $2500, using your core amp.

 

[George S.]

WOPL sniffer is one of those techs. VERY good.

 

[WOPL Sniffer]

Plus I have Waterproof feet now

 

[laatsch55]

You mean dessicated feet...you in Az man...

 

[WOPL Sniffer]

You mean dessicated feet...you in Az man...

Yeah but I spilled Thompsons Water Seal Stain in my tennis shoes

 

[laatsch55]

So you have sealed, dessicated feet..

 

[WOPL Sniffer]

Yep, it aint pretty. Plus add on the Undercoating all over my legs

 

[kwingylee]

A lot of work for NO GAIN????? HUH? A WOPL'd 400 will smoke a Stocker full comp or otherwise. I assume by your first post that you either have a Carver C4000 Preamp, or a Carver 4000T..... They didn't make a C4000t. The 4000t responds VERY WELL to upgrades. There are several threads on this site. Welcome aboard....

You are right its says 4000T... I had a C4000 a long long time ago...

 

[MarkWComer]

Why do I need new chasis, heatsink and "backplane"? Seems like a lot of work for no gain. Point to point wiring is good and unless the heat sinks offer larger surface area, why would I change them? and lose the transistor covers?

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!

 

[Gepetto]

You mean dessicated feet...you in Az man...

Wow Perry is an AzMan??

 

[FredR]

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..

Welcome to the fraternity my friend.

 

[e30m3mon]

Welcome @kwingylee ! I too was on the fence about changing from quasi- to full- complimentary output stage, but I also dug into the historic posts that describe the differences - and with the advice of those who posted above - I can honestly say I'm glad I made that leap to full-complimentary. White Oak ( @Gepetto Joe) has developed some incredibly high quality kits that are sure to please your ear and ensure your successful completion. Take your time and check your work along the way. Good luck!