Gibsonian's Cherry Pl 700 Ser I, soon to be a PLWO-1000

[laatsch55]

I've answered every e-mail!!

 

[laatsch55]

Now I have.

 

[Gibsonian]

Heat in the voice coil is the main culprit. If you start to approach the X max of the driver, the suspension will also begin to behave a little differently, contributing to the compression. Most all is simple heat though.

On your speakers, what is the rated power? I'm guessing you may be exceeding it.

I'm visualizing something more like "
congestion" , at certain power levels to reproduce the input the speaker can not act fast eough or far enough??

I wouldn't pull your leg Lee, it really is heat in the voice coil that cause compression in drivers. If it cannot move far enough, you have exceeded xmax of driver, and you might be doing that as well. Pmax on your woofer is 150 watts, so it would appear you are overdriving your speakers by a fair margin, and you can get away with it for awhile with clean power like the PL's provide. If you ever make the PL 1000 clip on your speakers, they will have moved in and out for the final time me thinks...............

 

[laatsch55]

Scott, I didn't think you were pulling my leg., I'm just amazed at the SPL these thnings can produce and still live to do it again. When i say it's like CPR in the sweet spot..... it really is.

 

[laatsch55]

Progress!!
I really don't like the fact that the "Hum" shield is an isolated ground. I would rather isolate the hum shield with the chassis the final ground. To do that it takes a few spacers, inserts, some hand drilling and counterboring and it's accomplished. The pure copper bus bar I couldn't resist.
The AC main is now relocated to the tranny side along with the fuseholder.
There is also a pair of gold plated RCA jacks.

 

[laatsch55]

Scott, I'm swapping those 18,000 uf PS caps for a couple 22,000 uf Adcoms.

 

[speakerman1]

AND?

Larry

 

[laatsch55]

SWhat???

 

[speakerman1]

JUST SAYING

Larry

 

[laatsch55]

Last time I did a Series I Joe mentioned that there was very little "thermal inertia" inherent in the thin "hum shield". I don't believe he can say that now. Things will go pretty quick now. The Bridge Rectifier will b enefit greatly from having it's heat sucked away by that chunk of 1/4" thick copper strap, 2" X 3". Besides that it just looks too damn cool!!

 

[laatsch55]

I also like stainless allen heads in place of the slotted black machine screws. I hope the amps owner does too!

Scott??

 

[laatsch55]

Power supply hookups done and workin my way south.

 

[laatsch55]

Ok, the power supply section wasn't quite done, is now.

 

[Gibsonian]

I like the stainless bolts, the massive buss bars, the 22% higher capacitance, the new wires and terminations. Industrial, commercial, bulletproof, Maytag, etc come to mind as I watch you work Lee. It's all good here!

 

[laatsch55]

Hookay, glad to hear it Scott. When I start in on the wiring it's hard to say whoa. Just a few more wires.

 

[laatsch55]

The end is in sight. Got the DC protect boards mounted and wired, the 2N3403's on the chassis and strain reliefs epoxied to the chassis. After work tomorrow, solder Joe's board and then some testing.

 

[laatsch55]

Why do you solder only one end of the shield on the shielded pairs coming up frpom the RCA jacks??

 

[speakerman1]

I don't know why but I have read about them only connecting one end of the shield; but they never said why. So I guess it gets a HMMMMMMMMMMMM. LOL

Larry

 

[laatsch55]

Right down, left to go.

 

[laatsch55]

Prevents a low level ground loop------------ I think.