Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thread

[stuwee]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

The flatscreen was removed, the 300 watt incandescents removed, all wall hangings removed, AND LOOK AT THE METERS!!!!! That's on an amp that tested over 500 WPC!!!!
+2 DB on left, +2.5 DB on the right.!!!!!!!!!!!!!

AW JEEZZZZ!!!!!!!!!!!!!!

OMG!! You crazy coot...that's insane

 

[laatsch55]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

And it was VERY< VERY loud, simply amazing. Can't keep mainline fuses in it now, i believe I screwed up the power supply, either a switch, a BR or ????? Rail fuses stay good, main power fuse WILL NOT stay. Something simple on the mains "in". Checking now.

 

[laatsch55]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Houston ......we have a problem..........the Bridge Rectifier is TOAST!!!!!!!!!!!!!

 

[mlucitt]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Jeez Lee, how do you destroy a 25 amp bridge with a 10 amp fuse? Oh, and the fuse should not be wrapped in tin foil...

Now you get to put in a 35 amp bridge!

I just tested my amp with half of the outputs and I will post some pictures.

Mark

 

[mlucitt]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

With Q11-Q16 installed (half the outputs) I was able to get almost 100W RMS out of the amp with no clipping. The DC offset at this point is .003 VDC on the left channel and .006 VDC on the right.

Is my math right here? I measured 27.95 VRMS from the left channel on my Fluke 77 DMM. 27.95 x 27.95 = 781.20 (squared). 781.20 divided by 8 (Ohms) = 97.65 Watts. Is this right? With the same input the output on the right was 27.85 VRMS with no load. Loading the outputs dropped the output voltage .03 VRMS on the left side and .16 on the right showing the benefit of a stiff power supply. All measurements were at 120 VAC household power from my 10 Amp Variac.

I may have an issue with the DC bias. On the right channel, I can adjust it to .350 VDC with no input, after the amp warms up (R20R is almost in the middle). The left channel will not go any lower than .575 VDC when I am adjusting R20L. I replaced the burned bias resistors with precision 10 Ohm 5% 1W devices. I will put the rest of the output in and see what kind of results I get.

Here is a picture of the amp driving a .707 VAC, 1Khz tone at 12.5 Watts into the 8 Ohm load resistors.

Lee, what input level do you use for testing? I just want our measurements to be comparable.
Mark

 

[mlucitt]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Is this a pretty picture or what?

Mark

 

[mlucitt]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

OK, silly me, I looked in my poorly copied PL 700B service manual and the input is listed as 1.75 VAC. When I bumped my inputs up to exactly 1.75, The measurement at the outputs (both left and right) went up to 61.5 VRMS. I'm calling that a success because I think that equates to 472.78 Watts per channel. That gives me 945.56, OK call it 946 Watts of power. I think I could weld thin metal with that! I'm going to plug it into the PL 2000 and see how it sounds. If it sounds good, I will be offline for several hours.

Yeah,

Mark

 

[laatsch55]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Do you have ypur dummy loads hooked up?? What I do with mine is drive them to clip and measure the output voltage just before that! Dude!! Excellent Job!!

 

[laatsch55]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Were ya pluggin my faceplate support???

 

[laatsch55]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

If your drivers and outputs are not tight in the sockets(like what is after 30 years) bias will be all over the place.

 

[stuwee]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Thats just Bea-U-Ti-fuL

 

[mlucitt]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

I'll check the sockets but most of them seemed to seat with some authority. I guess it only takes one...

So here is where I started out today. Half the drivers in and lots of voltage out but not the full amount of current. I also boosted the test signal after this picture from .707 to 1.75 VRMS.
[attachment=2:g5rmgf1k]Half The Drivers Installed Into The Wall.jpg[/attachment:g5rmgf1k]

Then I installed the rest of the outputs and fired up some Live Humble Pie - Rockin' The Filmore. During "I Don't Need No Doctor" (track 7) I almost cried. The tears were welling up in my eyes and I could not focus because my eyes were actually vibrating in my head. Lee - you know what I am talking about.

[attachment=1:g5rmgf1k]PL700B Rockin' at 470 Watts.jpg[/attachment:g5rmgf1k]

It was so loud, but also clean and clear. I could hear the cymbals over the vocals, something I have never heard on that track. I had to sit down in front of the speakers and have a beer. I understand completely now why people HAD to have these when they came out.

The sheer power is hard to describe. Not just loud, but you can feel each time the drummer hits the bass drum kick pedal. My ears are ringing but not from the buzz of speaker distortion, more like after a loud session with the headphones. The sensation is that my ears are still experiencing some of the vibrations the way your arms tingle after you climb off a Harley. The handlebars are no longer shaking but the muscles in your arms don't know that.

I wanted to turn around and show somebody how awesome this was, but there is no one here to show. I am stunned at the ability I now have to push the JBLs to the limit of their capabilities (and they have lots of reserve). My Hafler DH-220 has just about half the power and I thought it was loud - and it is but not near as clean and crisp at close to 500 Phase Linear Watts.

The heatsinks were running much cooler with a musical input when I checked them after a few tracks. I guess 1Khz is a pretty demanding signal.

I'm ready for the next mod, but I want to listen to some more AC/DC, Led Zep, and Yes first.

Thanks so much to Lee for your support and thanks so much to Joe for a truly great product.

I had a slight thump at turn on the first time with these speakers, not the second time. At turn off, it ran for almost a minute at low volume as the massive capacitors discharged. Then a small crackle. Nothing disconcerting at all, and certainly not a risky event for the speakers. This is with no speaker protection, no DC blocking cap in front of the board, and passive JBL 3110 crossovers so everything gets through.

All I can say is wow, and I am going now to listen to some more music at ridiculously high sound pressure levels, they way it was intended. The only thing I can compare to this is when I attended the California Jam on April 6, 1974. Hey, that is about the time my amp was made... They used Tycobrahe amplifiers to generate 54,000 WRMS and I heard every watt.

Here is the stack I am listening to right now (I'm using the Hafler CD player).
Mark
[attachment=0:g5rmgf1k]Bright Phase Linear Stack.jpg[/attachment:g5rmgf1k]

 

[stuwee]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Mark, what a great story, you made me cry too! No small feat...Awesome stack, I haven't seen a PL tuner in years, and you have wood cases

 

[mlucitt]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

I got no clipping with the 1.75 VRMS input signal. I am a bit squeamish to take it much past that. My voltage measurements were with the 8.0 Ohm dummy loads, but now I am connected to 5 Ohm speakers. Let's see with output voltage at 61.5 VRMS and a 5 Ohm load, that would be 756 Watts per channel. No wonder my ears are ringing, I was blasting tem with 1512 Watts. Can that be right?

Can you check your input voltage at the start of clipping? I want to see if I can replicate that.

Are we crazy?
Mark

 

[mlucitt]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Thanks Stu. It has been a dream of mine for 40 years to get to this day. I remember reading the Stereo Review magazines back in High School and there was no way I could afford this equipment, plus my parents would never let me enjoy it. Now I can afford it and use it and I have to say, after 40 years I am not disappointed one bit. It is everything I thought it would be.

The most amazing thing to me is everything works the way it should, now that we have the most amazing PL 700B main board from White Oak Audio.

Mark

 

[Gepetto]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Hi Mark
Thanks for the very enjoyable progress report. Glad you brought that old beauty back to service. I still have the pics of the way you received it. Looks like a totally different amp at this point.

On your bias setting, check your Q6 for that channel, if it is marginal or has already given up the ghost, it will behave that way, no response to adjustment. While your distortion will be fine, you are running more class A power through the output stage at idle than you probably desire.

Glad you are finally enjoying some music through it.

Joe

 

[laatsch55]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

AHHHHHHHHHHH..............somebody UNDERSTANDS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! what is happening at Casa le latich!!!!!!! I KNOW EXACTLY how ya feel Mark!!! Vibrating eyeballs tells it all!!!!!

 

[laatsch55]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

I got no clipping with the 1.75 VRMS input signal. I am a bit squeamish to take it much past that. My voltage measurements were with the 8.0 Ohm dummy loads, but now I am connected to 5 Ohm speakers. Let's see with output voltage at 61.5 VRMS and a 5 Ohm load, that would be 756 Watts per channel. No wonder my ears are ringing, I was blasting tem with 1512 Watts. Can that be right?

Can you check your input voltage at the start of clipping? I want to see if I can replicate that.

Are we crazy?
Mark

Yeah were crazy, that's why were here!! I don't monitor input voltage on the power test. I just crank the input till it clips then read output voltage. I think it is perhaps immaterial at this point as +2.5DB on the 700's meters amounted to 11:30 on the Spec 1 volume Knob. I have never gotten past 12:00 with any amp!!

 

[mlucitt]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

I just finished listening to Yes's "Awakening" from the Yessongs album at sound levels that approach the sublimely insane. If you are not profoundly moved on a physical, spiritual, and emotional level after listening to that track at realistically live volumes, there is something wrong with you. Steve Howe's guitar was right in my face and the keyboards that Rick Wakeman uses to generate other-worldly sounds seem to float around the room before coming to rest at my feet and then dissipating like the smoke of the fogging machines.

Joe, I should have been more clear, but my head is a bit fuzzy now (in a good way). The bias adjustment works fine. I can go from about 1.5 VDC to .5 VDC, but I cannot get it to go below .5 and closer to the ideal of .35 VDC. I can live with it for now because it sounds great and all the other measurements are very good. I will check it again in a few days. I have another Q6 but it is such a pain to change out.

Thanks,
Mark

 

[laatsch55]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Now Mr. Mark if you want your experience to enter the new age...............time for......SHPONGLE!!!!!!!!!!!!!!!!!!!!!!
The telling of your experiences when at concert levels makes me sure we are kindred spirits.