Richard's PL Beastie Rework

[Richard D]

"Brown Cow", cool. I'm gonna have to suggest a vacation to all my neighbors...

Did the other meter quit, or are they just not hooked up?

 

[laatsch55]

They have a limited shelf life...

 

[jbeckva]

"Brown Cow", cool. I'm gonna have to suggest a vacation to all my neighbors...

Did the other meter quit, or are they just not hooked up?

No, it's fine. Just barely registering even at that volume level, heheh..

 

[Richard D]

Hey Jer, any updates?

 

[jbeckva]

Hey Jer, any updates?

Well you're in luck.. I am going to pull a meter off of one of mine. That and do a lil bit of work on the LED's to make it bulletproof. I would still like to really put it under some torture testing, so give it a few more days.

 

[Richard D]

You da man, test away, I don't want to break it once I get my mitts on it...I plan to do some serious jamming.

 

[laatsch55]

You are in for a treat..

 

[jbeckva]

Got the meter in, and swapped in my "5 LED" rev "B" series I light strips (ey... they aint "pretty", but they work, last-wong-time too...)

Almost... tomorrow, we torture... I'd show you another vid but it's 2am, and I can't get those meters anywhere CLOSE to detectable movement with these D9's and "she bear" downstairs.. hehe.

 

[jbeckva]

So far it's told me "Thank you sir, may I have another!".. Got it as far up as 57 volts RMS (that's 406 watts per channel into 8 ohms) before my "nerve" gave out. Absolutely NO sign of clipping.

Got it cooking for a few at around 150W. Man, that fan assembly really REALLY helps the heat dissipation. That's definitely going to be good for you if you intend on hours upon hours of reedonkulous SPL's (I can only do maybe a song or two before my ears cry uncle).

Meters around zero ... they can go higher... You should notice the 5 led "difference".. Like I said, the 5 LED was revision "B".



Clean waveform, even at level "ridiculous"... I need to get an attenuator for the scope, as we're pushing it beyond the scale...



At least the voltmeter can tell the tale... it still had plenty to go, but yeah... I think my nerve gave out at that point...

 

[Richard D]

I'm guessing this will be a good "party" amp. My house is a ranch-style. One side, approx 1/3 of the house, is bedrooms, with a door closing the hallway and rooms off to the rest of the house. According to some charts I found, the front room was just barely large enough for a pool table, so I bought one. But it was real cramped, so we started knocking out walls. Relocated the washer, dryer, and water heater to the two side by side closets in the hallway, on the far side of the house. So now I have basically a big room, about 33'x27', with a bar, and pool table. Most listening will be done while hanging out, shooting pool and partying. That's why I figure the 901s, while not the best speakers for sitting in a Lazyboy parked in the "sweet spot", will shine in this environment.

 

[laatsch55]

It's a good "anything" amp.

 

[wattsabundant]

Damn nice of you Lee - that'll be a fantastic beginning to the clean up of this guy.

Hey Jer. I've just gotta see a photo of the ass end of the transformer with the big bolt sticking out the backside when you get a chance - with the cover removed of course. Hopefully Lee hit the head on the nail on the head with his suggestion that it was used as a way to suspend the amp in a rack.

As usual I'm late to the party on this...The bolt sticking out is support for the xfmr. That was part of the mod I used to do on 400/400II's for PA systems a long time ago. The mod also included a power switch and B+/B- fuse for each channel on the front panel. We sent off the 400II faceplate to a machine shop to have it milled for the fuse holders. They really looked good, not like the hack jobs most people did.

 

[jbeckva]

Well.... (gulp).... folks we had an "incident" tonight.... And JOE.. dagnabit.... you're like the "Prophet of PLWO" sometimes. You had some reservations on those 100V caps, and seeing as how this guy's been "clocked" at close to 108 yup....

(sad story to follow)...

So there I was... just chilling with the amp on.. barely anything... and then I hear my UPS "click" and hear this funny sound from it at the same time. Music was still going... hmmm.. wtf? Then my UPS pops up that warning.... "you have overloaded your UPS"...

OH SHIT

As soon as I hit the power on the amp, PWOOOOOOSSSSHHHHH!!! I hear something like a steam valve go off.. then all this nasty ass smoke pours out of the top. FWUUUUUCK!

Get it apart... one of the cap's spooged a good amount of electrolyte, and man .. it's HOT AS HELL...

DAMN DAMN DAMN.. Well Richard, it was good it was still here! But we're looking at new caps again. I'll take the hit for that.

BUT... I think guys I'm going to have to go with what I can get, and also NOT put anything in this "hottie" below 150 wvdc! Can't take that chance.

I see 11,000 uF's available right now that are 150V and will fit. Think that ought to be "enough" guys? Again, I can't take the chance of this happening again. I probably should replace the BR for good measure, too.

(dang... yep Lee... we gotta "keep em" for a week or so sometimes, eh??)

 

[laatsch55]

Yep, I haven't had a bad Adcom yet. Had some counterfeit Hitachi's in my Spec 2.

 

[jbeckva]

Yep, I haven't had a bad Adcom yet. Had some counterfeit Hitachi's in my Spec 2.

Was this "actual useful information"?

I'm not taking any chances since the rails on this one are extremely high, and Joe's "prophecy" has come true (dang Joe... next time click your heels, spin around 3 times and kill a chicken, ok???). Even if that does mean going down in total capacitance, which I just did by going with 2 11K/150's, and a new 35A BR for good measure. We'll see how that does come middle of next week, I guess.

 

[laatsch55]

Jer, I've been runnin so hard this month folks are lucky to get any information outta me, useful or not.

 

[wattsabundant]

Well.... (gulp).... folks we had an "incident" tonight.... And JOE.. dagnabit.... you're like the "Prophet of PLWO" sometimes. You had some reservations on those 100V caps, and seeing as how this guy's been "clocked" at close to 108 yup.... ......

Get it apart... one of the cap's spooged a good amount of electrolyte, and man .. it's HOT AS HELL...

BUT... I think guys I'm going to have to go with what I can get, and also NOT put anything in this "hottie" below 150 wvdc! Can't take that chance.

I see 11,000 uF's available right now that are 150V and will fit. Think that ought to be "enough" guys?

So we're clear on something, the DC bus voltage is directly dependent on line voltage. That doesn't change from one amp to another. The P/L amps were spec'ed at 120 VAC. At my house the xfmr is 75 feet from the panel. At the bench I usually read 123 VAC or so.

I've got a 700B soaking on the bench today. With a line voltage of 121.5 The DC bus is +/_ 102.5. Assuming the ratios are right, if jbeckva read 108VDC on the amp and the meter he used is accurate, that equates to a line voltage of 128VAC. If the UPS he has is a true online type with a sinewave output then something is wrong with the UPS. If it is an offline type then the line voltage is running on the high side and the utility company needs to look into this. This could also be a high resistance neutral issue at the panel or the transformer.

Any power supply I design I assume a working voltage of +/- 10% of nominal. For a nominal line voltage of 120VAC, the caps should be able to operate from a line voltage up to 132VAC.

At my day job we have confirmed the tighter tolerances of today's capacitors. You no longer get 15,000uf when you spec out 10,000. The maximum operating voltage is not +20%.

If time allows I'll set up one of my 700B's with 100V caps and run it for a while in 130VAC range and report with the details. In the mean time what is the preferred cap on the WOPL mods?

 

[NavLinear]

So we're clear on something, the DC bus voltage is directly dependent on line voltage. That doesn't change from one amp to another. The P/L amps were spec'ed at 120 VAC. At my house the xfmr is 75 feet from the panel. At the bench I usually read 123 VAC or so.

I've got a 700B soaking on the bench today. With a line voltage of 121.5 The DC bus is +/_ 102.5. Assuming the ratios are right, if jbeckva read 108VDC on the amp and the meter he used is accurate, that equates to a line voltage of 128VAC. If the UPS he has is a true online type with a sinewave output then something is wrong with the UPS. If it is an offline type then the line voltage is running on the high side and the utility company needs to look into this. This could also be a high resistance neutral issue at the panel or the transformer.

Any power supply I design I assume a working voltage of +/- 10% of nominal. For a nominal line voltage of 120VAC, the caps should be able to operate from a line voltage up to 132VAC.

At my day job we have confirmed the tighter tolerances of today's capacitors. You no longer get 15,000uf when you spec out 10,000. The maximum operating voltage is not +20%.

If time allows I'll set up one of my 700B's with 100V caps and run it for a while in 130VAC range and report with the details. In the mean time what is the preferred cap on the WOPL mods?

Hey Don,

I have read in other threads at this site that Lee and others have found that not all of the Phase Linear transformers were made the same. It seems that the person winding the transformer was not always consistent so some of these were made with different ratios. If I remember correctly this story was related to Lee by Ed Blackwood. If there are deltas between transformer builds than I can understand variations on the output voltages assuming a constant input voltage.

I have a 700 that I use and now my curiosity has been peaked. I'll have to open it up and take some measurements.

Any ideas for replacement reservoir caps?

 

[laatsch55]

So we're clear on something, the DC bus voltage is directly dependent on line voltage. That doesn't change from one amp to another. The P/L amps were spec'ed at 120 VAC. At my house the xfmr is 75 feet from the panel. At the bench I usually read 123 VAC or so.

I've got a 700B soaking on the bench today. With a line voltage of 121.5 The DC bus is +/_ 102.5. Assuming the ratios are right, if jbeckva read 108VDC on the amp and the meter he used is accurate, that equates to a line voltage of 128VAC. If the UPS he has is a true online type with a sinewave output then something is wrong with the UPS. If it is an offline type then the line voltage is running on the high side and the utility company needs to look into this. This could also be a high resistance neutral issue at the panel or the transformer.

Any power supply I design I assume a working voltage of +/- 10% of nominal. For a nominal line voltage of 120VAC, the caps should be able to operate from a line voltage up to 132VAC.

At my day job we have confirmed the tighter tolerances of today's capacitors. You no longer get 15,000uf when you spec out 10,000. The maximum operating voltage is not +20%.

If time allows I'll set up one of my 700B's with 100V caps and run it for a while in 130VAC range and report with the details. In the mean time what is the preferred cap on the WOPL mods?

Don, I have not run a higher voltage on the 700 caps than 100 volts. The windings on PL amps do vary. Not so much with the Schemacher's but definately with the in house version.

 

[Michael F]

Well.... (gulp).... folks we had an "incident" tonight.... And JOE.. dagnabit.... you're like the "Prophet of PLWO" sometimes. You had some reservations on those 100V caps, and seeing as how this guy's been "clocked" at close to 108 yup....

(sad story to follow)...

So there I was... just chilling with the amp on.. barely anything... and then I hear my UPS "click" and hear this funny sound from it at the same time. Music was still going... hmmm.. wtf? Then my UPS pops up that warning.... "you have overloaded your UPS"...

OH SHIT

As soon as I hit the power on the amp, PWOOOOOOSSSSHHHHH!!! I hear something like a steam valve go off.. then all this nasty ass smoke pours out of the top. FWUUUUUCK!

Get it apart... one of the cap's spooged a good amount of electrolyte, and man .. it's HOT AS HELL...

DAMN DAMN DAMN.. Well Richard, it was good it was still here! But we're looking at new caps again. I'll take the hit for that.

BUT... I think guys I'm going to have to go with what I can get, and also NOT put anything in this "hottie" below 150 wvdc! Can't take that chance.

I see 11,000 uF's available right now that are 150V and will fit. Think that ought to be "enough" guys? Again, I can't take the chance of this happening again. I probably should replace the BR for good measure, too.

(dang... yep Lee... we gotta "keep em" for a week or so sometimes, eh??)

Are those the Adcom caps?