PL meter question

[Northwinds]

Is there a way to calibrate the meters to reflect the extra power WOPL's have? Obviously they are calibrated for the original 200w spec. Just wondered if this was possible and if this was something Joe has thought about also?

I found this link but it's way over my head

http://meterbuilder.com/mb1/interfacing-analog-meters.html

 

[Gepetto]

Is there a way to calibrate the meters to reflect the extra power WOPL's have? Obviously they are calibrated for the original 200w spec. Just wondered if this was possible and if this was something Joe has thought about also?

I found this link but it's way over my head

http://meterbuilder.com/mb1/interfacing-analog-meters.html

Simple to do Ron but everybody would want something different, that is the rub.

The current PL400 meters are calibrated (rough and tough) to indicate 0dB on the meter at 50W RMS out for an 8 ohm load or 100W into a 4 ohm load.

I have thought about it Ron. The RevB Light Board has 2 jumper settings, the original sensitivity and an even more sensitive setting (-6dB voltage or 12.5W out at 0dB) because most users complain that the 400 meters barely move and they want to see more movement at their normal listening levels. To date Ron, you are the only user to register a complaint on that side of the spectrum.

Anything is possible...

 

[Northwinds]

It was not a complaint Joe, just someone on AK said my meters must be out of calibration because I had the needles near flat and the amp had plenty of power to go. I just wondered if it was possible, no complaint at all so sorry if it came out that way. I did not know the original meters were calibrated to 50w at 8ohms, I assumed they would have been calibrated much higher. I learn something new everyday! Many people when they see meters in the red assume it's a bad thing (like when you overdrive a recorded signal when making a cassette recording)

 

[Gepetto]

It was not a complaint Joe, just someone on AK said my meters must be out of calibration because I had the needles near flat and the amp had plenty of power to go. I just wondered if it was possible, no complaint at all so sorry if it came out that way. I did not know the original meters were calibrated to 50w at 8ohms, I assumed they would have been calibrated much higher. I learn something new everyday! Many people when they see meters in the red assume it's a bad thing (like when you overdrive a recorded signal when making a cassette recording)

I know it was not a complaint Ron.

That is just my colloquialism for customer observations. I often joke about people registering the "official complaint."

I am sure your meters are quite close to proper calibration. Dixson made very consistent meters. Most power amp providers do similar to what Phase Linear did, not all that uncommon.
They all hate warranty claims.

Remember Phase Linear was producing amps at the time with PL909s in them. They had much more reason to be concerned when users pushed their amps hard when you consider the output transistors available to them.

PL909

Absolute max continuous collector current = 3.5A
Absolute max peak collector current = 3.5A
Absolute max power dissipation = 100W
Absolute max collector-emitter voltage open = 300V
Absolute max collector-emitter voltage biased = 300V
Maximum operating junction temperature = 150C
Ft = 2MHz
SOA = unspecified

Compare that with the MJ21196

Absolute max continuous collector current = 16A
Absolute max peak collector current = 30A
Absolute max power dissipation = 250W
Absolute max collector-emitter voltage open = 250V
Absolute max collector-emitter voltage biased = 400V
Maximum operating junction temperature = 200C
Ft = 4MHz
SOA = 2.5A for 1 second at 80V Vce

Do you notice some subtle differences there?

 

[Gepetto]

It was not a complaint Joe, just someone on AK said my meters must be out of calibration because I had the needles near flat and the amp had plenty of power to go. I just wondered if it was possible, no complaint at all so sorry if it came out that way. I did not know the original meters were calibrated to 50w at 8ohms, I assumed they would have been calibrated much higher. I learn something new everyday! Many people when they see meters in the red assume it's a bad thing (like when you overdrive a recorded signal when making a cassette recording)

And when you make a cassette that is recorded too much in the red, all you get is a saturated recording. When you do that to an amp, sometimes stuff blows up!

 

[Northwinds]

I know it was not a complaint Ron.

That is just my colloquialism for customer observations. I often joke about people registering the "official complaint."

I am sure your meters are quite close to proper calibration. Dixson made very consistent meters. Most power amp providers do similar to what Phase Linear did, not all that uncommon.
They all hate warranty claims.

Remember Phase Linear was producing amps at the time with PL909s in them. They had much more reason to be concerned when users pushed their amps hard when you consider the output transistors available to them.

PL909

Absolute max continuous collector current = 3.5A
Absolute max peak collector current = 3.5A
Absolute max power dissipation = 100W
Absolute max collector-emitter voltage open = 300V
Absolute max collector-emitter voltage biased = 300V
Maximum operating junction temperature = 150C
Ft = 2MHz
SOA = unspecified

Compare that with the MJ21196

Absolute max continuous collector current = 16A
Absolute max peak collector current = 30A
Absolute max power dissipation = 250W
Absolute max collector-emitter voltage open = 250V
Absolute max collector-emitter voltage biased = 400V
Maximum operating junction temperature = 200C
Ft = 4MHz
SOA = 2.5A for 1 second at 80V Vce

Do you notice some subtle differences there?

I see large differences actually LOL

I think I understand what you mean about the meters. For some reason, I always though max undistorted output would be 0dbs. Anything above would be adding distortion. I know that's not the case with the WOPL's. It just seems wierd running at about 125 or so wpc and having the meters flat when there is so much more amp to go. I am afraid sometimes of hurting them (the meters) through overexcursion. In reality, I apparently have never cranked either amp to it's full potential because of this so no worries of ever blowing something up LOL

 

[Gepetto]

It was not a complaint Joe, just someone on AK said my meters must be out of calibration because I had the needles near flat and the amp had plenty of power to go. I just wondered if it was possible, no complaint at all so sorry if it came out that way. I did not know the original meters were calibrated to 50w at 8ohms, I assumed they would have been calibrated much higher. I learn something new everyday! Many people when they see meters in the red assume it's a bad thing (like when you overdrive a recorded signal when making a cassette recording)

Perhaps another relevant reason PL did what it did was they were introducing very powerful direct coupled SS amps in the age of relatively low power amps (i.e. tube amps). Most speakers at that time were designed to be very efficient because of the tube amp limitations. PL was probably concerned that most users would blow up their (35W rated) speakers. They were probably right about that. So if they sized the meter red zone to start at 50W then they were already giving the person that was used to their 35W per channel tube amp a 43% boost!

From what I recall, the AR3 was the first inefficient speaker to really show up on the market that needed more than the 35W per channel that was the benchmark at that time.

 

[laatsch55]

OK lets take.....say.....A Spec 2. The service manual says put so many volts out..BOTH CHANNELS....the adjust to 0db. That voltage reading corresponded to 250 watts RMS into 8 ohms, it's advertised max power at a stated distortion rate. The Spec 2 will do 338 before clipping. The Japanese were fighting the "Made in Japan" of low quality perception. Meters can say anything you want them to say, as with any indicator..

 

[laatsch55]

Could also have been, distortion is bad for speakers....I mean how does a set of K-Horns designed to handle 100 watts continuously take 250- 300 for hours?

 

[laatsch55]

And when you make a cassette that is recorded too much in the red, all you get is a saturated recording. When you do that to an amp, sometimes stuff blows up!

HUH? What?

 

[laatsch55]

That's why I blow em up...SO YOU DON'T HAVE TO!!!

 

[Gepetto]

That's why I blow em up...SO YOU DON'T HAVE TO!!!

And I thank you for that Lee. A 3-4# trout is a nice catch...

 

[laatsch55]

oN A FLYROD a pure gas...

 

[Northwinds]

Could also have been, distortion is bad for speakers....I mean how does a set of K-Horns designed to handle 100 watts continuously take 250- 300 for hours?

Because they are magic K-horns driven by magic amps with almost no distortion up to clipping? I wondered about that myself when Paul was talking about driving his 75w speakers to insane levels without hurting them. Blackie will trip the CV's internal protections no problem but Sally does not, still trying to figure that one out since the CV's are rated at 300w each

So much to learn (or at least understand)

So Joe, your pretty much saying PL deliberately calibrated the meters low because there was not a lot real high power speakers back then for home use and it looked good to have the meters peaking up around 0dbs? This would satisfy asthetics as well as protect low powered speakers by giving a warning to users that when they started going into the "red" they were on the verge of possibly damaging their speakers due to low efficiency? Trying to wrap me head around this. Maybe this is why there is no description of what the lower numbers mean on the PL meters ie 100 would be 100w or 100% power output before distortion/clipping range? Other amps I have had in the past with meters represent wpc, the lower grid of numbers always had watts ratings. The PL's just have numbers

I am sure I am looking like an ass here trying to decipher what you all mean but I really would like to understand what the meters actually indicate

 

[Gepetto]

oN A FLYROD a pure gas...

I bet, testing the flex in your rod??

 

[Northwinds]

oN A FLYROD a pure gas...

Try a 40lb King Salmon on a flyrod, that is a blast (of course it involves a lot of running and slipping and potentially breaking your ankles LMAO)

 

[laatsch55]

No, the flex is there to take the shock out of the trouts movements so youi don't tear a 3 lb tippet apart. Flyrods are built to be stiff on a forecast and less so in the backcast. A fish has to be "played" not "horsed" on a flyrig. You have to tire them out which means keeping them on for awhile, which is where skill is helpful. Anything over 1-1/2-2lbs is a joy...

 

[Northwinds]

No, the flex is there to take the shock out of the trouts movements so youi don't tear a 3 lb tippet apart. Flyrods are built to be stiff on a forecast and less so in the backcast. A fish has to be "played" not "horsed" on a flyrig. You have to tire them out which means keeping them on for awhile, which is where skill is helpful. Anything over 1-1/2-2lbs is a joy...

Sadly, when my Dad passed away, my uncle grubbed the flyrods my Dad gave me. They were handbuilt Fenwicks. Now when I go for Steelhead and King Salmon, I use a 14ft noodle rod with a openface reel hold as much 8lb line as it can. The rod beats the fish just like you say. The lighter the line, the more shock the rod has to take so as the light line is not snapped. Someday I would like to get another flyrod. I have one out in the garage that is made out of split bamboo. I think it's just over 9ft long. It has a very old JC Higgins flyreel on it. I would not trust either with a nice sized Steelhead or King on the other end

 

[laatsch55]

Any evidence of who made the rod??

 

[Northwinds]

Any evidence of who made the rod??

Not that I see Lee, a local guy who is an avid flyfisherman said it was made in the 40s or 50s and is from Maine. He could tell how the ferrels were wrapped or something like that??? It's very stiff and whatever laquer they used is peeling in places on it