400 Series 1 Build

MarkWComer

MarkWComer

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#23
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Gaston, SC
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Victim of the record bug since age five
#23
Pulpmillguy said:
This makes me want to do another one sooooooo badly...been watching that WOPL1000 build and drooling over that one.
Click to expand...
Thinking… personal loan from the credit union…
But I want that new Pulse Linear preamp…
And speakers…

(Better get a BIG loan…)
 
Pulpmillguy

Pulpmillguy

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#24
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Details, details
#24
MarkWComer said:
Thinking… personal loan from the credit union…
But I want that new Pulse Linear preamp…
And speakers…

(Better get a BIG loan…)
Click to expand...
Hell, just refinance the house...or rob the damn bank:cool::cool::cool:

I got the speakers...but am in the same boat regarding the preamp...and I want to get my turntable and vinyl back from ex #1 but not sure that is going to happen.

Hey, getting back to something you said a while back about the WOPL700 actually being capable of 500w/ch (Joe, comment please) due to the upgraded output transistors. The electronics might be able to pump it thru but the power supply is only good for like 960...970 watts transformer rating (too lazy to go look) so you might be able to go almost 500/ch rms but you got NO headroom...I guess if you piled a bunch of big-ass electrolytics in the power supply it would be better but still you need a bigger transformer to really let the old gal stretch her legs and that is why Joe has spec'd the much larger transformer for the One
 
Gepetto

Gepetto

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#25
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Old 'Arn Enthusiast
#25
Transformer VA rating is largely dependent on the wire size inside the transformer and the temperature rise before it exceeds the UL insulation class rating. Most all common transformers use UL Class B insulation systems indicating they are good for up to 130C temperature rise. The large the copper wire diameter, the smaller the loss involved due to IR heating of the winding wires. Thus if you are not hammering your amp on a continuous basis, you will not hit this rating limit and thus be able to enjoy periods of higher power output. The windings have thermal inertia so they do not instantly heat the entire winding mass up on periods of peak power, similar to your soldering iron that takes some time to heat up.
 
Pulpmillguy

Pulpmillguy

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#26
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Details, details
#26
Gepetto said:
Transformer VA rating is largely dependent on the wire size inside the transformer and the temperature rise before it exceeds the UL insulation class rating. Most all common transformers use UL Class B insulation systems indicating they are good for up to 130C temperature rise. The large the copper wire diameter, the smaller the loss involved due to IR heating of the winding wires. Thus if you are not hammering your amp on a continuous basis, you will not hit this rating limit and thus be able to enjoy periods of higher power output. The windings have thermal inertia so they do not instantly heat the entire winding mass up on periods of peak power, similar to your soldering iron that takes some time to heat up.
Click to expand...
OK, but you still haven't answered the question regarding how much power the full blown WOPL (like what I did) is capable of delivering to the speaker terminals. I know you give lots of fancy gain curves in the literature you provide with the kits but in simple English man...what is it good for RMS (assuming the power supply doesn't choke)?

All I know is mine sounds FANTASTIC, thank you so very much for bringing the old gal back to life.
 
Gepetto

Gepetto

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#27
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#27
Some on this forum have measured ~500 WPC at clipping during testing... it is up to the transformer you have and the line voltage where that point will occur. And the power supply will choke as we have said...it is not rated for those continuous power levels.
 
Pulpmillguy

Pulpmillguy

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#28
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Details, details
#28
Gepetto said:
Some on this forum have measured ~500 WPC at clipping during testing... it is up to the transformer you have and the line voltage where that point will occur. And the power supply will choke as we have said...it is not rated for those continuous power levels.
Click to expand...
I knew that sucker sounded good...

Good thing that I live out in the country and only have one neighbor across the street...next closest is half a kilometer away!
 
mlucitt

mlucitt

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#34
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Jun 24, 2011
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#34
laatsch55 said:
That 525 probably had 108 rails...
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Lee, I think you had one with the hottest transformer. How hot was THAT one?

Also, clipping is subjective. Most people cannot detect a good percentage of clipping distortion at high Sound Pressure Levels, even though it is obvious on a scope. I believe the RMS voltage does go up a little bit during clipping, therefore the Power in Watts continues to increase.
From Wikipedia:
"Amplifiers have voltage, current and thermal limits. Clipping may occur due to limitations in the power supply or the output stage. Some amplifiers are able to deliver peak power without clipping for short durations before energy stored in the power supply is depleted or the amplifier begins to overheat."
And...
"Because the clipped waveform has more area underneath it than the smaller unclipped waveform, the amplifier produces more power than its rated sine wave output when it is clipping."
Clipping 1KHz 10V DIV Clip at 5 Ohms.jpg
 
G

George S.

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#38
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#38
Joe has new design PCB's soldered on those power supply caps. Are they still 4 lug or did 2 lug dictate a new design?
 
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