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Rev. A to Rev. E differences and Quasi vs Full
- Thread starter Vynuladikt
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Some people think it is unproductive to convert the PL400 to a full complementary amplifier, preferring to upgrade only the PL700B or PL700 Series II. I like the PL400 and PL400 Series II, I think they sound wonderful and 200 watts (more with WOPL) is enough for most people.
My advice would be to invest in the new output transistors (maybe you only need 8 MJ21195G), the WOA Backplane/Wire kit , and the Rev G1 Dual Mono Control Board kit. You will be rewarded with an amplifier that sounds better than 90% of what is out there today. You will never look back.
My advice would be to invest in the new output transistors (maybe you only need 8 MJ21195G), the WOA Backplane/Wire kit , and the Rev G1 Dual Mono Control Board kit. You will be rewarded with an amplifier that sounds better than 90% of what is out there today. You will never look back.
My advice would be to invest in the new output transistors (maybe you only need 8 MJ21195G), the WOA Backplane/Wire kit , and the Rev G1 Dual Mono Control Board kit. You will be rewarded with an amplifier that sounds better than 90% of what is out there today. You will never look back.[/QUOTE]
just wondering why you recommend the G1 dual mono control board kit over just the full comp Rev E control board kit. Looking to do a WOPL on my Pl 400.
just wondering why you recommend the G1 dual mono control board kit over just the full comp Rev E control board kit. Looking to do a WOPL on my Pl 400.
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- Halfbiass...Electron Herder and Backass Woof
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Post #22 tells about RevG
Cathy Has Returned | Page 2 | Phoenix Audio Community Forums (phxaudiotape.com)
Cathy Has Returned | Page 2 | Phoenix Audio Community Forums (phxaudiotape.com)
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Hey everyone, thanks for the input. I have already ordered all new outputs MJ21195G and MJ21196G for the 700 and was planning on ordering the WO driver board soon. This just made my decision to go Rev. G. My current 400 WOPL sounds fantastic, but always wondering if it could be better. Think I'll build the 700 and then decide if I want to put anymore into the 400.
Still waffling on spending the extra for the backplane for the 700 or not.
Still waffling on spending the extra for the backplane for the 700 or not.
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I have to way into this 400 discussion a bit.
Here is my rant. Please correct me me if I am incorrect with anything here.
I believe that to increase volume enough to hear the change in loadness you need to increase the volume 3db. And the power needed to increase 3db is done by doubling the output. So very little difference between the 250 watts a 400 puts out and 400 watts a 700 puts out. There are significant gains in amp stability running the 700 in low ohm loads and should be preferred for that use. I am building a 40 output dual 500 for those needing 2 ohm setup so stay tuned for that one
Now anyone who said a WOPL upgrade puts out more power is very misleading. The power output is controlled by the rail voltage which does not change from stock to WOLPed. So it puts out the power as stock in both 400 and 700 upgraded. Now the phase linear topically puts out more power than its rated when one channel is driven anyway.
As to WOLPing a 400 that is a great amp at the end of the day. With efficiency speakers you can blow your house down. Just ask Lee.
I have serval 400 series II amps in various configurations. All work and sound just as the 700 does and even my WOLPed dual 500. The only thing is it puts out a little less power. If you don’t run full out why do you need it? Well the answer is head room for those deep base notes that come from time to time. But you can live very well with the 400.
I am attaching a photo my amp I use with the tv.
Here is my rant. Please correct me me if I am incorrect with anything here.
I believe that to increase volume enough to hear the change in loadness you need to increase the volume 3db. And the power needed to increase 3db is done by doubling the output. So very little difference between the 250 watts a 400 puts out and 400 watts a 700 puts out. There are significant gains in amp stability running the 700 in low ohm loads and should be preferred for that use. I am building a 40 output dual 500 for those needing 2 ohm setup so stay tuned for that one
Now anyone who said a WOPL upgrade puts out more power is very misleading. The power output is controlled by the rail voltage which does not change from stock to WOLPed. So it puts out the power as stock in both 400 and 700 upgraded. Now the phase linear topically puts out more power than its rated when one channel is driven anyway.
As to WOLPing a 400 that is a great amp at the end of the day. With efficiency speakers you can blow your house down. Just ask Lee.
I have serval 400 series II amps in various configurations. All work and sound just as the 700 does and even my WOLPed dual 500. The only thing is it puts out a little less power. If you don’t run full out why do you need it? Well the answer is head room for those deep base notes that come from time to time. But you can live very well with the 400.
I am attaching a photo my amp I use with the tv.
Attachments
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2 WOPL 400s, biamping a pair of 15" Dayton Audio Ultimax subs in the standard knockdown enclosure kits, and a pair of restored JBL L-150 Millenniums. Works WONDERFULL! However, my next WOPL will be a 700 for the subs, 400 for the JBL woofers, 400 for the mid and tweeters. Triamp. Yeah, I've got the sickness. Don't tell my wife!
Whoa Nellie...
Technically, you are correct; but in practice that never happens. True, the total rail voltage in a PL700 is 200 volts and this does not change after a WOPL upgrade. But to say the power output is controlled by the rail voltage is incorrect. It would be more correct to say the output is "limited" by the rail voltage; and at 200 volts, that theoretical power would be 5000 watts (200 volts x 200 volts / 8 Ohms = 5000 watts) or 2500 watts per channel. It just ain't so.
Now the magic of the WOPL upgrade is the increased efficiency in the front end and the higher SOA of the newer outputs. I routinely measure power output before the WOPL upgrade for my customers and have recorded voltages at the output of 52 vrms, 54 vrms, and 56 vrms per channel (338 watts, 364 watts, and 392 watts). After the WOPL upgrades, I was able to record output voltages of 62 vrms, 63 vrms, and 66 vrms (480 watts, 496 watts, and 545 watts). The peak power ratings are even higher, given the increased headroom and the ability to handle an increased input without clipping.
How is this possible? Closer tolerances during manufacturing, increased consistency, and design improvements thanks to WOA.
Try it yourself and see what your WOPL will produce. I would be surprised if you record less than 62 vrms at one channel when driven by a 1kHz signal at 2 vrms. There will be no clipping.
For a WOPL 400, you should be able to see the stock output of 44.72 vrms increase to at least 50 vrms (312 watts) per channel with no clipping.
Technically, you are correct; but in practice that never happens. True, the total rail voltage in a PL700 is 200 volts and this does not change after a WOPL upgrade. But to say the power output is controlled by the rail voltage is incorrect. It would be more correct to say the output is "limited" by the rail voltage; and at 200 volts, that theoretical power would be 5000 watts (200 volts x 200 volts / 8 Ohms = 5000 watts) or 2500 watts per channel. It just ain't so.
Now the magic of the WOPL upgrade is the increased efficiency in the front end and the higher SOA of the newer outputs. I routinely measure power output before the WOPL upgrade for my customers and have recorded voltages at the output of 52 vrms, 54 vrms, and 56 vrms per channel (338 watts, 364 watts, and 392 watts). After the WOPL upgrades, I was able to record output voltages of 62 vrms, 63 vrms, and 66 vrms (480 watts, 496 watts, and 545 watts). The peak power ratings are even higher, given the increased headroom and the ability to handle an increased input without clipping.
How is this possible? Closer tolerances during manufacturing, increased consistency, and design improvements thanks to WOA.
Try it yourself and see what your WOPL will produce. I would be surprised if you record less than 62 vrms at one channel when driven by a 1kHz signal at 2 vrms. There will be no clipping.
For a WOPL 400, you should be able to see the stock output of 44.72 vrms increase to at least 50 vrms (312 watts) per channel with no clipping.
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Mark very cool, very illuminating! I'm going to download the service manual this next weekend and see what it takes to measure mine.Think I have everything but a load bank, which I should be able to make. Thanks for this. I've often thought my S1 has a slightly hotter transformer than the S2, I'm going to find out.
I have a 700 with new dual mono board, no backplanes (Cathy)so not full comp and a 400 with older main board rev that is not dual mono, so fully comp. Fully comp easily wins the SQ battle. I wouldn't pass on the back plane/full comp option. Definitely not after hearing it.
Cathy was fitted with a D or E rev board until I blew that up, and when Lee sent her back repaired and with the dual mono board installed, the improvement over the old rev was obvious as well.
Progress is good, don't pass on it unless you're broke!
Cathy was fitted with a D or E rev board until I blew that up, and when Lee sent her back repaired and with the dual mono board installed, the improvement over the old rev was obvious as well.
Progress is good, don't pass on it unless you're broke!
