FFT on WOA PL PCB

T

THD+N

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Dec 10, 2012
Messages
139
Laatsch55 / Gepetto,
Since I am new here, I was wondering how much testing has been done on the WOA PCB. Have you done an FFT on it? If not, I could run it on my AP with digital option and post the graphs for additional archive information. I'd be glad to do it.

Obviously, I would need to borrow a PCB, but I would return it. I could also post a "stock" PL-36 PCB for comparison.

I know you have an AP Laatsch and I am not sure what options it has.
 
The ATS-1DD has an all digital suite and is FFT capable. Also has the 24-196khz option installed.
 
I would suggest buy one and populate it, you'll want to run one in one of your amps anyway once you hear it.
 
Mallory 20kuF-100VDC (1).jpgI'm doing a few upgrades of my own... I'll start by using these Mallory caps to upgrade the PS section. I also want to redesign the entire driver PCB with a design that is a bit more modern. I'll keep the triple output stage though. Since this is a hobby, no telling when I'll get the first PCB done for testing.
 
Yes, but still good. They have never been used, but appear to be OK and have been "reformed". In my 700II or 700B, both amps easily make rated power as designed when using these caps.
 
The line that says 9601 means that it was made 1st week of 2001 Doug.
 
The three numbers in front of that (362) Are assigned to MaLLORY. iF A CAP IS LABELED like those we habve that say Adcom, Adcom doesn't make caps but through the code, which is 658 that is CD. Cornell-Dubilier
 
THD+N said:
Yes, but still good. They have never been used, but appear to be OK and have been "reformed". In my 700II or 700B, both amps easily make rated power as designed when using these caps.
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Don't doubt that a bit, they all seem to until they leak or short. had quite a few of the 40 year old Sangamo test better that the newer caps.
 
THD, telling folks on this forum that you want to design your own driver board is a bit like telling to Pope to get some religion. We have all "been there, done that." You will not buy or build a better board than the White Oak Audio Phase Linear (WOAPL) board that is part of the discussion in this thread. Countless hours of engineering, SPICE simulations, testing, multiple revisions, and constant analysis have conspired to create the board we are now using. I would strongly suggest to take Lee's recommendation and try one because, "you'll want to run one in one of your amps anyway once you hear it." This goes for the PL400 or the PL700/700B.

Cheers,
Mark
 
mlucitt said:
THD, telling folks on this forum that you want to design your own driver board is a bit like telling to Pope to get some religion. We have all "been there, done that." You will not buy or build a better board than the White Oak Audio Phase Linear (WOAPL) board that is part of the discussion in this thread. Countless hours of engineering, SPICE simulations, testing, multiple revisions, and constant analysis have conspired to create the board we are now using. I would strongly suggest to take Lee's recommendation and try one because, "you'll want to run one in one of your amps anyway once you hear it." This goes for the PL400 or the PL700/700B.

Cheers,
Mark
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Ok, let me clarify my stance... I have no intention of trying to "out do" or "better" what Lee and Gepetto have done. I commend them. I am perfectly capable of designing and laying out PCB's. I do it strickly for my own pleasure. I like the PL amp design... I have about 15 PL amps bought from ebay I tinker with. However, I have always wanted to design a "modern" driver board using the 'ole PL "triple design". This is really all for my own edification and knowledge.
 
THD & N , I look forward to seeing the result of your efforts. That's what this place is all about, a dissemination of information. My efforts to Joe's board have been as a cheerleader, I couldn't design a voltage divider, but I'm a heck of a parts changer. Like I said looking forward to your efforts.....
 
laatsch55 said:
THD & N , I look forward to seeing the result of your efforts. That's what this place is all about, a dissemination of information. My efforts to Joe's board have been as a cheerleader, I couldn't design a voltage divider, but I'm a heck of a parts changer. Like I said looking forward to your efforts.....
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"That's what this place is all about, a dissemination of information." I concur. Just wanted everybody to know that I was not looking to stir up the hornets nest, but to add any knowledge I may find out along the way. Different amp topologies have different sonic signatures... AKA - transfer function.

I like tube based amps as well and prefer single-ended Class A with no feedback (except for very low bass, here solid state reigns). One of my favorite amps is a 2A3 based home brew design (with tube based power supply as well) that puts out 3.8 Watts RMS into 8-Ohms. For my style of listening, it puts out just enough power for most casual listening. It is a perfect match for my Klipsch Heresey's.
 
THD, Sorry if I came off as "you can't do that here." That was not my intention at all. I was just simply pointing out that there is a "modern" driver board when your post made it sound like there was not. If you want to make your own driver board you will get lots of encouragement because that's what we do here. If any of us can help, just let us know and we can chime in.
 
mlucitt said:
THD, Sorry if I came off as "you can't do that here." That was not my intention at all. I was just simply pointing out that there is a "modern" driver board when your post made it sound like there was not. If you want to make your own driver board you will get lots of encouragement because that's what we do here. If any of us can help, just let us know and we can chime in.
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No problem. It is hard to write clearly sometimes when your brain is working faster than your hands... Let me clarify my definition of "modern" driver board - Something along the lines of Doug Self or Randy Slone. I really admire these guys for putting together a lot of good information on amp design.
 
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I own 2 of G. Randy Sloans books, but we have in Joe a walking , talking G. Randy--what a resource....
 
I think anybody involved in repairing or designing audio amplifiers should own G. Randy's " High Power Audio Amplifier Construction Manual", very good reading along with a lot of theory.
 
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