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Basic Transformer Testing
- Thread starter nelsress
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No Nelson
Quasi-comp refers to quasi-complimentary output stage as opposed to full complimentary.
Quasi-comp is when the output stage is all NPN (or all PNP) where the lower half of the output current amplifier uses a small signal PNP coupled with a high power NPN transistor to simulate a high power PNP transistor.
Full comp uses NPNs in the upper half and PNPs in the lower half of the current amplifier stage.
Someone did install the wrong output transistors. The 2SD555 transistors should not be used in the output of a PL amp.
Quasi-comp refers to quasi-complimentary output stage as opposed to full complimentary.
Quasi-comp is when the output stage is all NPN (or all PNP) where the lower half of the output current amplifier uses a small signal PNP coupled with a high power NPN transistor to simulate a high power PNP transistor.
Full comp uses NPNs in the upper half and PNPs in the lower half of the current amplifier stage.
Someone did install the wrong output transistors. The 2SD555 transistors should not be used in the output of a PL amp.
Thanks Joe, I think I understood what you said but let me run it by you, if you don't mind. Are you intimating that both the 400 and 700B amps leave the factory with quasi-complimentary output stages and one of the big things that you've done is convert them to full complementary? And, as I believe Lee pointed out, the quasi-comp or factory models never came with the NEC transistors that almost completely populate the rear plate? Am I finally understanding or is that just wishful thinking?? Thanks again.
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Nice
You're right, I don't know what I was thinking, thanks for the offer to take it off my hands. 
Think she could help? Oh hell, what am I saying, who would care until she left anyway? I'm calling this one, 50 shades of Nav!? The timing's right!! LOL Any one of "Nav's Avs" is welcome to swing by and whip it into shape!!
But seriously, thanks, I feel fortunate, it was just a diligence/timing thing, mixed with some luck, lots of luck. I caught the listing at 2 AM and it had only been listed 4 hours before but on the other hand, I've missed out on a bunch of stuff that was listed for 4 hours or less before I got to it. I don't do this for a living, it's only an obsession!
I don't know Nelson - that amp looks pretty fcuked up. I think you should give it to me. 
Nice score dude - a beautiful specimen. Do you need someone to whip it into shape. Maybe she can help. This seems to be my theme for tonight:
Nice score dude - a beautiful specimen. Do you need someone to whip it into shape. Maybe she can help. This seems to be my theme for tonight:
Think she could help? Oh hell, what am I saying, who would care until she left anyway? I'm calling this one, 50 shades of Nav!? The timing's right!! LOL Any one of "Nav's Avs" is welcome to swing by and whip it into shape!!But seriously, thanks, I feel fortunate, it was just a diligence/timing thing, mixed with some luck, lots of luck. I caught the listing at 2 AM and it had only been listed 4 hours before but on the other hand, I've missed out on a bunch of stuff that was listed for 4 hours or less before I got to it. I don't do this for a living, it's only an obsession!
The other two pieces
Just heard back from the seller, he said he wants $500 for both the 4000 Series I preamplifier and the 5000 Series I tuner. It would certainly be a nice stack to have and I've heard good things about the tuner but I don't know anything about that preamp, other than it's pretty darn cool looking! Any ideas on sound quality, build quality, and upgrades like with the PL amplifiers for these pre's? Any ballpark estimates to what it would take to get the entire stack (amp included) up to spec or better would be much appreciated. It looks like I might be entertaining the thought of selling some stuff, based on what you guys think about these units. Thanks folks!
Just heard back from the seller, he said he wants $500 for both the 4000 Series I preamplifier and the 5000 Series I tuner. It would certainly be a nice stack to have and I've heard good things about the tuner but I don't know anything about that preamp, other than it's pretty darn cool looking!
Any ideas on sound quality, build quality, and upgrades like with the PL amplifiers for these pre's? Any ballpark estimates to what it would take to get the entire stack (amp included) up to spec or better would be much appreciated. It looks like I might be entertaining the thought of selling some stuff, based on what you guys think about these units. Thanks folks!
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Thanks Lee
I see fitz43's listing. Based on Joe's comment about mainly being a fan of PL amps alone I was figuring on avoiding PL pre's, of course I could be wrong, maybe the ones he's offering are good ones? I'm familiar with the Crown, which is a decent preamp, or at least at its current age, would be with a good going over and re-cap. I'd love to know which one or ones do you like on fitz43's list, Lee?
I see fitz43's listing. Based on Joe's comment about mainly being a fan of PL amps alone I was figuring on avoiding PL pre's, of course I could be wrong, maybe the ones he's offering are good ones? I'm familiar with the Crown, which is a decent preamp, or at least at its current age, would be with a good going over and re-cap. I'd love to know which one or ones do you like on fitz43's list, Lee?
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The 3600, and 3800 are good pre's... They take about 150.00 worth of work to bring em up to snuff. The 3300 II is an excellent pre-amp. My favorite of the bunch followed closely by the 3600. I haven't worked on a 3800 but it's supposed to be better than the 3600. The 3600 and 3800 just need newer op-amps and some recapping to help the low frequency response and they're good to go. Doug's 3300 II is already sold. I've threaded a 3600 fix , Skynard77 had one I worked on and it turned out very well. The 3800 would be just as good I'm sure. Great phono sections...
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I've heard great things about them but have never seen or heard one myself. They bring pretty good bucks for being a Pioneer and for their vintage. They're not any newer really than a PL 3300 II, are they? For that reason, I have to believe that a Spec 1 would also need a little work, at least some power supply cap replacements, yes?