HELP! Rescuing Dad's old PL400 S2 (pics)

lightfall said:
Green Bay Packers all the way! My wife's sister from Philly is coming in tomorrow so we better win today or I will get verbally assaulted tomorrow.
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I think your Packers will spank the Eagles today. Matthews is an animal and they've finally turned him loose...
 
If you White Oak the amp it will handle even the "short circuit" impedance curve of the 9Kappas. (see my 700 conversion thread) RSIIIa will be no problem whatsoever.
 
Damn the first channel appears to be creeping up to 410mv even w the pot turned fully clockwise.

I hope you are right about Clay, I know they don't want to treat him like a middle LB but what works, works.
 
Yea I've been reading about the impedenxe on these rs3as and it definitely worries me. I Am going to get this thing going in stock form (hopefully) and then upgrade and enjoy the hobby process and are/post upgrade performance. I also like photography but I forced myself to start with a kit lens, and then a $cheap lens, until I ended up with my current setup. Same with tracking a car and building my cycles, I try my darndest not to do the best upgrade right away haha!
 
lightfall said:
Damn the first channel appears to be creeping up to 410mv even w the pot turned fully clockwise.

I hope you are right about Clay, I know they don't want to treat him like a middle LB but what works, works.
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She'll run a little hotter is all. Whats your DC offset?
 
Clay has a motor that doesn't quit. Move him around...make the offense LOOK for him....if they're looking for him they're NOT lookin for other things.
 
lightfall said:
Yea I've been reading about the impedenxe on these rs3as and it definitely worries me. I Am going to get this thing going in stock form (hopefully) and then upgrade and enjoy the hobby process and are/post upgrade performance. I also like photography but I forced myself to start with a kit lens, and then a $cheap lens, until I ended up with my current setup. Same with tracking a car and building my cycles, I try my darndest not to do the best upgrade right away haha!
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I would not be worried, I drove the PISS out of my first WOPL and it was only a quasi with Infinity Quantum 5's w/ the dual coil Watkins 12" woofers which are also known as amp killers (they killed a Nikko Alpha and an Adcom something within an hour. She would get hot and somewhere there probably is a pic of the amp with a huge box fan on top of it that cooled her right down

KEEP a fan on it when your cracking the walls
 
Before I left to watch the pack I checked the DC offset across both outputs and it was 3mv left and 4mv right. I think I checked it correctly. I powered up, warmed up, set the MM to read dv MV and then put a probe on the +/- of each speaker terminal.

Does that sound right? I'm surprised my bias crept up to 415mv on both but the DC offset looks OK.
 
I am still an hour from home, but on the way I am pondering. What is the concesus on the sweet spot for gain control on the preamp and amp? What settings on each will generally give the best SNR?
 
Oh yeah, Sanchez certainly didn't hurt our efforts. Minnesota at home may be more challenging than meets the eye and the real challenge will be Brady two weeks from now.
 
so thats why it was quiet downstairs. I'm the anti-football fan but my mother is an Eagles fan. Not much cheering at the TV. I had it drowned out with music anyway. Sherwoods sound a lot better than sports announcers.


I also run mine wide open on the amplifier. If my preamp was overly touchy though, I'd have no real concern about dialing the amplifier back some so that it didn't go from 0 - ear bleed at the slightest crack of the volume knob.
 
I managed to set up the unit upstairs last night but had to tiptoe as to not bother the baby. Initially I set up per the manual, with the turntable and the amp plugged into the switched sockets of the preamp. What I noticed was that I got some faint sound out of the speakers but there was an intermittent thump that seemed unusual. I disconnected the speakers because my wife yelled at me and I was worried. I then turned the unit back on and noticed in the right channel on the LED display an occasional spike in the db that would essentially go to clipping, it was intermittent and only on the right. I was very tired so went to bed. This morning I woke up, I unplugged everything from the AMP and powered back up with no speakers and tone control/ambience disabled and the bass knobs turned down on the preamp: no thumping noted on the LED display. with preamp and/or amp volume up the LED display did not budge, whereas the right channel seemed to pick up some noise at around 1 o clock on the gain setting. I think something is up with the preamp, maybe an incompletely cleaned pot or something. Anyway, just wanted to update what happened.

MAN it looks gorgeous on the desk though!
 
Only initially I attempted to play vinyl. I had some faint sound come through on the speaker but there was an occasional deep thump coming from the speaker and it drove the woofer hard for a split second. That is when I pulled the speaker connections and tried to isolate the issue before my wife told me to get my ass to bed. I didn't want to attempt to play any more music until the thumping was spiking on the right channel was settled. I will attempt a digital source next as a matter of course and isolate the possibility of the turntable adding to it and then see if one of the tone pots or something on the preamp is causing crackling or something in a step by step process. I had very little time to do any proper troubleshooting and should have waited to post until after I had a chance to really observe what was going on.

When I get off tonight I plan to try this again without the turntable and amp plugged into the preamp and then the amp into the surge protector. I was also nervous that the surge protector may have been bad somehow as the protection light was not solid green but pulsing green. No other electronics have issues.
 
What pre-amp? What amperage on the surge protector?

An amp is very noisy when hooked to speakers with no pre-amp hooked up and the inputs not shorted. Plus the factory PL's did have some turn on/off thump.
 
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