No more 60 Hz hum in a PL2000 preamp.

They seem to have done things a little differently for sure. Think it was because the 700 amp was the first product.
Below is a 2000 preamp chassis sitting on a 700 amp chassis. Very similar design construction and dimensions.
 

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George S. said:
O.K., so I now have films in C24 and C44 and everything is good. I really don't understand the issue I was having. Perhaps the blown phono Browndog was the issue or the fact that I didn't have the self shorting phono jacks installed.
Anyhow, #1 is done. Now going to borrow some parts out of the test unit and finish #2.
Click to expand...
The way PL should have built it...
 
Put the voltage to #2. 119 VAC line voltage this morning. B+ and B- are both 13.4 VDC with 25 ohm resistors in series with the secondaries and opamps installed. Going with this resistor value, same as I'm now using on #1.
 

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Both preamps are finished. It took a lot of work and time, but was worth it. They sound so much better than before.
Stopped and visited my father today. Mentioned I'm going to rebuild a PL5000 tuner next. He gave me a Boonton 102D FM-AM Signal Generator and a HP 5334B Universal Counter along with the manuals. Said they worked last use but it's been several years.
I'm going to need a larger work space.
 

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George S. said:
Both preamps are finished. It took a lot of work and time, but was worth it. They sound so much better than before.
Stopped and visited my father today. Mentioned I'm going to rebuild a PL5000 tuner next. He gave me a Boonton 102D FM-AM Signal Generator and a HP 5334B Universal Counter along with the manuals. Said they worked last use but it's been several years.
I'm going to need a larger work space.
Click to expand...


Never EVER turn down free test equipment...
 
Just be very gentle with the old PL boards. Keep your soldering to 700 deg F and don't linger and you'll be O.K. Get up to 750 and the trace will delaminate. A properly calibrated iron is essential. I use a Hakko clone thermocouple to check mine. Yeh it's a cheap clone, but uses genuine Hakko sensors.
 

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The Powerful Difference said:
Sir Yes Sir - Copy all, will comply! George, my best buddy's father taught me at age 16 how to rebuild carbs & also took me through my first engine build. He gave me countless tips about technique, and in particular how to avoid killing the patient while on the operating table. Funny how Mr. Laramore's tips have served me so well in so many unexpected places since then...

But with Mr. Laramore's mentorship I went on & did my first solo engine rebuild successfully! And already my confidence in restoring my 2000 to something I would want to listen to is much higher now that I've spent the evening reading this entire thread from the beginning. THANKS AGAIN for your generosity with the tips!!!

dave
Click to expand...

Funny that you mention your childhood and the mentorship Mr Laramore extended to you. I was fortunate (one might say "damned!") to have grown up in a small neighborhood where I had several "Mr Laramores" but each with a different specialty: mechanic, TV/audio repair man, carpenter, welder and a machinist. Now I spend my time in the Man Cave turning wrenches and tweaking electrons in retirement. I've offered my two son in laws and a few kids in the neighborhood some mentoring, but all seem too occupied in disposable electronics and video games. Oh well....we out here seem to be the last of a dying breed of guys breathing new life into vintage hardware.

It's good to be out here with y'all!

@George S. Did you ever get around to creating that PDF or a final shopping list of parts you came up with during the 2000-II project? I noticed my right channel has dropped a few DBs and when I turn the balance control full right, there is an unusual buzzing sound coming from the left channel. Going to order some parts before pulling out the Weller "scalpel". Will replace the back row of RCAs with through-hole type whie I have it apart this time.
Thanks again
Al
 

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] Did you ever get around to creating that PDF or a final shopping list of parts you came up with during the 2000-II project? I noticed my right channel has dropped a few DBs and when I turn the balance control full right, there is an unusual buzzing sound coming from the left channel. Going to order some parts before pulling out the Weller "scalpel". Will replace the back row of RCAs with through-hole type whie I have it apart this time.
Thanks again
Al[/QUOTE]
Unfortunately, no. Never got to it, but hope to get to it in the future. Need some more testing equipment and earned expertise and experience first. On those PL2000 jacks, notice they are all self grounding. They have 3 solder legs. One hot and two grounds. The inputs use that second ground, but the outputs don't. That second ground on the outputs is a isolated solder pad. I replaced all of mine with NOS jacks and have a thread with the link to supplier.
Here is a link to the best PL2000 service manual scan I've found on the web. It comes from Don Watts Abundant and is hosted on the AudioKarma site.
http://akdatabase.com/AKview/displayimage.php?album=94&pos=1
 
George S. said:
] Did you ever get around to creating that PDF or a final shopping list of parts you came up with during the 2000-II project? I noticed my right channel has dropped a few DBs and when I turn the balance control full right, there is an unusual buzzing sound coming from the left channel. Going to order some parts before pulling out the Weller "scalpel". Will replace the back row of RCAs with through-hole type whie I have it apart this time.
Thanks again
Al
Click to expand...
Unfortunately, no. Never got to it, but hope to get to it in the future. Need some more testing equipment and earned expertise and experience first. On those PL2000 jacks, notice they are all self grounding. They have 3 solder legs. One hot and two grounds. The inputs use that second ground, but the outputs don't. That second ground on the outputs is a isolated solder pad. I replaced all of mine with NOS jacks and have a thread with the link to supplier.
Here is a link to the best PL2000 service manual scan I've found on the web. It comes from Don Watts Abundant and is hosted on the AudioKarma site.
http://akdatabase.com/AKview/displayimage.php?album=94&pos=1[/QUOTE]

Time = Enemy
 
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