David's PL 2000

Phase Linear Phanatic · Sep 27, 2014

Okay so I have this PL 2000 I'd like to incorporate into my system. I got it at a garage sale a while back for maybe $100 with the wood case so the price sounded right. It functions but thing is it needs some TLC. So I'd like to pick the brains of some people way more knowledgeable in vintage gear than me. (That's namely everybody).

It has what looks like oxidation on the Input jacks. (see pic). And I think that's what's giving me the intermittent cut-out of audio on the left or right channels. I can wiggle the RCA's and get static then sound. Or none at all. Solder joints look and feel solid. So what recommendation specific to this problem does anyone have to clean these? (if indeed that's the issue).

Next I have NO chassis ground post. Now I am not sure if this plays any role whatsoever to the pre-amp or potential ground loop/hum issues, but since I have no internal diagram to look at, I am not sure if this hole here (missing ground post) is supposed to be connected to anything internally. I.E. the control board for the RCA jacks?? Also please notice I have what seems to be a missing solder trace on the board by the chassis ground hole. I don't know if that's intentional by design or what? I "tried" to rig it with a jumper because I do NOT know how u fix missing solder trace on a printed board? Can anyone tell me?

OR tell me if what I did was dead wrong and dumb? I'll accept that! ;-)

My limited knowledge here is why I ask. Any help fixing the issues is much MUCH appreciated gentlemen. It's always a work in progress.

laatsch55 · Sep 27, 2014

The chassis ground can be a bolt. Mainly for turntables ground. You did a good job of fixing the broken trace, but your so anal at work I'm surprised you didn't bend a piece of bare #18 and lay it in the outline of the old trace and solder it in place.

Now, the RCA's.......they suck. Always have and always will. You can buy a bunch of individual cinch down RCA's or individually lean each one. De-Oxit D-100 in the small bottle with the needle applicator Blot it on and let it soak. Then flush with D5. This is also where I've used an 1/8 inch carbide burr by hand to cut through the thicker stuff.

Phase Linear Phanatic · Sep 27, 2014

laatsch55 said:

Damn Lee, you're spot on! I actually DID do that at first. I wanted to make it looked like that trace never lifted! But I didn't like the way it turned out. I guess your acknowledging that that trace SHOULD be there. That's good. (think of what I did as the duck-tape fix for a solder trace. Looks like shit but it works)

Thanks for the chassis ground answer. I have just the thing for it.

And the RCA's..........(sneer)...... that sounds like a pain in the ****. But I guess it's cheaper than buying another one that looks better and works as it should. I'm trying not to go "TOO" Frankenstein on this thing. I'll look into the de-oxit. :thumbright:

Now on a side note: What I DID notice today is when I touch my finger to the face plate; I get a hummmmmmmmm, then its gone after I let off. Granted, it's not in its wood case, and the metal is on my metal work bench. Derrrrrrrr........ :confused3:

What's the weirdest part to me though; is that when the volume pot is ALL the way down and not off, I can STILL hear music from the speakers? Not what you suppose THAT is??? I think it did that even before I ever touched it?

Speaking of anal at work; Here's some snippets of a pneumatic solenoid valve panel I wired. Took me about two days. But let me tell you; I made a cheater wire as a go-by and made sure all 256 wires were perfect! If it's 1/16" off; I re-do it. Maybe I take work a little 'too' seriously?................ :confused1:

laatsch55 · Sep 27, 2014

Actually it looks like a "supertweaker" project....hmmmmm......Dude , don't ever do speed..you would never finish a project.

On the 2000. Does it still have the cap accross the power switch??

Phase Linear Phanatic · Sep 28, 2014

laatsch55 said:

I took a picture of it. If you're referring to the ceramic disc looking thingamabobby here pictured; then yes Lee.

What's up?

NavLinear · Sep 28, 2014

It has the cap and the 33k resistor - seems to be one of the design features of PL. I'd think the resistor is ok to pull but the cap protects the switch assuming it is similar to the PL3300 preamp.

laatsch55 · Sep 28, 2014

The cap can be leaking and keeping the pre op-amps on enough to hear things after turning off...

laatsch55 · Sep 28, 2014

Do you legend the wires too?

NavLinear · Sep 28, 2014

laatsch55 said:

Good point. The current draw isn't much on power up so maybe tossing both is ok. If one would want to keep this feature a simple replacement of the cap would take care of that.

FYI Dave - the cap was installed to protect the power switch and the resistor was there to allow a voltage sufficient with the power switch off to provide a voltage to keep the ICs happy. This provided a mechanism to keep the logic state the same between power cycles.

laatsch55 · Sep 28, 2014

Phase Linear Phanatic · Sep 28, 2014

NavLinear said:

Sounds logical. (see what I did there)?

So let's assume I want to keep things the way they were designed. And still assuming this is the only cause of the symptom right now; what proper method is there to test the leaking cap? Keeping it simple to a guy with minimal test eqptment is key here......

The circuit board has a lot of caps on it too and everything is original. Could any one these being bad as well also cause this?

Note: when power switch is all the way down, then you click it to OFF; it goes "click" and I get a loud pop from the speakers. LOUD. It's an instant pop, and not the kind of pop delay typically heard when a PL amp is powering down. Keeping in mind also this pre is being used in conjunction with a PL200 series 1.

I'm ready to try some things after breakfast today as it has my attention on the bench today. Pending your guys feedback. Thanks!!

Phase Linear Phanatic · Sep 28, 2014

laatsch55 said:

Yes Lee. Every single one. Both ends.

Skratch · Sep 28, 2014

Phase Linear Phanatic said:

Damn Lee, you're spot on! I actually DID do that at first. I wanted to make it looked like that trace never lifted! But I didn't like the way it turned out. I guess your acknowledging that that trace SHOULD be there. That's good. (think of what I did as the duck-tape fix for a solder trace. Looks like shit but it works)

Thanks for the chassis ground answer. I have just the thing for it.

And the RCA's..........(sneer)...... that sounds like a pain in the ****. But I guess it's cheaper than buying another one that looks better and works as it should. I'm trying not to go "TOO" Frankenstein on this thing. I'll look into the de-oxit. :thumbright:

Now on a side note: What I DID notice today is when I touch my finger to the face plate; I get a hummmmmmmmm, then its gone after I let off. Granted, it's not in its wood case, and the metal is on my metal work bench. Derrrrrrrr........ :confused3:

What's the weirdest part to me though; is that when the volume pot is ALL the way down and not off, I can STILL hear music from the speakers? Not what you suppose THAT is??? I think it did that even before I ever touched it?

Speaking of anal at work; Here's some snippets of a pneumatic solenoid valve panel I wired. Took me about two days. But let me tell you; I made a cheater wire as a go-by and made sure all 256 wires were perfect! If it's 1/16" off; I re-do it. Maybe I take work a little 'too' seriously?................ :confused1:

View attachment 16456 View attachment 16457 View attachment 16458 View attachment 16459

Does the hum go away when you bolt the faceplate to the chassis ?

Phase Linear Phanatic · Sep 28, 2014

Yes. I put them back on this morning. However, I still have audio bleed-through at volume knob all the way down. Same big old loud POP! when switched to OFF. If it's as simple as eliminating that cap, I'll try that. Obviously I don't have a replacement. I'm sure mouser does. But as long as I have this issue, I cannot use it in my main audio rig.

Also fixed the chassis ground as Lee stated. I used a machine screw. I also took pics. I think I'm going to have to really get into those RCA contacts. They are all black and nasty. That's gonna take some time.

laatsch55 · Sep 28, 2014

Do you have a 2000 service manual?? The bleed through can be an op-amp problem , along with selector switch cleaning. Look at the selector switch. It's very hard to get the stuff where it's needed. Desolder it and give it hell. The pressurized version of the D-100 is needed there. As you move the switch the little access holes will incover more areas that will need a squirt or two. When youy have soaked the entire internal wheel actuate about 50 times frem extreme to extreme then flush with D5 and actuate about 50 more tims then do a final flush....

The bleed through can indeed be a bad cap other places also. It takes a process of elimination approach sometimes....the axial caps can be replaced with radials, check back o a couple of the 2000 threads to see how it's done...

laatsch55 · Sep 28, 2014

That cap and resistor are supposed to eliminate arcing at turn off/on, that's where ou are probably getting that pop. Measure DC voltage at the output of the pre also, just to see if you are passing any appreciable amount to the amp, it can and does happen..

Phase Linear Phanatic · Sep 28, 2014

No I do not have a service manual. The PL2000 and PL200 were a garage sale combo and I got both with no manuals either. Plus (whisper.. they kinda smell like an old musty basement). LOL! But whaddaya want for cheap? All my other PL gear was purchased through meticulous people like me and no issues. With all manuals.

The meter measured negative on any DC at the outputs. I did spray what little canned air I had left into the selector switch. I did a quick ON-OFF, ON-OFF, ON-OFF over and over again of the volume on/off switch. And changing audio input selection at random to see about the POP.

Sometimes I got NO pop. And then others I did. At random. Even if in the same position. I'd power on and wait for the "click" from the relay on the PL200 and then turn the pre-amp back off. So there doesn't seem to be any specific point at which I get that pop. Random. But at least process of elimination says the pop is not CONSTANT.

Continuing the process of elimination test, on bleed through I checked with the input to the AUX using my phone. Just to make sure it wasn't only at the tuner. I got it there too.

Sounds like I need a thorough cleaning regardless. I have to buy the deox-it though as I have none. So we will try again next week.

Phase Linear Phanatic · Sep 28, 2014

laatsch55 said:

A supertweaker project hmm? I did a search of that "term" supertweaker. As I haven't heard that term before. And this is what I found.

[TABLE]
<tbody>[TR]
[TD="align: left"]
[/TD]
[TD="align: left"] [HR][/HR]
Repeated rapid movements usually accomplishing very little.

Tweaking is a feeling like an obsession to do things requiring fine motor movements.

Things that require very little mental analysis or intelligence, but a lot of meaningless movement. Washing dishes, Computer games, making projects that never work and never get completed. Taping duct tape, aluminum foil on windows. Crawling in the carpets and rugs looking for dropped dope.

And I mean this tongue in cheek; Sooooooooooooooooo.....................................what exactly are you trying to insinuate Lee?

[/TD]
[/TR]
</tbody>[/TABLE]

laatsch55 · Sep 28, 2014

Not my definition. A supertweaker in my world is an old speedfreak who is OCD CUBED...wasn't a putdown...

Get a service manual from Rick, you are going to need it. We can not reference parts if you do not have one...

Phase Linear Phanatic · Sep 28, 2014

I know it wasn't a put-down. That's why I said 'tonge in cheek'. This was taken from the "Anti-Meth" website. Of which they define that as urban slang or whatever. Meth ain't my problem for sure. The OCD thing and being "square"? Oh yeah that's me. High on the German side for sure.

But since we are on the topic; allow me to hijack my own thread for a sec to give ya a bit a perspective on how I feel about working. I'd describe myself as pretty boring and like it that way. But hey, OCD has it's benefits. Work seems to be the only real thing I excel at and I put all my energy there. It's made me the main wiring lead in the shop. Yet.......I've turned down requests to be foreman several times and even requests to going into the office with the engineers and working there to get the CAD right on paper before it hits the shop. Because well....................there's just SOMETHING about getting your hands dirty and creating something. A fullfillment I did not find the last seven years sitting behind a desk reading engineering and architectural drawings and doing CAD. I was good at that too. But mentally exhausted. I guess you could say I "downgraded" in terms of responsibility and thinking. I mean honestly I feel a monkey could do my job, BUT...................... I've secured a job that makes me feel rewarded when I go home. And oddly enough; it pays handsomely when you are the main dude there? That's all that matters I guess.

Yeah, I am going to go read the PL2000 links here. I didn't find any under the "pre-amps" section specifically titled to the 2000. Any chance you could direct me in the proper direction?

And who's Rick? What's his user name? Ordering the deox-it as we speak. hopefully we will get further next weekend. Thanks for the help!!!!

David's PL 2000

Chief Journeyman

Administrator,

Chief Journeyman

Administrator,

Chief Journeyman

Attachments

Veteran and General Yakker

Administrator,

Administrator,

Veteran and General Yakker

Administrator,

Chief Journeyman

Chief Journeyman

Chief Journeyman

Chief Journeyman

Administrator,

Administrator,

Chief Journeyman

Chief Journeyman

Administrator,

Chief Journeyman