Cory's Phase Linear 2000 Ser I Unit #2

[NavLinear]

I sort of figured a tool would be involved as shooting from the hip could make it difficult to get all of them alligned. Any issues with pads lifting with this unit?

On another note it sure is interesting that a lot of the electronics of this era did not remove the flux from the printed circuit boards after soldering. The hardware I worked on in the 70's was meticulously cleaned after soldering. We knew! Besides QA wouldn't let this get through.

 

[laatsch55]

Traces and pads are solid. No liftage. Yeah, what is up with the flux?? That was understood then, lazy wave solder??

 

[NavLinear]

Traces and pads are solid. No liftage. Yeah, what is up with the flux?? That was understood then, lazy wave solder??

I'm not sure what's up with the flux. Back then we used freon and trichloroethylene 111 in a vapor degreaser that cleaned the shit out of the boards. Flux is a good thing when soldering as it cleans the area and helps in getting a good solder joint but it must be cleaned after the fact. We hand soldered thru-hole boards until the mid to late 80's - of course in small quantities we still hand solder. After the components are soldered to the boards they are cleaned using a solvent.

I still use leaded solder, RMA flux and some nasty ass solvent to clean the boards in all of my projects - old school I guess.

 

[laatsch55]

Ditto...

 

[Gepetto]

Watch the bad ass solvents as they destroy today's electrolytic caps, damaging the seals and destroying the printing on the outside of the sleeve. Isopropyl is a good safe choice.

I also recommend no clean flux solder like Kester 245. I use SN63PB37 #50/245 type for most projects.

It leaves less flux residue than the classic Kester 44 that you probably use. The residue is much easier to remove using Isopropyl alcohol than the 44. If you do decide to clean the no-clean, make sure you clean it good, with no residue left behind.

You really do not have to clean either type, the flux left behind is non corrosive. In the case of rosin, it is benign. In the case of the no clean #245, the flux catalyzes with the heat of the iron and becomes benign.

 

[NavLinear]

Watch the bad ass solvents as they destroy today's electrolytic caps, damaging the seals and destroying the printing on the outside of the sleeve. Isopropyl is a good safe choice.

I also recommend no clean flux solder like Kester 245. I use SN63PB37 #50/245 type for most projects.

It leaves less flux residue than the classic Kester 44 that you probably use. The residue is much easier to remove using Isopropyl alcohol than the 44. If you do decide to clean the no-clean, make sure you clean it good, with no residue left behind.

You really do not have to clean either type, the flux left behind is non corrosive. In the case of rosin, it is benign. In the case of the no clean #245, the flux catalyzes with the heat of the iron and becomes benign.

Thanks for the inputs Joe. I did follow your advice with the WO controller board and used the 95% Isopropyl to clean the boards and it worked well. We occasionally use Isopropyl for cleaning boards but we usually use Ensolve - a trichlor replacement - but we don't use the type of electrolytic caps that are used in audio and other home electronics.

Thanks for the tip on the flux and solder. Next time we do a purchase I'll get some to compare. At work I just dug up some solder made in the early 90's - we disposed of the old stuff a year or so ago.

 

[BigSkyCory]

Looking great Lee. On my other 2000 that you worked on for me, you seemed to think the op amps were maybe going out. How many are there and how hard is it to replace them?

 

[laatsch55]

Cory, on that one I was anticipating changing them at some time down the road. Yours I desoldered the op-amps and soldered in machined sockets. Take the top cover off and look. There will be one on the back left, one in the middle and one in the middle right. See if I socketed all of them. The one on the left is an RC 4739 and it's in the phono circuit. The one in the middle is the hi gain amp and is a RC 4136. The one on the right is for the ambience circuit and is also an RC 4739. Check and see if the noise follows with ambience knob being turned.

 

[laatsch55]

Joe, when I use acetone, the board is plumb vertical and I try to avoid open thru holes, so far so good.

 

[BigSkyCory]

Lee,
The noise does not change when I turn the ambience knob. I can only notice it when there in no music playing. But as soon as I turn on my amp the static/hiss sound is noticeable through my speakers, more in the mid and tweet. Gets louder when I turn the volume knob up. I can not notice it when music is playing. Other than that it seems to be working awesome. Maybe I'm just being too picky.

Cory.

 

[laatsch55]

Have you tried another amp to see if it follows or stays with the one swapped out. Old and failing op-amps can generate a lot of noise. I was hoping it was the RC 4739's so you could swap the phono IC for the ambience IC and isolate it that way. Are all the op-amps socketed?

 

[laatsch55]

Sir Joe, what was the recommendation for bypassing some of the 4136's outputs??

 

[Gepetto]

Geez Lee, that was late one night. Do we still have that thread on the forum. You and I were deep into it at one point.

 

[laatsch55]

Yeah it was Joe and I perused the 2000 thread and it must have been an offshoot into another thread. I'll look further. that was the Series OO. This latest one is a Ser I.

 

[Gepetto]

My Stuff only goes back 500 posts and it predated that Lee.

 

[BigSkyCory]

Yes I have tried different amps. Same noise with different amps. Lee, I am 95% positive that you socketed those op amps in. I'll try to take a closer look tonight. I do have a volt meter thing. Doesn't mean I know how to use it, lol....

 

[laatsch55]

Yes I have tried different amps. Same noise with different amps. Lee, I am 95% positive that you socketed those op amps in. I'll try to take a closer look tonight. I do have a volt meter thing. Doesn't mean I know how to use it, lol....

Time to learn then../...your daddy was remiss in that department. Every son should know how to use one of those. You can even troubleshoot a computer power supply with one.

 

[laatsch55]

My fatsack of replacement RCA jacks were not quite exact replacements. So, I have to desolder and disassemble the originals and do the de-oxit thing along with actually scraping the contact surfaces.

 

[NavLinear]

Bummer. Did they not align with the chassis?

 

[laatsch55]

I had gotten them to do that, but the rear profile on the originals were round and had a shoulder to seat in the back wall. the new ones have a square profile and would have had a different standoff from the wall.