My new PL 700 Ii

[cloud9alpine]

Hi, I acquired this Phase Linear 700 II from a friend, it's my first one. I plugged it in and got nothing, then I noticed it would click on intermittently when I touched the lowest fuse holder on the back, the meters read at far left. Then I turned it off, but the meters stayed on... Then I checked the fuse and the end was toasty and it was cracked but the element looked intact. So I turned it off, put the fuse back in and now it's suck in there.

I know very little about these things. Ill probably send it off to be repaired or upgraded eventually. I'd like to use it someday.

Anyway, I heard this is the spot to go for insight about these amps so I figured I'd introduce myself. I'm Tobin, im not good with electronics repair, I like rock, punk, funk, soul, and blues.

 

[MarkWComer]

Yeah, that fuse looks pretty toasted, I’d replace it.

There are two HUGE capacitors inside and it takes a while for them to discharge completely, so the meters staying lit are indication of a bit of a charge left in them. I also have a 700 that I’m rebuilding, and during my initial checkout, the thing still played for a little bit after I turned it off! Turning off the power just prevents “new” current from entering the circuitry and replenishing those capacitors.

Not meaning to be an attention whore (but I will anyway...) look for me on YouTube- Mark5W8Comer- and look over my Phase Linear upgrade videos. They’re geared for people who haven’t done much electronic repair. Maybe you’ll decide NOT to send it out and undertake a satisfying adventure!

And welcome to the forums!

 

[MarkWComer]

OH- You’ll need to shop for a preamp for that baby...

 

[kingman]

Welcome Tobin! Good luck in repairing the Phase.

 

[jbeckva]

Welcome to Phoenix, Tobin good to see you here. Very nice looking amp! Take the covers off and snap a few pics of the innards.

 

[oldphaser]

If the Phase Linear 700 series 2 amp has LF351's I.C.'s in it, check the (2) large 7.5K ohm dropping resistors mounted on Malco pins on the side of the pc board. If they are Rockwood brand, they should be replaced automatically with at least 5 watt 7.5K ohm resistors. The TRW brand PW5's were OK.

NOTE: Earlier 700 seriers 2's had LF356's and used lower value 2.5K ohm dropping resistors which did not have the same reliability problems as the Rockwood brand. You might also consider replacing the LF356's with LF351's and the dropping resistors at the same time with 7.5K ohm. The LF351's had better slew rate, lower distortion and a reduced turn-off thump.

There were also (2) other 7.5K ohm (2 watt) resistors located near the bottom of the pc board. One in each channel. They are known to go up in value and should be replaced as a matter of course as well. If the 2.7K ohm resistors located next to them are 1/3rd watt they should be replaced with 1/2 watt resistors too.

Ed

 

[WOPL Sniffer]

Since the last poster didn't see your comment about "im not good with electronics repair" and "I know very little about these things. Ill probably send it off to be repaired or upgraded " find a Tech here and either get it serviced (It won't last), or upgrade it (It will last the rest of your life) and you'll be able to dump any other amp you have thought about keeping... They are cheap to upgrade when compared to buying something almost as good...... Good lunch and welcome aboard.

P

 

[MarkWComer]

They are cheap to upgrade when compared to buying something almost as good...... Good lunch and welcome aboard.

P

Hammer hits nail...

 

[cloud9alpine]

I cleaned it up and wrapped the knobs in woodgrain di-noc because one had an unsightly scratch. Here's a few more pictures. It appears to have all wrong fuses in it so next step is to replace those and see if it will even power on.

I wish I could ask the previous owner why it was shelved but he is no longer with us.

Thanks for all the info everyone.

 

[laatsch55]

If you do not have a variac and a dim-bulb-tester , put in 2 amp fuses in the rails and an 8 amper in the mains, ya might burn the 8 till caps are charged . It might just save some additional problems if you have some now you do not know about.

A pretty clean lookin Ser II.

 

[cloud9alpine]

Not meaning to be an attention whore (but I will anyway...) look for me on YouTube- Mark5W8Comer- and look over my Phase Linear upgrade videos. They’re geared for people who haven’t done much electronic repair. Maybe you’ll decide NOT to send it out and undertake a satisfying adventure!

Mark, I just checked out your videos, they look super helpful. I always appreciate an oppurtunity to acquire new skills and experiences is so ideally I'll use this new-to-me amp as a pathway to learning a new skill and perform the White Oak upgrade myself.

 

[WOPL Sniffer]

If you have not soldered before, get a practice board or several and practice practice practice. Nothing will stop a project faster than BAD SOLDERING. Some take this skill for granted but if you have not been trained or at the very least done a bunch of soldering, disaster will strike. I'm not trying to scare you but it's a bitch to try to learn how to solder using YouTube..... Heat is the enemy and not controlled correctly, can and will damage circuit boards to where they can't be salvaged and "Open the Wallet" is the word(s) of the day. But I do wish you good luck should you undertake a WOPL. The end result is a friggin party just waiting to happen. But, if you get in over your head, even the best guru's on this site may not be able to undo bad things without maybe causing others. Not only will it kill the components from overheating, it can cause lifted pads/runs and they would have to be repaired and without the correct tools for setting new PTH's, the results will be ugly and unreliable. Joe also offers his boards already built so that would and could be a cheap option. Soldering the PEM's on the back plane boards is tough even for a seasoned tech.........

P

 

[jbeckva]

I hate them PEMS but understand the necessity LOL. Yeah what Perry said..

 

[MarkWComer]

I was surprised that the PEMs on the backplanes went pretty easy this go round.

Ahhh... the joy of a new Weller!

 

[MarkWComer]

I cleaned it up and wrapped the knobs in woodgrain di-noc because one had an unsightly scratch. Here's a few more pictures. It appears to have all wrong fuses in it so next step is to replace those and see if it will even power on.

I wish I could ask the previous owner why it was shelved but he is no longer with us.

Thanks for all the info everyone.

Wow! Looks beautiful!

 

[MarkWComer]

If you have not soldered before, get a practice board or several and practice practice practice.

P

There’s a Chinese site- banggood.com- that sells little kits. Yeh, little stuff like digital alarm clocks and LED “Christmas trees.” Right- cheezy little stuff, but soldering principles and order of assembly rules still apply. They have a cool little 5V peak-to-peak oscilloscope with an LCD display that I bought. Cool junk to play with!

 

[laatsch55]

I was surprised that the PEMs on the backplanes went pretty easy this go round.

Ahhh... the joy of a new Weller!

That's EXACTLY what needs to happen....with enough heat , it's doable....

 

[MarkWComer]

Mark, I just checked out your videos, they look super helpful. I always appreciate an oppurtunity to acquire new skills and experiences is so ideally I'll use this new-to-me amp as a pathway to learning a new skill and perform the White Oak upgrade myself.

Preparing a new upload now...

 

[laatsch55]

If you have not soldered before, get a practice board or several and practice practice practice. Nothing will stop a project faster than BAD SOLDERING. Some take this skill for granted but if you have not been trained or at the very least done a bunch of soldering, disaster will strike. I'm not trying to scare you but it's a bitch to try to learn how to solder using YouTube..... Heat is the enemy and not controlled correctly, can and will damage circuit boards to where they can't be salvaged and "Open the Wallet" is the word(s) of the day. But I do wish you good luck should you undertake a WOPL. The end result is a friggin party just waiting to happen. But, if you get in over your head, even the best guru's on this site may not be able to undo bad things without maybe causing others. Not only will it kill the components from overheating, it can cause lifted pads/runs and they would have to be repaired and without the correct tools for setting new PTH's, the results will be ugly and unreliable. Joe also offers his boards already built so that would and could be a cheap option. Soldering the PEM's on the back plane boards is tough even for a seasoned tech.........

P

Wow!! Nice post Bud!!

 

[WOPL Sniffer]

I was surprised that the PEMs on the backplanes went pretty easy this go round.

Ahhh... the joy of a new Weller!

I bought a pair of these.... One for a daily driver and a spare..... The pencils are not cheap but I put this one through hell and am using the same tip for 2 years. Just a swipe across the damp sponge to steam clean it, and then tin it with fresh solder and it will last a long time.... But these units at 160W and an 80W iron and you can do the tough jobs..


Weller WD 1M