Phase Linear 2000 troubleshooting

Gepetto

Gepetto

Administrator
Staff member
#102
Joined
May 15, 2011
Messages
14,042
Location
Sterling, MA
Tagline
Old 'Arn Enthusiast
#102
MarkWComer said:
Cracked open my 4000 to look it over. Since I'm going to Capacitor Hut to buy some stuff for other phono projects, decided to recap the preamp. In another thread I expressed my agony with these suckers, but came to the realization that some caps are audio grade, as are on the White Oak driver board. When should I worry about this?

I'm figuring that the power section (1000µ/50v x2, 47µ/35v x2, and 50µ/35v x3) really don't need "audio grade" caps since they deal mainly with the power to the unit, not really a signal path component.

I'm dealing with the PL 40 board on the bottom (it says "UDDER MUDDER" on it!) for now, will deal with the correlator and tone circuits later. I do notice some low level electron hiss, and expect that it's either related to capacitor or resistor value drift that comes with age.

Opinions, anyone?

I also see that some of the ICs in my 4000 are the same mentioned in this thread- looks like some of the edges of the epoxy are chipped. Hmmm... Suspicious...
Click to expand...
Right Mark, the power section should just have high quality, low ESR type caps put in those locations. If I recall correctly, there are NO op amps in the straight through path (if you defeat all the bells and whistles) on the PL4000, just discrete transistors. The op amps come into play if you enable the bells and whistles.
 
MarkWComer

MarkWComer

Veteran and General Yakker
#105
Joined
Nov 1, 2014
Messages
3,507
Location
Gaston, SC
Tagline
Victim of the record bug since age five
#105
Gepetto said:
Right Mark, the power section should just have high quality, low ESR type caps put in those locations. If I recall correctly, there are NO op amps in the straight through path (if you defeat all the bells and whistles) on the PL4000, just discrete transistors. The op amps come into play if you enable the bells and whistles.
Click to expand...
To clarify: Those 7 caps alone do not need to be audio grade, all others would benefit from being audio grade?
 
MarkWComer

MarkWComer

Veteran and General Yakker
#111
Joined
Nov 1, 2014
Messages
3,507
Location
Gaston, SC
Tagline
Victim of the record bug since age five
#111
Gepetto said:
If I recall correctly, there are NO op amps in the straight through path (if you defeat all the bells and whistles) on the PL4000, just discrete transistors. The op amps come into play if you enable the bells and whistles.
Click to expand...
78MG and 79MG in the PS cage, 2x 7904, MC3340, 3x 4739- two of these near the inputs have chipped epoxy. All of these are on "UDDER MUDDER" board, since this board directs signals to the daughtercards, they undoubtedly have some effect on signal (except for the ones in the power supply cage). Daughtercards look like centipede farms- loads of chips!

Gepetto said:
Benefit is a questionable term when it comes to the 4000 preamp Mark :)
Click to expand...
Like it or leave it, it's what I have. I know it has a bad rep and isn't the premier preamp, but this one works and the 3000 is lobotomized/epileptic.
So... Yea or nay on the other caps?
 
MarkWComer

MarkWComer

Veteran and General Yakker
#115
Joined
Nov 1, 2014
Messages
3,507
Location
Gaston, SC
Tagline
Victim of the record bug since age five
#115
laatsch55 said:
Mark....nothing to escalate Bud....we are what we are....no harm intended...
Click to expand...
I would have been the escalator (that didn't really sound right, did it?). The comment just hit on a thin spot of my skin- I realize it wasn't intended to insult. The PL4000 doesn't have a good rep and I knew it when I bought it- just anxious to hear the partially WOPL'd PL400 pump away, the PL3000 didn't work, and the Marantz phono stage sounded way too mushy. The 4000 doesn't sound awful, but I do detect room for improvement.

laatsch55 said:
Have you counted how many caps there are to replace in that unit?
Click to expand...
Primary concern for the time being is UDDER MUDDER- got 'em all accounted for, daughtercards will be done later. Yeah, there's lots of 'em scattered throughout, lots of electrolytics. I don't see any bulging or leaking on any of the others.

I think I'm just making busy work for myself, honestly.
 
laatsch55

laatsch55

Administrator,
Staff member
#116
Joined
Jan 14, 2011
Messages
74,914
Location
Gillette, Wyo.
Tagline
Halfbiass...Electron Herder and Backass Woof
#116
When I was gonna do a 4000 I think I counted 79 of em.....I think. IIRC, anything but the power supply had something to do with the signal so I went with audio grades everywhere. I replaced he axials with radials....
 
Gepetto

Gepetto

Administrator
Staff member
#118
Joined
May 15, 2011
Messages
14,042
Location
Sterling, MA
Tagline
Old 'Arn Enthusiast
#118
MarkWComer said:
78MG and 79MG in the PS cage, 2x 7904, MC3340, 3x 4739- two of these near the inputs have chipped epoxy. All of these are on "UDDER MUDDER" board, since this board directs signals to the daughtercards, they undoubtedly have some effect on signal (except for the ones in the power supply cage). Daughtercards look like centipede farms- loads of chips!



Like it or leave it, it's what I have. I know it has a bad rep and isn't the premier preamp, but this one works and the 3000 is lobotomized/epileptic.
So... Yea or nay on the other caps?
Click to expand...
Is yours a Series 2 Mark?
 
MarkWComer

MarkWComer

Veteran and General Yakker
#120
Joined
Nov 1, 2014
Messages
3,507
Location
Gaston, SC
Tagline
Victim of the record bug since age five
#120
Gepetto said:
Is yours a Series 2 Mark?
Click to expand...
Yes, series II. Was also looking at the Carver 4000 at the time but didn't want the ambient circuit with the internal amp. Wanted to play with sonic holography. The PL4000 was from original owner and wasn't scuffed or scraped up- looked damn pretty!
 
You must log in or register to reply here.
Top