Any Phase Linear Experts out there?

Mouser has a bunch of different 1N4004 diodes. Any manufacturer or variant preferred over the others?
 
callab_gte_net said:
The service bulletin which was issued 10-81 concerning the "revision of model 700II and 400II from quasi-complimentary to full complimentary output stages" has some errors in the schematics. Including the D107 and D108 on the 700 II's and D108 and D109 on the 400 II's. These (1N4004) diodes do not exist on any fully complimentary 400 II or 700II amplifier I have ever seen including the PRO 700's and I have worked on quite a few of them. But then again one never really knows until they see every single fully comp 400II and 700II amp that Phase Linear ever made. So I could be proven wrong. The fully comp 700II's started with serial number 7A10701 around January 1981 and continued with the PRO700's.

I have also converted quite a few quasi-comp amps to fully comp. In the mid 1990's when I began converting amps over to a fully comp output I always had a fully comp amp sitting next to a quasi comp amp when I did the conversion to compare to. I have done it so many times now that I can do it from memory. I have told a number of people over the years that you shouldn't try converting an amp over to a fully comp output using these schematics alone or you might make some mistakes.

As to why these diodes were removed on the fully comp amps, I don't know why...I will have to ask Dean Nissen tomorrow. If he can't provide me with an answer perhaps Terry Pennington who did a lot of the design work on these amplifiers could.

By the way, there is a simple modification Dean showed me a few years ago that dramatically reduces the total harmonic distortion to levels as low as that of the 300 II. If my memory serves me correct it is in relocating C106 and C206. If you compare the Phase Linear 300II schematic with the 400II and 700II PL-36 pc board schematic you may be able to figure out where the capacitor locations are different. The (rare) PRO700 schematic I believe has this illustrated. The PRO 700 pc boards I have seen were drilled with an extra set of holes next to the 40412V1 transistor for relocating this capacitor.
Click to expand...
Hi

Have you ever converted a marantz 1120?

Thanks
Robin
 
P.L.F. said:
Thank you Don,
Good to know! From the moment I once discovered a solid paper-clip instead of the right fuse can expect virtually anything in the socket… I guess in Europe ANSI fuse standards are not that common, which may lead owners to ‘unlimited fantasy’ sometimes.
Regards
Click to expand...

I had a really funny experience with this once, a buddy came over with his car stereo that would severely distort any where above the 1/4 vol. I noticed the power at the amp would drop way low every time a loud note tried to be played. After opening the hood I asked when he got the nifty light under the hood that pulsed with the music. Turns out he put a dome light bulb in place of his 40 amp in line fuse. I know this wasn't phase linear but definitely fuse related lol.
 
Hey all you helpful phase linear users out there. I recently was givena PL400 s1 that's in absolutely perfect condition inside and out, it also came with a box with a set of new outputs, driver transistors, strip of diodes and all the little tin can style transistors on the drive board. I ordered a DC protection board from ebay (the one with the 30amp audio quality relays) because smoking my speakers isn't something I want to do lol. My question is about getting the 12-19vdc needed to power the DC protection board. Is there somewhere inside my amp I can tap into or do I need to install a separate psu to supply the 12-19v??? I wanted to get the board from watts abundant but after several emails over the past ~2 months I wasn't able to get a reply, so now I've already mounted the one from ebay and everything is hooked up except for the power. Any advice would be greatly appreciated and I'd love you forever. Thank you.
 
Awhile waiting for someone who has actually tried it II would be looking for a wallwart which puts out 12-15 VAC. Or you can use an ordinary transformer. I don't see any simple way of tapping, other than a couple of dropping resistors on one of the ~60 VAC secondaries,. The Lamps are 6V so that route leads nowhere. Good luck.
 
P.L.F. said:
PL 700 II full complementary outpu repairs - cont.

Back to the project after 6-week break...

Current status:
- PL36 driver board works fine, all issues resolved - it allowed to put drivers in.
- Driver stage works fine
- All outputs in and final stage work fine – DC Offset readings around 2mV, the amp powered at the nominal PS voltage.
Still problems with signal flaw input->output – tracing in progress.

Some lessons for forum members as part of their own DIY repair projects are attached here in PDF – might be useful as rather not fully documented in PL700II service manual (many tx to THD+N!).

However the main issue for my amp, after stabilizing the driver board functioning, I think was a poor contact inside TO-3 sockets causing fault resistance for the power transistors leads.
Click to expand...


I Have the same Problems, So what fixed it? you have a big gag in time and Parts you replaced and a lot of steps which are unknown. thanks if you are still on the forum?
Also the Input RCA Resistor to ground , in my amp 700 II it is not install for both channels (R105 220k) is this a problem?
Thanks
 
Last edited:
P.L.F. said:
PL36 wiring & marking - fully comp. output stage
I think, cracked it... It is apparently undocumented PCB version of PL36 designed for fully complementary output - have a look at the pictures attached (specially #3). There are two key points that seem to be different:
- factory embedded solution to cure possible oscillations at NPN/PNP predriver stage (cer.cap C->B)
- new wire: pre-driver C -> output common C.
Worth to mark it on the schematic - I leave it for a volunteer :)..
Inspection will be continued...
Cheers
Click to expand...

Did anybody find or make a drawing of the 4-Capitors and their jumpers ?
My full comp 700 II does not have the caps and the board looks a little different than this one which might be a newer one?
Thanks
 

Attachments

  • 4-cap.jpg
    4-cap.jpg
    105.4 KB · Views: 16
The caps are slow down caps from base to collector to stop oscillations. The driver board is the full comp (latest) version. Latest = 1981
 
Thats the better constructed board too, the older ones were a phenolic board that were a bit prone to heat damage and lifted traces. My Pro 700 has that same light tan board. The earlier PL-36 board I worked with also had a lot of carbon comp resistors that were way off value, the light tan board has carbon film resistors that hold up better.
 
d3imlay said:
The caps are slow down caps from base to collector to stop oscillations. The driver board is the full comp (latest) version. Latest = 1981
Click to expand...
Thanks
Do you know the Valve of the Caps?
Same as the 400 II full comp , same values?
 
Last edited:
You must log in or register to reply here.

Similar threads

wirewood
phase linear 400 II
Replies
2
Views
829
Brad Muller
Brad Muller
S
phase linear parametric equalizer
Replies
2
Views
987
stereograph
S
MoneyBird
Carver Phase Linear 400... Any Infor Anyone?
Replies
13
Views
677
gadget73
gadget73
B
Any Phase linear 2000 fans out there?
Replies
6
Views
1K
blackthorne
B
SpeakerLabFan
More Carver / Phase Linear gear
Replies
5
Views
6K
SpeakerLabFan
SpeakerLabFan
Back
Top Bottom