releone71
Active Member
I agree. This is NOT my personal thread. This is the thread of all the PL enthusiasts
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Any Phase Linear Experts out there?
- Thread starter fdejong
- Start date
I agree. This is NOT my personal thread. This is the thread of all the PL enthusiasts
releone71
Active Member
Agree...:yes: In the forum I see several other threads like this one on other brands where the discussions go on and on through several arguments starting from the first post. Each post gives the cue for a different discussion, but always on PL gears after all...isn't it?:thmbsp:
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releone71
Active Member
P.L.F.
Active Member
Absolutely agree. This thread works fine. So far a lot of valuable input. In my comments to Waynedb I assumed new topic as possibly bringing more focus from a wider group of enthusiasts, that's all. Always as an option where he decides, not where it is decided for him... And to be clear - far from any 'crapping' perception either...
Tx
Hello everyone. First of all let me say that I am truly sorry for causing such an uproar in an otherwise peacefull thread. I have studied manuals, and read every tech bulletin that I can get my hands on, and I have decided that I can probably fix my amp, given the right amount of time and especially with the knowledge and backing of the fine minds of this forum. But with time restraints of work and family, and lack of proper equipment, I think I will pass for now. I honestly think by the time I buy the equipment I could probably afford to send this amp to a proffesional several times over. Maybe in a few years as my knowledge proggresses I will give it a go. For now I think my talents will be better suited working on my Phase 3 speakers that are in need of repair, while my amp is away at the shop.
In the mean time, and please try to be civil with your answers - I have one more question. I have seen multiple shops and people that will service a Phase 700 series 2, but who has sent an amp for repair, and who have you sent it to. Also, my dad still has his Phase 4000 Series 2 preamp, anyone know anybody who is good with these?
Thanks again to all who tried to help me, especially releone71 and P.L.F.
In the mean time, and please try to be civil with your answers - I have one more question. I have seen multiple shops and people that will service a Phase 700 series 2, but who has sent an amp for repair, and who have you sent it to. Also, my dad still has his Phase 4000 Series 2 preamp, anyone know anybody who is good with these?
Thanks again to all who tried to help me, especially releone71 and P.L.F.
laatsch55
Super Member
Wayne, YOU DID NOT CAUSE an uproar, i only referred to crapping as a very real possibility, not that I thought it was at the time . More like I was playing devils advocate.
My personal take on it was almost to a T as releone andPLF, the more the merrier.
As far as test gear, 44.00 dollars for a used Leader 2 trace scope, 37.00 for an eico tube type signal generator(circa 1959) sine and square wave, an 80.00 10 amp variac, and misc dim bulb tester. The bargains are out there, make yourself accessible to them and they will come. Looking forward to your journey in Fine, Fine musical reproduction.
My personal take on it was almost to a T as releone andPLF, the more the merrier.
As far as test gear, 44.00 dollars for a used Leader 2 trace scope, 37.00 for an eico tube type signal generator(circa 1959) sine and square wave, an 80.00 10 amp variac, and misc dim bulb tester. The bargains are out there, make yourself accessible to them and they will come. Looking forward to your journey in Fine, Fine musical reproduction.
P.L.F.
Active Member
Phase Linear 700 series II renovation
For repairs a good info here: http://www.audiokarma.org/forums/showthread.php?t=236890&highlight=Phase+Linear, see thread #10 on that page. I'd suggest a PM for instance to d3imlay.
P/L 4000 II pre-amp is a fine gear. I like its sound. Probably you only need to deox some switches, pots, RCA's and contacts on the main PCB, where pre-amp boards are plugged in. Recapping can be considered for same reasons as mentioned in thread #66 here.
Regards
Wayne,
For repairs a good info here: http://www.audiokarma.org/forums/showthread.php?t=236890&highlight=Phase+Linear, see thread #10 on that page. I'd suggest a PM for instance to d3imlay.
P/L 4000 II pre-amp is a fine gear. I like its sound. Probably you only need to deox some switches, pots, RCA's and contacts on the main PCB, where pre-amp boards are plugged in. Recapping can be considered for same reasons as mentioned in thread #66 here.
Regards
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releone71
Active Member
Nice drawing. It is useful for taking note of the NPN/PNP position in the respective rows between the heatsinks.
Good news today. This afternoon I received the parcel with the complete repairing kit. Attached is some picture of the kit and the power transistors, matched and separated per channel. The seller sent me a batch of 2009 ON SEMICON MJ21196G and a batch of 2010 MJ21195G. According to the explanation of the seller, NPNs are marked with a red + and PNPs with a black -. The devices marked with a big red dot on top are the transistors selected as drivers.
Note: the codes on the transistors seem to indicate they were produced between the end of December 2009 (21196) and the end of January 2010 (21195). I'm reporting these data as a support to a previous post by D3imlays, where he asserted it is difficult, with today's technology, to find in the same batch a device absolutely out of spec.
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kconnor
Well-Known Member
He's correct. Over the years I have tested thousands of transistors made by major semiconductor manufacturers, released and prototype. Tolerances for parameters like Vgs_th, BVdss, transconductance typically vary 1.5% or less. Now and again you will run across an oddball that is out of line with the others but still within spec. I've never found one that didn't meet the data sheet parameters.
It wouldn’t hurt to match devices or at least test them for consistency if you got the time or access to test equipment. I would kind of feel better about it if it were mine. Maybe that’s just because I’m old school. Is it absolutely necessary? Probably Not.
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P.L.F.
Active Member
Hi releone71,
Seems a solid basis for nice project to start! Power outputs are matched in the way mentioned here: http://www.audiokarma.org/forums/showthread.php?t=293316&highlight=Phase+Linear&page=3, post #33? Curious to read the supplier info on that...
By the way, will you go for silipads or mica insulators? Interesting article on the topic is on Elliott Sound: http://sound.westhost.com/heatsinks.htm#7.
Ciao
P.L.F.
Active Member
Phase Linear amp - matching power transistors
Hi kconnor,
How practically one can perform such matching? Any test circuit you have in mind? The P/L 700 II output transistors are operating at high current. Beta matching serves not much value if this test is done at low current, as usual approach - right?
I believe a similar discussion is here: http://www.audiokarma.org/forums/showthread.php?t=297332&page=2, e.g. post #16 from Don: [...] I check the voltage drop across emitter resistors to verify current sharing. [...] And see also previous remark from 2chanman, post #14, who's point was rather not to spend time on matching outputs these days, adding: [...] the low value emitter resistors (and in some cases, base resistors) connected to each output transistor tend to equalize current sharing. [...]
Your view?
Hi kconnor,
How practically one can perform such matching? Any test circuit you have in mind? The P/L 700 II output transistors are operating at high current. Beta matching serves not much value if this test is done at low current, as usual approach - right?
I believe a similar discussion is here: http://www.audiokarma.org/forums/showthread.php?t=297332&page=2, e.g. post #16 from Don: [...] I check the voltage drop across emitter resistors to verify current sharing. [...] And see also previous remark from 2chanman, post #14, who's point was rather not to spend time on matching outputs these days, adding: [...] the low value emitter resistors (and in some cases, base resistors) connected to each output transistor tend to equalize current sharing. [...]
Your view?
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releone71
Active Member
mmmmm...that post refers to the other guy (from California) on eBay selling a different output kit. He claims his kit will work at the best without the use of the usual capacitors to stop oscillations. I don't know if the seller I purchased my kit from matches the transistors the same way, but he probably pays a particular attention in matching the devices which have to work as drivers (checking for beta), the ones marked with a red dot on top in the picture.
Yes, I will go for silipads. Placing silipads is more practical than placing micas and with a PL 700 you have to repeat the operation 24 times!! Replacing the old devices is faster and you don't have to mess with the thermal compound. I have them in my upgraded Quads 303 and they work really good. Never had a problem:thmbsp:
P.L.F.
Active Member
Phase Linear 700 II - fully complementary output
NPN/PNP position? Here you go, sir
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NPN/PNP position? Here you go, sir
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releone71
Active Member
NPN/PNP position? Here you go, sir
:thmbsp:Very kind from you...and excellent job!!:tresbon:
P.L.F.
Active Member
A 'must read' thread for all who want to start P/L amp restoration: http://www.audiokarma.org/forums/showthread.php?t=43186. Compliments to EchoWars!
releone71
Active Member
:yes: only brand new sil-pads under my transistors...I don't really want to short them!!