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Thread: Phase Linear 700 ??

  1. #16
    Senior Member BMWCCA's Avatar
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    As long as everyone's just tossing about unsubstantiated opinions—and considering the original poster had been quite happy with his previous Crowns—let me add that I, too, am a happy Crown customer, have been for over 35 years, and still have the first one I ever bought in daily operation. Off the top of my head I believe I have nine Crown components. Any chance I get to buy quality made-in-USA items, I will do it! Believe me those opportunities don't come up very often these days: My last pair of Levi's® 501® jeans were made in Egypt!


    Though I will admit, Kiwi makes some damn fine shoe polish! Oh wait. That's made-in-USA, too.
    ". . . as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway."—Greg Timbers

  2. #17
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    - Every Phase Linear 700 I owned ( 3 in total ) dumped DC before they were rebuilt ( electrically & 2 mechanically ) .
    - I was lucky because my " magic-smoke mishaps" never burned the traces on the amps puny circuit board ( as was fairly common with severe amp failures ) .
    - Therefore, I never had to replace a charred pcb .

    - Those amps cost me muchos monies in recones for my Gauss 4882 eighteens ( working in W460 / W151 horn bins ) .
    - Muchos $$$ ( in Canada Dollars ) Muchos .

    - I never held a grudge against Bob Carver ( for his shortcomings in design/protection chops ) Hell, I still own 8 of his Carver 1.5 amps .

    - A Crown 300a was one of my first amps / it was quite underpowed for my usage .

    - I still have a single PL700 here on my bench awaiting a chassis rebuild .
    - I can't sell it since it's chassis is cracked & broken .
    - Being a conservationist at heart / I just can't bring myself to throw away things that might be resurrected into something useful .

    >< cheers

  3. #18
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    Quote Originally Posted by BMWCCA View Post
    As long as everyone's just tossing about unsubstantiated opinions—and considering the original poster had been quite happy with his previous Crowns—let me add that I, too, am a happy Crown customer, have been for over 35 years, and still have the first one I ever bought in daily operation. Off the top of my head I believe I have nine Crown components. Any chance I get to buy quality made-in-USA items, I will do it! Believe me those opportunities don't come up very often these days: My last pair of Levi's® 501® jeans were made in Egypt!


    Though I will admit, Kiwi makes some damn fine shoe polish! Oh wait. That's made-in-USA, too.
    Kiwi shoe polish was originally made in Australia by a Scotsman who named the product after his Kiwi wife. But you probably knew that, right? My unsubstantiated opinions seem to concur with the many and I have seen many Phase Linears go up in flames. I have also seen many a Crown with smoke emanating from it. Although I consider the Crown to be head and shoulders above the PL they are not even in the same ballpark as the 80's series amps from Perreaux.

    Allan.

  4. #19
    Senior Member BMWCCA's Avatar
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    Quote Originally Posted by Allanvh5150 View Post
    My unsubstantiated opinions seem to concur with the many and I have seen many Phase Linears go up in flames. I have also seen many a Crown with smoke emanating from it. Although I consider the Crown to be head and shoulders above the PL they are not even in the same ballpark as the 80's series amps from Perreaux.
    My point was not to dismiss Perreaux but to simply add to the anecdotal information supplied here. Unsubstantiated is what these opinions are and that's why we call them opinions. Call them "empirical" if you want. For a picture-perfect dictionary definition of "unsubstantiated" look no further than this claim made on the Perreaux website itself:
    In the entire history of Perreaux and after the sale of many thousands of units, warranty claims have been virtually nil.
    It's also easy to over-state power outputs. And that Perreaux model listed in your Ebay link as 700-watts is rated by the manufacturer at 200wpc @ 8-ohms. No one's denying that the 2105 is a good value at $500 and they've been trading at or around that number on Ebay for a while. I'd try one out if there was one near me. I love New Zealand, understand your patriotic support of its products, and hope to visit some day!

    Anyone have a Perreaux they want to put in the next Mid-Atlantic JBL speaker shootout? All I can tell you is I have two PS-400 Crowns I spent a total of $300 for that sound and work great with my L7s, L5s, L96, and L80Ts. Currently my 4345s are running bi-amped with a Crown D150A-II I bought when it was one-year-old, and a DC300A-II I bought out of a movie theater renovation on Ebay probably ten years ago. Sounds great to me, but then that, too, is simply empirical evidence. I know there are many here running Crowns and I don't recall any flame-out stories. We run MacroTechs all day and night long, outside in the heat of summer, pushing 1 and 2-ohm loads and in ten years nary a complaint. I feel comfortable relying on Crowns to pull easy duty in my home systems. My 030's have had nothing but Crown power put to them since 1973. I'm a satisfied customer. My neighbor, on the other hand, is the original owner of both a Phase Linear 400-II and a Phase Linear pre-amp, both sitting on his work bench, both in failure mode. :dont-know
    ". . . as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway."—Greg Timbers

  5. #20
    Senior Member SEAWOLF97's Avatar
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    My engineer friend in Sydney was telling me about a Perreaux / BGW connection ...I cant remember if it was a shared design or not , email is gone,,,mebbe I'll ask him again.
    Have also heard that BGW made the big amps for Bose

    I know they are highly sought after in Oz, and
    there is a reason why they were all over Vegas , Hollywood and the White House

    BGW Timeline
    • 1971 - Started production in a garage.
    • First product the Model 1000 Laboratory Power Amplifier introduced the following new concepts to the industry:
      1. Modular Construction
      2. DC Speaker protection
      3. Magnetic circuit breaker mains protection
      4. Low impedance operation

      5. 1974 - Selected by Universal Studios to supply amplifiers for the Sensurround Systems for the movie Earthquake; Introduced Model 750A and 500D - Proves very successful with 500D replacing Crown DC300 as the new Industry Standard



    http://www.bgw.com/about/bgw_timeline.asp
    nowadays SeaWolf can't even sing ...

  6. #21
    Administrator Mr. Widget's Avatar
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    Quote Originally Posted by SEAWOLF97 View Post
    1974 - Selected by Universal Studios to supply amplifiers for the Sensurround Systems for the movie Earthquake; Introduced Model 750A and 500D - Proves very successful with 500D replacing Crown DC300 as the new Industry Standard
    I remember BGW as being a highly regarded line back then, but I wouldn't use the Sensurround System as a recommendation for anything other than loud distortion.

    Don't know much about the Phase Linear 700, but I did briefly own a 400... was suckered by those big sexy meters... I was not impressed with the sound of the amp at all.


    Widget

  7. #22
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    Phil,

    I have 3 Perreaux amps, want to have the shoot out at my place

    From the 80's (2) 6000B and (1) 3000B

    Mark
    Think center channel for 250TIs; (2) 108s, a 104 and a 44ti, now what?

  8. #23
    Senior Member BMWCCA's Avatar
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    Quote Originally Posted by opimax View Post
    I have 3 Perreaux amps, want to have the shoot out at my place
    Yeah boy. This is sounding like more reasons to have too much fun! Are your L250/250Ti's back together? I know we talked about 10" and under for speakers, but if we're gonna compare amps, we really should do that with something big. And I can always find an excuse to drag a spare pair of L7s for comparison, again. I can cover 2x Crown 200-wpc amps and one Soundcraftsmen 200-wpc (both @ 8-ohms), and about as many 100-wpc as you can count on one hand. Guess we need to find someone with a BGW, too. No Phase Linears on my speakers, please!!

    We can always play the AFLAC commercial on Heather's new Daffy Lips.
    ". . . as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway."—Greg Timbers

  9. #24
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    response in this thread on forum announcements

    2nd east coast LHS social event

    BTW , no one complained about off topic but I started a new thread
    Think center channel for 250TIs; (2) 108s, a 104 and a 44ti, now what?

  10. #25
    RIP 2010 scott fitlin's Avatar
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    Quote Originally Posted by robertbartsch View Post
    Wow - great story!

    How do you think the 2225 dust cap shot off? Was the VC so hot that it melted the cap glue before it burst into flames? The driver is rear vented; right?

    So the amp was dumping DC into the loads?
    The glue melted, the pressure was too much for the rear vent, and forced the dustcap forward.

    PL 700,s were known for dumping DC, ESPECIALLY when overdriving them hard, which is what guys used to do! Like I said, PL protection circuitry will let you drive the amp as hard as you want to, putting out up to twice it's rated power, but this power is contaminated with severe distortion. And DC when the amp fails.

    For one reason or another, I LOVE the sound of Crown! I have tried, and own MANY BRANDS OF DIFFERENT THINGS, I always come back to crown. Crown has been the most reliable amp for me over the years, and i have had amps fail in use, always uneventfully. Leaving my loads intact and unhurt. THIS is a GOOD thing.

    scottyj

  11. #26
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    I really like the Crown DC300 series, good! sound, very dependable, and reasonably priced. Of course there are sonically better audiophile power amps, but they will cost many many times what you can get a clean DC300 for.

  12. #27
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    Quote Originally Posted by BMWCCA View Post
    It's also easy to over-state power outputs. And that Perreaux model listed in your Ebay link as 700-watts is rated by the manufacturer at 200wpc @ 8-ohms.
    Just FYI, The PMF series amps were seriously underated for some reason. Although I have never been offered an explanation from the factory I do know this to be true. As an example the PMF 1050 is rated at 100W into 8 ohms, the 3000B is rated at 180W into 8 ohms. The power supply and the circuit are identical. I have always been pleasently surprised when I put one of these amps on the scope. They are often looked over as dinosaurs but they reprodece audio very nicely. There is no protection circuitry whatsoever and the componant count is very small. Disregarding the output devices there are only 5 other transistors in the whole circuit. Very simplistic, the circuit was very similar to the guidelines setout bu Hitachi in the original mosfet data.

    Allan.

  13. #28
    Senior Member BMWCCA's Avatar
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    Quote Originally Posted by midlife View Post
    I really like the Crown DC300 series, good! sound, very dependable, and reasonably priced.
    I know it's not a quantum leap in age or sophistication, but if I were you I'd be looking for a Series-II DC300A or (better yet) a PS-400. All the good stuff you loved but better protection and some more modern features, like (in the PS-series) turn-on delay. But that's just me!
    ". . . as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway."—Greg Timbers

  14. #29
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    Quote Originally Posted by BMWCCA View Post
    I know it's not a quantum leap in age or sophistication, but if I were you I'd be looking for a Series-II DC300A or (better yet) a PS-400. All the good stuff you loved but better protection and some more modern features, like (in the PS-series) turn-on delay. But that's just me!
    I second the motion,

  15. #30
    Senior Member Ian Mackenzie's Avatar
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    On the PL 700 thing I have some experience.

    We ran a 700B (brand new not Ebay crap) for 15 years without any issues swinging -3 db into 2231As without any speaker damage. We then ran dual 2235Hs a side without any problems for extended periods in a pro rack with a large fan.

    The only failure we experienced was user error when the pre /mixer power was accidentally turned off before the power amp.

    Semiconductors do breakdown over time and the output stage (like any pro amp) must be replaced with the right devices by a qualified tech and this amp has had that service once in the past 30 years.

    The chassis were originally sheet aluminum and unless they were properly braced that lead to relaibility issues. Same goes for heat. People would also run them without a solid mains supply and that is asking for trouble.

    I then ran a Clair Bros 700B series 2 for 10 years (steel chassis) that was previously used exclusively by Jands for Clair Bros S4 boxes in dozens of racks for massive S4 arrays. They were the only amp ever specified for those systems at the time and I think Clair Bros know what they were doing.

    If you buy off Ebay expect problems. We have seen this time and time again around here.

    As to Perreaux they were legendary in the Pro Scene in the 80-90's and are used by Studios world wide.

    Aust Monitor's K2 was another serious contendor but not by current day standards.

    I am not sure why people want to have a yabba fest over such old amps when the the dollar per watt has come down so much over the past 10 years. It makes no sense to buy an amp on Ebay



    As to the original question you can safely drive them into 4 ohms but refer to the manual regards the line fuses and run a fan on the heatsinks. They are optimised for 8 ohms however as that is where they are most efficient.

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