PL 700B Question

88Z52

88Z52

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Worlds foremost vinyl hater.
I listened to a Phase Linear 700B through a set of Infinity Monitors and was pretty darn impressed. I think I want one.

Doing a little research it seems PL's can die for no reason and take everything with them. :confused1:

Couple of questions for anyone who might know.....
1. Do they really just die for no reason and destroy the world? I find that a little hard to believe, it would seem PL would have never gotten a UL approval for something that would catch on fire or destroy itself for no reason if used correctly. Were they UL or ETL approved?

2. If question 1 = true, I see a lot of upgrades available that claim to resolve the safety issues and enhance the amps performance. If anyone out there has done this I would be interested in knowing what upgrades are necessary and how much would it cost?

On the amp I heard the owner said that other than having a few of the power transistors replaced (and there was no other damage), the amp was all original and he is the original owner. It's been around over 40 years. Apparently there are quite a few of them still working. Why the bad rap?
 
They did not have a DC protect circuit so when an output died or something went south on the driver board could find it's way to the speaker outputs. Then the speakers could fry. The amps themselves would not ignite, but the speakers could.

Check the WOPL Building section to see what we are doing to these amps now. They'll stand with some of the best amps made now.
 
laatsch55 said:
They did not have a DC protect circuit so when an output died or something went south on the driver board could find it's way to the speaker outputs. Then the speakers could fry. The amps themselves would not ignite, but the speakers could.

Check the WOPL Building section to see what we are doing to these amps now. They'll stand with some of the best amps made now.
Click to expand...

I was meaning to ask in the first post.... I keep seeing that. What is WOPL?
 
A "White Oaked Phase Linear"...what we call a PL after all the White Oak Audio upgrades have been done...
 
88Z52 said:
I was meaning to ask in the first post.... I keep seeing that. What is WOPL?
Click to expand...

The 700B I have was 16 years old when I got it in 1990 and it had been in some kind of studio. I wanted it for band PA. In that time it took out a PA speaker and one bank of output transistors 2 or 3 times. It was functional when it went into my closet for a few years and when I hauled it out again, failed, got improper repaired, failed once more and back to the closet. After a couple of years, I discovered this site and with much coaching from Lee and others (to the tune of 400+ posts on my end) proceeded to rebuild it. A short that refused to be identified, prompted intervention and a suggested White Oak conversion was performed. When functioning in stock form, it was a great sounding amp but nothing like now. I have a couple of well regarded preamps, not expensive but good ones, and this revamped 700B revealed their faults in all their glory. I'm still working on that. Maybe a White Oaked Phase Linear is too good?
 
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88Z52,

You've come to the right place to learn about a WOPL. Why don't you pop into introductions and give us some ammo to work with (current system/expectations)? Seriously, we don't want to steer you into something you may not be ready for, not all speakers can handle a WOPL.

I am not WOPL'd (yet). Took about a year lurking here to decide what I wanted. No, I have not even heard a WOPL (yet). Basing what I'm going to do with my PL400 on the expertise and professionals reviews from the fine folks here at Phoenix. We have a lot of professional musicians here and they seem to be blown away with a WOPL's sound/output.

Stick around, hear what others are saying and ask questions. BTW - Welcome to Phoenix. Not gonna find a nicer bunch of guys willing to help.
 
Fishoz said:
88Z52,

You've come to the right place to learn about a WOPL. Why don't you pop into introductions and give us some ammo to work with (current system/expectations)? Seriously, we don't want to steer you into something you may not be ready for, not all speakers can handle a WOPL.

I am not WOPL'd (yet). Took about a year lurking here to decide what I wanted. No, I have not even heard a WOPL (yet). Basing what I'm going to do with my PL400 on the expertise and professionals reviews from the fine folks here at Phoenix. We have a lot of professional musicians here and they seem to be blown away with a WOPL's sound/output.

Stick around, hear what others are saying and ask questions. BTW - Welcome to Phoenix. Not gonna find a nicer bunch of guys willing to help.
Click to expand...

Hi Fishoz!

Besides having the best avatar here (my favorite brew) you might be who I need to talk to....

I recently heard a stock PL 700B and really liked it. There are a lot of folks here who really seem to like the WO upgrades so they must be pretty good but in all honesty I really liked the stock unit. My speakers are very efficient so I don't need a lot of watts. I liked the punchy sound and clarity of the amp. Was nice!

What I am interested in is NOT having the amp destroy my speakers. How do you protect yours or do you?
Most of the articles I read about them failing usually involved someone doing something they probably shouldn't have been. The 700B I heard was stock and probably 40 years old. No one ever did anything crazy with it and it's fine.
It was barely warm at normal levels.

The owner of the amp made a interesting comment when I asked him about all the bad press... He said "They are like the original 427 Shelby Cobra. To much power and whoever could afford one could have one but that didn't mean they knew what they were doing. As a result most of them were crashed." He went on to say "To many self proclaimed "audiophiles" burned them up and blamed the amps."

Sounded legit to me. :iconbiggrin:
 
You are exactly where I was when I came to this forum. I love the sound of my PL400 but heard all the "flame linear" stories as you did.

I cringed thinking of what could happen to my beloved 808's if the PL went awry. Have since found that my 808's have their own protection built in but that did not relieve my worries. Now, as in the case of most vintage collectors, I only ask - what could possibly be better? The answer, as I've seen this past year, is a WOPL!

My PL400 is being taken down tonite for a roadtrip west. Another WOPL review will be forthcoming after the July 4th weekend if all goes right.


Do I know if I will be satisfied? Don't know for sure, but I would rather play with spending money on a WOPL than $5000+ for a Mcintosh or other amp that boasts the same power and quality.

I am not a tech person, I only know what I like to hear. Improving what is good sounds like a win to me!!!
 
BTW - my avatar good??? You haven't seen Nav's yet!

Hit the info thread and Nav will send you one of his babes.


Whoa.....shit, just noticed, hit 1000 posts!!!!!
 
88Z52 said:
Hi Fishoz!

Besides having the best avatar here (my favorite brew) you might be who I need to talk to....

I recently heard a stock PL 700B and really liked it. There are a lot of folks here who really seem to like the WO upgrades so they must be pretty good but in all honesty I really liked the stock unit. My speakers are very efficient so I don't need a lot of watts. I liked the punchy sound and clarity of the amp. Was nice!

What I am interested in is NOT having the amp destroy my speakers. How do you protect yours or do you?
Most of the articles I read about them failing usually involved someone doing something they probably shouldn't have been. The 700B I heard was stock and probably 40 years old. No one ever did anything crazy with it and it's fine.
It was barely warm at normal levels.

The owner of the amp made a interesting comment when I asked him about all the bad press... He said "They are like the original 427 Shelby Cobra. To much power and whoever could afford one could have one but that didn't mean they knew what they were doing. As a result most of them were crashed." He went on to say "To many self proclaimed "audiophiles" burned them up and blamed the amps."

Sounded legit to me. :iconbiggrin:
Click to expand...

You should be seeing something from one or more of the administrators shortly.

When I mentioned mine taking out a PA speaker and a bank of outputs on more that one occasion, there was no misuse or modification.
 
62vauxhall said:
You should be seeing something from one or more of the administrators shortly.

When I mentioned mine taking out a PA speaker and a bank of outputs on more that one occasion, there was no misuse or modification.
Click to expand...

There are enough stories to make me believe they can go South with no notice but its easy enough to find other brands of amps that have done it too.

A lot of people used them for everything because they could. They certainly have the power and people wanted the PL sound. It was my understanding they were designed to be for home audio use.

Are some of these issues due to age or has this been going on since they were new? They are almost 50 years old... One should expect some trouble.
 
88Z52 said:
There are enough stories to make me believe they can go South with no notice but its easy enough to find other brands of amps that have done it too.

A lot of people used them for everything because they could. They certainly have the power and people wanted the PL sound. It was my understanding they were designed to be for home audio use.

Are some of these issues due to age or has this been going on since they were new? They are almost 50 years old... One should expect some trouble.
Click to expand...

The consumer market would certainly have been the largest one to target when it was introduced. But it was a benchmark amplifier so was soon adopted into a lot of professional applications. You will find threads here referring to Phase Linear stage amplification used by at least Pink Floyd & Aerosmith but there were many more. Could be wrong, but I think The Who used it as well.

I've learned far more in a year on this forum about it's idiosyncrasies than during almost 30 years in the HiFi business. Certain conditions can arise internally within the amplifier that can deliver ~100 volts to a speaker. Could be wrong, but I think that was due to limitations of the component parts available when the amp was designed. Lee or Joe would be a whole lot more enlightening than me.
 
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62vauxhall said:
The consumer market would certainly have been the largest one to target when it was introduced. But it was a benchmark amplifier so was soon adopted into a lot of professional applications. You will find threads here referring to Phase Linear stage amplification used by at least Pink Floyd & Aerosmith but there were many more. Could be wrong, but I think The Who used it as well.

I've learned far more in a year on this forum about it's idiosyncrasies than during almost 30 years in the HiFi business. Certain conditions can arise internally within the amplifier that can deliver ~100 volts to a speaker. Could be wrong, but I think that was due to limitations of the component parts available when the amp was designed. Lee or Joe would be a whole lot more enlightening than me.
Click to expand...

Thanks 62vauxhall,

All input is appreciated and encouraged here. I'm trying to learn a little before I jump in.
 
Read through a few of the WOPL build threads. I test and post the results of each amp built. The only thing they have in common after a complete White Oaking is the faceplate, meters and transformer, the rest is brand new, Joe even has new chassis availasble..
 
Fishoz said:
You are exactly where I was when I came to this forum. I love the sound of my PL400 but heard all the "flame linear" stories as you did.

I cringed thinking of what could happen to my beloved 808's if the PL went awry. Have since found that my 808's have their own protection built in but that did not relieve my worries. Now, as in the case of most vintage collectors, I only ask - what could possibly be better? The answer, as I've seen this past year, is a WOPL!

My PL400 is being taken down tonite for a roadtrip west. Another WOPL review will be forthcoming after the July 4th weekend if all goes right.


Do I know if I will be satisfied? Don't know for sure, but I would rather play with spending money on a WOPL than $5000+ for a Mcintosh or other amp that boasts the same power and quality.

I am not a tech person, I only know what I like to hear. Improving what is good sounds like a win to me!!!
Click to expand...


You are fixin to get WOPL'D/K'd as soon as you get here....
 
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