Topic: Repair or replace 1976 Phase Linear 400 amp?

[bootray]

My 1976 PL 400 had some output transistors and caps replaced a few years ago
and I have been happy. Recently an unpleasant sound and smell was emitted from the 400 indicating another trip to the shop for caps and transistors. Soon it will be 
totaly restored, but at what price? I already dumped $200 in it, and the unit is only
worth around $400. I am currently using the 400 to power my MG2 pans, along
with a 1966 Marantz 7T Preamp, Rega 2.5 w/Dynavector 10x5. Not super high end
gear but very nice sound.
The pans are power hungry and a pal suggested that I consider a high power
sound reinforcement amp like a used Crest or Crown. He says design
improvements make these   amps as clean and transparent as the used audiophile
amps at Audiogon. Is this true?
I have a limited budget of around $500.
High power transistor amps are not cheap, even used, on Audiogon and 4-600
watt models are scarce. I seem to remember a high watt Audio Research
transistor amp from 30 years ago. I am hard pressed to think of good options.
Many of you have audiophile knowledge here and I trust your opinions.
Suggestions please? Thanks for your time...
Ray

[cshepherd]

I'm sure your friend means well, but Crest and Crown amps aren't what you're looking for.  400-600 watts just aren't necessary in a house.   Magnepans are 5 ohm loads and they need a little juice, but 100-150 watts is plenty.  I think you'd be better off selling your pre amp and buying a higher quality integrated (like a Musical Fidelity or a McIntosh) and avoiding the pro audio market.  I know the MF amps have built in phono stages sufficient for your high output MC cart.

Good luck,
Chris

[boojum]

It seems we always disagree opn something.     OK, I run two hafler 500's mono-bridged to put out ~1,200 watts into 4 ohms steady.  I drive SoundLab Pristines, KEF 104/2's and a pair of AR2ax's with them.  The Pristines suck up a lot, the KEF's can handle it and sometimes (Funkytown) cause the amps to overheat and go into cool-down mode.  This is an extreme case.  In the '39 Worlds Fair Western Electric tested a lot of audio - developed the Fletcher-Munson curve as a part of it - and determined that 80 watts was necessary to faithfully reproduce solo piano.  And that was when speakers were pretty efficient. 

I like a lot of headroom.  I do not always bend the walls with playing it too loud, in fact I do that very rarely.  But I am assured of ample headroom for anything.  So, it is a difference of opinion.  My solution for you: listen to various setups.  Try out the two or three at home you really like and see what works the best.  It is like picking mics for a venue: some work better than others.  And buy a little more quality than you can afford.  You won't regret it.

[cshepherd]

Well, we both own Sound Labs.  That's a start   .  There was a set of mid-80's Maggies in our family for a number of years.  I would rather power them with 100 watts that cost $5 per watt than 500 watts that cost $1 per watt.

Chris

[tiberiusbkirk]

wow, this is the first forum I've been in where there's two
members who have Sound Labs speakers.
Both my brother and BIL has them, driven by Krell KSA 250's.
Is there a team Sound Lab or something?

[guysonic]

There were many owners of Phase Linear power amps (sometimes called 'Flame' Linear) that swear by them for exceptional good sounding powerful operation (BUT also known to frequently 'swear at them' for burning up). 

Good advice to look for more stable modern power amp not requiring you to keep you fingers crossed and a ready fire extinguisher.

[boojum]

Well, we both own Sound Labs.  That's a start   .  There was a set of mid-80's Maggies in our family for a number of years.  I would rather power them with 100 watts that cost $5 per watt than 500 watts that cost $1 per watt.

Chris

You wouldn't happen to be selling the "100 watts that cost $5 a watt would you?"      Other than that I do not see your point. Unless it is to get less bang for your buck.  I own SoundLabs, KEF 104/5's, AR2ax's and a pair of small Paradigms.  They all have their virtues.  The SL's are the finest sounding speakers I have ever heard.  I am sending them back to get re-voiced (new upgraded diaphragms).  I love 'em.

[Frank in JC]

Other than that I do not see your point.

Watts are not created equally.

[boojum]

Quality was not a parameter.  The statement was: "I would rather power them with 100 watts that cost $5 per watt than 500 watts that cost $1 per watt."   The differences are minimal at best and illusory at worst.  When the amps can be distinguished as "better" and "worse" in a double-blind test then I will accept with ease that one is better than the other.  Until then it is no more than very subjective opinion.   

[Frank in JC]

Quality was not a parameter.  The statement was: "I would rather power them with 100 watts that cost $5 per watt than 500 watts that cost $1 per watt."   The differences are minimal at best and illusory at worst.  When the amps can be distinguished as "better" and "worse" in a double-blind test then I will accept with ease that one is better than the other.  Until then it is no more than very subjective opinion.   

Sorry, I didn't realize you're a DBT'er.  I understand now 

[Church-Audio]

My 1976 PL 400 had some output transistors and caps replaced a few years ago
and I have been happy. Recently an unpleasant sound and smell was emitted from the 400 indicating another trip to the shop for caps and transistors. Soon it will be 
totaly restored, but at what price? I already dumped $200 in it, and the unit is only
worth around $400. I am currently using the 400 to power my MG2 pans, along
with a 1966 Marantz 7T Preamp, Rega 2.5 w/Dynavector 10x5. Not super high end
gear but very nice sound.
The pans are power hungry and a pal suggested that I consider a high power
sound reinforcement amp like a used Crest or Crown. He says design
improvements make these   amps as clean and transparent as the used audiophile
amps at Audiogon. Is this true?
I have a limited budget of around $500.
High power transistor amps are not cheap, even used, on Audiogon and 4-600
watt models are scarce. I seem to remember a high watt Audio Research
transistor amp from 30 years ago. I am hard pressed to think of good options.
Many of you have audiophile knowledge here and I trust your opinions.
Suggestions please? Thanks for your time...
Ray

I would get a Bryston 4b and be done with it IMO its one of the best power amps ever made. And the 25 year warranty ain't to bad ether.. Some here say stay away from the pro market.. I strongly disagree! Check out Bryston..

Chris

[boojum]

Quality was not a parameter.  The statement was: "I would rather power them with 100 watts that cost $5 per watt than 500 watts that cost $1 per watt."   The differences are minimal at best and illusory at worst.  When the amps can be distinguished as "better" and "worse" in a double-blind test then I will accept with ease that one is better than the other.  Until then it is no more than very subjective opinion.   

Sorry, I didn't realize you're a DBT'er.  I understand now 

Yes, it is hard to argue with facts.  Subjective impressions are valued nowhere as highly as in the world of high-end audio.  And testing, which is accepted in every scientific and engineering arena, is decried in high-end audio.  There has to be a reason that facts are rejected.   

[guysonic]

Quality was not a parameter.  The statement was: "I would rather power them with 100 watts that cost $5 per watt than 500 watts that cost $1 per watt."   The differences are minimal at best and illusory at worst.  When the amps can be distinguished as "better" and "worse" in a double-blind test then I will accept with ease that one is better than the other.  Until then it is no more than very subjective opinion.   

Audible differences between amps with nearly identical specifications do occur for a few reasons.

One is because different types of speakers present very unique complex (NOT simple passive resistive) loads to an amps output making driving clean sounding audio and/or surviving without output stage burnout a design challenge.

[boojum]

In a double-blind test all would be the same but the item being tested.  In this case the amps.  Stereo Review ran a "DBT" at a show years ago.  All attendees were invited to participate.  Hands down a cheap receiver beat out an expensive Levinson dual-mono stereo package.  Just another reason that high-end audio hates DBT.  As usual, YMMV     

[guysonic]

In a double-blind test all would be the same but the item being tested.  In this case the amps.  Stereo Review ran a "DBT" at a show years ago.  All attendees were invited to participate.  Hands down a cheap receiver beat out an expensive Levinson dual-mono stereo package.  Just another reason that high-end audio hates DBT.  As usual, YMMV     

Hard to believe, AND likely not really true rumor-tech stuff anyway.  Don't you just HATE getting the 'conclusive results' without the glory details making all the difference for chance of knowing truths of the matter. 

In this case. and if being shocked to attention by out-of-technical-context claims, think better to have ability to drill a little deeper knowing the magazine issue and full testing setup details.  Otherwise to me, just another unsubstantiated rumor holding only limited truth for normal user expectations and working conditions.

[Church-Audio]

In a double-blind test all would be the same but the item being tested.  In this case the amps.  Stereo Review ran a "DBT" at a show years ago.  All attendees were invited to participate.  Hands down a cheap receiver beat out an expensive Levinson dual-mono stereo package.  Just another reason that high-end audio hates DBT.  As usual, YMMV     

Hard to believe, AND likely not really true rumor-tech stuff anyway.  Don't you just HATE getting the 'conclusive results' without the glory details making all the difference for chance of knowing truths of the matter. 

In this case. and if being shocked to attention by out-of-technical-context claims, think better to have ability to drill a little deeper knowing the magazine issue and full testing setup details.  Otherwise to me, just another unsubstantiated rumor holding only limited truth for normal user expectations and working conditions.

There is always more to gear then just technical specs.. There is how it actually sounds most of this audiophile bullshit does not sound like anything. And when you ask the so called audiophiles to quantify the actual performance of a peace of gear they use fancy words like sound stage and blackness seem to be the "buzz words" Few of them really have a clue. Most of them would fail miserably any double blind test. If more of us would buy with our ears instead of tech specs then most of us would be listening to much cheaper audio gear then we presently own.. And there would be no need for magic sound crystals or magic AC wall plates... Or fancy Silver Ac cable to connect our power amps too. But to each there own.

[Stagger]

Well, we both own Sound Labs.  That's a start   .  There was a set of mid-80's Maggies in our family for a number of years.  I would rather power them with 100 watts that cost $5 per watt than 500 watts that cost $1 per watt.

Chris

There is an old saying, "If the first watt sounds like crap, why do you want 499 more of them?" I subscribe to this theory myself. My amp puts out right around 65 watts with KT88 tubes in ultralinear mode. Hardly a high powered amp but it sounds great. I have compared it to a number of higher powered (and priced) solid state amps including Conrad Johnson, Threshold, and a Krell integrated but none of them had the sweet mid range and grain free upper registers that I found pleasing to the ear. While Maggies and stats do require more juice than my SF's I still think Chris' advice is valid. Pro gear is designed to fill large spaces at high volume. Accuracy, low THD, and tonal balance are typically secondary considerations on lower to mid priced pro audio amps. I liken it to seeing people driving Hummers in the city. You can do it but it simply is not designed for that use as it is overkill in some areas (in this case off road suspension and power) and lacking in other areas (fuel efficiency, ride comfort, size). Ideally, you can listen to a number of choices with your speakers but I would look for amps that are designed for home use and sound quality over a tank-like pro audio amp. As stated YMMV.

Oh and to Chris' credit he has not once made a product recommendation comprised of one of his products in this thread.

[boojum]

In a double-blind test all would be the same but the item being tested.  In this case the amps.  Stereo Review ran a "DBT" at a show years ago.  All attendees were invited to participate.  Hands down a cheap receiver beat out an expensive Levinson dual-mono stereo package.  Just another reason that high-end audio hates DBT.  As usual, YMMV     

Hard to believe, AND likely not really true rumor-tech stuff anyway.  Don't you just HATE getting the 'conclusive results' without the glory details making all the difference for chance of knowing truths of the matter. 

In this case. and if being shocked to attention by out-of-technical-context claims, think better to have ability to drill a little deeper knowing the magazine issue and full testing setup details.  Otherwise to me, just another unsubstantiated rumor holding only limited truth for normal user expectations and working conditions.

I read the article when I still subscribed to the magazine.  It was about 20 years ago and if I had the foresight to know it would be of such value I would have saved it.  I think it is pretty hard to find differences in amps these days.  The price tag has a powerful effect.  You had better say your new Lirpa mono-block tube amp sounds better than anything else in all of Christendom: the just cost you $12,000 a chassis and you'd look pretty stupid if you didn't say that. 

As I remember the article it was "all things the same" except the amp.  The attendees were the usual mix of propeller heads, geeks, "audiophiles," press hacks and the mentally unbalanced.  You've been to them as have I.  They are fun.  A combo of carnival, science, science fiction and hucksters.  Remember the Shoon-Mok disks??  Those tiny little discs of some wood-like product that improved your sound by I forget how much but it was a lot.  And the price for those little teeny discs was a lot, too.  Many folks bought them and their mysterious powers.  They did nothing.  Anyway, the original question was about the DBT.  Lots of different amps, all the rest stayed the same.  Pioneer beat M-L to the chagrin of all there.  I loved it and I truly regret not saving the issue.

L8R

[boojum]

Well, we both own Sound Labs.  That's a start   .  There was a set of mid-80's Maggies in our family for a number of years.  I would rather power them with 100 watts that cost $5 per watt than 500 watts that cost $1 per watt.

Chris

There is an old saying, "If the first watt sounds like crap, why do you want 499 more of them?" I subscribe to this theory myself. My amp puts out right around 65 watts with KT88 tubes in ultralinear mode. Hardly a high powered amp but it sounds great. I have compared it to a number of higher powered (and priced) solid state amps including Conrad Johnson, Threshold, and a Krell integrated but none of them had the sweet mid range and grain free upper registers that I found pleasing to the ear. While Maggies and stats do require more juice than my SF's I still think Chris' advice is valid. Pro gear is designed to fill large spaces at high volume. Accuracy, low THD, and tonal balance are typically secondary considerations on lower to mid priced pro audio amps. I liken it to seeing people driving Hummers in the city. You can do it but it simply is not designed for that use as it is overkill in some areas (in this case off road suspension and power) and lacking in other areas (fuel efficiency, ride comfort, size). Ideally, you can listen to a number of choices with your speakers but I would look for amps that are designed for home use and sound quality over a tank-like pro audio amp. As stated YMMV.

Oh and to Chris' credit he has not once made a product recommendation comprised of one of his products in this thread.

I appreciate that you like your current tube amp a lot.  That is why you own it.  There is no direct correlation between bucks and quality in audio.  Some good equipment is very expensive; some is not.  Much of the audio world is science fiction.  Super jim-dandy whiz-bang equipment comes and goes.  The stuff which is really good finds people who buy it and buy it a lot.  The over-priced stuff is just that, and finds a very small following.  I am attaching a copy of the specs for the DH-500 which I use.  These are inexpensive amps with good specs.  That was part of the charm of hafler.  You may not be familiar with them.  They are spec'ed at 8 ohms.  I run mine into 4 ohm speakers so these conservative power figures are doubled, and then doubled again because the amp is mono-blocked and I run two.  David Hafler retired and sold the business to some other folks who no longer make the DH-500.  Mine is still cranking along just fine.  There are other good amps out there at reasonable prices, too.

Cheers

[boojum]

In a double-blind test all would be the same but the item being tested.  In this case the amps.  Stereo Review ran a "DBT" at a show years ago.  All attendees were invited to participate.  Hands down a cheap receiver beat out an expensive Levinson dual-mono stereo package.  Just another reason that high-end audio hates DBT.  As usual, YMMV     

Hard to believe, AND likely not really true rumor-tech stuff anyway.  Don't you just HATE getting the 'conclusive results' without the glory details making all the difference for chance of knowing truths of the matter. 

In this case. and if being shocked to attention by out-of-technical-context claims, think better to have ability to drill a little deeper knowing the magazine issue and full testing setup details.  Otherwise to me, just another unsubstantiated rumor holding only limited truth for normal user expectations and working conditions.

There is always more to gear then just technical specs.. There is how it actually sounds most of this audiophile bullshit does not sound like anything. And when you ask the so called audiophiles to quantify the actual performance of a peace of gear they use fancy words like sound stage and blackness seem to be the "buzz words" Few of them really have a clue. Most of them would fail miserably any double blind test. If more of us would buy with our ears instead of tech specs then most of us would be listening to much cheaper audio gear then we presently own.. And there would be no need for magic sound crystals or magic AC wall plates... Or fancy Silver Ac cable to connect our power amps too. But to each there own.

Too bloody true!

[cheshirecat]

Well, we both own Sound Labs.  That's a start   .  There was a set of mid-80's Maggies in our family for a number of years.  I would rather power them with 100 watts that cost $5 per watt than 500 watts that cost $1 per watt.

Chris

There is an old saying, "If the first watt sounds like crap, why do you want 499 more of them?" I subscribe to this theory myself. My amp puts out right around 65 watts with KT88 tubes in ultralinear mode. Hardly a high powered amp but it sounds great. I have compared it to a number of higher powered (and priced) solid state amps including Conrad Johnson, Threshold, and a Krell integrated but none of them had the sweet mid range and grain free upper registers that I found pleasing to the ear. While Maggies and stats do require more juice than my SF's I still think Chris' advice is valid. Pro gear is designed to fill large spaces at high volume. Accuracy, low THD, and tonal balance are typically secondary considerations on lower to mid priced pro audio amps. I liken it to seeing people driving Hummers in the city. You can do it but it simply is not designed for that use as it is overkill in some areas (in this case off road suspension and power) and lacking in other areas (fuel efficiency, ride comfort, size). Ideally, you can listen to a number of choices with your speakers but I would look for amps that are designed for home use and sound quality over a tank-like pro audio amp. As stated YMMV.

Oh and to Chris' credit he has not once made a product recommendation comprised of one of his products in this thread.

I appreciate that you like your current tube amp a lot.  That is why you own it.  There is no direct correlation between bucks and quality in audio.  Some good equipment is very expensive; some is not.  Much of the audio world is science fiction.  Super jim-dandy whiz-bang equipment comes and goes.  The stuff which is really good finds people who buy it and buy it a lot.  The over-priced stuff is just that, and finds a very small following.  I am attaching a copy of the specs for the DH-500 which I use.  These are inexpensive amps with good specs.  That was part of the charm of hafler.  You may not be familiar with them.  They are spec'ed at 8 ohms.  I run mine into 4 ohm speakers so these conservative power figures are doubled, and then doubled again because the amp is mono-blocked and I run two.  David Hafler retired and sold the business to some other folks who no longer make the DH-500.  Mine is still cranking along just fine.  There are other good amps out there at reasonable prices, too.

Cheers

Hafler founded Dynaco which made some legendary amps... I run an ST-70 that I'm very happy with.