Strength, Durability, Clean Sound, Cosmetic appearance.
Will drive most speakers.
Unbeleivable Durability. Clean Sound.

Blows original AGX-5 Fuses when driven to it's limit.

I had this amp since new either 1973, or 74, I can't
remember the exact year.
I paid 500.00 for it new. Not bad for 400 watts into 8 ohms.
This is not a wimp of an amp. It weighs 42 pounds net.
I had this amp around,such as picnics with Altec Valencia
speakers that took 300 w/speaker at 8 0hms. I have driven it
almost to it's limits for 10 hours without at a time without
any problem.
I am now driving a pair of KEF Reference threes with it.
If you can find this amp at a good price, It will equal,
or exceed amps costing 2000.00.
This Bob Carver amp was way under priced.

Great drive and detail, smooth but with clout

Odd Shape, have bare chassis version

This amplifier has one of the largest voltages around
driving the output transistor stages and with the 1975 selected Motorola output trannies, it becomes one of the best sounding amplifiers ever heard in my circles.
It seems that no matter how far you turn up the volume
the listening pleasure is still there, whereas if you
drive a Krell, for example, the family leave the room.
As a professional musician, used to studio monitoring, I
can confirm that with JBL4411 Monitors one end and a
studio mastered tape @ the front end, the Phase Linear
400 must be the most underated amps of all time.
Wish I could get my hands on more of the UK 240 Volt
versions.You lucky americans, that can pick them up for just a fewhundred dollars. In the UK thay are becoming a cult amp
and hence a premium £2K plus, if you are lucky.

Similar Products Used:

Naim NAC52 Pre-Amp NAP135 power amps

Very Fast,Uncommonly Accurate, with really cool VU's

Odd shape and hard to find parts if repair is needed

When Bob Carver showed up at one of Mcintosh's Dealer sponsored "Amplifier Blowout" Demos in the early 70's,the guys from the big "M" knew he was on to something. His home-spun "Canned Amp"(he built the amplifier inside of a coffee can and ran it straight off the 110 in the wall socket)spec'd out at an unbelievably flat-lined 700 wrms!(thats as high as the test equipment went)The amp also kicked the circuit breakers and knocked out the power in the store. After the lights were restored the two Mcintosh reps' pulled the young man aside and told him what they really thought. Well, 2 months later Phase Linear was born and the rest, as they say is History.
That first "amp in a can" was to become, with a few refinements like a real power supply and brushed aluminum chassis, the Phase Linear 700. With time and money Mr. Carver was able to refine that original design into the now famous, and much more managable model 400, and later the 400B. Three companys and 25 years later the PL 400 is still one of the milestones of amplifier design. A true work-horse that can still be had for under a dollar a watt! Enter me......A pro musician and recording producer/engineer since 1974, I have seen, heard, and even listened(yes, there is a difference!)to almost every quality amplifier that has come to market. What I say now is backed up by over 25 years experience and much success with the Phase Linear 400. When I opened up my first "real" recording studio in 1994 I went on a search for the best amplifier I could find for control room monitoring and multitrack mixdown. As most of you know this is extremely critical to the recording process and requires amplification that is ultimately "perfect" in every respect. A true reference amplifier can not add, or subtract one iota to the sound as it comes from the source, on it's way to tape. And then at the other end from mixer to the Monitors, and finally to the two track master. Accuracy and sound quality are the name of that game! With price being no object, I went looking for just such an amplifier. I should have simply gone over and disconnected my stereo! B&K,Hafler,McCormick,Yamaha,Crest,Altec(tubes & SS), the list went on and on. I finally settled on a pair of massive McCormck DNA-1 Run mono into a Niles Multi-speaker switching unit which allowed me to compare a pair of JBL l-100's(the pro version), UREI Time Aligned Mains, and a pair of custom(ouch! they were spendy)KRK Near/Mid field monitors as well as my trusty Yamaha NS-10 near-fields. This set-up sounded great. The "Big Mac's" provided all the power and accuracy I thought I would ever need with only minimal equalization from my TL Audio Stereo 4-band Tube Parametric. Enter one good ole Atlanta Georgia late summer thunder storm with complementary Hail and Lightning......and Poof!(actually it was more of a loud "clack"!)and...... 4,000 dollars worth amplification turned into the worlds most expensive boat anchor. What to do? The amps are fried, the client is pissed 'cause he's convinced the mix was the next best thing to the Beatles, I'm pissed cause I just watched many thousands of dollars in time and product go up in smoke(literally),The wifes' pissed 'cause, well thats just the way she is most of the time when she has to be around me and my toys(anybody out there know what I mean?, and that brings us back round to What to do?.....Voila! Enter the Phase Linear 400. Until this very moment I had always considered the 400 a souped up sound reinforcement type of P.A.amplifier that was good enough to double as a stereo amplifier. What I didn't realize was that the 400 is also one of the most accurate amplifiers I have ever heard. No, it is the most accurate. At least for multitrac mixdown to 2-trk master. When I hooked up the 400 into the system it was immediately apparent that something was wrong with the sound. So, I simply removed any equalization that was interfering and Wham!Bam! Thank you Bob! What a great sound. The UREI's sounded perfect and the JBL's, which had up till then been a bit light on the lower octaves came alive with a thunder from down under that I had not heard before. When re-listening to old mixes it became apparent that we were overcompensating for the lack of roundness in the mix by boosting the frequency in the 80-120 hz area. With the 400 the sound that was coming through the speakers was exactly what was going on tape/ Eureka! Needless to say, everbody in the room heard the difference right from the first few notes. The clarity in the upper registers also benefitted from the Phase 400 as the 12khz and up area no longer required the attenuation of the TL Audio EQ. Accuracy is one thing, but good sound is another. Most engineers would agree that a perfectly flat amplifier can be a pretty dull soundng thing, causing fatigue and general malaise in the mixing room. The phase while dead-nuts accirate somehow gets around the sterility of most so called "reference" amplifiers. Mixing suddenly became a much more pleasurable experience. The overall soundstage was increased 20-30% without effecting the placement of the individual instruments in the mix. The stereo field suddenly became more pronounced requiring constant attention so as not to isolate too much one side to the other. The amp made me pay closer attention to my work.It gave me increased possibilities in the stereo mix that had been hidden before and generally improved everything. I have since purchased 9 Phase Linear 400's for my studio and personal use. If the amplifier has a down side it is this. The Motorola transistors that reside on the rear heat-sinks require matching to the point that they all must be replaced when even 1 fails. This is not only expensive, but now almost impossible to do as they are no longer made and are getting harder and harder to find. What this says is that the amplifier, while great in most respects it can become unstable at higher operating levels when the transistors are not properly matched. In fact, the amplifier will run hot on one side or the other and eventually fail if they are not all replaced at the same time with xstr's from the same batch, presicely matched.Also, while I have read amongst the reviews here that these amplifiers are "Bullet Proof" I find that not to be the case at all. The phase linear 400 is a very tempermental amplifier and is subject to overheating and blowing fuses. I have solved many of these small problems with an external fan set up to blow across the rear of the amplifier's heat-sinks. Of the nine that I own, only 5 are in working order. My tech has been unable to get replacement xstr's for the last 1 1/2 years. I will keep them with hopes that someone, someday has the good sense to mfg. anothe run of 10,000 or so units. Because of the scarcity of parts I am always on the look out for another "perfect" amplifier to use when the last of the 400's dies. Unfortunately, I am sad to say that alas, I have found nothing that even comes close to the clear, accurate, and down right massive sound of the Phase Linear 400. Bye the way, I also own 2 of the 400b's and they sound just as good but just don't look as cool. Like most classic products, when they try an improve later versions it just goes one way and that is usually down. See UREI Ln1176, LA-2, LA-3,LA-4, ect. If you have read this far I guess you have figured out that I am a bit biased about these amplifiers. Maybe it's my unique system, I don't know. What I do know is that no one product has contributed to my success in the field more than this amp. Buy 1, hell buy 3 or 4. I did

Similar Products Used:

B&K, Altec 1269,Hafler DH500,ect,ect.