phase liner amp

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You're asking about two entirely different things.
Phase Linear amplifiers were powerful compared to their competition, but never particularly good. You don't say whether you're trying to buy one used or build one. If you're trying to build one, start by checking parts availability. Some of the transistors may not be in production. If you're trying to buy one, don't pay very much for it and bear in mind that if it breaks you'll be up against the parts availability problem again. The company is long since gone.
The most expensive amplifiers at this time are well over $100,000.00 and climbing.

Grey
 
Ex-Moderator
Joined 2002
CBS240 said:
What could possibly be the justification for such ridiculous cost?

Ah, a debate that has had many outings here on diyAudio. Suffice it to say they ask that price because some people are prepared, for whatever reason and whatever we think of them, to pay it. And a good thing too, it gets money out of the hands of those rich $%^&&^$£ and back into circulation. ;)
 
Why do Porsches cost what they cost? Or Mercedes? Or Ferraris?
Why do tiny apartments in Manhattan cost more than my entire house on 2 3/4 acres of land?
Why does anything cost what it costs?
A fair price is that which has been determined by the buyer and the seller. It's called supply and demand, and it's an innate part of any capitalist system. Unless you intend to pass laws intended to control prices it's just the way things are.
Might as well complain about the weather.

Grey
 
GRollins said:
...If you're trying to build one, start by checking parts availability. Some of the transistors may not be in production. If you're trying to buy one, don't pay very much for it and bear in mind that if it breaks you'll be up against the parts availability problem again.

Grey


Although Phase Linear has been out of production for some time, parts are available. I stock all of the original transistors or accepted substitutes. Of course the original outputs are long gone, but better devices are available.
 
What about their preamps

I am always astounded at the amount of debate that Phase Linear seems to raise in audio forums.

I have always wondered about their preamps, and in particular the old 4000 series and all of their inbuilt processing.

I recently stumbled across one of the 4000 series 1 preamps, which is in excellent cosmetic condition, but unfortunately it does require internal repair.

I bought it, and now I am unsure if it is worth the effort to get it up and running.

Any thoughts???

Regards
George.
 
phase linear

Their two main amplifiers are the 400 and the 700. I own a 700B which I purchased in non working off of an eBay auction. I paid $200 for mine shipping included. They tend to go higher, and many sellers charge unreasonably high shipping charges ($80 to $100), so be careful. A working 700B will be more expensive of course. I bid on several before I won mine.

I don't think you'll experience any flame outs in a home listening environment. If you want one for a band sound reinforcement, I think you'll have problems and should look for something more ruggedly built. If you want a high power solid state amp for home use, it has done a very good job driving several different speaker systems for me. I consider it to be neutral sounding, and it handles low frequencies very well.

Mine required one new driver transistor and 2 output devices. One of the outputs was a replacement and was installed shorted. All the transistors are available, as is a service manual and a couple web sites with fixes for common problems. There are germanium devices in the protection circuit that would be harder to find. From the schematic, it seems like it could easily be rebiased for a silicon transistor.

Eventually, I plan to rebuild the driver circuit more along the lines of the Douglas Self "blameless" approach. But for now, it does fine.

Sorry to ramble. Bottom line, I think it's a reasonable pick up if you don't have to shell out wads of cash.

Good luck!
 
"I am unsure if it is worth the effort to get it up and running."

The delay chip is no longer available.

The jacks are usually shot too, NLA. I suppose you could fabricate a board to mount new ones.

The 4136s are not so hot, and no pin-for-pin sub is available.

A while back I dumped a working one cheap.
 
djk said:
"I am unsure if it is worth the effort to get it up and running."

The jacks are usually shot too, NLA. I suppose you could fabricate a board to mount new ones.

The 4136s are not so hot, and no pin-for-pin sub is available.

A while back I dumped a working one cheap.

The 4136 can be replaced by an adaptor board if necessary. Search for browndog 4136. The jacks are subject to cracked solder joints and break easy. They're ok if you insert the plug without side to side twisting.
 
PL4000

Thanks for your comments djk, d3imlay.

Well the PL4000 is up and running, but it was not without its heartache and a lot of work.

The job was not helped by the fact that someone else must have tried to repair it before me, and made a mess of it.

This is what was required:

1.Clean all of the switches

2.Relpace the voulme pot (was completly shot), and also required some creative modifications.

3. Rebuild the power supply.

4. Replace over 40 electrolytics, including some matching for the delay.

5. Redo some wiring, including all of the 240V

6. Has 2 broken RCA jacks

7. Resolder countless joints, and repair some cracked tracks.

8. Stabilize from further damage lifted tracks.

9. Pull the entire face plate off and a good clean.

I have not hooked it up yet, but on the bench it appears to have a very clean wave on the scope, and no signs of anything abnormal, except for the joy stick control, which seems to balance across the diagonal rather than true side to side.

I will yet you know how it sounds when I hook it up this weekend.

Anyway, here is a pic of the final rebuild.

Regards

George.
 

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PL4000

Well

I could not wait untill the weekend, and managed to test the preamp tonight.

In summary, what a fantastic sounding preamp, and in particular, the phono stage.

I am very glad that I decided to fix er up, rather than ditch it.
However, it does have some rather unusual charecteristics.

1. Engaging the "correlator" - what ever that is, results in an immediate loss of treble, regardless of the setting. Best left off.

2. The Threshold control / PK expander control does not work well on pure acoustic and vocal recordings. Seems to have a pumping effect.
However, on material that has very fast, lower register attacks,such as a kick drum, the audio effect is quite good.

But after all of that, I simply defeated or turned off all of the whiz bag stuff.

In summary, suprisingly good, and well worth it, provided you can find one without paying too high a price.

Hope someone finds this usefull.

Regards
George.
 
GeeVee

I have a PL 4000 and also Carver C 4000 pre amps.

If you have not met the "autocorrelator" before, here is how Bob Carver describes it...
"This circuit removes 8db of background noise from any source. It discriminates betweenwaveforms typical of music and random noise. It constantly compares and computes what can pass and what must be blocked over a wode range of frequencies..........You may sense a loss of highs even though we assure youthat frequency response is unaffected! This is due to psyco-accoustic affect where our hearing mechanism equates the presence of high frequency noise content with "definition/airiness" of the source. After you have lived with the autocorrelator for a while you will be offended by the noise you had endured before"

I hope this helps.

Don
 
PL 4000

Hi Don

Thanks for your comments. That certainly is interesting.

The tests that I did tonight, were only fo about 2 hours, with 50% of the time spent with the preamp / system running as background music, to check that no problem developed after it had warmed up.

Therefor 1 hour of solid listening may not be enough to formulate and opinion on the autocorrelator.

Yes you are correct, there was an immediate reduction in the high frequency, so at the very least it would appear that the autocorrelator is opperating correctly.

I am not quite sure what to make of Mr Carver's statement. If our ears do equate this noise to "definition/airiness", then could this be a good thing?

After all, definition and airiness are qualities that I do look for.
But--- Perhaps my definition of airiness is not the same as Mr Carvers.

This is very interesting, and I will look into this further.

Once again, thanks for your comments.

I would be very interested to know what your personal thoughts are, since you own a PL 4000 also.

Regards
George.
 
George

Initially I approached the "add ons" on the Phase linear 4000 and the Carver C4000 pre amps from a sceptical point of view. I took the view that if other "greats" in audio did not propose similar things they were probably just gimics from Bob Carver.

However after extended listening, I began to change my view. I think the autocorrelator works on some recordings; but not on others. I have found it most effective on "dirty" recordsand on some cd,s. I have not found it effective on "clean" records. I think you have to try it a few times on different sources and different recordings.

I find the Pl 4000 and the Carver C4000 surprisingly good to listen to. And, these amps were built in the 1970,s and 1980,s!

Don
 
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