Phase Linear 2000 Series II Preamp -- clicks off but won't shut up!

This is more to document than an actual plea for help, but any suggestions, ideas, comments are welcome.

I recently acquired a Phase Linear Model 2000 Series Two Preamplifier.

Everything works and performs well except the Power Off knob does not power off the sound on the preamp.

As I turn the Power/Volume knob down, it doesn't go completely silent but it goes down to a low level.

After the Power knob "clicks off" and the red power light goes out, I can still hear sources playing albeit at a low inoffensive level. Just dismaying and freakish more than anything else.

My work around is to plug the 2000 into a switched outlet on the amplifier, so when I power off the amp, it also powers off the 2000 preamp. In addition, I also have the amp plugged into a power strip which is also powered off for the night. More for peace of mind than anything else.

Another AK member said this Off/On power switch problem may be a common occurrence with Phase Linear/Carver components.

Other than that, the performance and sound is really enjoyable and certainly worth the $60 I got it for from craigslist.

Attached are pics of the Phase Linear Model 2000 Series Two.

All the pots and knobs are oversized and velvety smooth in operation. The circuitry is minimal and the box depth is remarkably shallow --- equivalent to an equalizer or I think the size of a shoe box for Shaquille O'Neal sandals.

Angle


Power/Volume pot with black, white, yellow wires


Bottom view: wires to power supply


Long shot shows rest of pots on top side


Closeup switches


Bottom view: shows access to push button switches. Also bottom level has access to Ambience and Balance pots which are not shown.


Full frontal with Pioneer TX-7800 tuner on bottom.

A few years back, I acquired a Phase Linear model 3500, series two preamp, and my power switch did not function either. I suppose I could order one direct from Carver, but I figured, what the hey, and bypassed it, with the preamp itself connect to a surge protector outlet strip!

If the signal level of the of the selected source is very high output level, then it is possible that it is finding it's way throughout the preamp. With my phase linear 3300 preamp I only have two or three clicks on the volume control before the sound is very loud.

cademan said:

I suppose I could order one direct from Carver,

Click to expand...

The Phase Linears haven't been supported by anyone in years and years. Carver has nothing for the repair.

I own the same preamp since new.

Correction, I've been supporting them for years and years.

Watts Abundant

datsunmike said:

The Phase Linears haven't been supported by anyone in years and years. Carver has nothing for the repair.

I own the same preamp since new.

Click to expand...

d3imlay said:

If the signal level of the of the selected source is very high output level, then it is possible that it is finding it's way throughout the preamp. With my phase linear 3300 preamp I only have two or three clicks on the volume control before the sound is very loud.

Click to expand...

What you say makes sense about "throughout the preamp."

I also plugged the tuner into the preamp aux and tape 1 and 2 IN jacks to see if it was just the tuner jacks, but I got the same results when clicking off the Power/Volume knob on the preamp.

I also have the tuner plugged into a switched outlet on my amp (HK PM665). So if I click off the 2000 preamp first, the tuner still plays. But if I turn off the "source" tuner manually, the sound goes out. So I do have some options.

Thanks all for inputs. Makes me more comfortable knowing this isn't a totally oddball situation.

Well.........as of last month, Carver is back in business repairing the old 1978 and up Phase linear equipment!

The Phase Linear equipment has also been supported by Dean Nissen (the last factory service manger at the Lynnwood Washinton plant) since the factory shut down in December 1982.

Dean had a web site on AOL that went down on October 31,2008 when AOL shut down all AOL web sites. An archived copy of the web site can be found at http://web.archive.org/web/20071208055327rn_1/hometown.aol.com/PhaseTek/

Dean has registered a new site on http://www.phaselinear.info which I hope he will have up and running sometime this year. Stay tuned.

By the way, one of the most common failure modes of the 2000 series preamps is the power switch/ volume potentiometer. Sometimes its the power switch and other times it is the volume potentiometer. When the volume potentiometer goes bad you will not have equal tracking of the volume pot and one channel will be significantly louder than the other. Dean only has a couple spares left.

Thanks on the switch source and sites. I'll check them out.

When I first got it, the craigslist description noted static in the balance.

When I tried it out, it was static in the balance and volume and switches. And uneven output.

In fact, one channel would cut out altogether as I pressed the Stereo/Mono or other buttons. A thorough deoxit/faderlube has got the balance even for both channels on startup. It took a lot - a lot of working the controls and switches. Still some pop on switches but acceptable since they are usually not needed once set.

Now it is actually better than some of my other vintage receivers which may need some warm up and/or jiggling to finally get equal output. All in all a very solid performer sonically without the nervousness and anticipation of how long will it take to warm up and sound clean and even.

If anyone is still looking, the Series II Japanese made Alps Electric Co., Ltd potentiometers. not sure what the part numbers or specs are though.