Recent content by oldphaser

I was on the phone a couple days ago with a gentlemen in the Seattle area who I knew about decades ago but never talked to previously. He said that the coffee can amplifier did exist. He stated that he had a repair shop in the late 60's and early 70's and Bob would stop by his shop because Bob...

At Lee’s request, I am providing this post. NOTE: I have been away from this forum for almost a year. I wonder who the Phase Linear employee was that built the amp? I know a Gary C, Gary K and there were several Charles (Chuck’s) at Phase Linear. Most likely it was built up from parts that...

Don, Most people have no idea how much grief I got from Dean over the 25+ years I worked with him when I replaced the XPL909's, FPL909's, etc with MJ15024 (and later MJ21196) output transistors in series 1 amplifiers. He hated dealing with the oscillations that they created and in some...

Glen, I was asked many years ago either on this forum or elsewhere to post some schematics for the fully comp 700 series two amplifier. I hesitated at that time because I knew there were some errors in the schematics and that some debate would follow. Most notably is the inclusion of the fly...

As you already know, the 200 series 1 service manual appears to be lacking some details in the meter sensitivity section. I will post it here for others to see. Step #20 Apply enough input signal (2K Hz) to the left channel so that the -12 dB LED comes on, with the meter sensitivity switch on...

The DC offset spec in the Phase Linear 700 service manual (for serial numbers 0 thru 773-200) stated: "using a voltmeter, adjust the offset controls so that the meter indicates 0 (zero) volts at the speaker terminals between hot and ground. The controls are readily adjusted simply by using the...

The Phase Linear 700 (Edmonds Washington version of the) owners manual states: INPUTS "... the Phase Linear 700 is equipped with direct coupled inputs as well as normal coupled inputs. For high fidelity reproduction, the "normal" coupled inputs are to be used. The normal inputs provided...

Marco, I always try to give credit where credit is due. If it weren't for Dean's willingness to share his knowledge and time with me who knows where I'd be now? "A good friend is someone who makes you better than you might otherwise be". (Mary Maxwell Gates - Bill's mom) Ed

So this has more to do with converting the amplifier to a fully complementary output than something to do with using a WOPL backplane board. This can also be accomplished by re-wiring the output stage like Phase Linear did on all of their fully comp 400 and 700 series two amplifiers.

Joe, Which is easier to accomplish? Rewiring the original output stage or building a WOPL back-plane from scratch? Also what improvements were made to the backplane boards in Rev C versus the previous Revision B? Thanks! Ed

Marco, It was Dean who posted the 4000 service bulletin update on our website. ELECTROLYTIC CAPACITORS IN SERIES 1 (JOYSTICK) 4000's 6/00, UPDATED 6/05 (The first new service bulletin since 1982!) COUPLING CAPACITORS: In the past several years I have noticed a significant increase of IEC...

Marco, As you probably are already aware of, Phase Linear used (2) different versions of RCA pc board mount jacks on the 1000, 2000 and 4000. One has a round body and the other a square body. These RCA jacks have shorting capability when not in use. On the 1000 there are a total of (8) RCA...

I got to thinking about this some more. A.P had mentioned that they were working on a dual rail secondary. Phase Linear started working on the Dual 500 (in 1977) long before the DRS series (in 1981/2) and it too had a dual rail secondary. However it starts on high rail and only switches to...

Yes the amplifier would more than likely continued as it was if it were not for the FTC. A.P. Van Meter told me about the phone calls he was receiving from the FTC on a regular basis about what Phase Linear was going to do to meet the spec. There was little they could do to the 700B as there...

I have revised/edited my previous post (#13) several times.