I posted in on Face book if anyone wants to look there:
https://m.facebook.com/story.php?st...4E5Nka3ufl&id=100000115705087&mibextid=Nif5oz
https://m.facebook.com/story.php?st...4E5Nka3ufl&id=100000115705087&mibextid=Nif5oz
My 700w series 1 on the bench
- Thread starter GeorgeP
- Start date
Hello George,
I personally am not a member of Facebook. Why not post the details of your build here on Phoenix?
Many of us are Phase Linear addicts, and especially WOPL modified Phase Linear amplifiers.
Your early 700 has it's own set of challenges that we don't often see, and all of us enjoy following a challenging build, with lot's of pictures!
I was able to read the text that you submitted on the Facebook posting, and disagree with you giving credit to " David Carver...a 25 year old engineering kid"....starting Phase Linear. It was Bob Carver, see below. Just a tiny bit of the "Bob Carver Legacy".
There are many experts and a few ex-employees of Phase Linear on this forum, so they may step in, however having owned these components myself for over 47 years, I offer the following:
Bob Carver started Phase Linear in his home in Richmond Heights, Edmonds area, north of Seattle, WA in about mid-1969.
Phase Linear was founded by Bob Carver in 1970.
With the help of Carver's partners Steve Johnston and Jack Goodfellow, Phase Linear was launched in 1970 in a small building at 405 Howell Way in Edmonds, Washington.
The first component to be manufactured was the model 700 power amplifier, with 350 watts per channel.
1970 to 1973 model 700
700b debuted in August of 1973.
Bob Carver left Phase Linear in late 1977.
Carver Corporation launched in 1978.
J.P. Van Meter joined Phase Linear in 1974, bringing with him his design experience working at Macintosh and University Sound. When Carver left Phase Linear in 1977, Van Meter became the Chief Design Engineer and the Engineering Manager. Under his direction the Series II models were designed and built, and introduced in 1978.
700 Series II introduced in 1978.
I personally am not a member of Facebook. Why not post the details of your build here on Phoenix?
Many of us are Phase Linear addicts, and especially WOPL modified Phase Linear amplifiers.
Your early 700 has it's own set of challenges that we don't often see, and all of us enjoy following a challenging build, with lot's of pictures!
I was able to read the text that you submitted on the Facebook posting, and disagree with you giving credit to " David Carver...a 25 year old engineering kid"....starting Phase Linear. It was Bob Carver, see below. Just a tiny bit of the "Bob Carver Legacy".
There are many experts and a few ex-employees of Phase Linear on this forum, so they may step in, however having owned these components myself for over 47 years, I offer the following:
Bob Carver started Phase Linear in his home in Richmond Heights, Edmonds area, north of Seattle, WA in about mid-1969.
Phase Linear was founded by Bob Carver in 1970.
With the help of Carver's partners Steve Johnston and Jack Goodfellow, Phase Linear was launched in 1970 in a small building at 405 Howell Way in Edmonds, Washington.
The first component to be manufactured was the model 700 power amplifier, with 350 watts per channel.
1970 to 1973 model 700
700b debuted in August of 1973.
Bob Carver left Phase Linear in late 1977.
Carver Corporation launched in 1978.
J.P. Van Meter joined Phase Linear in 1974, bringing with him his design experience working at Macintosh and University Sound. When Carver left Phase Linear in 1977, Van Meter became the Chief Design Engineer and the Engineering Manager. Under his direction the Series II models were designed and built, and introduced in 1978.
700 Series II introduced in 1978.
Ok, Ill try to post the pics.
Yup...a pull down found the gallaryintermitterende! of pics.
Doing LEDs for the meters, since there is no WO meter board for this model. Added 4 leds / meter. Not yet happy with it...need to add a diffuser inside the meter case to get rid of the directional shadows look. I can figure this out to get an "even look".
Also replaced the input DC/NORMAL switch...was intermittent!
Relay board, getting an addition for the UPC 1237 chip. Breadboard working good!
Yup...a pull down found the gallaryintermitterende! of pics.
Doing LEDs for the meters, since there is no WO meter board for this model. Added 4 leds / meter. Not yet happy with it...need to add a diffuser inside the meter case to get rid of the directional shadows look. I can figure this out to get an "even look".
Also replaced the input DC/NORMAL switch...was intermittent!
Relay board, getting an addition for the UPC 1237 chip. Breadboard working good!
Attachments
The relay board, in testing stage, had to replace a small bipolar npn with an N-CH Mosfet for the relay drive circuit. The UPC- 1237 relay drive pin is only 0.7V when it goes low. I set up the circuit so the gate of the mosfet sees 0.7 off, to 7.5V to turn it on.
A schematic to interface with the relay board I purchased to get this working is attached. Note: Whattsabundant is a great guy, and Im not going to make a competitive product to replace his product. Thats not why I did this, Im just having fun, and his kits are awesome. I'd like to just help this guy get more out of this if I can if he chooses, since he put in so much in this to help the community here...to save their speakers!
A schematic to interface with the relay board I purchased to get this working is attached. Note: Whattsabundant is a great guy, and Im not going to make a competitive product to replace his product. Thats not why I did this, Im just having fun, and his kits are awesome. I'd like to just help this guy get more out of this if I can if he chooses, since he put in so much in this to help the community here...to save their speakers!
Attachments
Thanks for the reply. To my amazement, the caps I pulled out measured almost 6 to 7 uF! All still good! But, as you suggested, the added newer lower value type 0.33uF in parallel to the older ones would have worked fine, but the new Metal films are superior to what was there with a much lower ESR, and take less space, and NEW. I'll fully check this amp out for noise and high end response and report the results down the road. The new power devices will be installed next week. Hope its all stable! Lol.
I did some more work on the LED lighting for tbe meters. Installed strip LEDs three in each meter case. 15 ohm ballas resistor fir each strip, added a diode for DC. Looks really Good.
Also added a modified 400W relay board with the UPC 1237 CHIP, so now the circuit detects much lower offset. If any want details, reply.
So...
New volume pots
New Norm/DC switch
New Relay LED on front panel
New Power supply Caps and Rectifier.
New LEDS for meters.
Pics of most attached.
Doing Frequency responce tests to recap old board, then replace all Output transistors to the 250V 16 amp types.
Also added a modified 400W relay board with the UPC 1237 CHIP, so now the circuit detects much lower offset. If any want details, reply.
So...
New volume pots
New Norm/DC switch
New Relay LED on front panel
New Power supply Caps and Rectifier.
New LEDS for meters.
Pics of most attached.
Doing Frequency responce tests to recap old board, then replace all Output transistors to the 250V 16 amp types.
Attachments
Also...last night I replaced the 10 electrolytic caps on the pcb. I checked offsets for each pair replaced as I went along, so I would know each fix was ok. New caps much better...no leakage, so the offsets needed a tweak!
They are the blue ones, and the two large brown ones in the pic. Brown ons are 4.7 uF film, to replace the 4.7uF electrolytics (C2) in the signal path. Lower distortion!
The New Output transistors going in this weekend. Then...done and listening test of the brute!
They are the blue ones, and the two large brown ones in the pic. Brown ons are 4.7 uF film, to replace the 4.7uF electrolytics (C2) in the signal path. Lower distortion!
The New Output transistors going in this weekend. Then...done and listening test of the brute!
