New member drug out a 700 and was sent here :-)

[PhilcoFord]

Hi, My name is Bob Moore and got the gift of retirement 3 years ago, and sorting through lots of old projects, usually too many at once. Dad was a Philco guy all the time I knew him and left way to soon leaving me with a yearning for all sorts of old electro mechnical stuff and I have collected pretty well.

Just pulled this gnarly old 700 out of the back closet as I am also working on a couple other amps. Started building popular electronics SWTPC amps back in the 60's and 70's then graduated to other stuff as it became available.

The 700 had a blown main fuse, but found out one channel is ok by leaving the other fuses out, so now wondering how many bad outputs etc, never worked on an amp quite like it! I can run it on a lightbulb ballast and wondering if probing all the emitter resistors is a way to start or if I should try and start unplugging them and start testing out of circuit??? and what is ON Semi replacement recommended? Just got a set of MJ15003/4's for the Marantz 15 I have apart but these NPN's seem to have a higher rating with the 100V rails . . .

Thx for the add!

-Bob

 

[WOPL Sniffer]

Glad you came over Bob. Do some digging, lots of good shit here man. I'm sure a couple of the guru's on the original 700 will chime in soon. You never know when us old guys will wake up from our naps....

 

[Fishoz]

You’ll have that 700 singing soon Bob. Everything you need can be cobbled here. Contact Gepetto (Joe)...White Oak Audio. He’s got all the upgrades you’ll need. Many documented builds to watch/read. Welcome to Phoenix.

 

[WOPL Sniffer]

You’ll have that 700 singing soon Bob. Everything you need can be cobbled here. Contact Gepetto (Joe)...White Oak Audio. He’s got all the upgrades you’ll need. Many documented builds to watch/read. Welcome to Phoenix.

That's an original split face 700. Not as much available.

 

[WOPL Sniffer]

Hi, My name is Bob Moore and got the gift of retirement 3 years ago, and sorting through lots of old projects, usually too many at once. Dad was a Philco guy all the time I knew him and left way to soon leaving me with a yearning for all sorts of old electro mechnical stuff and I have collected pretty well.

Just pulled this gnarly old 700 out of the back closet as I am also working on a couple other amps. Started building popular electronics SWTPC amps back in the 60's and 70's then graduated to other stuff as it became available.

The 700 had a blown main fuse, but found out one channel is ok by leaving the other fuses out, so now wondering how many bad outputs etc, never worked on an amp quite like it! I can run it on a lightbulb ballast and wondering if probing all the emitter resistors is a way to start or if I should try and start unplugging them and start testing out of circuit??? and what is ON Semi replacement recommended? Just got a set of MJ15003/4's for the Marantz 15 I have apart but these NPN's seem to have a higher rating with the 100V rails . . .

Thx for the add!

-Bob

I'd start by Off-Lining the outputs/drivers one at a time.

 

[grapplesaw]

Hi Bob Welcome

You can follow this procedure to find blown output transistors. Of coarse make sure the power is off and power caps are fully discharged before poking at that thing. It’s kind of deadly. Remove rail fuses to isolate each channel

 

[Lazarus Short]

WELCOME!

 

[kevin]

Well you can bet that your in the right place …. Welcome.... Look forward to watching you repair that Monster and bring it back to life !!!

 

[PhilcoFord]

Thx, sounds like a good plan!

Hi Bob Welcome

You can follow this procedure to find blown output transistors. Of coarse make sure the power is off and power caps are fully discharged before poking at that thing. It’s kind of deadly. Remove rail fuses to isolate each channel

 

[kingman]

Welcome!

 

[Bradrock]

Welcome to Phoenix Bob! 3rd gen FoMoCo man here. My folks & grandparents had Philco EVERYTHING! And it was good product too.

 

[PhilcoFord]

This amp has a pretty ugly chipped black painted face, not sure if that is typical of the early models or if someone repainted a nice anodized front panel? Also meter faces showing a couple cracks, not sure if it is plastic degradation or what! I think it wants some paint stripper, I usually use carb cleaner And I could use more room and another tech bench or two! OCD . . .

 

[PhilcoFord]

Welcome to Phoenix Bob! 3rd gen FoMoCo man here. My folks & grandparents had Philco EVERYTHING! And it was good product too.

Thx, started as MoPar in HS then Ford bought Philco ~'61 where dad worked and died on his BD 10/5/70 and Ford products started coming and going all too often, except for the '67 GT/A 289 Mustang the folks helped me buy as a lease turn-in in '68. Just bought my first 'new car' last year- Tesla Model 3 joins the stable along with a project '58 Dodge wagon, another '67 Fastback 'stang bunch of motorcycles, projects projects projects! lol anyone in norcal get in touch for laughs, right outside of sacramento sierra foothills after escaping sunnyvale/south bay area! Apple 7 years in the good 'ol days, Adaptec 10 years in Milpitas then 12 years at Intel Folsom doing 1st level FA on their SSD's

 

[PhilcoFord]

Did you know Philco built a Satellite? This was Dad's 'pride and joy' at work ~1960- https://en.wikipedia.org/wiki/Courier_1B (and so far we are lucky here not to be affected by the power shutdowns! isolated pocket near a substation

 

[WOPL Sniffer]

Did you know Philco built a Satellite? This was Dad's 'pride and joy' at work ~1960- https://en.wikipedia.org/wiki/Courier_1B (and so far we are lucky here not to be affected by the power shutdowns! isolated pocket near a substation

Bob, I say that the satellite is a Disco Ball they launched (Kinda early for a disco ball). Iffn it looks like a disco ball, gotta be a disco ball!!!!!

 

[WOPL Sniffer]

They say it was "Lost" right after launch? Disco Balls can't be too hard to find........ They are all Chinee with all the mirrors and stuff......

 

[bill7621]

Welcome to Phoenix Bob. You'll like it here. All these guys are laid back and take everything in stride.

 

[bill7621]

Like your "similes" Perry

 

[jbeckva]

Hi Bob,

First thing I'd do is (well, if you really REALLY want to have it last from your repair) junk all of the outputs except the bottom row drivers (typically RCA 401's and whatever escapes me at the moment), and replace them with on semi MJ21196's. Check the physical condition of the sockets as well as all emitter resistors to be sure none are out of spec. Just one could be walking wounded, and fail down the line taking out what you already replaced.. shower.. rinse.. repeat.

Put together a WO driver board in quasi mode, 700 DCP from Don Imlay plus new main caps if they're the old 9800's, then fire that guy up again with a dim bulb and whatnot. LMK if you need a 700 series I faceplate - I think I have one sitting around in the other room clean but doesn't come with the smaller meters.

Bob Moore sounds familiar for some reason.. Welcome to Phoenix.. post up some pics of the amp when you have some time!

 

[PhilcoFord]

They say it was "Lost" right after launch? Disco Balls can't be too hard to find........ They are all Chinee with all the mirrors and stuff......

The first one dad watched blow up just after lift off, second one ran for about a day then locked up with a software glitch. Disco balls don't use ~7 R2R's lol
ok you guys asked for it, philco spam and real world Bob's shop tour . . .