Kevin's "I Want a Phase Linear 700 B White Oaked" thread

[soundude]

Joe now is the voltage swing dependant on the level, meaning at lower than rated output or even say 25% loaded does it still see that kinda voltage? So the base will sit at full voltage and as the bias becomes more positive it has the transistor conduct to a ratio?

 

[soundude]

Lee all those albums are just about downloaded, unfortunatly only downloading at 75KB, was 100KB when I started....3 songs left...Yeah!! 4hrs...

 

[Gepetto]

It is definitely load dependent John. At low listening levels a 150V rated device would probably survive. But digital music has a very large dynamic range so even at reasonable listening levels, a loud passage could put you up near the stops. That is what Lee was discussing in an earlier response.

 

[Gepetto]

Yeah Mark, they actually made the 4281 and 4302 in the TO-3 can a while back. Probably still findable as NOS but no longer made as new. Too bad, these were the best devices.

 

[soundude]

Hey on another note want to order that light kit for this, and also you have the alps pots since the amp is open...once I close it up dont want to open for a while...shouldn't have to either...thanks Joe this thing sounds great!!!

 

[laatsch55]

Left side done. Emitter resistor replacement is.....................tedious.

 

[kevin]

kevin, the 700 is an all NPN output stage in an emitter-follower arrangement, with the negative half fed by the inverted driver Q7.

Thanks for the up-date Lee but I knew that already by looking at the pics.... hehehehe...

 

[laatsch55]

Well, glad you knew,. but it really was directed at Johnny D., but you knew too, ...so.........what don't you know???

 

[kevin]

See... That shows what I know... I thought you were talking to me .... Here is what I think know.... When I get that thing looks like all im getting of the old amp is the transformer, the wire, and the case it came in.... lol. Your doing a number on this thing !!!!

 

[soundude]

Lee looks like your burning the midnight oil...really getting into it, lotta work there. Just do yourself a favor and look over those rail solder joints!!!
What brand resistors are those 1%ers?

 

[mlucitt]

Yeah Mark, they actually made the 4281 and 4302 in the TO-3 can a while back. Probably still findable as NOS but no longer made as new. Too bad, these were the best devices.

Mouser has the TO-264 formats for $5.86 each. I'll keep looking for the TO-3 formats. It would be great if I could find 20 PNP devices (MJ4302A) to drop in one of the PL 700 amplifiers.

 

[Gepetto]

You are looking for the MJ in the TO-3 Mark. They introduced the L version when they went to the plastic pack.

 

[mlucitt]

I was thinking TO-3 and typed the TO-264 (TO-3PBL) package designation. Corrected, thanks.

Have you ever used the NJL type with the biasing diode on the same die as the junction?

 

[laatsch55]

Lee looks like your burning the midnight oil...really getting into it, lotta work there. Just do yourself a favor and look over those rail solder joints!!!
What brand resistors are those 1%ers?

Yep, had already found two bad solder joints on the one side.
Xicon I believe John.

 

[laatsch55]

See... That shows what I know... I thought you were talking to me .... Here is what I think know.... When I get that thing looks like all im getting of the old amp is the transformer, the wire, and the case it came in.... lol. Your doing a number on this thing !!!!

That's how it usually turns out Kevin, regardless of the warplans. After the first shot it's all from the hip after that.
The faceplate and meters are the same. Gonna have some brand new knobs though.

 

[laatsch55]

Managed to get the right channel stripped of ER's BR's and another bad socket. This one had separated from it's insulator/bushing part.

Finally wore out the Jazzer catter.

 

[laatsch55]

Houston--------.............???????>>>>>>!!!!!!!!..............

 

[ksrigg]

I know there has been some discussion on fans for the 400 and 700 amps, and I recently found thes on GearXS.com for 39 cents each. It had to be mispriced, but they may still be available. They are 12 V DC and draw .14 amps each. Three of them could be mounted in a frame ( as Lee has done) as they are smaller than the ones Lee made for mme. Question is...how to wire them. Do I simply get a 12V DC wall wart and wire the three together and on to the end of the power supply? I'm just looking for some help in doing this the right way...I know I probably don't want to series wire these? How is the best way to go about this...

Here is the link if anyone else would like to stock up on some 39 cent fans.....

http://www.gearxs.com/Everflow-80mm-2PI ... fan&page=6

 

[kevin]

Sure is a nice kitty cat !!!!! What I want to know is .... Will that remote work that cat ?????

 

[ksrigg]

Kevin...can you find the angle aluminum and fasteners I'd need to make up these fan units? I think Lee said 3/4" and he also had the part number for the fasteners in a thread somewhere...Is there a Home Depot near your work? I know we don't have one here in Wise..