Johnny D's 700 Adventure

[laatsch55]

Builders choice, no particular advantage for any, or.

 

[laatsch55]

So you want 2 of the 10 space TO-3 sinks?? And on the bias trannie straps I'l send 4 of them.

 

[soundude]

Hi Lee, I'm bidding on 1 heatsinks now with 410's in them on ebay from the link you sent me so lets see if I win the bid, but would need one more so I can buy one from you. If I win the bid I'll send you the 410's and the 909's and 555's since I will be using the newer transistors. I would just need 2 bias straps rite?
Would I use a PL20 board from Joe? Or is there a different board for the 400?

 

[laatsch55]

Same board for all 3 builds. I will take any and all trannys you want to send. I think I had to give 23.00 for my batch of sinks and tranny's, so that's what I would bill ya for. 2 bias TO-92HS's is all you need .

 

[soundude]

did you pay that for a batch or apiece for the heatsinks? The to-92hs's are the straps rite?
So far still the only one bidding on the heatsinks....YEH!!

 

[laatsch55]

That was apiece.

 

[soundude]

Ok cool, heatsinks count me in for one unless I loss the bid, then I'll need 2, called and can do a walk in for the transformer so hopefull by this time next weel i will have the heatsinks and the transformer and I can start on the output...Does the heatsinks have the sockets?
Lee, I noticed on one of the schematics from the service manual, the ac output on the secondary side is 115-0-115 for the 400. Is that a misprint?

 

[laatsch55]

Yes it is John. Unrectified ac on the secondary should be around 56. The heat sinks have the sockets, 2N5039 drivers and RCA-410 outputs, 5ohm 25wat wire wound emitter resistors, and a cute little harness and plug.

 

[laatsch55]

AC voltage X 1.4 minus 1 volt for voltage loss over BR is a pretty close estimate.

 

[soundude]

Cool, thanks for the explination.
I'm not going to need the transistors or the resistors since none of them will be implemented into the amp. What amp were those heatsinks from with all those 410's?

 

[laatsch55]

A servo amp of some sort would be my guess.

 

[laatsch55]

" Judge me not by the sheen on my Faceplate, but by the weight of my transformer"

Seen on a sig line on AK.

 

[Gibsonian]

" Judge me not by the sheen on my Faceplate, but by the weight of my transformer"

Seen on a sig line on AK.

That's a classic!

 

[soundude]

Lee, check this out...http://www.antekinc.com/pdf/PS-15N80R.pdf" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;
I feel that the amp should have more current though, does this look right?
I know 1.5kva is speced but for the amp, but seems like needs more power!!! Just don't have it captian....[attachment=0:2o50uis1]1075581324_f8697267a0.jpg[/attachment:2o50uis1]

 

[laatsch55]

Plenty of current for a 400. The 80vdc is too much if that's already centertapped and not enough if it isn't.

Ok ,looked a little closer at it, on either 80vdc tap you can take either plus or minus, very cool little power supply.

 

[laatsch55]

From how I read it John you have 9 amps per 80vdc tap, so you would have 9 amps on the plus rail and 9 amps on the minus rail, double what you need, so it's just right of course.

 

[laatsch55]

" Judge me not by the sheen on my Faceplate, but by the weight of my transformer"

Seen on a sig line on AK.

That's a classic!

I thought so too Scott, that's why I had to post it.

 

[soundude]

Cool thxs Lee, That powersupply is nice has caps and rectifiers and regulated 12, 17 0r 24 volt secondary winding. Nice for a LED power meter using LM3915s. I won the bid to the heatsinks but it has wafer sockets, not the robust ones on yours. Havent heard from the seller yet though..thinking of just buying the 2 heatsinks from you...by the way how many do you have?

 

[laatsch55]

28 or 30 of em.

 

[laatsch55]

Johnny, those sockets are actually pretty damn good. They fit the sink like a glove, and are every bit as good as the old PL sockets. The green and black phenolic I have are pretty sensitive to the leads being a lot more tapered than what they are. The first set i put in I blew the back out of 3 sockets before i figured out what was going on. With the square ends on the factory TO-3 leads I thought it was just a snug fit, but no, they were getting hung up and blowing the plastic bosses which kept the lead tabs in place.