Nick Danger's WOPL 400 Series II Build

Thanks for going into your reserves for the repair parts- you are quick!
 
That's what ya do when ya blow other people's stuff up....
 
Getting very excited about this amp, Lee. That coupled with brutal saying he would take a peek at the Yammie later this month, I may be talking to you about the Blocks sooner rather than later. Was it you that knows a fabricator for the faceplates?
 
Man, that was expeditious to say the least. Guess it's a bit late to request an IEC connector for the power cord......d'oh. Maybe I'll remember for the next build.
 
Nick Danger said:
Man, that was expeditious to say the least. Guess it's a bit late to request an IEC connector for the power cord......d'oh. Maybe I'll remember for the next build.
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Upon first glance, I'd say there's not much room if at all. 700 chassis' are different.. more opportunity there. Unless it came in from the side, but that makes it hard to rack or mount up.

Still have to solve the meter sensitivity challenge. Next time I'll pay attention to the shaft diameter when shopping for rotary switches (the one I ordered came in.. and well... it was "measured and found lacking" LOL)
 
And I heard the relay click....

And I said to myself, self... that was the nicest thing I heard all day.. heheh

-16mV offset, both channels
bias dialed to 380 mV

Time for a "victory smoke"...
 
Yeah, I find myself holding my breath for the click to haoppen...
 
Ran a few tests. Distortion was around .006 @ 2khz driven to about 100 watts. Frequency response not deviating more than .1db 20 to 20K, -3 dB point at 70K. Burned in a little with 200 WPC. No clipping across 20 to 20K. (gotta figure out how to do S/N hehe).

Suffice to say, it's ALIVE. Listening now, and it's no worse for wear..

Got a(nother) "robbed" 2N1305 in place, but have some NOS coming early this week. That's the last time I don't replace the "germs"... expensive lesson in both time and $$$. Until then she's going to take it easy... no beatings til later.. hehe.
 
I think you can do a SN by doing amplitude, rated output, then cut the input, the difference between residual and max out in DB is your SN.
 
jbeckva said:
Ran a few tests. Distortion was around .006 @ 2khz driven to about 100 watts. Frequency response not deviating more than .1db 20 to 20K, -3 dB point at 70K. Burned in a little with 200 WPC. No clipping across 20 to 20K. (gotta figure out how to do S/N hehe).

Suffice to say, it's ALIVE. Listening now, and it's no worse for wear..

Got a(nother) "robbed" 2N1305 in place, but have some NOS coming early this week. That's the last time I don't replace the "germs"... expensive lesson in both time and $$$. Until then she's going to take it easy... no beatings til later.. hehe.
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Did you figure out the root cause of the failure? I guess those germanium transistors are best replaced to keep the amp from imploding.

I'm sure you have this but I copied it from my service manual. Good job and quick fix Jer.
 

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NavLinear said:
Did you figure out the root cause of the failure? I guess those germanium transistors are best replaced to keep the amp from imploding.

I'm sure you have this but I copied it from my service manual. Good job and quick fix Jer.
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I'm pretty sure it was the 1305, Dennis. With a short emitter to collector (could have had one on the base leg too initially), that's essentially tying the channel's output direct to it's negative drive transistor (also kerplooyeeed.. ).

Yeah upon retrospect... you just never know how close to failure old parts can get, until it's too late.

Listening to it now... Yeah Doug... this one is on the order of Kev's 400 I did for him. Speee-tacular!! Every instrument is clearly defined and positioned. I can fall in love... heheh.. :hello1:
 
jbeckva said:
I'm pretty sure it was the 1305, Dennis. With a short emitter to collector (could have had one on the base leg too initially), that's essentially tying the channel's output direct to it's negative drive transistor (also kerplooyeeed.. ).

Yeah upon retrospect... you just never know how close to failure old parts can get, until it's too late.

Listening to it now... Yeah Doug... this one is on the order of Kev's 400 I did for him. Speee-tacular!! Every instrument is clearly defined and positioned. I can fall in love... heheh.. :hello1:
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Keepin' fingers and toes crossed!
 
jbeckva said:
Hehe..

So on the meter sens switcheroo.. Joe and I continued trading a few more emails. I think I have a better plan now, so if you want we can give it a shot. Gotta find the RIGHT dang switch tho heheh.
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Would be way cool for a low- level listener like me, but it's up to you, Jer. Maybe a 4 position switch: Off/Low level setting / Med level setting/ factory setting.

Should I start looking for an appropriate shipping case for her soon? ;-)
 
Good job Jer, just fixin to turn the Variac knob to the right on Przems...

I can't figure out anything on the Sens switch from the 700 schematic...
 
Nick Danger said:
Would be way cool for a low- level listener like me, but it's up to you, Jer. Maybe a 4 position switch: Off/Low level setting / Med level setting/ factory setting.

Should I start looking for an appropriate shipping case for her soon? ;-)
Click to expand...

Lee's going to give me my xmas present.. hehehe..

No, not really.
 
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