Another WOPL 700B buld

[Billboard]

New fuses installed, drivers installed, stable bias, +-15v, excellent bias.

Installed one row of outputs, everything still stable, installed all of the outputs, all seems well.

Whats next? wire up the input pots and run some test tones? what output voltage, what frequency?

I do have one 8 ohm load on hand.​

 

[laatsch55]

Start with 10 volts output at 1Khz, work up to 65 volts out, that's clipping....

 

[laatsch55]

How many watts is your load??

 

[NavLinear]

New fuses installed, drivers installed, stable bias, +-15v, excellent bias.

Installed one row of outputs, everything still stable, installed all of the outputs, all seems well.

Whats next? wire up the input pots and run some test tones? what output voltage, what frequency?

I do have one 8 ohm load on hand.​

What is the wattage rating of your load resistor?

Damn - too slow on the keyboard. Lee got to it first.

 

[Billboard]

1000 watts

 

[NavLinear]

1000 watts

Damn - you've got that covered and then some.

 

[Billboard]

Ran both channels at 10 V p/p, then cranked it up to 50 V p/p (that is all my ipad/tone generator will output).

All looked clean and stable.

Connected up a set of test speakers and now she is playing some Steely Dan. Sound very good, I will let her sing for a bit in the basement, still waiting on an LED board, then I will assemble the front plate and bring "Ruth" up to the main room and see how she does.

 

[Billboard]

Here is a picture of Ruth at this point

 

[laatsch55]

Lookin good....

 

[Billboard]

For my next build, how do you guys prep the transformer, I just cleaned and painted the cover, do you guys paint the transformer? Too late for this build at this time, but the next one I would like a better looking lump.

 

[WOPL Sniffer]

Oh man, do I dig the lacing!!!!!!!!!!. We were taught in the old days in the Nav to do that but that's old school bro...... since the chumps with no sense of workmanship or imagination invented zip ties, we NEVER see this technique...... I got a big fat woodie..... but, I gotta use zip ties..... I forgot the how and the what....... bravo.... you be my hero now Bill.

 

[Billboard]

Thanks Perry, we still use the lacing cord in the Telco industry, I know how to use it to secure wire to overhead racks, but just took a guess on using it to bundle a wire harness. Lacing cord is used at work because it is impossible to pull too tight, where a plastic zip thing can be secured too tight. Plus the lacing cord will not scratch you when working in the overhead racks.

 

[Billboard]

Meter board goes in tonight, quick question, no ground required for meter board. Why no grounds for the left and right inputs?

I have

1=right input
2=-20db switch R
3=orange, from 20db switch
4=grey from 20 db switch
5= 20 db switch L

14=AC
15=AC
16=left input

 

[Gepetto]

Meter board goes in tonight, quick question, no ground required for meter board. Why no grounds for the left and right inputs?

I have

1=right input
2=-20db switch R
3=orange, from 20db switch
4=grey from 20 db switch
5= 20 db switch L

14=AC
15=AC
16=left input

ground is 3 and 4


4 is ground in
3 is ground out to the attenuator switch

 

[WOPL Sniffer]

For my next build, how do you guys prep the transformer, I just cleaned and painted the cover, do you guys paint the transformer? Too late for this build at this time, but the next one I would like a better looking lump.

I go over the whole thing with the green scotchbrite pads, clean the wires with a rag with a bit of acetone, prime it with some self etching primer and then a light coat of semi gloss black. Tape up the serial number of the trans cover, carefully apply stripper, clean, sand and then straighten the flange all the way around, then clean again, and hit with self etching primer. Sometimes it's a bitch to get the paint to stick to the cover. Some covers were tin and some were die cast. The die cast covers are a mofo to get paint to stick to as corrosion has sunk in over the eons since the amps were built. even the aluminum parts get the treatment depending on how bad they are. I end up spending a lot of time on them. Then, after a couple days, hit them with a coat of clear. you CAN use semi gloss for the covers too. They look nice like that. Be careful with the serial labels. They have a piece of clear plastic over the label and it is easy to lift it so after paint, but before clear, pull the tape off the label and clear over it. PULL THE TAPE OFF AS SOON AFTER YOU PAINT IT BLACK. Otherwise the paint makes the tape nearly impossible to peel off if the paint has totally hardened. Sometimes, if I have time, I leave the cover up on the shelf for a couple weeks to fully cure. I also pull the old rubber bumper/foot off the cover and put a new one on. The original is riveted on, just drill out the rivet and drill the hole in the cover to accept a 10-32 screw and put a nut on it from the inside. Double nut it and use locktite so you don't have fod floating around should it work loose. Make sure the 10-32 screw is not too long or it will dig into the wiring of the trans and POOF.... Lights out.......

TMI bro????


Perry

 

[Billboard]

ground is 3 and 4


4 is ground in
3 is ground out to the attenuator switch

where does the "ground in" come from? the bus bar?

I will wait for an answer, but I assume the busbar, cause that is where all of the grounds come from, except one chassis ground.

 

[laatsch55]

Yep, got it in one Bud.....

 

[Gepetto]

where does the "ground in" come from? the bus bar?

I will wait for an answer, but I assume the busbar, cause that is where all of the grounds come from, except one chassis ground.

Yes, the ground bus bar between the caps.

 

[Billboard]

I am happy to report that the amplifier is done, kinda sad it is over, it was an awesome adventure.

Next on the bench will be a sad Pioneer SX-580 with one dead channel.

 

[laatsch55]

Excellent Bud!!!!