Derek92994's 700 Ser II White Oak conversion

[laatsch55]

Check to make sure that the pots are not touching any part of the light board.

 

[laatsch55]

And , does it act the same with the meter attenuation switch in the minus 20db setting?

 

[derek92994]

Took off Face Plate and inspected. Pots not touching, everything else is clear from touching. Yes it does the same thing when the 20db switch is on.

 

[laatsch55]

Then ya got one of the wires reversed somewhere...

 

[derek92994]

I just checked the two photos with the old and new light board, I have connected the wires correctly. Any wires that are the same color were numbered so the correct order was used when installing the new board.

Old Board:

New Board:

Which wires should I try swapping or is there something else I can do to troubleshoot this?

 

[WOPL Sniffer]

Derek, I got my pic out of the wire connections and it looks to be correct. Just verify with the multiMeter that the white wires you have going to pads 1, 4 and 15 are going to the right place. I only use white wire for grounds so it's easy to trace. The Attenuator switch is a BIG PROBLEM and they are impossible to clean or find new ones.

Pad 15 you have a white wire on and it should be one of your AC lines (14 and 15)
pad 4 you have a white wire on and it should be ground from the ground bar on the caps or star ground.
Pad 1 you have another white wire on and is your right channel input (pad 16 is left channel input)

It appears your attenuator is correct connection wise, (but may be dirty inside) does it always act FU or can you mess with the attenuator knob and get the meter to work corretly???


Perry

 

[derek92994]

Derek, I got my pic out of the wire connections and it looks to be correct. Just verify with the multiMeter that the white wires you have going to pads 1, 4 and 15 are going to the right place. I only use white wire for grounds so it's easy to trace. The Attenuator switch is a BIG PROBLEM and they are impossible to clean or find new ones.

Pad 15 you have a white wire on and it should be one of your AC lines (14 and 15)
pad 4 you have a white wire on and it should be ground from the ground bar on the caps or star ground.
Pad 1 you have another white wire on and is your right channel input (pad 16 is left channel input)

It appears your attenuator is correct connection wise, (but may be dirty inside) does it always act FU or can you mess with the attenuator knob and get the meter to work corretly???


Perry

I get the same behavior at 0db or 20db setting, of course there is more meter movement at 20db. As for checking where the wires go, I will look into this tonight as I have an appointment to attend shortly. Thanks for your advice.

 

[WOPL Sniffer]

If it's not affecting your audio, just the meters, your attenuator switch is probably afu. It messed me up looking at the thread title "700 Series II WO conversion" and you are showing a 700B meter/light board....

I just had one of mine go bad, doing the same thing, they are crap and if you try to take it apart and clean it, you may never get it back together again. Ask Lee....

I found a switch that would work but it is too big and interferes with the light board. There are switches out there that will work, just need to take the time to suss it out.

 

[WOPL Sniffer]

What is TV?

Ok I will Isolate it, but I don't want to power it down

I notice you said you have a buzz, I had the same thing, do you have LED lights near it (not your light board/meter board). I have an LED set up for my turntable and when I plug it in, it gives me interference. I was just going through this post trying to figure where the series II left off and the 700B started.

 

[derek92994]

I notice you said you have a buzz, I had the same thing, do you have LED lights near it (not your light board/meter board). I have an LED set up for my turntable and when I plug it in, it gives me interference. I was just going through this post trying to figure where the series II left off and the 700B started.

The Buzz is gone, I had the amp powered up for months and the buzz was getting louder very slowly, when I could just hear it in the listening position I decided to power the amp down over night. Ever since then the buzz has been gone, the amp is powered down each week night, and is sometimes left on all weekend.

 

[derek92994]

I'm very tired from the working week and have decided to just enjoy the music tonight, lets see what Lee has to say about the troubleshooting and I shall investigate further tomorrow morning when I'm more fresh. Its 5:15pm here now, time for dinner, a drink and some loud music.

Thanks for your info though, will keep an eye on this thread. I could never tell if the attentuator was bad as I have only had 1 meter since getting the amp, the needle fell off the left channel meter during transit, long way to australia.

 

[WOPL Sniffer]

What transformer does it have on it? Is it the original Series II Transformer with a 700B Face on the amp?? The voltages to the Light Board/Meter Board are different and will cause crazyness. The taps for a 700B are like 6.3VAC for the light board, and the series II transformer is like 5VAC. I tried to see the power connector above the transformer mounted on the chassis but cant tell. Most of the series II's had a yellow and orange wire coming from the transformer to the 2nd and 3rd hoop on the connector and they were stranded wire from the trans. The majority of the 700B's had a pair of single strand (heavy) wires going to the 2nd and 3rd post. I could be way off but it's hard to see what you got going on. Make sure the 2 ac wires are coming from the 2nd and 3rd loop on that power bar above the transformer. there is a real tiny wire from the first loop to the second which acts as a fuse for that 6.3.


What is the serial number on the transformer backplate?

 

[WOPL Sniffer]

I'm very tired from the working week and have decided to just enjoy the music tonight, lets see what Lee has to say about the troubleshooting and I shall investigate further tomorrow morning when I'm more fresh. Its 5:15pm here now, time for dinner, a drink and some loud music.

Thanks for your info though, will keep an eye on this thread. I could never tell if the attentuator was bad as I have only had 1 meter since getting the amp, the needle fell off the left channel meter during transit, long way to australia.

Yup, you can hold off for Lee, No Problem.

 

[derek92994]

A bit hard to read, but some of it is there. The original amp had a hard life on the road until it was in a truck roll over. Lee used what parts he could to build this beauty from scratch. Its been a brilliant amp.

 

[WOPL Sniffer]

My question was--- Was it a 700B originally or was it a II ???? I can't read the serial number.

 

[WOPL Sniffer]

I went back to the first few pages and it says it's a series II and if that transformer is from a series II, you will have issues with the 700 Light board. The old light board may not have had a problem with the lower Series II voltage but the new LED board might. The rest of the WOPL parts are no problem, just the ac for the light board.

 

[derek92994]

My question was--- Was it a 700B originally or was it a II ???? I can't read the serial number.

Only Lee will know the answer to that. All I know is that it was a Clair Bros amp.

 

[derek92994]

I went back to the first few pages and it says it's a series II and if that transformer is from a series II, you will have issues with the 700 Light board. The old light board may not have had a problem with the lower Series II voltage but the new LED board might. The rest of the WOPL parts are no problem, just the ac for the light board.

I think I heard Lee refer to the light board as a "high voltage" light board at some stage.

 

[laatsch55]

That light board is specially built to handle the 12 volts from the series II transformer. The only thing Series II about that amp is the transformer.

 

[WOPL Sniffer]

Cool.... I couldn't read all 100 pages.