Left channel out (still causing trouble!)

[denti alligator]

Ok, switched it back to 2L/4L going to A5/B5, and the negative lead of the D cells going to A1-A7/B1-B7. This is how the manual says to do it. Certainly doesn't seem right.

Here are the new voltages:

1  -0.015
2  1.566
3  0
4  1.524
5  -0.029

6  16.09
7  24.16
8  8.03

A1  0.21
A2  14
A3  -0.013
A4  14.06
A5  1.566
A6  14.06
A7  0

B1  -0.026
B2  13.74
B3  -0.027
B4  13.74
B5  1.519
B6  13.75
B7  -0.022

I'm getting sound in the R channel. I've swapped input and output cables and tubes. I'll re-heat solder joints once we get the voltages right. Note: I accidentally left it on all night and drained the batteries, so I'm using "old" 9Vs that are measuring 8. I'll head out to buy new ones for more accurate readings, but obviously that's not the main problem.

[denti alligator]

GOT THE LEFT CHANNEL WORKING 

Reflowed a few more L channel joints. One of them must have been the culprit.

So: now let's get back to why the voltages are off... or are they still?

[Paul Birkeland]

So: now let's get back to why the voltages are off... or are they still?

Now that it's working, you should remeasure. 

[Paul Joppa]

No, it's not right. Sorry if my directions are wrong, or confusing - I have a bad flu and I'm pretty punchy the last couple weeks!

The D cell negative should go ultimately to tube pin 5. D cell positive to pins 1/7. You should see about 1.5v at pin 5, and about 3.0v at pins 1/7.

There is the switch in the way, and I'm going back to bed without figuring it out yet ... maybe tomorrow unless PB steps in, he's more familiar with the wiring, I don't have a Quickie at home.

[denti alligator]

Now that it's working, you should remeasure.

Voltages are as given above, though I did switch it back to the "mistaken" manual wiring. Should I switch it back? Or just reverse the D cell?

Paul, sorry you're not well!! Hope you're better soon.

[Paul Birkeland]

Without getting too confused by batter orientation, you can just flip the D-cells around and remeasure the voltages.

When they are in the proper orientation, the plate voltage pops right down where you want it.  If they are flipped, you barely get any voltage at all.

In the new version of the Quickie, the PJCCS actually won't operate with the batteries in backwards (a good thing).

-PB

[denti alligator]

Voltages with D-cells reversed:


1  0
2  1.59
3  0
4  1.55
5  0
6  16.41
7  24.59
9  8.2

A1  3.128
A2  23.55
A3  0
A4  23.56
A5  1.59
A6  23.55
A7  3.127

B1  3.063
B2  22.88
B3  0
B4  22.88
B5  1.572
B6  22.96
B7  3.066

Are these OK? Looks like pins 5 and 6 are a bit low.

[Paul Birkeland]

Those voltages would be consistent with 9V batteries that are somewhat low, but a circuit that is otherwise working.  How does it sound?

[denti alligator]

Those voltages would be consistent with 9V batteries that are somewhat low, but a circuit that is otherwise working.  How does it sound?

Pretty good!

[Paul Joppa]

Excellent! Now the numbers look right.

[denti alligator]

Thanks for your help, guys!!

[denti alligator]

Turned on the Quickie for the first time since solving this and the L channel is out again!

This is what happened last time: I reflowed some connections, it worked, then didn't work after a couple days.

It's not as if I'm a bad solderer... might there be something else at play here?

By the way, voltages all look to be OK.

[Paul Birkeland]

It's very likely a loose connection that's moving around as you're using the preamp.

[Paul Joppa]

IF the solder joints are good, then consider the tube socket.

[denti alligator]

Thanks, guys. A quick reflow job and it's working again. But I'm doubtful it will last long... We'll see.

Interesting here is how much better I like the sound of my SEX amp with the Quickie! I really miss it when it's out of the chain. That's kind of surprising.