Extended Foreplay 3 Help

[John EH]

I resoldered every hook up wire on the regulator board and now I have faint glow in three LED's. Voltages are the same.

John

[Paul Birkeland]

Can you do the I/O pads on each of the outboard boards as well?

Is the center 12AU7 glowing?  It would appear to not be operational at this point.

-PB

[John EH]

Can you do the I/O pads on each of the outboard boards as well?

Is the center 12AU7 glowing?  It would appear to not be operational at this point.

-PB

Regulator 12AU7 is glowing

Left Board
A side
I - 162.7
O - 95
B side
I - 0
O - 96

Right Board
A side
I - 163
O - 75
B side
I - 0
O - 78

Obviously I need to see why I'm not getting any I voltage on the B sides.

[Doc B.]

Check to see if you have all of the jumpers on the boards. It is pretty easy to miss one.

[John EH]

All jumpers installed.  5 on the reg board and one each on the grounds of the C4S boards.  All ohm out ok.

[Paul Birkeland]

The "I" on the B side is the ground, don't look too hard into that

At this point, you could actually listen to your preamp, which is good, but the regulation is still off.

Is there any way you can post a photo of the center C4S board?

Also, it is good to double check that the wires leaving the Kreg pads are going to the appropriate tube socket pins. 

-PB

[John EH]

Yeah I saw that when I saw the wire running to the center tube socket!  Ha ha.

It's working and sounds damn good.

Stand by for the photo

[John EH]

Photo.  Only thing of note is the LED I subbed which I mentioned in the first post.  Radio shack 276-026a. 

[John EH]

Oh yeah K wires go to R3 and R8

[John EH]

In the photo the B end upper LED is the one not lit.  The other three are very dim.  My subbed LED is dim.  Ohm meter diode setting says they are installed correctly.

I followed the trace at the top of the board to the last LED leg in the line and got 1.8v with the diode checker.

They all seem to have 166 (or so) volts on both sides of each one.

[Paul Birkeland]

Oh yeah K wires go to R3 and R8

Yes, they should, but if you have them switched, things fall apart.

You can set your meter to the continuity beep, then put one probe on + on the A side.  Either pin 1 or pin 6 will beep for that connection.  Now move your probe to the K pad on that side, then move to the accompanying cathode (3 for 1, 8 for 6) and you should get continuity. 

If they are switched, the regulators can't keep things in balance.

That dim LED could be from the adjacent R1 not being well soldered.

-PB

[John EH]

Oh yeah K wires go to R3 and R8

Yes, they should, but if you have them switched, things fall apart.

You can set your meter to the continuity beep, then put one probe on + on the A side.  Either pin 1 or pin 6 will beep for that connection.  Now move your probe to the K pad on that side, then move to the accompanying cathode (3 for 1, 8 for 6) and you should get continuity. 

If they are switched, the regulators can't keep things in balance.

That dim LED could be from the adjacent R1 not being well soldered.

-PB

On + pin one beeps.  Moving to K makes pin 3 beep.

I'll reheat the R1's

[John EH]

Reheated the R1's and K's.  Same same.  3 dim LED lights.  Voltages the same.

[John EH]

Regulator tube PLENTY hot too

[Paul Birkeland]

Can you swap in a different 12AU7 to the center socket?  Everything looks just spot on, but the 12AU7 is not cooperating.