Need help with PJCCS

[tominredbank]

Hi and hope someone can give a hand. Built and used the Quickie with great success. A couple weeks went by and I installed the PJCSS. The right channel works fine but not the left. I checked and rechecked all my connections and went over the solder joints.All the voltages are where they are supposed to be on both A and B but  dead silent on the left. I imagine I can rule out the diodes if it shows proper voltage. Think a bad transistor?

[Paul Birkeland]

(Assuming you have the Quickie 1.1)

If the OB/OA voltages are both below 25V, then the PJCCS is functioning correctly. 

If the voltage at OA or OB matches IB, that would indicate an issue with the CCS.

First, swap the D-cells from side to side to be sure one isn't dead.  (With the PJCCS, they must be oriented properly)
Also, swap the tubes from side to side just to be sure.

If that doesn't help, what I would do is to solder a bare piece of wire temporarily between the center lugs of each level of the volume pot.  This will short the inputs together, and you can use this to see if the problem is before the input to the 3S4.  If this doesn't help, let us know.

-PB

[tominredbank]

Hi and thanks for the response. I just measured OA at 35v ,,, OB at 24v and B1 at 35v. At this point thinking of leaving it out. Do you agree I can rule out diodes? Do you know how I can check transistors? Thanks,,,tom

[Paul Joppa]

OA at 35v means the tube is not conducting. Most likely is the center terminal on the transistor (to which OA is connected) - it harder that the other solder joints to get it hot enough. Second most likely is the tube may not be getting filament power from its D cell. The glow is nearly impossible to see, so trace the wiring and check the voltages on that tube.

[tominredbank]

Thanks for the info. I`ll give the transistor a try when I get back from vacation,,, tom