85K in one channel, 100K in the other?

[hansandersen]

Hi all,

I just finished assembling a Quickie.  First kit ever, first time with a soldering iron, et cetera.  Most everything went smoothly (aside from trimming a wire too short to reach Terminal 9 - thank goodness Terminal 10 was handy and unused!)  It sounds great pushing a pair of AudioEngine 2's, and once I get a proper case finished up I'll try it out in the big rig.

Only one mystery remains - In the final resistance-testing step, Terminal 1 ranged from 0-100K as expected, but Terminal 5 only ranged from 0-85K.  Is this within reasonable tolerance?  If not, how could I go about addressing it?

Thanks,
-Hans

 

[hansandersen]

Same Quickie, two new problems:  First, nevermind the proper case finishing, I stuck it in the big rig anyway.  And noticed that every 12 seconds, there's an audible, consistent BZZT out of the left channel.  Each bzzt lasts about 200ms and it's loud enough that it's still very obvious and annoying when playing music.

It's not the source, because it happens even with no source components hooked up.  It's not the tubes, I swapped them and it stayed on the left side.  It's not the cables or any downstream components, I hear this in two systems (although with the little Audioengines I have to strain to notice).  It's probably downstream of the potentiometer, because this happens regardless of where the volume is set.

Second, I seem to have accidently broken something, as the right channel stopped working.  Voltage is 0 at A1, A3, A5, and A7, and 36V at A2, A4, and A6.  T2 is 0 as well.  All other terminals are working as expected.  All the solder joints in the path look okay, but that's no guarantee as it's a first-time soldering job!

Any help would be greatly appreciated.

 

[Paul Birkeland]

I would guess that the connection to the cathode of the offending channel is bad (the wire that leaves the 1k resistor/1000uf cap to the tube socket) since you aren't getting any voltage there.


I think that periodic noise may be your cell phone.  Turn it off and see if that helps.

-Paul

 

[hansandersen]

Thanks for the advice.  I strengthened some weak solder joints, and I completely removed, replaced, and re-soldered the wire from T1 to A5.  Now I'm getting "-1.5" V at A1 and A7.  (as opposed to 1.5V at B1 and B7.)  Flipping the appropriate D battery is turned that from "-1.5" to "1.5".  This seems bizarre to me - not bizarre that flipping the battery changes the polarity, but bizarre that the polarity was negative when the battery was "properly" inserted.

Meanwhile, A2, A4, and A6 are still 36V. Any advice on where to look next?

Thanks,
-Hans