[Mountain-ear]

Hi all -

I moved to a new house, and all the gear has been in storage for a couple of months.  I finally got a chance to hook things up, and I seem to have lost the right channel on the pre-amp.  Here are the symptoms:

     -- When playing tuner or CD, I get sound on the left channel but not the right.
     -- Rotating the balance knob doesn't seem to have any effect (other than shifting from the speaker that plays to the speaker that doesn't).
     -- If I push the R Mono button, both channels go out.
     -- If I push the L Mono button, both channels play.
     -- I tried changing the tubes in on both channels, but it didn't change anything.

Any suggestions on what to do next (aside from shipping it back to Frank)?

Thanks.

Steve

[avahifi]

Since you get both channels out when you use the Left Channel button, then both audio channels of the preamp are working fine.

The issue must be ahead of the active circuits.  The most likely culprit is dirty contacts in one of the pushbutton switches.  Pull the cover, spray each of the switches from the top with Caig Labs Deoxit D5 contact cleaner, exercise each of the pushbutton switches several times and try again.  Deoxit is available from Parts Express.

The switch contacts are gold plated and never oxidize by themselves, but something in storage could have contaminated them. If this does not help call me for more help.  651-330-9871

Frank Van Alstine

[pansixt]

Stellar Customer Support Huh West By God?

I also have the T-8.

James

[Mountain-ear]

Just one of the many amazing things that Frank does for his customers.

Thanks, Frank!  I think I can get De-Ox-It at Rat Shack, in which case, I'll try it tomorrow.

Steve

[Hydro]

Are you sure you are getting an input on both channels? Try switching the input cables and see if the problem stays the same.

[avahifi]

Since the issue was reported to occur on two different input sources, both tuner and CD, we can assume the issue is not with a source or with the cables connecting the source to the preamp.

Likewise, if there is two channel output when switched to left mono, which feeds the signal from a single input to both audio channels, then we can also assume the issue is not with an active audio channel, the output cables, or the amplifier.

Thus the issue must be somewhere after the selector switch and ahead of the controls.  The only parts remaining to investigate would be the switch contacts or very unlikely a broken wire or a bad solder connection into the switch board or out of the selector switch.

Inadvertently have a shorting RCA plug inserted into a Tape Out jack would do the trick too.

Frank Van Alstine

[Listens2tubes]

Inadvertently have a shorting RCA plug inserted into a Tape Out jack would do the trick too.

Frank Van Alstine

I have a cable connected to Tape 2 Out going to my desktop computer. The cable terminates as a stereo ¼" phone plug. If that plug is loose in it's socket or disconnected but partially grounded to the computer, this same problem occurs.