Bottlehead Forum
Bottlehead Kits => BeePre => Topic started by: Lee Hankins on June 29, 2013, 08:38:40 AM
-
When I use the fine selector switch the left channel has no sound, have been looking at the manual for days and have not been able to find the problem. Both channels work using the course switch, and the right channel works with the fine switch, left channel has no sound with the fine switch.
Cordially,
Lee Hankins
-
Lee, grab your meter and go for it. I'll bet it is a misplaced wire. I have confidence you can trace the circuit (which I don't know).
-
Hi Lee,
I'm not sure if I understand how it's working. You say the coarse works but the fine makes no sound. They are cascaded together, so if the fine is not passing signal, the coarse shouldn't be working either. Or is the fine passing signal but just not adjusting the level?
-
Hi Dan,
The course works as it should, the fine works at 0db on both channels, when one adjusts the fine volume (away from 0dB) no sound comes through the left channel, right channel works as it should. This makes no since to me, and have "grab your meter and go for it" trying to figure this out on and off for several days now. Even replaced the BeeQuiet with 100 ohm PAC pots, worked as it should, sounded really nice with the PAC pot.
Only try to use the knowledge from the board as an last resort. Only took two months to get the amps left channel working, ending up purchasing new boards for the left channel, worked immediately after installing the new boards (Thank you, Eileen). My trouble shooting was just not working, I keep blaming it on my "chemo" brain. I really get embarrassed having to ask for help, shouldn't let it bother me but it does. Not sure if this is a healthy trait. :)
Cordially,
Lee Hankins
-
Shoot, Lee you have built some of the most awesome looking versions of our amps I've ever seen. No need to feel bad about talking through a tough dog. We do that kind of thing at work all the time. Some times we just need someone's different perspective to help figure put something that eludes us. Unfortunately I am away from my notes today. But PB knows the design inside-out. I'm sure he will take a look here and post some suggestions.
-
Hello Lee,
On the fine switch, there is the pair of resistors that come in from the 5 lug terminal strip to the lower lugs on the coarse switch, then a teflon wire leaves that same lug and goes to the coarse switch.
If you had that wire on the offending channel leaving one of the upper switch lugs (like the one that should have no resistor on it), you would get the exact symptoms described.
I just built out Clark's BeeQuiet last night, if you pop a photo up of your build, I can look it over for you.
-PB
-
Thanks Paul,
That was the problem, thank you very much. I did look at those connections but it just did not register that they were not identical, kept seeing the samething on both sides. Again, thank you very much.
Listing to Bach right now, great sounding preamp. I now need to finish the woodworking, hope that this will be one of the best looking amps that I have ever built, using a bamboo cutting board as the sides, the top has been covered with Alsa graphite FX Sheeting, interesting look, easy to install, no painting.
Cordially,
Lee Hankins