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previous: Bernie Baer Barry, grounds tied in at t... -- 1092459173 View Thread

Re: Substitute tubes....

8/14/2004 9:45 AM
Bruce /Mission Amps
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Re: Substitute tubes....
I'm fairly certain the jacks are not the real issue but I'll send you some new ones.  
I'd say before you do anything further, remove the jacks and make sure all the solder joints are good, with nothing plugged into the jack the switches are closed and after reinstallation, the jacks are grounding propperly... especially to the 82022uF cap of the 12AY7.  
If you can tap around and still find a noise here and there,... and it does it at certain frequencies, it can be a multitude of different problems.  
One of which could be a shorting jack that does not short out but you'd only hear a noise if the offending channel's input jack is open and that channel's volume control is turned up.  
Causing a change in noise by messing with the tone control should be a signal that you might have a parasitic oscillation going too.  
 
By the way, I need to set the record straight.  
Not all those questionable switching jacks were bad.... there were only a few bad ones in a new box of 100.  
These were "supposed to be" Switchcraft jacks... that ended up being some unmarked Chinese import thing that was substituted with out my vendors knowledge.  
After four or five problem jacks in as many kits and finding a few open ones in my parts bin, I pulled them.  
The next batch were all marked Switchcraft again.  
More importantly, I've not run across ANYONE who had all 5 of the jacks be bad in one amp PLUS, I've was been able to adjust any of the bad ones to work properly by retensioning the switch blade of the jack in question.  
 
Bruce

 
Replies:
Bernie Baer Thanks Buce,I'll just rewir... -- 8/14/2004 8:23 PM
Bernie Baer Seems that normal:2 jack is not sho... -- 8/14/2004 10:21 PM