04-26-2017, 07:17 PM
Well...I have good news and bad news.
Good news: The IBAM board is hooked up, as are the 10 ohm resistors.
[Image: http://www.philcoradio.com/images/phorum...00_036.jpg]
Bad news: I found this warning in another AudioKarma thread, so after performing the test called for in that thread, I put the original weak Fisher 7189 tubes in place, and set the Variac to 110 volts.
My IBAM doesn't work.
The voltage across every 10 ohm resistor is fluctuating between 57 and 65 mV. And the trimpots have no effect. The sound is now distorted (probably, I suppose, because of the bias now being wacky?). D**n the luck.
I shall have to set this aside for awhile, and will return to it sometime next month. In the meantime, I would certainly appreciate any comments, suggestions, etc.
Edit: Forgot to mention...last night I cleaned the socket contacts of the V20 (7199) tube socket with DeoxIT and one of those tiny brushes meant to be used between one's teeth. The left channel seems to be OK now (no longer suddenly popping in after a few seconds' delay).
Good news: The IBAM board is hooked up, as are the 10 ohm resistors.
[Image: http://www.philcoradio.com/images/phorum...00_036.jpg]
Bad news: I found this warning in another AudioKarma thread, so after performing the test called for in that thread, I put the original weak Fisher 7189 tubes in place, and set the Variac to 110 volts.
My IBAM doesn't work.
The voltage across every 10 ohm resistor is fluctuating between 57 and 65 mV. And the trimpots have no effect. The sound is now distorted (probably, I suppose, because of the bias now being wacky?). D**n the luck.
I shall have to set this aside for awhile, and will return to it sometime next month. In the meantime, I would certainly appreciate any comments, suggestions, etc.
Edit: Forgot to mention...last night I cleaned the socket contacts of the V20 (7199) tube socket with DeoxIT and one of those tiny brushes meant to be used between one's teeth. The left channel seems to be OK now (no longer suddenly popping in after a few seconds' delay).
--
Ron Ramirez
Ferdinand IN