K3cT
Headphoneus Supremus
- Joined
- Apr 1, 2007
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I thought you could buy the TO-220 thermal and electrical isolation package from Mouser and that was what I did for each and every heatsink in my Beta22.
I thought you could buy the TO-220 thermal and electrical isolation package from Mouser and that was what I did for each and every heatsink in my Beta22.
It appears I put in the trim pots in backwards, as Anonanimal guessed. I had assumed that the marking on the board should have matched up with the arrow symbol on the trim pot, but it seems that marking was referring to the position of the control screw. I verified my mistake by checking the trim pot data sheet and Beta 22 schematic.
I guess the question now is what parts are likely to have blown as a result.
Also a general question regarding the B22. I have this desire to have a remote control input and source selection, the easiest implementation I thought would be to bypass all attenuation on the B22 and use it as a headphone "power amplifier" and using a high quality (possibly Audio GD Phoenix) pre-amp as the control center and using its remote source switching and volume knob. Is this feasible or would it be self defeating in the pursuit for "perfection"? The absolute best speaker setups seem to always have an active preamp ahead of the power amplifier.
Hi, I just wanted to ask those that purchased a Glass Jar Audio kit whether or not some of the important components are matched as recommended by AMB?
Ti... you are an evil man! I now absolutely have to build that!
what a strange fix. it shouldnt matter which way the trimpots are installed... it only alters the direction of adjustment, not the total adjustment as pin two is the wiper. Something else must have happened, maybe a bad joint or something?>
When VR1 and VR2 are mounted backwards, their direction of adjustment is indeed also reversed. If you then follow the β22 website initial setup procedure and pre-set those trimpots fully-counterclockwise before powering up, you've just set them up for maximum bias. On a β22 this means a lot of current is going to flow through the stages, and the output MOSFETs are going to get really hot in no time.