Trouble shooting is where my knowledge and expertise is lacking, I am more of a parts changer. I have been in the process of building and F6 and for the most part things have gone very well. A lot of that is due in part of 6l6s help.
The other day I went to wire up one channel, I had my VOM on the .47ohm resistor and was ready to adjust the bias. I turned the amp on and got no voltage across the resistor. I verified I had voltages going into the board and checked voltages around some of the resistors. I thought I had found a fried resistors but it turned out to be a false alarm. While I had the board out I noticed their was a hole in one of the keratherm pads I had installed. I am confident it was not there when it was installed it. Prior to installation I cleaned the heat sinks and check for burrs prior to installation.
Any help would be greatly appreciated.
The other day I went to wire up one channel, I had my VOM on the .47ohm resistor and was ready to adjust the bias. I turned the amp on and got no voltage across the resistor. I verified I had voltages going into the board and checked voltages around some of the resistors. I thought I had found a fried resistors but it turned out to be a false alarm. While I had the board out I noticed their was a hole in one of the keratherm pads I had installed. I am confident it was not there when it was installed it. Prior to installation I cleaned the heat sinks and check for burrs prior to installation.
Any help would be greatly appreciated.
-issue is what , exactly?
I get not voltage ratings across the bias resistor R2 on board B. I am afraid I have fried a MOSFET because of a hole in the keratherm pad.
I bought the boards from the diyaudio store and I have been following the build guide pretty thoroughly. The schematic can be found on the build guide done my 6l6.which outputs , which exact schematic ?
I can post photos later tonight when I get home.care to post few detailed pictures ?
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Please post schematic.
What voltage do you measure across zeners?
Since I can no longer use photobucket to host images the best I can do at the moment is a link for the schematic. http://www.diyaudio.com/forums/gallery/data/500/F6_DIY_SCH.gif
I get 5.08V across Z1 and Z2.
That is your problem.
You need at least 6.2V Zeners
Where would I start looking for the cause of the lower voltage?
Where would I start looking for the cause of the lower voltage?
Are you using 5.1V zeners?
So I used the wrong zener?
Yes.
There is an error in the circuit diagram.
Are you using 5.1V zeners?
Correct....I do have some 9.1s somewhere but any other value I will have to order.
Recommendation is 6.2v zeners with 3k3 resistors.
Like this.
Can you send me a mouser link to LM329? Do you modify one of the legs because LM329 does not look like the axial zener diode I have in there now?
just use normal zenner
tweak it later , while listening next amp you're going to make
This is rather addicting so I can easily see myself tackling another amp.
Hopefully tonight once I get my girls to bed I will tackle this problem.
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