i've just finished modifying the input stage according to the diagram on mardis's site. Blackgates are still on order so I used some plain electrolytic caps rated 2.2uf 50v with 22k 1/4watt resistors. The amp plays fine for a few minutes, then it outputs heavy sputtering/distortion. Could this be due to the caps I used?
The diagram
shows the negative lead of the cap going to the resistor right? Are the blackgate c series nonpolar? Am I using the wrong type of cap?
thanks.
The diagram
An externally hosted image should be here but it was not working when we last tested it.
shows the negative lead of the cap going to the resistor right? Are the blackgate c series nonpolar? Am I using the wrong type of cap?
thanks.
It's been my experience that just about every foul up can be fixed. You just need to look at the input schematic and poke around a bit with an ohm meter to find "other" end of the trace...then bypass the trace with some blue wire.
I have to give mad props to those who've been able to solder thru hole leads onto those smd pads and get it to work. I would'nt even attempt it. For me it was much easier to remove all the parts in the signal path and then bridge these with blue wire. Basically making a direct signal path from the pot's connector to the signal inputs on the chip. I then ran the leads from my input caps thru the holes left behind by the removed connector.
I have to give mad props to those who've been able to solder thru hole leads onto those smd pads and get it to work. I would'nt even attempt it. For me it was much easier to remove all the parts in the signal path and then bridge these with blue wire. Basically making a direct signal path from the pot's connector to the signal inputs on the chip. I then ran the leads from my input caps thru the holes left behind by the removed connector.
I have the same question as KEC, because i read over and over that people use electrolyts as inputcap; in all me amps the inputcap is a good quality cap with no polarity (most off the time i use chateauroux polypropylene (MKP)).
i always thought a electrolyt is no good inputcap, but please tell me if i am wrong, and why i am wrong.
i always thought a electrolyt is no good inputcap, but please tell me if i am wrong, and why i am wrong.
I think people use NP electrolytics, such as Black Gate N or NX series, because they are physically small.
A film or film and foil cap of 2.2 or 3.3 uF is a very large cap.
If you have space in whatever chassis you are using, a film cap will work fine. If you have a LOT of space and money, try using a paper in oil cap, like the Jensen.
I personally use Sonicaps in all of my Tripath amp builds.
A film or film and foil cap of 2.2 or 3.3 uF is a very large cap.
If you have space in whatever chassis you are using, a film cap will work fine. If you have a LOT of space and money, try using a paper in oil cap, like the Jensen.
I personally use Sonicaps in all of my Tripath amp builds.
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