Eureka!

johngalt47 · 28th November 2004, 01:37 PM

My gainclone works!

I would like to thank Brian for the kit, Peter for the chassis and everyone who posted questions and the people who answered those questions.

So far it isn't completely assembled because I was doing some trouble shooting. Initially it was blowing 250vac 2 amp fast blow fuses at the input from the mains but that was fixed by changing to 3.15 amp slow blow.

By the way, the transformer is a +- 18vac, 300va from Plitron. I put a 19ohm load on the output of the diode board and the output of the board dropped from 27.5vdc to around 16 or 17vdc at about 870 ma.

I measured the temp of one of the diodes with that load and it only reached about 111 degF.

The dc offset on one channel is 71mv. I haven't measured the other yet since I don't have it connected to a speaker.

I'm using a separate preamp to do the source switching and volume control right now.

Nuuk · 28th November 2004, 03:29 PM

Quote:

The dc offset on one channel is 71mv. I haven't measured the other yet since I don't have it connected to a speaker.

Do not connect a speaker to measure the DC offset. A 10 ohm resistor is much cheaper to replace if there is anything wrong!

Apart from that, congratulations and it should sound even better in stereo!

johngalt47 · 28th November 2004, 03:46 PM

LOL

I used a multi-meter to check the offset....

Sorry for the confusion.

Scribble · 30th November 2004, 11:04 AM

I beleive Nuuk was reffering to using the 10 ohm resistor as a load on the output, While measuring the DC-offset with a multimeter.

And to NOT connect a speaker as your unaware of the DC-offset and it could be in the range of "speaker cooking"

johngalt47 · 30th November 2004, 11:27 AM

Yes, I understood and no, I didn't connect the speaker before checking the offset.

I didn't connect any load while checking the offset. I'll do that.

28th November 2004, 01:37 PM	#1
johngalt47 diyAudio Member Join Date: Mar 2004 Location: Texas	Eureka! My gainclone works! I would like to thank Brian for the kit, Peter for the chassis and everyone who posted questions and the people who answered those questions. So far it isn't completely assembled because I was doing some trouble shooting. Initially it was blowing 250vac 2 amp fast blow fuses at the input from the mains but that was fixed by changing to 3.15 amp slow blow. By the way, the transformer is a +- 18vac, 300va from Plitron. I put a 19ohm load on the output of the diode board and the output of the board dropped from 27.5vdc to around 16 or 17vdc at about 870 ma. I measured the temp of one of the diodes with that load and it only reached about 111 degF. The dc offset on one channel is 71mv. I haven't measured the other yet since I don't have it connected to a speaker. I'm using a separate preamp to do the source switching and volume control right now.

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28th November 2004, 03:46 PM	#3
johngalt47 diyAudio Member Join Date: Mar 2004 Location: Texas	LOL I used a multi-meter to check the offset.... Sorry for the confusion.

30th November 2004, 11:04 AM	#4
Scribble diyAudio Member Join Date: Dec 2002 Location: Western Australia	I beleive Nuuk was reffering to using the 10 ohm resistor as a load on the output, While measuring the DC-offset with a multimeter. And to NOT connect a speaker as your unaware of the DC-offset and it could be in the range of "speaker cooking"

30th November 2004, 11:27 AM	#5
johngalt47 diyAudio Member Join Date: Mar 2004 Location: Texas	Yes, I understood and no, I didn't connect the speaker before checking the offset. I didn't connect any load while checking the offset. I'll do that.

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