Hi All! I have a Onkyo Integra A-8057, works fairly well, bought it used. With no inputs plugged in, if I select any input (CD, tape etc) if I turn the volume all the way up, its relatively quiet. If I select the phono input, from about 4 on up white noise is very audible. Since it doesn't happen on any other input, Im assuming its something in the phono preamp. I managed to find a manual with a schematic online. I have an old scope, and have a little experience using it.
Found a few comments on the web related to power supply, but this doesn't seem like the issue since its only on one input. Read a post about noisy regulators, is that a good place to look? If so, anyone have similar issues, able to fix it with replacement regulators?
Found a few comments on the web related to power supply, but this doesn't seem like the issue since its only on one input. Read a post about noisy regulators, is that a good place to look? If so, anyone have similar issues, able to fix it with replacement regulators?
There's nothing wrong, the phono stage inputs must be properly terminated in order to measure the phono stage output noise.
A typical value would be around 1k ohms. An input short would be ok, but will give more optimistic results.
Same applies to line inputs, but the output noise will be much lower than the phono, due to the lower gain.
A typical value would be around 1k ohms. An input short would be ok, but will give more optimistic results.
Same applies to line inputs, but the output noise will be much lower than the phono, due to the lower gain.
1 kohm is actually quite wrong, 1 kohm in series with 470 mH would be reasonable.
Otherwise I agree with rayma. Phono inputs are much more sensitive than line inputs, so you hear their noise much sooner, and with an open input, you get much more noise than in normal use. Good chance that there is nothing wrong with the amplifier.
Otherwise I agree with rayma. Phono inputs are much more sensitive than line inputs, so you hear their noise much sooner, and with an open input, you get much more noise than in normal use. Good chance that there is nothing wrong with the amplifier.
Exactly. I was fortunate enough to meet him at a book signing.
He's a long time US public TV personality on his show, and he also helps in the fund raising.
https://www.pbs.org/redgreen/index.html
https://www.pbs.org/redgreen/index.html
Thanks/all. Ive had a few other amps, sadly lost in various moves. An old AR I wish I had, around the same wattage 60 or so, but with no input connected, there was some noise but not this much. Its like a waterfall. I haven't hooked it up to a turntable yet, but will do so tomorrow and check the noise. * Yeah, Im a long time Redd Green fan: "Spare the duct tape, spoil the job". Favorite Redd Green episode: he power washed a 1980's Dodge with a 5000psi power washer. * Audio is way cool, have to learn stuff.
Question for you all: This is a mid 1980's amp, Couldn't those electrolytics be getting shaky at this point?