|
|
Post by tonycamphd on Apr 10, 2016 20:06:23 GMT -6
dexter. can you email me hi res photos of the inside of your box? I just fixed a clients noisy headphone amp in his box. I am curious if they are the same issue. I actually removed the headphone amp completely for diagnosing the problem. The noise is still there. Just so everyone knows, my unit is a Superbeast I, not II. And yes there is 60hz hum in my previous clip, but I said that the new dual powersupply I made got rid of that hum. I also replaced the crystal for the dix9211 with a CMOS clock oscillator -- it changed the noise quite a bit. Listen: Clip
The part of the clip with no noise is from disconnecting the clock oscillator after the unit is locked to the signal. It does still work after disabling the oscillator but as Svart said the PLL will start to drift, so it's not really a suitable fix to just switch it off. PS: This is on the noise floor of the unit. You have to turn it up fairly loud to hear this stuff, but it should not be there. If you were going to use outboard gear like a slammed compressor, or reamp guitars through a high gain amp - it's not going to be usable with this noise. that seems a 480hz buzz with harmonics, that is related to 60Hz directly, I'm still betting it's a grounding issue? |
|
|
|
Post by dandeurloo on Apr 11, 2016 8:09:17 GMT -6
Dexter, one more question. Is it the same noise on both the left and right channels? Since its the SBI it uses separate PCB's per channel. So, if its the same on both channels then we can guess its not local to the channel pcb's and is one of the other daughter pcb's.
|
|
|
|
Post by dexter on Apr 17, 2016 15:33:56 GMT -6
Yes the same noise is in both channels. It is slightly louder in the right channel, and that is the pcb with the regulators and the DIX9211.
|
|
|
|
Post by actualsizeaudio on Jun 29, 2016 12:12:58 GMT -6
Anyone interested in helping me change out my power supply?
|
|
|
|
Post by ebomb321 on May 5, 2020 20:43:25 GMT -6
super old thread, but i have the same whine and have since day one. im running AES from my RME UFX and get the whine in 48, 96, but if i set the UFX to lets say 95904hz or 96096hz sample rate the squeal is almost gone. Im thinking this is an issue with the clock? I really do like this DAC, but i can no longer deal with the noise. Has anyone figured this out yet? |
|
|
|
Post by johneppstein on May 5, 2020 21:13:07 GMT -6
Fellas - I'm about to try and repair, then mod, my Superbeast and PCM4222. I could use some help. Thought I'd start a thread so we could document this in hopes that there may be others who would benefit from this archival of knowledge. First, the problem. The Superbeast generates a pretty healthy level of what I would call white noise (high pitch hiss), with one side being slightly worse than the other. Since I know Ross has had issues with his op amps overheating, I'm guessing that I've got a bad AD4898. I'm going to focus on the Superbeast repair first. If I can get through that, then I'd like to explore a couple of mod options. Here is a gut shot:  I'm assuming that the AD4898's are the one's with the hillbilly heatsinks siliconed to the top?  Here are two more hiding under another PCB board.  Here is what I will be using to replace them, based on advice from tonycamphd    Also, the above pic looks like copper wire. I have some conduit left over from a studio build. Can I just strip some out from that? I'm not sure what gauge it is. Does it make a huge difference? I think it's just standard house wire. So, first things first. How the heck do I get the old AD4898's out of there? Do they just pop out or something? Or are they soldered in?  Could you please refrain from using Photobucket, or any other "photo hosting site" that insists on smearing their logo across the middle of the picture? It kinda defeats the purpose of posting "gut shots" of projects.
Nobody (or hardly anybody) seems to have this problem, so there MUST be another, more viewer friendly, way.
|
|
|
|
Post by indiehouse on May 6, 2020 5:32:23 GMT -6
Could you please refrain from using Photobucket, or any other "photo hosting site" that insists on smearing their logo across the middle of the picture? It kinda defeats the purpose of posting "gut shots" of projects.
Nobody (or hardly anybody) seems to have this problem, so there MUST be another, more viewer friendly, way.
That was 4 years ago. I don’t use photobucket anymore, are they even still around? There wasn’t any watermark back then when I posted these. Regardless, pretty sure Johnkenn wants people to use third party hosting for photos so as not to eat up storage space. I use Imgur these days. Ask me again 4 years from now, though. |
|
|
|
Post by johneppstein on May 6, 2020 12:12:50 GMT -6
Could you please refrain from using Photobucket, or any other "photo hosting site" that insists on smearing their logo across the middle of the picture? It kinda defeats the purpose of posting "gut shots" of projects.
Nobody (or hardly anybody) seems to have this problem, so there MUST be another, more viewer friendly, way.
That was 4 years ago. I don’t use photobucket anymore, are they even still around? There wasn’t any watermark back then when I posted these. Regardless, pretty sure Johnkenn wants people to use third party hosting for photos so as not to eat up storage space. I use Imgur these days. Ask me again 4 years from now, though. Ok, I'll try to remember.... ; ) |
|
|
|
Post by svart on May 6, 2020 21:35:28 GMT -6
super old thread, but i have the same whine and have since day one. im running AES from my RME UFX and get the whine in 48, 96, but if i set the UFX to lets say 95904hz or 96096hz sample rate the squeal is almost gone. Im thinking this is an issue with the clock? I really do like this DAC, but i can no longer deal with the noise. Has anyone figured this out yet? Unfortunately it's a matter of poor design and implementation. Lots of his converters have had a myriad of issues like the one you're having. It could be as simple as soldering a bunch of ground wires to redirect the ground currents, but there's no easy way to explain how. I've repaired a couple, but they all had different causes, but the root of the issues with RM units are always poor design and build quality. |
|
|
|
Post by EmRR on May 6, 2020 22:19:44 GMT -6
Could you please refrain from using Photobucket, or any other "photo hosting site" that insists on smearing their logo across the middle of the picture? It kinda defeats the purpose of posting "gut shots" of projects. it didn't when this was posted 4 years ago, Photobucket shit the bed, like crap on the internet tends to do with age. |
|
