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McIntosh Transformer causing noise in speakers while disconnected.
- Thread starter ClassG33
- Start date
Golf
Senior Member
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Quite interesting to see all those »120 Hz apart« peaks, in a way based on a 60 Hz starting point.
I was wondering about that too and gave up on explaining them to myself.
the source is a symmetrically clipped 60Hz.
This will give you all odd harmonics:
60*3 180
60*5 300
60*7 420
etc..
<?> Is this correct?
As there is also a 40Hz component there for full duration of the clip. What sw are talking of btw?
EDIT: 40Hz is not there for the full duration.... , must be an other effect with the selected audio clip
Its 46.5 Hz...
Last edited:
depends on the shape of the clipping but in general: yes!
I also used audacity..
But the first picture with the 'peak at 40Hz' has with an fft of 2048 only a resolution of +/-20Hz.
The sw interpolates this to a smoother graph, suggesting more resolution that is not really there.
IC. Thank you.
Ahhhh... Thanks...
Sokel
Master Contributor
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Not the narrow one though,I posted the next expanded ones where resolution is better.
restorer-john
Grand Contributor
I cannot believe you bought one of those too!
Sad you cannot use the gen and the DSO at the same time, but it's a cute little thing isn't it? The voltmeter is useless, as it the component tester, and the IR decoder is worse, but for $50, the DSO isn't horrible. I like it for giggles.
Get a few of these from Ali so you don't tear out the jacks:
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- Thread Starter
- #459
***FINAL UPDATE***
Photos of setup attached, and I'm quite proud of the cable management say what you will :`) No cables touch the ground and the routing of power cables to avoid analog cables is probably the best I can do in this space.
Yooo I'm sorry to leave the thread hanging!! I started a new job pretty out of the blue and have been very busy so this had to wait. So:
New MC255 Amp is in, and setup is complete.
-Regarding the unboxing: As mentioned, aesthetically prestine, unlike previous. Packaging even came with little bead satchel packaging freshener, which made me feel warm and fuzzy inside :`)
-Regarding Internal amp surge noise when powering on: SO QUIET!! When powering on the previous amp, the surge noise was strong, and lasted up to a couple of seconds. When I put my ear up to the chassis, I could hear the Transformer and Power Supply on the inside. It also drew a solid peak of 6-8Amps when it powered on, but immediately went down to normal. The new one good as silent on the inside. This was very assuring.
Regarding sending noise to disconnected speakers with zero connections other than power: WAYYYYYYYY BETTER holy FFSFSFSF!! So relieved!! BUT, it still happens. I am chalking it up to poor shielding on the B&W speakers, but I am not sure still. This happens all the time in Pro-Audio setups with much lower end gear, but this was the first time I've noticed with Hifi gear. I recently put a Mac 1.25k mono block right next to a 802D4 speaker in a showroom, then next to a KEF BLADE II, and indeed the same thing happened on both speakers. Although it was so minimal I highly doubt anybody has probably ever noticed this. But the fact that it happens in other setups tells me that you probably have to spend some goooood money to find speakers shielded enough to deal with amps of this magnitude. I am chalking it up as unavoidable, but negligible. At this point, the noise from my analog cables are creating more noise (as opposed to the opposite before) and that is a good thing.
- **Seeking Advice on this one**
Regarding General Noise: On top of the things I've been working on, I am also suspicious that I have a grounding issue somewhere. I get a definite 60hz noise/buzz when I plug in the RCA interconnects. This was previously unnoticeable because of the noise from the amp, but now that that is better, a new noise has become apparent. There is a little noise from the speaker cables, but the interconnects introduce the most noise at this point soon as they're connected from AVR/PRE to Amp.
I've tried:
A) All sources on same outlet/circuit/ surge protector.
B) No sources connected, just AVR/Pre,PowerAmp, each interconnect one by one between the two.
C) When turning up volume knob, the only noise that increases is the highest hissy frequencies, but these do not start to increase until 80% gain or so.
D) AVR/PRE by itself and sources, without power amp. This was clean by itself.
So, how do I ground the amp to the AVR within a grounding cable? There isn't a specified screw on the amp for this, and I do not want to try somewhere stupid and damage anything.
Thank you all for being on this journey with me. It was 100% a defective amp, and everything sounds amazing as one would expect. I love B&W so much, and I love what McIntosh does to the sound. The pairing is so brilliant for my ears and my heart was literally broken the entire time I dealt with this process. I learned so much, I love this Forum!! Thank you!!!!
Photos of setup attached, and I'm quite proud of the cable management say what you will :`) No cables touch the ground and the routing of power cables to avoid analog cables is probably the best I can do in this space.
Yooo I'm sorry to leave the thread hanging!! I started a new job pretty out of the blue and have been very busy so this had to wait. So:
New MC255 Amp is in, and setup is complete.
-Regarding the unboxing: As mentioned, aesthetically prestine, unlike previous. Packaging even came with little bead satchel packaging freshener, which made me feel warm and fuzzy inside :`)
-Regarding Internal amp surge noise when powering on: SO QUIET!! When powering on the previous amp, the surge noise was strong, and lasted up to a couple of seconds. When I put my ear up to the chassis, I could hear the Transformer and Power Supply on the inside. It also drew a solid peak of 6-8Amps when it powered on, but immediately went down to normal. The new one good as silent on the inside. This was very assuring.
Regarding sending noise to disconnected speakers with zero connections other than power: WAYYYYYYYY BETTER holy FFSFSFSF!! So relieved!! BUT, it still happens. I am chalking it up to poor shielding on the B&W speakers, but I am not sure still. This happens all the time in Pro-Audio setups with much lower end gear, but this was the first time I've noticed with Hifi gear. I recently put a Mac 1.25k mono block right next to a 802D4 speaker in a showroom, then next to a KEF BLADE II, and indeed the same thing happened on both speakers. Although it was so minimal I highly doubt anybody has probably ever noticed this. But the fact that it happens in other setups tells me that you probably have to spend some goooood money to find speakers shielded enough to deal with amps of this magnitude. I am chalking it up as unavoidable, but negligible. At this point, the noise from my analog cables are creating more noise (as opposed to the opposite before) and that is a good thing.
- **Seeking Advice on this one**
Regarding General Noise: On top of the things I've been working on, I am also suspicious that I have a grounding issue somewhere. I get a definite 60hz noise/buzz when I plug in the RCA interconnects. This was previously unnoticeable because of the noise from the amp, but now that that is better, a new noise has become apparent. There is a little noise from the speaker cables, but the interconnects introduce the most noise at this point soon as they're connected from AVR/PRE to Amp.
I've tried:
A) All sources on same outlet/circuit/ surge protector.
B) No sources connected, just AVR/Pre,PowerAmp, each interconnect one by one between the two.
C) When turning up volume knob, the only noise that increases is the highest hissy frequencies, but these do not start to increase until 80% gain or so.
D) AVR/PRE by itself and sources, without power amp. This was clean by itself.
So, how do I ground the amp to the AVR within a grounding cable? There isn't a specified screw on the amp for this, and I do not want to try somewhere stupid and damage anything.
Thank you all for being on this journey with me. It was 100% a defective amp, and everything sounds amazing as one would expect. I love B&W so much, and I love what McIntosh does to the sound. The pairing is so brilliant for my ears and my heart was literally broken the entire time I dealt with this process. I learned so much, I love this Forum!! Thank you!!!!
Welcome back! Hmmz... Grounding issues are not my forte. They can be insidious issues that cause all sorts of stuff. I best leave this one for one of the local experts more knowledgeable than I. Great to see you are nearly 100% of the way completing your system to your satisfaction.
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