Well just to complicate matters, I listened to the trouble spots in both tracks I mentioned in my opening post (Don’t Know Why & Quando, Quando, Quando) through two sets of headphones from my studio. They were Sennheiser HD 300 Pros ($220) and HD 600s ($500), using my studio’s RME ADI-2 DAC headphone jack. None of the grunge present on the Maggies was audible through the phones. I don’t have any conclusions other than it doesn’t seem to be imbedded in the recording. Frequency response on them are 6-25k and 12Hz-39kHz.respectively. Hmmmmmmm.......
Do You Ever Get Glare/Raspy Sound on High Pitched Female Vocal Lines?
I sometimes get a harsh glare or slightly raspy sound on female vocal lines when they sing loud, high pitched notes. It’s hard to explain the sound exactly, but if you’ve ever experienced it, you’ll know what I’m speaking of. Two examples are Norah Jones, Don’t Know Why at 1:57 with line “You’ll be ON my mind”. The other is Michael Bluble’s Quando, Quando, Quando featuring Nelly Furtardo. Her line “I can’t wait a moment more, Tell me quando, quando, quando” at 1:53 is another good example. This happens at moderate to fairly loud volume levels.
Trying to determine if it’s coming from the midrange section or quasi ribbon tweeter, I’ve disconnected the speaker jumpers from one while keeping the other jumped and found it occurs in both the midrange and the tweeters. I’ve also swapped out two other DACs and have bypassed the preamp by going directly to the amp from the DACS, but it makes no difference. It doesn’t sound like clipping distortion or typical speaker breakup. I’ve even inserted 1 ohm resistors on the Magnepans and while it reduces it a bit, it’s still there. I can also hear it to a somewhat lesser degree on my old Theil 1.5s and KEF KS50s at fairly loud, but not crazy volume levels. Both of those speakers are driven with 400 watt @ 4 Ohms and a 300 watt @ 4 Ohms amps respectively. I can’t imagine that I’m clipping the amps.
Does anyone else have this occur on their systems? Any ideas on what’s going on here?
My system is Magnepan 3.7x speakers, PS Audio Airlens, Stellar Gold DAC, PMG Signature preamp & BHK 250 amp, streaming Tidal.
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- 102 posts total
Most likely culprit = dirty power. Link here. - - - After checking some examples mentioned above, I don’t hear any distortion on my revealing system. Many years ago, I thought that Eva Cassidy’s Live at Blues Alley was poorly recorded. Not anymore. Fixed it with clean power. Digital playback requires much TLC at each stage in the chain. - - - Dirty power comes from 3 primary causes: (1) the utility company (2) assorted appliances shared on the household circuitry: HVAC, computers, fluorescent lighting, dimmer switches, washer/dryer, refrigerator, etc. (3) the stereo components themselves - especially the digital ones - digital components regurgitate noise back into the system circuitry - which affects the SQ of the other components. - - -
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If things improve slightly with the resistors on the Maggies and disappear with headphones, I would suspect the BHK amplifier has a component or two that needs to be replaced. My first guess is that the bias has drifted and may need to be adjusted to spec (easiest to fix). Other things I would check would be the compensation caps, current source resistors and feedback loop passives. Anything that causes the bias to shift lower can distort the signal at specific frequencies. |
- 102 posts total