Bearing ground wire loose/disconnected?
Concerningly loud pops in vinyl playback
I have a problem I've been unable to diagnose yet, so I thought I'd gather some ideas. This is for a 2nd vinyl system in my girlfriend's home, not my main system. I've never had any issue like this in the main rig.
We're all used to annoyingly loud isolated "pops" from surface defects or perhaps static discharge during vinyl playback, but usually these are only truly annoying during quiet passages and tend to become relatively "outgunned" during heavy loud music. However, very occasionally (once every several records) I will get a POP so loud it is concerningly startling, even during loud playback of rock music. I don't like the tweeters being subjected to that, though they're fine so far. And it hasn't tripped the VAC 200iQ's protection circuitry yet, so there's that. Still, I don't like this. It's happened on the left and on the right speakers, so it's not isolated to one channel. Once it occurs, it is more likely to occur again within several seconds (and again), until I take the record off and start over. It seems to occur only starting at a certain high volume level on my ARC Reference 6 preamp (40 and above). The records and stylus are clean, and it's now occurred on multiple different records that I KNOW aren't the problem. So my suspicions are down to:
- Static discharge (I have a record brush with conductive fibers and use anti-static sleeves)
- Really bad overload reaction in phono and/or preamp, possibly prompted by static discharges and possibly because the gain is set too high in phono stages (I have the Hagerman set to 60dB for 0.8mV which I thought would be OK)
- Power line noise issue of some kind / EMI / RFI
- Tubes in the ARC Ref 6 going bad. Maybe PSU tubes? But it really seems to be instigated by a volume level on the Ref 6 going above 40.
This rig is kind of like my playground, so I have lots of gear at my disposal, much from the main rig. I've already swapped out many different components and had the problem reoccur on each of:
- Different Speakers (Tannoy TD10, Tannoy Glenair 10)
- Speaker cables (AQ Rocket 88, AQ KE-4/CV-8 biwire)
- Power amps (VAC 200iQ, Phison A2.120SE)
- Phono stages (Hagerman Trumpet MC, Herron VTPH-2A)
The consistent gear I haven't swapped out yet has been:
- Clearaudio Innovation Compact turntable, Universal arm
- Benz Wood SM cartridge 0.8mV
- Audio Research Reference 6 preamp
What do you think is most likely the cause, and how to fix it? I'm not real eager to "try" to reproduce the issue, for obvious reasons. But other than this issue, the rig sounds great - really enjoyable.
- ...
- 31 posts total
It’s not the pressings; some of these same records have been played many times on the main rig with no such issue. The problem here is not the presence of pops or surface defects, but the fact that they’re (once in a while) being amplified so prominently above the music, even when the music is very loud. I’ve been playing vinyl for many years, good vinyl and bad, and this is not normal.
@tomic601 You know what, that’s a great thought, thanks!! I DO in fact have spares. I think in the basement lol. Sovteks, nothing special, but unused and from Upscale. The current 6550 is a "NOS" GE that I guess could be suspect. All the other 6H30 have 380 hours, but might as well replace both power tubes as a precaution. Yeah, when it happened with the Herron - I'm pretty certain the Herron is not doing anything that would cause or exacerbate the fault. One more note: the power strip here is a cheap ~$120 Furman strip. Nothing like the AQ Niagara 7000 in the main rig :( |
Caps in lower end power conditioning or even power strips, even decent PC like PF-15i can sometimes do squirrel tricks…. recent bad experiences w same on a direct drive motor speed stability, worth isolating if ya can. I have an isotech w star ground that i now use to help isolate faults….. my Degritte works better on it, but only with a Cardas power cord… |
- 31 posts total