Who cares whether your name is spelled correctly. Like a half-full water bottle rattling on the table.
Need Advice: Vinyl Hum Issue
Hi everyone,
I’m looking for advice on a hum issue that only occurs with my vinyl setup. My digital chain is completely silent.
Important clarification:
I have been using the KEF KC62 via the high-level (L connector) for some time without any hum issues. The problem only appeared after I replaced the bare speaker wire connections with spade connectors at the Willsenton R8 binding posts to make the connection cleaner and more secure.
System Overview
Speakers
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KEF R3 Meta
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KEF KC62 subwoofer
What Changed Before the Issue Appeared
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KC62 high-level connection remained the same (L connector)
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Only change:
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Bare wire → spade connectors at the R8 speaker binding posts
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Tube rolling done around the same time:
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6SN7: Stock → Ray Select
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Power tubes: Stock KT88 → Tung-Sol EL34
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Prior to installing spades, the system was hum-free.
Digital Chain (No Hum – Completely Silent)
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Cambridge EXN100 streamer/DAC
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RCA out → Willsenton R8 integrated amp
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Speaker outputs → KEF R3 Meta
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KC62 connected via High-Level (L connector)
Result: Dead silent, even at higher volume
Vinyl Chain (Hum Present)
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Rega Planar 3
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RCA out → Cambridge Alva Duo phono stage (MC mode)
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RCA out → Willsenton R8 integrated amp
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Speaker outputs → KEF R3 Meta
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KC62 connected via High-Level (L connector)
Result: Audible hum
Detailed Symptoms
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Hum is present only on vinyl
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Hum increases with volume
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When the KC62 is disconnected, the hum disappears
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However, with the sub disconnected and volume above ~10 o’clock:
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Audible vibration / rattling
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Woofer cones fluctuate excessively, especially on low-frequency passages
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Touching the RCA plugs does not eliminate the hum
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I have not yet tested touching the tonearm
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Digital playback remains silent under the same conditions
What I’m Trying to Understand
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Could the spade connectors be creating:
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A different ground reference than bare wire?
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A tighter mechanical ground path exposing a phono grounding issue?
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Is this a known interaction between:
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Tube integrated amps
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Phono stages
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High-level subwoofer inputs
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Best practice for integrating a KC62 with a tube amp + phono stage
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Whether switching the KC62 to line-level RCA is recommended for vinyl use
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Whether tube rolling (EL34 + Ray 6SN7) could increase sensitivity to grounding noise
Goal
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Silent vinyl playback
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Proper subwoofer integration
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No hum, no woofer over-excursion, no vibration
Any advice or shared experiences would be appreciated.
Thanks!
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- 34 posts total
| Post removed |
I have a Rega P3-24 which I think is a similar configuration. It doesn't have a grounding cable - it grounds through the left RCA which I could not get to work on some phono preamps. So I had a lot of hum issues until I found the right way to get that ground to actually be grounded. This sounds like maybe two separate issues - either ground loop hum or acoustic hum bleeding back from sub to TT, and then separately possible ground hum from how problematic Rega's ground design is. First suggestion: eliminate the sub from the equation and take it out. Then work on absolute quiet grounding from the Rega. Once you have totally quiet without the sub, then see if you can determine what is the issue once the sub is back in. |
I'd like to claim that I misspelt your name on purpose to prove my post was by a "human" - something Audiogon asks me to prove every few minutes! But alas that claim would fall into the realm of alternate facts. Usually, when I start to type @ to link to usernames, I get a drop-down list. But often this facility does not trigger. By refreshing the page, and proving I am still 'human', I can usually get the drop-down list. Usually. Sometimes, when in the body of a reply. the @ triggers the drop-down but I cannot select anyone ... frustrating. By the way, I wish ChatGPT would learn the correct capitalisation for "Sonus faber" which is prominent in another active thread. I guess the problem is that so many humans get this wrong, ChatGPT follows the herd. Once it processes this thread, it might have second thoughts. I asked him why he got it wrong:
ChatGPT is far more than a Large Language Model, which we should assume is building a neural network of everything on the Internet. It also incorporates the ability of Expert systems to make logical inferences and to explain how it uses those inferences to reach conclusions. |
You quoted
But my old eyes cannot find this in ChatGPT’s original response, or anywhere else in this thread! I presume that this was the generated response to a new question like "why didn’t you use the phrase "acoustic feedback". So thanks for asking this question, as requested, on my behalf. @viridian noted that:
By the time ChatGPT gave its (his?) second response, lo and behold it included the term "acoustic feedback". By the way, a decade or so ago, I led a team of IT guys and lawyers to build an application using a legal Expert System. The primary goal was to assess whether a financial adviser was lawfully able to provide financial advice to a client. The Expert System (Softlaw) used backwards and forwards chaining inference engines operating on ’facts’. Softlaw ’facts’ had three potential values - true, false and don’t know. I introduced a fourth value - haven’t asked yet. Up to 5000 facts could come into play. The resulting application was phenomenal at explaining why it reached each assessment, including links to the legislation and regulations. |
- 34 posts total

