Attempting to solve hum on p80/s300

A place for DIY project discussions.
Ageagainstthemachine
Posts: 18
Joined: Mon Oct 10, 2022 4:57 pm
Has thanked: 24 times
Been thanked: 6 times
Great Britain

Re: Attempting to solve hum on p80/s300

Unread post by Ageagainstthemachine »

20230906_110826.jpg
20230906_110826.jpg (107.8 KiB) Viewed 7283 times
I spent the day moving things around.
This is about the best I can do for component separation, any cables that have to cross have been crossed at 90 degrees.. my digital gear is to the right of the pic but the hum is still there. When I next get chance I will play around with a ground wire again and see if I can reduce the hum as before.
I know its only a small issue but it would be nice if I could improve it.
NVA S300 - P80 (TDK 2CP-2511 pot ELMA selector switch) Audiolab 6000CDT - Topping D30 DAC - Project Debut Carbon DC with Ortofon 2M Blue - P80 Phono Stage - Technics RS-BX646 Cassette Deck (with tube buffer to up the low output) - Speakers are either modified Monacor Katana Open Baffle or Kralk Audio MK2 BC30 with PAW stands - most cables are NVA - Various sound treatment

User avatar
Fretless
Posts: 9386
Joined: Wed Nov 12, 2014 12:15 pm
Location: Somewhere in Holland
Has thanked: 1528 times
Been thanked: 2355 times
Netherlands

Re: Attempting to solve hum on p80/s300

Unread post by Fretless »

What about noisy mains ? Is the humming more or less at certain times of the day or on certain days ?

Fridges, freezers, washing machines ?

Industrial usage in your neighbourhood ? Solar panels ?

All things that RD used to moan about as NVA amps are sensitive to that.
These users thanked the author Fretless for the post:
Ageagainstthemachine (Wed Sep 06, 2023 7:58 pm)

Upstairs:
Vinyl
Pro-Ject 1.2 + Grado Sig Jr + Cambridge Alva Duo
DigiVolumio PC + Kiss DP-500 + Sabaj A20d
NVA: Cube2 + LS6+ Sabaj A10a (2) + Little Bear MC2
Downstairs:
Vinyl
Logic DM101 + Syrinx LE1 + Grado Sig MCX
DigiDenafrips Ares II + Volumio PC + Cambridge CXC
NVA: P50 (phono)Aiyima A07 MAX (2) + Arcam One
HP: Allo DigiOne + Sabaj A10d + AQ NightOwl
Office: Allo DigiOne SIG + SMSL M300se + Douk G4 (x2)
Mission 760 + Monolith 887 + German Maestro GMP 450

Ageagainstthemachine
Posts: 18
Joined: Mon Oct 10, 2022 4:57 pm
Has thanked: 24 times
Been thanked: 6 times
Great Britain

Re: Attempting to solve hum on p80/s300

Unread post by Ageagainstthemachine »

Fretless wrote: Wed Sep 06, 2023 11:44 am What about noisy mains ? Is the humming more or less at certain times of the day or on certain days ?

Fridges, freezers, washing machines ?

Industrial usage in your neighbourhood ? Solar panels ?

All things that RD used to moan about as NVA amps are sensitive to that.
I have an open living room/kitchen in a new build apartment with two mains circuits on the switch box for all sockets. As far as I can tell one circuit is for the living room/kitchen and the other for the hall, bedroom and bathroom. I had an electrical inspection and they're coming back to uprate the rcd's(?) as power dips and the speakers cut off for a fraction of a second.. Happens even if I switch the kettle on. I will ask him to clarify the circuits for me when he comes.... And possibly ask him about DC offset 😅

But I did make some progress and found that the cassette player and phono power supply are the two main culprits for hum. Not really an issue when I can just switch them off at the plug if I'm using the digital side.

I played around with earthing leads and it didn't have the same effect as it did before I moved everything around. I thought I'd whip the cover off the cassette player so I could be sure of a proper earth connection but found heat damage on the pcb. I know this damage is recent as I'd carried out a visual inspection a couple of months ago and now I'm curious if this damage could contribute to the hum... Or possibly the old electrolytics that are due replacement.
NVA S300 - P80 (TDK 2CP-2511 pot ELMA selector switch) Audiolab 6000CDT - Topping D30 DAC - Project Debut Carbon DC with Ortofon 2M Blue - P80 Phono Stage - Technics RS-BX646 Cassette Deck (with tube buffer to up the low output) - Speakers are either modified Monacor Katana Open Baffle or Kralk Audio MK2 BC30 with PAW stands - most cables are NVA - Various sound treatment

DaveyTed
Posts: 140
Joined: Mon Apr 26, 2021 10:01 am
Has thanked: 195 times
Been thanked: 190 times
Great Britain

Re: Attempting to solve hum on p80/s300

Unread post by DaveyTed »

Henley Audio can supply a power supply fitted with a three pin connection to minimise any hum problems. If you buy a new Project turntable I understand the dealer will change the power supply free if required.
These users thanked the author DaveyTed for the post:
Ageagainstthemachine (Sat Sep 09, 2023 11:52 pm)

Post Reply