Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Seduction => Topic started by: kgh on August 15, 2021, 01:25:53 PM

Title: Power line emi filter?
Post by: kgh on August 15, 2021, 01:25:53 PM
Hi all, I assembled a Seduction at least 10 years ago with no modifications except some JJ E88CC tubes. I've since moved, and my electricity is more than likely 'dirty'. The HVAC is a newer energy efficient design, and if I understand correctly, it isn't that great for audiophiles. When the compressor kicks on you can hear it 'click' on through the speakers and the lights will dim as well. I had a hard start kit installed which cuts down on the dimming of the lights. I can't vouch for the what it might have done to the stereo, since this was installed before I set up my listening area. However, the lights do not dim as much. My integrated amplifier is a Cambridge AXA-25, and when the volume is turned up to the max and switched to a blank input jack, I can barely hear any hiss and no hum. When it's switched back to the seduction, there is hiss and hum. The hum can be heard at moderate levels of listening in quiet passages and intros. My turntable is a Sony PS-X7 with an Audio Technica 'Green' cartridge. I thought about purchasing an emi filter such as: amazon dot com/outstanding-Filter-250VAC-Suppressor-Power/dp/B08D3MP48W/ref=pd_sbs_3/138-1207387-4652611?psc=1
or
amazon dot com/CW4L2-20A-S-Noise-Suppressor-Power-Filter/dp/B07FDYRQRY/ref=pd_sbs_13/138-1207387-4652611?psc=1

and or adding some of these ferrite core rings: 
amazon dot com/eBoot-Pieces-Ferrite-Suppressor Diameter/dp/B01E5E5IY4/ref=sr_1_37?keywords=dirty%20electricity%20filter&sr=8-37

Would an emi filter and/or the ferrite supressors help with the hum and noise?The seduction was much quieter in the last place I resided to where I could simply enjoy the music!

Humming for a better tune,

KGH


PS Why can't I post to outside links?

PPS: replace dot com with .com for the links



Title: Re: Power line emi filter?
Post by: Doc B. on August 16, 2021, 06:43:00 AM
The noises you mention are not those I would usually relate to noisy AC mains.  If the noise got worse only since you moved you might try measuring the AC mains voltage and the voltages in your Seduction to see if they are in spec. Voltage sag could create the hum issue. If voltages are good I would next try something other than the JJ tubes. I have experienced a lot of hiss from them at times. The cartridge you mention (I assume this is an AT95E) has what I would consider a somewhat minimal output level for the Seduction at 3.5mV. A more typical 5mV cartridge would help reduce the noise floor too.
Title: Re: Power line emi filter?
Post by: kgh on August 16, 2021, 01:25:04 PM
Thanks, Doc, for the response! I checked the mains at the wall outlet (121V) and on the back of the male power receptacle on the Seduction. It was 121V as well. I didn't want to touch anything else since the builder's manual could not be located after all of these years. If everything checks out fine, which tubes would you use as a replacement that have less noise and sound warm as my amp seems to favor the highs and mids?


Title: Re: Power line emi filter?
Post by: Doc B. on August 16, 2021, 01:28:50 PM
I like the Russian 6N23Ps we usually supply with the kits these days.
Title: Re: Power line emi filter?
Post by: kgh on October 02, 2021, 01:44:54 PM
I like the Russian 6N23Ps we usually supply with the kits these days.

Those really helped improve the sound! Thank you!!!