Extension leads with emi / rfi filtering

Teetonetal

Totally ignorant about this. Helpfully or snake oil?

Can they help keep a rig quieter at a gig?

ecc83

IMHO not a lot. in UK at least we enjoy pretty "quiet" mains supplies* and in any case a good deal of RF crap via other routes. Mainly input cables (always use balanced wherever possible) but RF can even be picked up on speaker cables and find its way back to the input stage via the NFB path.

Decent gear will have RF stoppers already fitted at mains inputs and some mains strip RF filter topologies can actually INJECT noise into the local earth!

I was there at the start of the transistor "revolution" and to keep thermostat cracks out of gear the filters (we made our own) needed to be fitted to the fridge etc. NOT the transistorized radiogram!

*This might of course change when we are all lumbered with "smart" meters but then I guess the army redundant meter readers can be re trained as RFI techs!

Dave.

Teetonetal

Interesting.

I ask as I want to buy a good mains lead with surge protection. One of the ones I looked at had filtering too. Not something I have even heard of... and of course a quick Google search reveals a whole industry...

Teetonetal

Well...

I ended up buying the lead with surge protection and the filtering, simply as it was on offer, so cheaper than the lead without filtering. 

Oh my word, at home the difference is enormous. 

My home rig is quite complex, with a mac, 2 monitors, Helix and T rex Goliath and a Samson S-phone all powered on the same multi way. Generally when I use my dd 1959 or other dirt in the helix loops, the noise floor increases dramatically. 

Now, it's completely silent until I use the High Gain 2nd Channel of the dd1959. Now that is reduced and useable.

I alos tested my problematic Orion. in My Brunetti FX loop. The noise has all but gone. So.... I'm actually speechless, the difference is so huge.

Gig tomorrow in St.Moritz at the Ski WM, smallish venue (300 people) and had massive noise problems there before, so intrigued to see if it goes away... (the industrial dishwasher shares the stage circuit, which caused huge issues last time...).

Even if it makes no difference in the live rig, I'm going to go back and get another one for my man cave!

Cabicular

Link?
ive made a massive difference in my place by removing all the dimmer switches from the lights but I still have some background RF from the kitchen appliances

simonk

I've got several of these:
Tacima 6 Way Mains Conditioner and Radio Frequency Interference Filter https://www.amazon.co.uk/dp/B000PS5700/ref=cm_sw_r_cp_api_uOfQyb1N94VDF

They effectively got rid of dimmer switch and the noise caused by using those power line adapters around the house and studio.

DJH83004

At source, our supply generation is very clean, but the prevalence of switch mode power supplies, found in most computer equipment and for what its worth quite a few class D bass amps and powered PA monitors, can cause havoc with mains supplies. Fluorescent light fittings and energy saving lamps with electronic ballasts can also cause mains borne interference. But the bottom line is in the majority of cases it is not a problem, so deal with it on a case by case basis I would suggest, as simonk has said. I have used conditioners to good effect in local studios in the past.  

Teetonetal

Well rig was quiet last night. So colour me impressed.

@cabicular I got the Swiss version of this https://www.amazon.co.uk/gp/aw/d/B003BIFLXO/ref=pd_gwm_simh_1?pf_rd_p=de8effd6-3a25-4e43-82ba-7b5108b051cd&pf_rd_s=blackjack-personal-1&pf_rd_t=Gateway&pf_rd_i=mobile&pf_rd_m=A3P5ROKL5A1OLE&pf_rd_r=SPHRYHYMH7YAG8SFEZ4N&pf_rd_r=SPHRYHYMH7YAG8SFEZ4N&pf_rd_p=de8effd6-3a25-4e43-82ba-7b5108b051cd

Teetonetal

^ why do amazon links often look ridiculous? 

Wazmeister

simonk said:

I've got several of these:
Tacima 6 Way Mains Conditioner and Radio Frequency Interference Filter https://www.amazon.co.uk/dp/B000PS5700/ref=cm_sw_r_cp_api_uOfQyb1N94VDF

They effectively got rid of dimmer switch and the noise caused by using those power line adapters around the house and studio.

Exactly the one I use mate, with the same positive results

Cabicular

Thanks Djents I'll get my virtual hand in my online pocket and give it a go