Audio Project Amplifier Speaker Loudspeaker Kit
diyAudio.com diyAudio Forums Archive > Top > Amplifiers > Chip Amps
 
Shielded cables? - Click HERE for Original Thread
Dxvideo
-Should I use shielded cables for gainclones box inside signal connections?
-If I use normal cables what happens?
-Because as I can see many photos of gainclones most of gaincloners use normal cable!
ukram
It is better to use shilded cable. With no shield there can be (capacitive?) pickup from transformer or fluorescent lamps etc. For the same reason it is good idea to use metal case.
ashwin
I have found that using good grounding practice (separate the high level and low level grounds and join them at the star point) and shielded cables result in no hum at all in my gainclones (which aren't in a metal case, BTW). I also found that using a non-shielded cable to the input of my GC from the source resulted in a slight hum, which went away when I used shielded cable. All shields are grounded at one point.

- Ashwin
Dxvideo
I use a metal case for my gainclone and chasis is connected to star gnd. And inside my signal cables are all shielded. But positioning of that cables very important, because when I move closer the shielded cables to the transformer, I heard a 100Hz noise! Shouldnt I use shielded cables inside the metal case? Does it make problem?

And the second question; for preamplifier, if I use the same mains transformer (with the gainclone) the 100Hz noise problem is back again! Now I use another little transformer for it. Does it always happens? Do you use two seperate transformer for gainclone and preamp?

Thanks a lot..
PMA
quote:
Originally posted by Dxvideo
-Should I use shielded cables for gainclones box inside signal connections?
-If I use normal cables what happens?
-Because as I can see many photos of gainclones most of gaincloners use normal cable!

Yes, you should use shielded cables.
ashwin
quote:
Originally posted by Dxvideo

And the second question; for preamplifier, if I use the same mains transformer (with the gainclone) the 100Hz noise problem is back again! Now I use another little transformer for it. Does it always happens? Do you use two seperate transformer for gainclone and preamp?

Thanks a lot..

This sounds like a ground loop. If the preamp and amp are fed from the same supply, then you need to run only one wire (i.e. the signal wire) from the preamp output to the amp input. Don't run the ground wire in the shielded cable from the preamp output to the amp input.

Hope that makes sense.

- Ashwin
Dxvideo
Thank you very much...

Page generated in 0.029242992401123 seconds with 17 queries,
spending 0.00858355 doing MySQL queries and 0.02065945 doing PHP things.

Powered by: Search Engine Indexer and vBulletin
Copyright ©1999-2009 diyAudio.com