Jump to content

Noisy battery elminators

Fred Salles

Recommended Posts


this is the second shoot in a raw where I encounter issues with Battery eliminator from Lectrosonics from rental house equipment. Woobling noise in the receivers. Both problem solve by switching to batteries. Strange thing is that the transmitters and their problematic battery eliminator were both different models. Last month an old UM200 with its 9v batelim (rx R1a) and this month a more recent SMDWB and its SM batelim (rx IFBlue) Both almost  similar noise although much louder on UM200. 
It happened at any voltage stage of my power system: switt VLock 180wh on vlock plate and xlr4 output. The vlock plate output is point to point here but it also provide  regulated voltages on usb C and DC 2.5. 
I have sennheiser G3 TX and lectrosonics LR RX running with battery eliminator without problem at all. Recorder SD888, powered by the same circuit. 
it seems to me that some battery eliminators have switching regulator with a frequency that somehow generate audible artifact in some situation and not others. I  still have to explore the issue further but I am on set on a feature  for now so no time. 

Any idea welcome 

Link to comment
Share on other sites

Happens with many battery eliminators from any brands, as long as different components are supplied by one power source. You're quite lucky not having this issue with G3 as I had (Sennheiser DC2 converter).

You can get rid of this by isolating. Meaning on the one hand with a balanced audio connection (not always possible and not always working) or on the other hand using a DC/DC converter with galvanic isolation.

DC/DC converters in a chain, meaning first isolating with one converter and after that converting voltage with another device unfortunately may also not work.

For me, I ended up making my "own" battery eliminators by soldering in parts from Traco Power THB series. That always works with any audio device, even with the cheapest consumer Bluetooth dongle.

Link to comment
Share on other sites

Thanks for your inputs.
Mungo you must be right, I assumed the Lectrosonics were all isolated.  These ones might not be. 


10 hours ago, Mungo said:

You're quite lucky not having this issue with G3 as I had (Sennheiser DC2 converter).

Indeed I made these ones myself, with miniature isolated dc regulators. Do not remember which brand I used but either Traco or XP power. 

Actually they might even be simple linear dc regulators, if I remember correctly.

And linears do not need isolation isn’t it? 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...