Do It Yourself Latest Topics

NP50 -BX1- LB61 discharger, test your batteries !

Sat, 29 Aug 2026 01:55:07 +0000

Hi there! hope you all do well, been a while.

I am working on a battery discharger... long due...
I made a version yeaaaars ago before i made my chargers, but times changed. so time for a new version.

So my idea is to get the discharge voltage as low as what a transmitter uses give or take 130mA for Lectro Zaxcom and Wisycom, and the one that needs a seperate setting the Sound deviced A20... since they hog power...
For this new version i will be using a constant current , by doing so the capacity the battery is showing comes closer to what you can expect on a transmitter in real life give or take. its slow but draining the batteries fast wont give a good result because loading the battery will drop the voltage and might cut off discharging pre mature.
it will be a 4 Bay discharger by the way.

They will have a small Oled screen that display the capacity and if i can, i implement a storage feature, so they can be drained to a voltage that keeps you batteries last longer while not been used. without degrading , the housing will have the same form factor as my chargers, because i like that.. and well i want to make as less new parts as i can
Do you guys have any ideas of things that you would like ? maybe (if the hardware lets me) i can add a feature.
Here a tiny photo of a premature test of the code and some hardware on a breadboard want to know if it works before i make some nice printed circuit boards. Testing the storage setting here. (dont mind the cluttered work place... thats me) and it will get a larger OLED display to see all batteries current capacity at once. instead of 2

have a nice weekend,

Greetings Joppe

Mixpre 6II aux in

Sun, 24 Aug 2025 02:02:31 +0000

I will be using 2 external mic press to feed 5 and 6 of my Mixpre6II

Need to make up a aux in cable from 2 XLR female to 1/8" TRS.

Question, if I may, do I tie XLR pins 3 and 1 together, or leave 3 open, and just pin 1 to sleeve, and respective pins 2 to tip and ring.

Thx

48v Phantom Power stepped down to 5V DC Bias

Tue, 21 Oct 2025 01:37:23 +0000

Plugging a lav mic directly into a mixer and needing an adapter to achieve this.
Cos-11 can handle between 3VDC to 10VDC. Adapter will be a 5P TA Male to 3P XLR Male. Connecting directly to a SD688.

Anyone here built an adapter before? There's a lot of mixed info floating about to achieve this.

Diy coiled cable

Thu, 06 Aug 2026 18:50:30 +0000

Can anyone recommend a nice quality and flexible coiled cable that you might be currently using? I need to redo a coiled boom cable, as well as a few jumper XLR’s. I’ve bought some coiled bulk in the past and it was shiny, really stiff and hard to work with. I had a bunch of loon cable in the past that to me was top quality. Had a nice matte finish and was very flexible in all temperatures.

Using Sennheiser EK100 Receivers as EK 300 IEM Receivers

Tue, 25 Feb 2025 19:29:24 +0000

I've decided to put some older G3 ENG receivers to use again as IEM receivers. There have been many threads asking about how to convert EK100 units by adding a pot and or amplifier circuit but that is just impractical.

So here is a little passive box I have put together which takes a mono signal from an EK100 and sends it to both L and R sides of any set of head phones. It also obviously allows the user to adjust the volume pot.

I've tested with Kz IEMs, crap dollar store buds, and Audio Technica ATM 20, 30, 40 and 50 headphones (not sure of the impedances).

With the Sennheiser transmitter driven somewhat hard (tickling the AF Peak limiter) they are plenty loud when the EK's AF OUT is set to +12db.

Anyway, with the low profile connector I've used the box and connector is 86mm x 31mm x 31mm or 3-3/8" x 1-7/32" x 1-7/32"

If there is any interest I could build a few more to sell.

Lectro RM App, Sleep & Wake Widget. Thats all.

Mon, 01 Jun 2026 15:25:21 +0000

install on android (app does nothing when clicked, you have to add widget to screen). done. no permissions. 3mb file. just sleep and wake for SMQs and better.

i made one years ago but it was a full screen app and the only comment i ever got was "how about a widget?" so i finally dusted off android studio and here it is.

sleepwake_widget.apk

Shure ULX service manuals?

Mon, 02 Mar 2026 07:04:43 +0000

Hello,

I am trying to repair a couple of Shure ULXP4 receivers but I can't find a service manual.

The fault is silly, audio drops out despite an excellent RF signal and the problem is in the pilot tone detection. I have verified that the transmitters work and I found

a tech note explaining how to disable pilot tone detection. Doing this audio will no longer drop but I would like to fix them.

https://service.shure.com/s/article/disable-tone-key-on-ulx-receiver?language=en_US

I will check electrolytic caps, which seem to be the most likely cause, but a service manual would be great.

The thing is, the Spanish official Shure service, Earpro, refuses to even have a look at them. According to the Shure website it is possible to purchase service manuals from Shure but the Spanish dealer refuses to supply them.

Any ideas?

Thanks!

DIY Follow Carts

Thu, 12 Mar 2026 12:16:25 +0000

There are some manufacturers around doing great sound carts and follow carts, but if you are like me and like doing a bit of DIY, I highly recommend this place for Europe based people.

www.tuli-shop.com

I have no association with them but they have good prices, good service and plenty of different profiles and accessories to do your unique project.

DIY Power Lavs with NP1 Battery

Sat, 09 Aug 2014 01:43:48 +0000

hey guys

So my kit has two Sony UWP series Wireless Mic Kits. These are only powered by two AA batteries. I know higher end receivers can be externally powered by a DC cable and a BDS system, but unfortunately the Sony's don't have a DC power jack.

I'm wondering if there's a way to have a DC wire going into "dummy batteries" that would then power the receivers. I could then hook up the DC to my BDS.

Here's what I'm working with: NP1 style battery, Hawk-Woods NP cup/BDS (Its the NPC-SQ4NS). The NP then powers a Sound Devices 302, and Sound Devices 702T from the Hawk-Wood's 4 pin hirose outputs.

I basically want a wire that goes from the Hirose output the Hawk-Woods connector to some sort of "fake AA" that will power the receiver.

Any suggestions?

COS11D repairs?

Sun, 19 Jun 2022 13:14:24 +0000

I think I remember reading about a person who repairs damaged COS11 mic heads. Can anyone point me in the right direction?

Shortest low profile male XLR connector

Wed, 25 Dec 2024 12:34:05 +0000

Hello,

I am searching for a low profile male 3 pin XLR connector that is less than 3.5 cm in length overall, cap included, ideally in Europe but not too fussed if it can be found elsewhere willing to ship to Europe

Any help or tips would be greatly appreciated, thanks!

Mattia

Need Help Identifying Sennheiser G2/G3/G4 transmitter/Receiver Unshielded Antenna Wire (Sennheiser G3 Mod)

Tue, 25 Feb 2025 23:57:04 +0000

I'm trying to make an SMA antenna perform as well as the stock Sennheiser G3/G4 antenna.

Does anyone know the specific type or name of this wire? Is it steel, copper, or something else? Also, where can I buy a good replacement?

Any help would be much appreciated!

Service providers for rewiring mic cables

Sat, 12 Apr 2025 12:37:57 +0000

Hi, I am trying to find any advice on good repair/service providers that can properly rewire some lav mic cable connectors for me. In tha past I've used Wilcox Sound but have been unable to contact them recently. Any suggestions?

Video Guide: Sony UWP wireless SMA modification

Fri, 31 Oct 2025 06:02:29 +0000

Hello sound and video people,

I recently posted a video detailing how to modify the Sony UWP-D series wireless kits with SMA antennas. Links to all products and tools used are in the video description.

There were videos and guides for modifying the Sennheiser G2/3/4 with SMA, but nothing for the Sony's besides some random Reddit posts with spotty information. I hope this will help the more novice sound and video/film people that might be using the Sony sets and are interested in having the SMA connectors for the antennas.

Thanks to all.

Hi-Q/AudioRoot Battery Terminal Cover - Any use, or am I just wasting filament?

Fri, 01 Jul 2022 13:31:06 +0000

Mostly as an exercise, and to please overzealous TSA people who sometimes insist on terminals being taped, I designed and 3D printed safety covers for my Remote Audio Hi-Q batteries for a recent trip. The cup has small bumps inside that keep it in place on the battery. Picture attached with one cover at each end, just for show.

Comments?

John

Battery Charging Stations/Cases

Fri, 29 Aug 2025 05:25:09 +0000

I’ve seen some impressive builds for charging stations in Pelican cases, and I’m looking for inspiration for my own. Would anybody care to share theirs? Please feel free to show not just photos of the station, but maybe how it was built, materials, etc.

Air Bagged 833 rig

Mon, 22 Sep 2025 18:46:51 +0000

My 833 rig was always slipping deep into my bag, could’ve used a simple foam block or 3D printed riser…but for $20 and an 11 second install my 833 now has air ride suspension with infinite work height adjustability and low profile travel mode. 10/10

https://www.lowes.com/pd/Johnson-Level-Air-Shimming-Tool/5001465067

IMG_8651.mov IMG_8652.mov

Hodges weights from archery suppliers with Ambient boom pole foots

Tue, 09 Sep 2025 08:43:50 +0000

Currently, I am using the tungsten weights from the brand Shrewdarchery (1 inch diameter )inside a custom resin printed piece that sits in an Ambient P35 boom pole foot. This works ok, but for a different concept I'd be curious, if the 1.25" diameter weights that seem to be more common in the archery world would still fit nicely in an Ambient P30 foot.
The P30/P35 have a nominal inside diameter of 30/35 mm and come with the 4/5 section Quickpoles. 1.25" are apparently 31,75mm.

So, anyone of you in the imperial world of measuring, if you have some 1.25" diameter cylinder and a 4 section Quickpole around, I'd be greatful if you could try to fit the rubber foot of the QP on the cylinder and report if that fits nicely without producing a dirt collecting gap on the top?

PSC 75 foot boom duplex

Sun, 31 Aug 2025 22:23:49 +0000

I have a never-used 75-foot boom duplex cable that I am curious as to whether anyone here has ever repurposed one of these successfully? I really don't want to throw this thing away, but as it stands, I really don't have a use for it. I don't think anyone is looking to buy one of these since we're all wireless.

Anatomy of the NP1

Wed, 26 Jan 2011 15:45:42 +0000

I picked up some consigned NP-L7S's recently, and one turned out to be faulty. Since they were used, I had no real choice but look into re-celling. I figured that either way it would be a learning experience.

First, they make these things NOT to be opened! I was able to eventually get in, but it required a combination of finesse and brute-force.

First, I removed both of the stickers from the outside of the case. I wish I had heated these up first, as I had a bit of cleanup on my hands afterward:

Next, I removed the four screws from the top and bottom of the battery case:

Once the screws were removed, the case was still glued shut. I heated the perimeter of the under-side of the battery with a hair drier long enough for the glue to loosen (this took a while). I was eventually able to crack the case enough to get a flat-head screwdriver in to work it off the rest of the way:

Here is the battery side of things. You can see a bit in this photo that in order to further ensure that people don't go poking around, they also glue the battery side to the casing... lovely:

Here is the top portion of the internal circuit board. You can see the surface-mount LED's for the charge indicator:

...And here is the terminal end of the circuit board. I was honestly surprised to see such complex circuitry inside this battery. My assumption is that its basically input and output voltage regulators, LED drivers, and the over-drain protection circuit. There are plenty of unpopulated areas of this board, which are presumably for the brains of the more expensive NP-L7. Either way, It made me feel a little better about shelling out what we do for these battery packs:

I was expecting the batteries to just be wired in series, but they're not! More of a series-parallel configuration:

Thats about all I have for right now. I found a source for replacement Lithium-ion cells, but at $7 or so per battery, I just don't know whether its worth the trouble and expense for me to replace them all. There is still a chance that something is malfunctioning on the circuit board and the batts are fine. I may just chalk this one up to "seeing how this thing ticks".

Anybody have any further insight or experience?

-Wyatt

Zaxcom RX200 loose BNC nut DIY

Sat, 14 Jun 2025 23:57:22 +0000

I know a lot of folks here are self-sufficient, but wanted to share my repair in case someone else has to do it and save you the trouble of taking out the wrong screws. It seems to be a problem that is very common amongst people I have talked to and I have two of them with this problem. I am repairing 2x of them right now. Just wish the nut was somehow on the outside, but not too hard of a fix. With the battery door to the left, If you remove the two larger screws shown below middle top and middle bottom, the two screws on the side near the battery door, and the four screws on the side to the right, a little Tweaker screwdriver pry at the seams in the panel will pop the panel right off giving you good access to the nut that needs re-tightened. Mine shown here came all the way off. Bummer in the field but some tape got me to limp back home. Some Loctite on this round should do the trick.

7-core microphone cable for DMS setup?

Sat, 12 Apr 2025 01:31:36 +0000

Hey all,

Do you have any recommendations for 7-core microphone cable for a DMS setup? The only specifically-7-core stuff I can find is designed for tube microphones (5 audio + 2 DC power). Does a simple 7-core audio microphone cable exist? Or is everyone just adapting 4-pair Mogami or Canare?

Thanks!

Best soldering iron/gun for basic cable fixes by a novice?

Mon, 25 Aug 2014 20:34:48 +0000

Hi all,

Did a search for "soldering" but didn't find a recommendation for a basic soldering gun/iron kit for a novice repair. I've got an ever growing pile of good cables that I'd love to fix - mainly 1/4 " guitar cords and XLR mic cables.

Is there a good soldering kit that you'd recommend?

In the meantime, back to the Youtube videos to learn more :-))

Thanks for your kind advice.

Keep well,

Dave

Cantar Mini bag

Tue, 01 Oct 2019 19:01:38 +0000

For the past few months I have been using my Cantar Mini. I work bag and bag cart, so in my search for a Cantar Mini bag I found only three sources and none of them really did what I needed done in a bag.

So I built two versions, the second is shown below in the photos. The first version shall never be seen in public.

All of the metal work and sewing I did, so please don't judge me!!

The Mini is not like any other recorder/mixer shape. So my design incorporates a frame much like the Aaton cheese plate offering. I wanted something fairly compact and have some features that I don't believe any other bag has.

By making it triangular I have created a space that now houses a permanent battery distribution system, battery cup for an Inspired Energy type battery, a USB power outlet and two attachment points for mounting two Lectrosonic dipole antennas. For me battery and antennas on other bags are an afterthought.

The total weight of the bag with no battery, is 2kg and that includes the BDS, USB power and the battery cup. So it's weight is on par with other bags. Dimensions are 30.5 x 28 x 23cm.

Since this design has the Mini in a vertical position, a flat surface means you would need to operate from a standing position. On a bag type cart this is not a problem. So for the times when you can sit at a table I added the folding design to allow you to operate and see the screen. I have small rubber feet on the metal surfaces to protect whatever table you set up on.

The sloped surface makes it a bit easier for me to operate as I don't have all of the button positions memorized. I am already thinking of changes in the third version.

Also shown is my minimalist take. Two wireless channels and a boom.

Reterminating an Audio Technica ATM350cW

Fri, 21 Apr 2023 21:33:20 +0000

I've come into possession of an Audio Technica cardioid lav: ATM350 (cW) (along with an omni cousin, an AT899c).

I'd like to reterminate it for Lectro, and I'm trying to figure out if this is even possible with this mic. With some digging, I've identified the pinouts on the existing connector, but I haven't found reliable information about the required bias voltage.

The official spec sheet lists 11-48V phantom, which obviously wouldn't work with anything except a plug-on transmitter, but that is for the cabled version, which includes an in-line adapter that accepts phantom. I have the "wireless version" (ATM350cW), which "features a 1.4 m (55") miniature cable terminated with a locking 4-pin connector for use with Audio-Technica UniPak® body-pack transmitters. No power module is included (or required) with the ATM350cW." It also identifies the "element" as "Fixed-charge back plate, permanently polarized condenser", which I think makes it an electret, and therefore powerable with a bias voltage (I'm not sure what else they could use in a lav anyway). All of which is to say, I don't think I'm completely off-the-wall in thinking I could adapt it for my Lectro transmitters.

By looking up the compatible Audio Technica wireless systems, I was able to get a pin-out for the locking hirose that it is currently terminated with. I found two slightly different specs

Audio Technica System9: Pin 1: GND, Pin 2: INST INPUT, Pin 3: MIC INPUT, Pin 4: DC BIAS +9V
Audio Technica 3000 gen3: Pin 1: GND, Pin 2: INST INPUT, Pin 3: MIC INPUT, Pin 4: DC BIAS +5V

That suggests the mic would work with a bias voltage of 5-9V. I also found this, which anecodotally suggests the mic may not work under 5V.

Which brings me to Lectro. As I understand it, Lectro "Servo" wiring supplies a regulated 4V bias, and non-servo wiring supplies a current-dependent voltage in the range of 2-5V.

With that in mind, has anybody here successfully reterminated this mic, for Lectro or any other system? Would it be better to try the non-servo wiring first, under the assumption that that might permit a higher voltage? Or would servo be more reliable? With non-servo wiring, I notice there's a number of mic-specific wiring patterns, mostly involving additional resistors. Can anyone help me shed light on how to pick the best wiring for this mic (should I try to test impedance? Are the resistors just to control excessive signal?)

What would the downside of starving the mic for voltage be? I'm assuming sensitivity (and thus noise floor) and possibly frequency response would be affected, but I'd love confirmation of what to listen for to check if the mic is powered adequately.

There's nothing critical riding on this project, other than wanting to have a cardioid lav in my collection, but I would love to learn from anyone that has messed with this mic in the past, or anyone who knows the ins and outs of Lectro wiring in more detail than is given in wiring guide.