Workshop – Xaudia

01-01-2013

Happy 2013

Thanks to all of our friends, customers and suppliers who helped to make 2012 another exciting and successful year for Xaudia.

Hot-rodded Reslo RB microphones

In 2012 we repaired 203 microphones for customers, an increase over 2011, and Reslo microphones were again very popular – we serviced 47 of them this year. Once again RCA mics came in second place (23), with AKG and Beyerdynamic in third and fourth.

Xaudia – microphones serviced in 2012

We sold a further 50 or so refurbished vintage ribbon microphones through our website, including about 25 ‘Beeb’ modifed Reslos. And we also introduced our own low noise ribbon microphone transformers for repairs and upgrades.

2013 looks to be just as exciting – we will be launching a range of guitar pickups, making a few more transformers, and also there will be some tube mic power supplies. And of course we will be here to repair your microphones.

Happy New Year!
Stewart & Jane
Xaudia.com

20-10-2012

Melodium 42B rebuilt

A few weeks ago we received this rather forlorn looking box of Melodium bits for service!

Melodium 42B stripped down to parts

The good news was that all the important parts were there, and despite some corrosion, the magnets and the transformer were on good shape, which meant that this vintage gem could be restored to some of its previous beauty.

Melodium 42B repaired and re-ribboned

The mic was stripped down and all the parts cleaned up in the ultrasonic bath. Then the magnets and some other bits were painted to stop the rust returning, and the motor reassembled. Dino (the owner) wanted to retain the vintage look of the mic, so the grills were straightened, de-rusted and then given some clear lacquer rather than being refinished. New grill cloth gives some protection against pops and wind blasts.

Then it was put back together and a new cable fitted with XLR output. And of course a new ribbon. The mic looks pretty damn cool!

Thanks to Dino Jakobsen of The Why Project.

21-08-2012

A typical day at the office

RCA 77DX under test at the Xaudia microphone workshop.

I think I always wanted my bench to look like the inside of the Tardis. Signal generators, oscilloscope, LCM meter, frequency counters, distortion meter, microohm meter, home built impedance bridge, and lots of other gadgets. And an RCA 77DX, of course!

20-08-2012

Straightening a dented mic grill

Here’s a rather deformed grill from a Beyer ribbon mic…

And here’s how we straighten it using a doming block….

Simply pick the nearest radius curve from the block, and push out the dents with a suitable doming ball….

Voila! The end result…

🙂

30-04-2012

Cadenza mic XLR modification

Cadenza ribbon microphones are quite common, but there seem to be more microphones than there are connectors for them. The mics were originally supplied with an integrated stand & connector, which was ideal for desk recording, but not very effective for hanging over a drum kit.

This mic was missing its connector, so here is a chop-job to convert to XLR output….

The connector was removed from the mic and the bottom thread cut off and filed flat. Then a piece of brass rod was machined to fit snugly into the base of the mic, and this was bored to accept a standard three pin XLR insert.

The XLR has the added advantages of making a good earth connection, and also gives a way of mounting the mic on a stand as it can be slipped into a standard mic clip. I think elongating the base makes the look more elegant too.

21-04-2012

Marvin the Meteor

We have just installed a second Meteor ME307 coil winder at Xaudia, for rewinding ribbon mic transformers, pickups and making new parts.

Meteor ME307 with electronic controller

In fact we have were recently given a pair of used machines, and combined the best parts to make one good one. We call this one Marvin, because of his striking resemblance to the robot of that name.

Marvin the paranoid android from the original TV series of Hitchhiker’s Guide to the Galaxy

Marvin the Meteor coil winder

Marvin even has a brain, although perhaps not the size of a planet. It has more sophisticated controller than our existing Meteor winder, which just has manual controls and a foot pedal. The newer model has preset adjustable ramp, speed, idle, and also a reverse wind setting, which is very handy and removes much of the human element from the winding. Let’s hope he isn’t bad tempered like his namesake !

10-02-2012

Making a spindle for winding pickups

Next week we will be making a few single coil pickups for Stratocasters, so I quickly made this simple little spindle tool to help with the job. It was machined this from 15 mm brass stock on the new mini-lathe, which arrived earlier this week. Below is the roughly machined spindle, before cleaning.

The pickup bobbin slips onto the 3mm post, supported by the wide shoulder, and is locked in place by a square of flatwork board, screwed into the side. This prevents the pickup from slipping on the spindle, without interfering with the wire as it is wound on. The barrel was turned down to 8 mm to fit the Meteor coil winder, although it could equally well be used on a power drill chuck.

It will certainly be much quicker and more accurate than screwing the pickup to a block of wood, which was my previous method.

09-02-2012

SC2 Mini-lathe

The mini-lathe is here!

Delivery was a little late due to the snow and ice, but it finally arrived on Tuesday. After unpacking and cleaning off the excessive quantities of grease, I made a couple of quick jobs as part of the learning curve – the best way to learn is by doing, even if it involves a few mistakes.

First up was to machine this little spindle to hold bobbins for the coil winder. The spindle is in two parts, and is made from 10mm diameter aluminium rod. The lathe is very handy for making little tools like this.

Then I used the lathe to replace the broken connector on this B&O microphone. The old connector was cut off, the hole widened and threaded to take an XLR output. Finally I can get this mic up and running! 🙂

B&O BM3 with XLR output

The lathe is a useful addition to the workshop, and is already proving its worth. It needs a few tweaks to set it up and take some of the slack out of the slides. Luckily, mini-lathe.com have excellent information and guides to setting up these machines.

01-01-2012

Happy 2012!

2011 was a big year, with lots of changes.

Although we have been fixing ribbon mics for our own studio and a few customers for several years, 2011 was the first year that we went public and began to advertise the re-ribboning service. The mic repairs were moved to their own special room, with a dedicated testing chamber. The other big development was the acquisition of our Meteor coil winder, and the decision to do transformer repairs and re-winds in-house. This has vastly expanded the services that we can offer.

In 2011 we repaired some 186 microphones, along with a few guitars, amplifiers, reverbs, DI boxes and so on.

Xaudia – Distribution of microphones serviced in 2012, by manufacturer.

The various models of Reslosound mics have been the most popular brand – there are still a lot of these around kicking around in Europe, and we serviced 37 of these in 2011. As one would expect, there were also quite a few RCA ribbon mics – 23 passed through our hands this year.

We would like to thank all of our customers for helping to make this such an excellent and fun year, and we look forward to even more exciting things in 2012.

Happy New Year!
Stewart & Jane
Xaudia.com

29-06-2011

Redneck wax potting bath

We needed a better way of wax potting our pickups and transformers. Here’s what we did on a budget…

Redneck wax potting bath for guitar pickups

It’s a hacked 300 Watt slow cooker, acquired from Tesco for the grand sum of £10, which contains an inner ceramic liner and holds about 3 litres. The probe is simply a cook’s thermometer (£14 from Barnitts of York).

It takes a little while to warm up, but sits at about 90 degrees all day, which is just about perfect for potting. The temperature can be further tweaked by running the bath on a variac.
Here’s a newly dipped transformer coming out of the soup – a mix of bees wax and parafin wax…

Update: 1 December 2011

The batteries in the cook’s thermometer died, and we really wanted to regulate the temperature and avoid the possibility of overheating the wax, so I built a little temperature controller into an old power supply box. The digital controller was ‘new old stock’ at £30 from ebay, and a 5 amp solid state relay and resistance thermometer came from Farnell to complete the setup. It works very well!

12-06-2011

Coil winding part 2

The new ME307 coil winder is up and running, and we’re jumping straight in to winding some guitar pickups. The idea was that this should be an easy place to start as they can be made with a single winding, and bobbins, wire etc. are all readily available. There is a big pickup winding community in interweb-land, so help and advice should be available.

The winder in action, with the pickup mounted on a metal plate that we made for the job…

Pickups typically use circa 42 AWG wire (0.0633 mm), which is a very fine gauge and requires care whilst winding and soldering to avoid breakages.

The wire tensioners that came with the winder were a little out of calibration, but with a little practice at setting the correct tension and winding speed, we could easily get 7000 turns onto a P90 bobbin with room to spare. It’s probably possible to get 8000 or 9000 turns with practice, to wind a really hot pickup. Here’s the first winding from the Meteor….

Looks nice! The next step will be to rewind some of the broken microphone transformers that we have accumulated over the past few years. But before that we need to mend the clutch plate, which is slipping.

07-06-2011

Our New Coil Winder – Meteor ME307

The ‘new’* Meteor ME307 coil winder has just arrived at the Xaudia workshop, after a 500 mile round trip to collect it…

We are very excited about this as it will expand our repair abilities and let us rebuild and rewind broken microphone transformers and guitar pickups. It has a counter to set the number of turns, foot actuated motor control, and of course the all important set of tensioners to allow the wire to be spooled at the correct tension.

The coil winder was probably built sometime in the 80’s and is built like a tank, with some beautiful Swiss engineering inside. Everything needed a little lubrication and a good clean and, although the machine has clearly seen some years of use, everything is still working perfectly.

ME307 internal gears and drive train.

We hope to be doing our first windings later this week…

21-02-2011

New workshop part 2: Construction Time Again

After a morning with glue and a staple gun, sticking acoustic foam to the soft walls, our new microphone testing chamber is up and running. Here are a couple of photos….

The chamber is hooked up to pink noise and swept-sine equipment, and can collect a frequency plot in a matter of seconds. I’m still working on validation, testing different speakers and mics for best performance, but the facility is already proving its worth.

14-02-2011

New workshop! (part 1)

It’s been a quiet month so far for blogging, but a busy one at Xaudia.

We’ve spend the last week building a new microphone workshop in the basement below the studio, including an ‘anechoic’ isolation booth for mic testing. Ralph & Jane have been helping out with building and painting.

Here’s the empty room, waiting to realise its potential: