new studios in Christchurch
Kevin Allison, who is a guitar tech for Stevie Wonder, has moved to Christchurch and started a new studio with an API 1608 desk (at a secret inner-city location). Also on the rumour mill is that another studio is being planned that will have an SSL desk. Watch this space.
Pricing old gear
Recently a Yamaha FS1R sound module came up for sale and the guy wanted $4000 for it. I thought this was way too much, and sure enough it turns out that the going rate for this unit is
$700 to $800. After trawling through forums to find recent sales, I came across a website that tracks the sales prices of used audio and music gear: http://www.prepal.com/manufacturers.htm
The FS1R is listed at an average resale price of $US498, tracked over 155 sales.
Pro Tools 9
I attended a Pro Tools 9 training day yesterday. Here's a short list of what's new...
32 channels of I/O (in and 32 out)
64 master faders
with Complete production toolkit:
up to 7.1 surround
192 active audio tracks
74 VCA tracks
PT9 HD Native:
uses low latency mode (bypasses plugins)
up to 4 interfaces (64 channels of I/O)
up to 7 cards
up to 2 interfaces per card
up to 10 interfaces
up to 160 channels of I/O
up to 16 channels (of any sort; digital, analogue)
2 limiter options in Hardware setup (softclip, curve)
8 ins, 8 Outs
2 mic pres
Monitor control - provides alternate mixes (e.g. 5.1, stereo) to the same monitors. Good for swapping surround and stereo sessions.
24 bit 192kHz
up to 64 send and rec streams
sample rate convertor
supports varispeed mode
Trevor Cox has published a website that identifies interesting sound locations (both natural and man-made) around the world: http://www.sonicwonders.org/
I play the keyboard at St Christopher's Anglican Church and last Sunday every time I played a top C note it sounded through the PA at full volume. Ah, great - a keyboard fault that sounds like player incompetence! I have struck this problem before with electronic keyboards, and it is caused by dirt getting into the keyboard membrane switches.
Originally, electronic keyboards had wire busses and short lengths of gold-plated wire to do the switching when a key was depressed. For the last 20 or so years, a cheaper membrane switch (using Force Sensitive Resistors) has been used on many keyboards. The switch 'contacts' are on a PCB, and are made when a conductive bead attached to the underside of a special rubber mat (the membrane) are pressed onto the PCB by the key.
I took the keyboard (a Kurzweil KME61) apart, and sure enough there was a speck of dirt on one of the top C contacts. It was easy to clean this with a miniature brush. While I had it apart I checked all the membrane switch pads, and found some others that had dirt in them too.
The problem really is that dirt gets in there in the first place. Membrane switches are designed to attach with lots of little feet that fix to holes in the PCB. This system does not seal the contacts off from the dust which invariable falls down between the keys. Unlike the old open contacts, once dust works its way in there is no way for it to get out again. If the keyboard was always sitting horizontal in a clean room it would be ok, but if the keyboard is moved, then when it is tilted, some of the dust will get under the membrane, and eventually interfere with the key contacts.
So, to stop this happening again I use masking tape to seal around the edge of the membrane switch. Why the manufacturers don't do this I don't know. Maybe they save 30c per unit!
It was pouring with rain this morning so I decided to do something I've been putting off for years - cleaning the inside of my grand piano. If you ever need to do this here is how to do it and what you'll need:
1. patience! - allow lots of time (several hours).
2. a set of artists brushes to loosen the dust. I used six, sized from no. 3 up to no. 20. A stiff bristle is best. Work the brush between the larger string gaps, taking care not to inadvertently do any 'tuning' by bending on the strings.
3. a really sucky vacuum cleaner. While carefully dusting between the strings with the brush have the vacuum cleaner going at maximum, using the upholstery nozzle. Unless you have an industrial strength vacuum cleaner it is probably a good idea to give it a rest after each half hour, so you don't fry its motor.
4. an old broomstick is handy to prop the lid up high enough to allow you to 'get under the bonnet'. Make sure it can't let the lid fall (as the weight would probably dice your head through the strings!)
5. be very careful when dusting the top of the dampers, as they can be easily bent.
6. the soundboard under where the strings cross is hard to reach. I used a very small rag attached to the end of some electrical cable to reach under the strings to clean this bit.
and here is the result - a 1988 piano that looks like new:
Ah, summer holidays - time for long walks with the dog, and catching up on this and that. I was given some shellac records (78s) a few months ago, and finally got some time to play them. When I put the first on one there was a weird squeal along with the music. The technical name for this condition is 'parasitic oscillation'. I thought about what might be causing it, then remembered that I had changed my amplifier since playing any 78s. The rather hot output of my 78 cartridge plus a higher gain input was the cause.
Now for the cure - I put an R substitution box in series and increased the resistance until the oscillation stopped. Then I read the value: 15KΩ. So that was the minimum series value to increase R by. I then got a 100KΩ pot and jumpered it up in an L-pad configuration, and wound the pot until the volume was similar from the 78 and radio inputs. Reading the pot values on the multimeter gave 66K in series and 33K for the shunt path. I selected the closest values (68K and 33K) from my 1% metal oxide resistor draw and soldered them in on the RCA plugs of the 78 record deck.
Job done - now back to listening to Bing, Elvis, and Doris Day.