Sunday 10 March 2019

Volca Bass Patch Sheet

I recently bought a Volca bass with the mind to incorporate it into a live electronic setup.
As I'm doing this and there are only some parameters that are saved with each memory patch on the Volca Bass I wanted to get a patch sheet.

I googled and didn't find any, so I scanned the back of the volca bass box and did some quick adjustments to blank out the settings and unnecessary text.

Obviously this is not my image, it belongs to Korg and therefore it is their copyrighted material but I thought I'd post it and I will take it down if I'm asked to do so.

I just thought it might come in handy for others.

I have printed out a page with 4 copies per A4



Tuesday 17 November 2015

Wurlitzer/Hohner P100 Portable Keyboard

Wurlitzer/Hohner P100 Portable Keyboard - Not Working



The other day I bought one of these keyboards off of ebay in a "for parts or repair/not working" state. I paid $90 which may have been a ripoff but there isn't too much info out there on these particular units so it was hard to know.
I listened to a few demos on youtube and it delivered the shrill, top-end, dinky vibe I was looking for so I bought it with the mind to fix it.

I do this often if the problem sounds fixable, e.g. Not powering up. This is usually an easy fix - I have had people call me a masochist.

The seller said that they could not get the unit to turn on. When I received, the first thing I did was open it up to look for an failed Electrolytic Cap on the power board.


Nothing looked bad but I reflowed some of the main solder joints to and from the transformer and across the fuse (which was also fine) and put everything back together.

I found a 12V adapter I had laying around, check the polarity of the plug and it matched so I plugged into the 'Car battery' power input and turned it on.

Immediately noticeable was a power hum and the fact that multiple keys were not working, which is common to old organs and keyboards; sometimes its a failed diode on the key matrix and sometimes (if it's consistent e.g. all of the G's or all of the C's) it's most likely a problem with a PIC chip.

I took note of the non-working keys and in the meantime searched around for another power supply to see if the hum was due to my external power not due to something internal.






I found a different power supply and the hum disappeared, I also found a cable to plug directly into the proper AC power inlet on the keyboard and that also worked fine. I'm not sure what the buyer meant by "It doesn't power up" but it definitely does and so happy days.

I tracked down which diodes corresponded to which keys on the panel board inside the keyboard and put a red mark above them. I'll get some substitute 1N4148 diodes for them tomorrow and switch them out.

Other than the key problem the keyboard works fine.
It was initially hard to track down info on this keyboard as I was searching for Wurlitzer P100. But noting the back of the keyboard:


I tried searching for Hohner P100 and more results came up including the manuals and schematics which allowed me to track down what diode was used on the panel board and search for substitutes.

I'll switch out the diodes and update after that. Here are some more pictures of the keyboard.





UPDATE: I found my multimeter and checked the diodes before I swapped them out and found they were functioning fine, so I took some Switch Lubricant to the contacts of the keyboard PCB and when I reassembled found that all the keys worked fine.
Fully functioning Wurlitzer/Hohner P100 with just a little spring cleaning. Prime.

Sunday 31 August 2014

Optimizing Video Playback in Logic Pro 8

I use Logic for audio post editing, it's an old version - Logic Studio 8, but it's pretty reliable and because I used it for music production prior to editing for film, I know the GUI really well and the hotkeys I need often.

After working on a few features using Logic I noticed that it functions a lot better with video if you take a few quick steps to set it up properly. This is assuming you use a dual-monitor setup with a dedicated picture monitor, if you don't, poor you.

Step 1: Video Format.
If you're doing SFX work it doesn't matter if the video resolution isn't amazing, that being said it can't be terrible but I can easily work with Standard Definition and the smaller the file size will help Logic handle the video.
For dialogue editing it may be beneficial to use HD at 720p just to ensure editing to lip-sync is as close as possible.
The main thing is getting a good file size for logic to handle; I use .mp4 using H.264 codec and whatever the source fps, SD sometimes even less - 480 x 272.
If you're supervising or running the show you can transcode using MPEG Streamclip, or if you're not then you'll probably get what you're given.

Step 2: Setting up Logic.
First go to Preferences/Video and set the Video Cache Resolution to 'Best' and Maximum Cache Size to the highest it can go.
Side note: When working with video in Logic it helps to have as much free hard drive space as possible as this will allow the computer to 'breathe' better.
I always have the Video file on my native hard drive although if you were using SSD via thunderbolt it may work faster; there's better people to ask about that one.
Second go to Settings/Audio and set the project to the right sample rate for the source material (dialogue or production FX).
Third go to Settings/Synchronization and set the frame rate to the source fps and if you need to offset the timecode to match your picture you can also do that. I always have the timecode printed onto the picture, as is standard practice.

Step 3:
Go to Options/Movie/Open Movie and it should open in a little pop-up window or in the inspector.

Step 4:
Go to Options/Movie/Import Audio to Arrange. This will load in the audio to your arrange window (surprise, surprise) to help with visual syncing of external files and allowing you to turn the video's audio on and off easily. If you don't setup the correct sample rate for the project before you do this, it will create audio issues once you correct the sample rate down the line.

Step 5:
Drag your video pop-up window over to whichever monitor will be your picture monitor, not your editing monitor.
Then go to Settings/Video, change the Video Output to 'Digital Cinema Desktop' and the Video Format to 'Digital Cinema Desktop Preview - Full Screen'.
And if it isn't already, turn down the Movie Volume.

That's it.

Your picture should run a lot smoother than if it was just in the pop-up window.
For me this has completely avoided frame skips and the scrubbing is a lot more accurate.

I'm not sure if it's a similar setup for newer versions of Logic but I'd say it's not much different.

Any tips or criticisms let me know in the comments.

Wednesday 6 November 2013

Zoom h4n & Sound Devices 442

Zoom h4n & Sound Devices 442:

a match not made in heaven, but on earth...


As much as I'd like to buy a great 4-track field recorder with time code, I can't afford one.
I can't even afford a 2-track with timecode.
The flexibility in naming the tracks and take numbers and having a mathematical link to the camera as well as an auditory one are but two of the features a great recorder would offer.

However, as money would have it, at this current time, I have a h4n.
In fact it is a battered h4n, in which I have replaced the headphone jack and broken the on/off switch, being reduced to turning it on and off with the leg of an LED or other such component.

For the record I don't use it onset as it would be too difficult to use in a hurry, but I'm often just offered another in its place. Which I'm kinda okay about, also kinda not.

When looking at the compatibility of the h4n and the SD442 online I didn't come up with much except forums that quickly went off topic and had people debating the number of recordable inputs on the h4n - for the record there's 4. (It says so in the manual H4n Manual)

The current film landscape has the usual onset setup as 1 boom and the actors lav mic'd, let's say 3 actors = 4 inputs.

The h4n can record all this alone, but it's interface is terrible for adjusting volume and for monitoring, it also has no routing options or output options. Not dissing the h4n, it just doesn't and I need them.

Enter the SD442, 4 inputs, 4 pre-fader direct outs, 2 master XLR outs, 2 master TA3 outs, headphone out, mono mic out, a couple returns and last but not least - mic powering (48V and 15V). That's not all but that's the basics.

Great.

It also has monitoring options, a great VU/PPM meter and nice preamps - something the h4n does not have.

If you're going to record onset sound you need monitoring options (for troubleshooting), you need output/routing options (recorders and camera) and it's great to be able to record multiple tracks, so that if you have problems with one lav it doesn't spoil the whole lav track (on a 2-track recording).

N.B. H4n's are so common, it's likely that multiple members of your crew may have them, including cameramen and maybe the actors themselves. Use 2 if possible and you can set one up as a 2-track backup recorder.

Here's how I hook up my 442 to a h4n for 4-track recording:

442 direct outs 1 & 2 run into the EXT Mic input on the h4n and 3 & 4 run into inputs 1 & 2 on the h4n. Done.

I made a cable that splits the stereo 3.5mm jack needed for the EXT Mic input to two TA3 connectors and then made two TA3 to XLR cables for the input 1 & 2.
If you run the direct outs as I stated they will appear on the h4n as they appear on the mixer - left to right. 
It's that simple and here's why it doesn't completely suck.

As per the h4n manual the EXT Mic input and inputs 1 & 2 are closely matched in performance.
EXT Mic - Impedance 2k Ohms with level -7 to -46dBm
Inputs 1 & 2 (XLR) - 1k Ohms with level -10 to -42dBm

The 442's pre-fader direct outs come after gain, HPF and the input limiters. This means that setting up your recorder with your mixer and creating a good gain structure is critical - even more challenging if running to 2-track back up from the master outs.

The default setting on the 442 direct outs is line level. Which you do not want.
The h4n will flash all sorts of red and the signal will distort even when the gain on anything is low. You need to change this setting in the 442 Setup menu, which is all in the Setup Chart (SD442 Setup Chart).
You can either run at line level or mic and you'll want to change it to mic. You'll also want to change the default Tone/Slate option so that you can send the 1kHz sine wav tone to the direct outs as well as the master outs.
This is how you calibrate your mixer and recorder, just like in any mixer recorder calibration (see H4n Setup with SD302).

To run the 2-track back up recorder you just run the 2 master balanced outs of the 442 to the inputs 1 & 2 on another h4n and pan accordingly on the 442. Then you can use any of the monitoring options to deal with the way you hear your audio.

Why not just run 2 h4ns and only use the 1 and 2 inputs? I hear you ask. You can. Do it.

The benefit in recording 4-track on one h4n is to cut down on possible syncing issues in post.
2 recorders means syncing the 2 recorders and syncing to picture in post. I've done it. It works 80% of the time (this is not mathematically accurate).
One of the problems with running two recorders without timecode is that over time (long takes) they will slightly shift and present syncing problems.
Not only that but the assistant editor or editor may lay the 2 stereo tracks into a timeline in a different order. This is due to the h4n filing system which dumps the 4 tracks into two stereo files (another draw back).

So one shot on the timeline may have the track list:
1 - Mic L (Boom)
2 - Mic R (Main Lav)
3 - Input 1 (Support Lav)
4 - Input 2 (Bit Lav)

And for another shot it could be:
1 - Input 1(Support Lav)
2 - Input 2 (Bit Lav)
3 - Mic L (Boom)
4 - Mic R (Main Lav)

Annoying!!!
You know what would solve these problems real easy?
A good 4-track field recorder with timecode.

But until then, you gotta work with what you've got.

Interesting Reads:
H4n full analysis
SD442 with H4n


UPDATE: After using this setup on a few shoots there are notable drawbacks to the audio quality on occasion from the EXT mic inputs on the h4n.
On some takes a hum may appear on the track, this is most likely due to the unbalanced nature of the input. It is easily removed via a good noise reduction tool, but it's a bad thing to have from the get go and noise reduction isn't a good practice to rely on.
I know what'd be a better fix... 

UPDATE 2: The sound that was appearing on the EXT mic input was the result of stereo encoding technology in the device and was fixed with firmware update 1.90.