8-bit Software (c) Duncan Webster April 1992
Issue 19 (c) Duncan Webster 3rd April 1992
SOUND SAMPLING ARTICLE
I have been using the latest Micro User sound sampler on my Master for
a couple of months now. For absolutely ages I had been trying to
obtain a sound sampler, Diluk Dias of TYB fame told me one time that
there was a plan for one in an old Micro User. I spent ages trying to
track this article down, I sent a cry of help through these columns,
no reply. I rang the Micro User, they only have back issues for the
last few months they reckoned.
I rang absolutely everywhere. Watford electronics were extremely
helpful, one bloke there spent ages sorting through old mags, but it
was all to no avail. Finally in total desparation I Rang Mike Cook at
the Micro User. He was really helpful. As I was explaining to him
what I was after he laughed. First of all the mag I had been looking
for was the wrong one, but secondly, he had apparently literally just
finished writing the article that was going to be published in the
Micro User concerning the new sampler. He sent me copies of the
origional sample circuit diagram and the new one as well. I examined
these diagrams and made a large number of phone calls to electronics
shops around where I live. There was only one bloke who seemed to be
anything like ready to help so I popped down to see him.
After much scratching of heads and great deliberations we decided
that, as I am not at all experienced in electronics, with the outlay
involved and the extreme likelyhood of expensive foul ups, it was
probably a more sound (sorry) option to go for the ready made sampler
offer. When the bloke in the shop looked at the circuit diagrams, he
reckoned that the origional sampler may be better than the new one, I
am not qualified to comment on that, but I think that the latest
sampler was built with compatability in mind. So I waited for the
article to come out in the Micro User. Off went the cheque in the
post, back came a little package in the post.
I mounted the board in a small plastic box. There are 2 small jack
plug sockets for mike and CD input, the CD input cuts out the mike.
There is a DIN socket for connecting the supplied lead to the user
port of my Master (out came Duncan's modem). There is a variable
resistor on the board so that sensitivity can be turned up or down, so
I put a hole in the box above it to enable a screwdriver to be
inserted to alter it. The power is taken from the user port. The
software that came with it did the job. It came as a series of
programs enabling you to take a sample and play it back, see the
waveform and an echo chamber. To take a sample, you just press a key,
the screen fills with garbage to give you an idea of when memory is
To save a sample to disc for later use takes some time as the data
taken in is converted, the saved file is actually half the length of
the origional sample taken. I wrote a program of my own which
incorporated most of the ideas in the software plus a couple of extras
which for instance allowed me to use the whole of my Master's memory.
In fact the program ended up doing all I wanted and being quite short
(&5E3 after running to be precise). The program allows you to input
and play back a Master full of sample, or a specified buffer length.
It also allows you to save an unconverted file to disc so that the
long conversion process can be carried out later, thus allowing you to
continue sampling without long breaks.
The echo chamber plays back the sample immediately and is useful for
fine tuning all the knobs, bits of wire, speakers, videos, radios,
tape recorders and children that inevitably get strewn around the
computer before finally committing the sample to memory and then disc.
The quality is not startling, in fact some times it can be hopeless,
but with a good origional at the right volume you can get acceptable
results. I use my programs Mix-Ed and Runbld to finish the job off.
If any members out there are interested in samples, but don't want to
get involved in the sample taking itself I have sent Duncan Webster
4.5 discs of numerous wonders, he may, if you ask him nicely, send
them on to you. If there is any interest shown, I may be spurred on
to experiment further. Oh! I almost forgot, you can get about 5
seconds of sample into a Model B. But as the file is converted to
save to disc it decreases in size, this means that you can join files
together and play back 10 seconds. To play longer samples means that
you have to stop occasionally to load in from disc. A Master will
sample about 15 seconds, again this increases to 30 seconds for
playback if you are prepared to join files together. You can of
course play back at a slower rate, and repeat sections several times
to increase playback time.