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Forums - Synths & synthesis
Subject: Tuning the TB
Viewing all 9 messages - View by pages of 10: 1
Original Message 1/9 03-Apr-00 @ 12:48 PM - Tuning the TB
Whats the best way to tune a 303? My 303 sounds way off when compared to my 777 and to my friends (909inc.) 303. I know how to tune it internally but should I like hit a C note on my Juno and program a C note on my 303 and tune to satisfaction or what?
ReZo-99
ReZo-99
Message 2/9 03-Apr-00 @ 01:08 PM - RE: Tuning the TB
I cheat and use a Yamaha G-tar tuner a YT150 prolly bout 20bucks your money. Easy peasy. Plug the 303 in to it, set it to "bass" play a C on the 303 with the filter open and all the other controls to max, adjust tuning accordingly. If the other notes have gone out of tune you need to re-scale the 303 using the width pot - TM3 I think, tune each note individually, can take a while!
Message 3/9 03-Apr-00 @ 05:30 PM - RE: Tuning the TB
nope! TM3 just adjusts Cutoff req. You can increase the range by tweaking it.
Message 4/9 04-Apr-00 @ 03:26 PM - RE: Tuning the TB
Yeah sorry it's TM5 labelled "Width" it set's the interval of the CV scale.
Message 5/9 06-Apr-00 @ 05:41 AM - RE: Tuning the TB
Last night I tuned up my 303. I used a shareware tuner I found on www.download. com. I found that it was tuned pretty bad to start with, and decided to retune it.
Tuning a voltage controlled oscillator such as that in the TB303 can be quite tricky, especially if you're doing it for the first time. It is tempting to twiddle with both the TUNE and WIDTH trimmers at the same time, getting yourself into a right mess...
Here's the best way to go about things. First of all, ignore the TUNE pot altogether. Set it to centre position, if you like. Now connect your 303 to the soundcard input (or hardware tuner, whatever). Go into Pattern Write, select a free pattern location and go into Pitch Mode.
Press the upper C button and then after this, press the upper C together with the UP button to get a C one octave higher than the first. For the time being, IGNORE the actual pitch of the note. Simply adjust the WIDTH pot until the frequency of the higher C is EXACTLY DOUBLE that of the C one octave below. Get it as precise as you can. Now you've correctly set the WIDTH pot. That is, you've set the interval correctly.
Now shove the screwdriver into the TUNE pot. With the tune knob in the centre position, press the lower C button. Adjust the TUNE pot to get a perfect C. This will be around 65Hz.
I got it tuned really well - better than I expected, considering the the TB303 actually uses a rather basic D/A converter.
Cheers,
Trev
Tuning a voltage controlled oscillator such as that in the TB303 can be quite tricky, especially if you're doing it for the first time. It is tempting to twiddle with both the TUNE and WIDTH trimmers at the same time, getting yourself into a right mess...
Here's the best way to go about things. First of all, ignore the TUNE pot altogether. Set it to centre position, if you like. Now connect your 303 to the soundcard input (or hardware tuner, whatever). Go into Pattern Write, select a free pattern location and go into Pitch Mode.
Press the upper C button and then after this, press the upper C together with the UP button to get a C one octave higher than the first. For the time being, IGNORE the actual pitch of the note. Simply adjust the WIDTH pot until the frequency of the higher C is EXACTLY DOUBLE that of the C one octave below. Get it as precise as you can. Now you've correctly set the WIDTH pot. That is, you've set the interval correctly.
Now shove the screwdriver into the TUNE pot. With the tune knob in the centre position, press the lower C button. Adjust the TUNE pot to get a perfect C. This will be around 65Hz.
I got it tuned really well - better than I expected, considering the the TB303 actually uses a rather basic D/A converter.
Cheers,
Trev
Message 6/9 06-Apr-00 @ 05:42 AM - RE: Tuning the TB
Oh, and it is pretty foolproof and takes no more than two minutes when you get the hang of it... :-)
Message 7/9 07-Apr-00 @ 03:25 AM - RE: Tuning the TB
Can anyone describe what each of
the small pots on the board do? To
my knowledge, going from the left,
the 5 pots are:-main tuning- fine
tuning- resonance level- pulse
width- and some cv function.
I have messed with then many times,
but I got my 303 to sound the way I
like, I also tuned it by ear. You can
hear how my 303 sounds by
following the link. also mine sounds
way different than "high society's"
Rezo-99's machine. Can the settings
of these 5 pots alone make that
much difference in sound?
Anyone got really into figuring it out?
909 Inc.
the small pots on the board do? To
my knowledge, going from the left,
the 5 pots are:-main tuning- fine
tuning- resonance level- pulse
width- and some cv function.
I have messed with then many times,
but I got my 303 to sound the way I
like, I also tuned it by ear. You can
hear how my 303 sounds by
following the link. also mine sounds
way different than "high society's"
Rezo-99's machine. Can the settings
of these 5 pots alone make that
much difference in sound?
Anyone got really into figuring it out?
909 Inc.
Message 8/9 07-Apr-00 @ 05:51 AM - RE: Tuning the TB
The main tuning and width pots are quite self explanitory. The width pot sets the interval of the oscillator. Once you have the width set right, use the tune pot to correctly tune the oscillator. By twiddling with these, you will not alter the dynamics of the sound other than simply tune the oscillator.
As for the freq pot, this simply sets the range of the external freq cutoff pot and affects the cutoff range of the filter that can be obtained from this knob. It is possible to get lower or higher filter cutoff frequencies using this pot.
Now then, the interesting pot is the CV pot. This actually sets the 5.333V power supply rail in the TB303. The CV pot is set to give this precise voltage as it's the reference from which the 1V/Octave CV signal is derived. It also provides the power for various other circuits, such as EGs and the filter. By adjusting this pot, you can swing this voltage rail above or below 5.333V and, by doing this, you will affect the dynamics of the filter. By increasing the voltage, you can increase the feedback going into the filter. In my 303 clone, I can make this voltage really high and make the filter SCREAM!
In my TB303, by setting the pot to the highest voltage, the filter sounds a bit more resonant and the overall sound is more squelchy. A lot of people's TB303's may be heard to scream a lot because they have twiddled this pot. You can change components in the filter's feedback path which has a better affect.
One thing about altering the CV pot is that you will then have to retune the oscillator using the tune and width pots, since you will have altered the D/A's reference voltage. Also, the CV output which comes out of the socket at the back of your TB303 will no longer be true 1 volt / octave.
Trev
As for the freq pot, this simply sets the range of the external freq cutoff pot and affects the cutoff range of the filter that can be obtained from this knob. It is possible to get lower or higher filter cutoff frequencies using this pot.
Now then, the interesting pot is the CV pot. This actually sets the 5.333V power supply rail in the TB303. The CV pot is set to give this precise voltage as it's the reference from which the 1V/Octave CV signal is derived. It also provides the power for various other circuits, such as EGs and the filter. By adjusting this pot, you can swing this voltage rail above or below 5.333V and, by doing this, you will affect the dynamics of the filter. By increasing the voltage, you can increase the feedback going into the filter. In my 303 clone, I can make this voltage really high and make the filter SCREAM!
In my TB303, by setting the pot to the highest voltage, the filter sounds a bit more resonant and the overall sound is more squelchy. A lot of people's TB303's may be heard to scream a lot because they have twiddled this pot. You can change components in the filter's feedback path which has a better affect.
One thing about altering the CV pot is that you will then have to retune the oscillator using the tune and width pots, since you will have altered the D/A's reference voltage. Also, the CV output which comes out of the socket at the back of your TB303 will no longer be true 1 volt / octave.
Trev
Message 9/9 07-Apr-00 @ 05:47 PM - RE: Tuning the TB
If I remember correctly TM3 (the cutoff trimmer) only significantly increases or decreases the upper range of the cutoff knob, to increase the lower range you have to drop the resistance of R47 (10k) or jumper it for zero cutoff! I think I put a 4.7k in mine for a nice deep rumbling but audible lower limit.
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