Tascam Porta 02 Mk II | 1/2 speed & Tape Stop FX | Simple voltage starve Pitch Mod using stock motor
2,465
Published 2022-01-15
The advantage of using a motor with a 4 pin input is you can attach two resistors in parallel, a base or calibhration trimpot and a larger pot accessible to the user oputside the unit's case. This method mimics the electrical topology of pitch controls on more expensive portastudios, and means you the user pitch control never slows the motor to a dead stop, it makes it maybe 20% slower, which is ideal for matching the pitch of the recorded material to an intrument you can't tune easily like a piano, but not so much fun for experimental sounds and textures.....
For the novice it is simpler,and requires fewer components to just wire in a potentiometer in series with the positive voltage inpiut of the supplied two pin motor, whichb is what I demonstrate in this video.
Doing this means you can easily run the tape at half or even quarter the original speed for crazy grainy textures you can't get from a standard pitch control. It also means that with the potentieometer at full resistance the entire 12 volts drops over the potentiometer and the motor stops completely, producing a "tape stop" effect you can usually only get with reel to reel players.
*Although the AC current which comes out of your wall is potentially lethal, that is converted by the Porta 02's external power supply into harmless 12v DC, so once I've tested that the PSU's output with a multimeter, I know I can tiouch the circuit while it is turned on without electricuting myself.
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All Comments (17)
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Yeah! Mods on these devices is super interesting. There is some info around, but sometimes not properly documented, and a lot of people discouraging trying them out... thanks!
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Hell ya, good to see you're getting into mods! I've been toying around with adding a built in spring reverb in the effects loop. Or even just sticking a pedal design and wiring it to the 12v power
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This is great! Seems like the most straight forward example I have seen of someone making this mod. A lot more straight forward looking than others would have you believe! Making me think I need to track down a Porta 02 Mk II.
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As usual a practical and educational video, many thanks Tetrakan.
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Third time now I have looked for some help online and you have been right there with the answers and much more in a very well presented, easy to follow tutorial! CHEERS!
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thanks for this!
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Thanks for the video! I gave this a try today. I didn't have a 500 ohm pot either, so I wired things up the same as you did with a 1k resistor. I tested the resistance and received the same values as you. It worked great once. When I turned off the machine and turned it back on again, the transport would no longer do anything when "play" or "rewind" were pressed. If I take the pot back out of the wiring, transport works just fine. I'm stumped on why this is the case. Update: Still don't get why the pot isn't working since the resistance values are good, but I replaced with a different pot and all is good now.
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just modded my porta03! works great with a 500 ohm potentiometer.
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If I add this mod will I still be able to achieve the standard tape speed of the Porto02 or will the pitch always be slightly off? Interested but I also use the Porto02 for making mixtapes (which it is excellent at) and don't want to mess up it's more utilitarian features.
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Very cool! Have you tried this with a 488? I'm just trying to play it at half speed for normal cassettes, although that 'tape off' effect is killer!!
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I'm really enjoying your videos! I have a little soldering experience, but I wouldn't want to jump into modding a piece of gear - any recommendations on how to get started?
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Would this work on a porta ministudio 7?
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I have a Tascam Porta Two that already has varispeed, but the machine is the High Speed version, so I want to slow it down to standard speed to play cassettes off the shelf, but still keep the HS effect for recording. Do you know of any good resources out there that can explain doing this type of mod? I can only find motor starve videos for players that don't have any speed control.
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I was wondering if this mod would also work on a Tascam 424 MKIII?
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Hello sir, thanks for the video i am no electrician and do not have any experience with them but still i tried doing this mod and the potentiometer works as a on off switch it doesnt really slow down the speed, it has jus 0 and 1 funtion could you please help understand how to make it working like you have?
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hey man, is there any way i could pay you to do this to my porta 02 mk2?
