john hardig Thank you very much. That is awesome to hear! Now I’m curious, which bends of mine have you done? Any videos?

@@SISKworks I used your Moogfest/harp delay circuit bends to make a eurorack delay module. I am also inspired by your use of ribbon cable. You turned me on to using pre-made inexpensive circuits to add functionality to my bends like changing out the capacitors in a function generator circuit to make an LFO. I also made myself a Hellophone microphone. And now I am working on using the LTC1799 to add a pitchbend wheel to a CASIO sa-76 project. The CASIO SA-76 sounds so good even without modification. I have eight of them sitting on a shelf. I would love to send you one or two of them for free. sorry no videos, I spend all my free time watching you and Kristian Bladsol and soldering. Let me know if you want some free Casios.

@@johnhardig9754 BTW this makes me so extremely happy to hear!

I did this mod again just last week and thought I was being super careful to keep track of polarity but somehow once AGAIN it was backwards. I almost wonder if these PWM board just always need to be wired in reverse or something. Or maybe I just wasn’t understanding the original circuit that I bypassed.

Yes you would have to bypass the internal voltage controller that is located INSIDE the motor. I think it should also work without bypassing but you just won’t have as wide of range of control.

@@SISKworks you're quite right, I did this with a shoe box style deck, I'd picked the wrong PWM circuit board and the range was small, no high speed, and the pot behaved like a hair trigger on the small amount of control it had. I'll be revisiting the project again now, and I'm going to revisit an old oil gobbo light projector, I tried the pwm hack on the gobbo wheel motor, didn't even turn, hopefully it'll work now.

Oh that makes me so happy to hear that other people are doing my projects. That is so great! As far as desoldering goes, I always makes sure to add more solder first before trying to remove the old. Seems odd but it really helps.

Do you have a link to the red 20kHz board you used?

@@SISKworks Yes I do, www.lightinthebox.com/en/p/au-pwm-dc-motor-speed-controller-5v-35v-5a-led-light-regulation-dimmer-switch_p7931785.html?prm=1.5.1.30 In the last unit I modified I was able to fit the whole board inside the case. I haven't been able to desolder the pot from these boards yet but it probably says more about my desoldering skills than the board. I just upgraded to a rework station so we'll see if the new equipment will save me.

@@themidithief4514 thank you!

You got that pot desoldered so easily. It's hard to get that thing off...

Sirius360 Thank you so much for this! This has been driving me crazy why this unit makes that noise but another one with a different model PWM board does not. I’ll have to try and dig up the specs on each to confirm but I suspect this is my issue. Thanks again. I really appreciate it!

Hi, I just installed a pwm on a cassette machine and it is causing an awful popping/buzzing sound which goes up in pitch as the tape speed increases. I checked the khz and it is maximum 25khz so should be within the range you suggest. Do you know what could be causing this? Grounding? EMF interference? Any advice would be really appreciated! Thank you!

@@mark_fox_music Sorry for the late response. If the noise goes up in pitch as the speed increases, it's propably the motor itselfe which makes that sound. The frequency of the pwm controller should stay constant. To get rid of the motor noise is a bit tricky. I had the same problem on one of my cassette players. I ended up using a different power supply just for the motor so the motor is not connected to the cassette circuit.

I commented earlier assuming this suggestion was for the pot value but now that I have read a little more it seems like pwm frequency is different? Do you know of a specific model that would work best for this type of mod?

@@idlefingerboards2629 i have used this one and it works great: a.aliexpress.com/_mMsGA2d i have moded 3 cassette decks already. sometimes the slower running motor can introduce noise in the system. you will hear a pitch which is higher when the motor runs faster and lower when it runs slower. this is not the fault of the PWM controller. in one unit it was really loud so I bought a different power suply just for the motor. so my whole deck runs off the normal power supply except the motor and pwm controller. because of that no motor noise can reach the system and distort my sound. I hope you won't have to do that. but just in case you run into this problem

Well I’m not exactly sure what you mean. One of the speaker wires should already be ground. That is just how circuits work. So if you use the same wires to make your new headphone output then it will already have a ground. So no additional ground needed.

Yes it should work the same way.

Yeah it should work on ANY device with a DC motor.

I have the same question!!

I too have the same question....

well if you guys didnt find out. basically, the motor requires a certain voltage to work properly. therrfore reducing the input voltage would not be a reliable way to slow the motor down. instead you use PWM to essentially turn the motor on many many times a second google pwm and duty cycle :)

Oh yeah. I didn't include any of that did I. Well now that I look back I see I actually bought on ebay and can't find them again. But looking on amazon these would also work. These are better than what I used because they are smaller. www.amazon.com/dp/B07W5NZPH1/ref=sspa_dk_detail_6?psc=1&pd_rd_i=B07W5NZPH1&pd_rd_w=ghWRj&pf_rd_p=45a72588-80f7-4414-9851-786f6c16d42b&pd_rd_wg=6b0B1&pf_rd_r=8R7B1CSMV2P8V7AH3HN7&pd_rd_r=c4a5f04f-d711-4bbe-996a-e7980cac59ee&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFXT0E5V1VXTFlWMFYmZW5jcnlwdGVkSWQ9QTA0MDMzNDUyRzlOQTY4RFVXTEhLJmVuY3J5cHRlZEFkSWQ9QTA2NTYyNDIyS1RBMzBZTVo2MDdGJndpZGdldE5hbWU9c3BfZGV0YWlsJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

Love the music, love the instructions. Just getting into this stuff soooo keen

Sorry, I didn’t explain that very well. The original pot had a built in switch (clicks on when you first turn it clockwise). But I wanted the PWM board to turn on with player so I just put a jumper (on the PWM board) where the two switch contacts would be. Without the jumper I would need to send 5 wires to the speed control pot but with the jumper I only need to send 3 wires. Totally not needed though. Works either way. Thanks for watching and commenting. Love to hear it when other people build my projects.

Yeah there are so many different versions. It’s hard to always find the same model since it seems they are made by a ton of different companies. This one looks exactly like the last ones I bought but is made by a different company. www.amazon.com/UMLIFE-Controller-Control-Switch-Dimmer/dp/B098B2LRSK/ref=mp_s_a_1_18?keywords=PWM+Motor+Speed&qid=1696263034&sr=8-18

The PWM board works by turning the power on and off really fast. A CV sequencer directly would not work. But you can connect a vactrol to the PWM pot and inject CV control that way. Ive done that a few times. Check out my KeyPlayer video

kzfaq.info/get/bejne/qLqJrLOUxsmmqqs.html

Yes you can still do this without bypassing the motor PCB but you just won’t be able to get a fast speed.

If you bypass the internal regulator that is inside the motor (which I didn’t show) you can get fairly fast speeds. But I’m not sure if it double or not. If you are using it to record, one thing to be aware of is that the PWM board does add a bit of motor noise at higher speed to the audio which is not ideal. It seems The only way around that is to have a completely separate battery pack for just the motor.

Yeah I saw his Instagram post but I’m confused, does it still have a tape?

@@SISKworks I think the Kalimba is built onto the door so it can still open and play tapes.

@@NickGoblin yeah I saw the video after posting that. You are correct.

@@SISKworks Now I finally saw it too. The acoustic is not that great but I'd love to check out that project where they put the tape player inside the kalimba instead.

I’m not really sure which one I used here since it was a few years ago. Just search Amazon for “Aobao DC motor PWM speed controller”

Thanks. One final question. What if you want to play the tape back at normal/standard speed. Do you add a switch or?

@@-______-______- you would just have to figure out where on the knob it sounds “normal” speed and mark that position.

I used a piece of ribbon cable and pulled 3 wires off but you could also just use three individual wires. Red wire was to bypass the switch built into the potentiometer when you turn it. Removing that potentiometer is probably the hardest part. I’ve even damaged a board in the past doing it. So be gentle.

I’m not too sure. But you don’t actually NEED to bypass that circuit if you can’t find it. You just might not be able to get super fast speeds.

@@SISKworks Thanks, Hopefully I can put this motor back together lol.

I know this comment is old, but as I understand it this won't work. The wires going to the motor are just power, wheras this is actually altering the circuitry inside the motor itself.

@@EpicStuffMan1000 Thanks! I tried putting the PWM kit on the wires going into the motor, and it worked. A pulse width modulator is just something that switches the power on and off at high frequency, so it makes sense that this works. However, I was getting a high-pitched noise, which I think was EM interference from the motor, and then the fuse suddenly blew on my tape player. That was probably unrelated! I suspect I nudged a croc clip and shorted something, but it's a really nice tape player (A Marantz CD330) so I didn't risk messing with the PWM kit any more. I used a potentiometer in series with the motor instead. It works pretty well: I can get down to about 30% speed before the motor stalls. Though below about 60% speed the pitch starts getting really unstable, due to the motor straining.

Yeah I would think that should work as long as the switch is wired between the motor and original speed controller.

@@SISKworks Ah awesome, thanks for your quick reply. Your tutorial is a lot better and more clear than others. Will be soldering away this weekend. If it doesnt work no biggie ofcourse, but I kind of like the idea of having 'normal speed' as a set setting instead of dialing it in

@@SISKworks broke off the tab of the original haha, let’s see if I can overcome laziness to fix it or just happy with the speed control ;)

If the turntable had a DC motor then yes it will PROBABLY work. I’ve never opened a turntable so I don’t really know what type of motor they have. But don’t almost all turntables already have speed controls?

@@SISKworks they have different speeds depending on the size of the record and some turntables have a speed/pitch control as well but they have extremely limited ranges. However they also usually have a strobe sensor to keep them in time and idk if that would cause problems. I think I’m going to give it a shot!

@@broke8246 yea you should definitely give it a shot. I have turntables but they have already have a fairly wide range of speed on mine as they are more of a DJ type. I never thought to try modifying them even further though. Would be cool if you could get some super slow speeds. You can also try reversing the polarity to get the motor to spin backwards which can be cool with vinyl (not so much for cassette haha).

@@SISKworks would it not just play the tape in reverse?

@@broke8246 not exactly. Yes,the motor will spin in reverse but since tape players are only driven one way it will just eat the tape. I know from experience. Over and over. Haha.

Yes I’m fairly certain that will work. Pretty sure I saw a video with someone doing exactly that.

@@SISKworks i tried now, and it works perfect. Now i can sequenz the motor speed. :-)

@@martinreim4805 awesome. I really wish I had that Field Kit too.

some PWM boards might have a trimmer or jumper pins select different ranges. Does your board have anything like that? I would also test by powering the PWM board directly from the batteries to see how it responds. Does it go faster and slower but just not in correct range? If so you could try feeding less voltage into the PWM board.

Wow thanks for the fast reply. It Does adjust but in highs only. I’m very new to electronics so I’m not sure about those features or even how to reduce voltage. This is the one I am using. www.amazon.com/UMLIFE-Controller-Control-Switch-Dimmer/dp/B098B2LRSK/ref=mp_s_a_1_5?crid=3AUMG4N784Q6L&keywords=pwm+dial+20khz&qid=1660085035&sprefix=pwm+dial+20khz%2Caps%2C146&sr=8-5

I not exactly sure. I speed it up enough that the algorithm wouldn’t hit me with a copyrighted violation and now I can’t even tell what song that was. I THINK I was listening to a DJ drum and bass mix so even if I knew which mix I probably still would not know what song. I just listened to that part multiple times and I still can’t make it out. Sorry.

Hmmm, I’ve never had that issue come up and I’ve done this mod a ton of times. I doubt it would be the PWM board. But to be 100% sure I would temp disconnect the positive wire going to the PWM board to see if the cracking goes away. Then reconnect to see if the cracking happens again. The PWM does cause a bit of motor noise to come through the speaker when running at high speed but it doesn’t sound like cracking at all.

Will try that, my PWM is also right at 20 khz so it may need to be higher, saw a comment about it causing extra noise if it’s lower than 20 khz

Ended up buying a whole new cassette player, this one was DD instead of belt driven, and it worked perfectly this time. Not sure if mechanism has anything to do with it but that’s the only thing that changed. Thanks for the help! Awesome mod🙌🙌

Almost all tape players have an adjustment inside the DC motor. But I’m am adding new speed adjust circuit and bypassing the one built inside the motor.

@@SISKworks Thanks Yes I understand just wondered if it was just this model or any flatbed cassette player. Thanks for your quick reply as it's quite an old post

@@mrfeenix1 the only players that I’ve found that don’t have that internal adjustment are super old/vintage players.

@@SISKworks Cool !! Time to go out and grab some tape machines !! Thanks :)

No not really. With a normal pot you might be able to get the tape to slow down just a little bit and then it will stop. You would only have a SMALL amount of control. But with a PWM board like I show you get a big range of control. From faster than normal all the way down to a super slow crawl. That is just NOT possible with only a pot.

Is buzz only when the tape is slowed down? Could be that the lower frequencies are harder for the speaker

That works! But if you use a PWM board you can get a much bigger range of control.

No, you won’t get very good range of control that way.