Numark PT-01 modding thread

[SouperRad]

I just got my PT01-S this week and have started to mod it (added the JDD2X2RS to it yesterday, have an mp3 decoder on the way and plan to have a 'DVS switch' to kill needle input to fader and replace with input from external source so the internal fader can be used on DVS output).

 

The new fader was a huge improvement, even if the scratch switch was a clever launching point to keep the unit price low - but it got me wondering if there's a 'cheap' way to get clean cuts even if it means a greater departure from the traditions of a fader than the switch was.

 

So my question to you is - is a 'scratch button' feasible? Like a plain Sanwa momentary button, functioning in the same way as the scratch switch?

 

In a single-button setup, for example, flare click could be moving the platter while tapping the button - and transform scratches could be holding the button down and letting go briefly (or vice versa).

 

Then a more functional setup might be 2 (or more) buttons in an XOR - thus following the above example flare clicks would be tapping any one button and transforms would be tapping any one button WHILE holding down one other button.

 

You could even run the buttons into a final XOR with a latching button/switch to 'hamster' style it and reverse what holding/releasing buttons does.

 

If the concept of replacing the PT01-S scratch switch with 1 or more buttons even makes sense - what would the wiring look like?

 

E: After getting more creative with my googling I found that such buttons were often used before sharp-cutting crossfaders were introduced, they were even called 'transform' buttons since mashing them would produce transformer-like scratches like I thought. Seems to be rather common knowledge in fact so apologies for being such a dunce. I'm still curious how they could be wired into a PT01-S - especially since I still haven't read anywhere of hooking up two such buttons through an XOR gate to allow 'flipping' between opening/closing the audio with button presses.

Edited April 14, 2018 by SouperRad

[Jam Burglar]

I had a transformer button on my old Intimidation Apex mixer. If I remember right it was set up to cut sound out instead of cutting it in. It only activated when held down. These work but they cut away from the idea of being able to hone/maintain skills when away from your "real" setup. Crabby type scratches ate obviously not happening with them.

 

I just got a line in amp and new internal speaker. Haven't installed yet tho.

[SouperRad]

I had a transformer button on my old Intimidation Apex mixer. If I remember right it was set up to cut sound out instead of cutting it in. It only activated when held down. These work but they cut away from the idea of being able to hone/maintain skills when away from your "real" setup. Crabby type scratches ate obviously not happening with them.

 

I just got a line in amp and new internal speaker. Haven't installed yet tho.

 

That's the exact setup I was envisioning - just with an extra switch to flip the functionality of the button (though what you described would be the default mode), and some extra buttons wired to allow for fancier 'moves.'

 

And yes I 100% agree that a transform button should never replace a fader so as to not mess with one's ability to play on other setups - I was merely doing a thought experiment as to whether or not there was a solution that was cheaper/as cheap as the scratch switch while providing cleaner, more reliable cuts. My post was supposed to be more of 'is this feasible' than 'lets toss our nice faders in favor of arcade buttons'

 

Anyways, I've been doing more research on fader circuitry - am I correct in thinking that I could implement what I'm thinking of by simply running the inverted button input through a nanofader where the linear pot would be hooked up? When the button is open the inverted input would be high, keeping the fader open, then when the button is pressed the inverted voltage would drop to gnd causing the nanofader to close.

[Jam Burglar]

Sooo, installing that line amp .... I smoked D6. I'm hoping that's the only thing that got taken out. The thing is I don't see it on Rasteri's schematic. Anybody know the specs for D6 on a PT01 Scratch?

[Mutis Mayfield]

Can you read the numbers or they are erased by burn?

[Jam Burglar]

Can you read the numbers or they are erased by burn?

 

Nah, they're burned.

[Jam Burglar]

 

I had a transformer button on my old Intimidation Apex mixer. If I remember right it was set up to cut sound out instead of cutting it in. It only activated when held down. These work but they cut away from the idea of being able to hone/maintain skills when away from your "real" setup. Crabby type scratches ate obviously not happening with them.

 

 

 

Anyways, I've been doing more research on fader circuitry - am I correct in thinking that I could implement what I'm thinking of by simply running the inverted button input through a nanofader where the linear pot would be hooked up? When the button is open the inverted input would be high, keeping the fader open, then when the button is pressed the inverted voltage would drop to gnd causing the nanofader to close.

 

 

This is where you get above my pay grade.

[Backtrack]

I think the PT-S has DC in and Original PT has AC in. That is why the schematic is not the same
That diode is prob circuit protection for the voltage regulator when batteries also installed. Thats my guess... I think a 1N4004 should work for you.

[Jam Burglar]

I think the PT-S has DC in and Original PT has AC in. That is why the schematic is not the same

That diode is prob circuit protection for the voltage regulator when batteries also installed. Thats my guess... I think a 1N4004 should work for you.

 

 

Thanks a lot Backtrack! You likely saved me a few hours of figuring that out and I may even have some on hand come to think of it. I was definitely powering off of the batteries so that makes some sense.

 

Not exactly sure what happened but I'll report back if I figure it out in case it helps somebody else out. I need to learn more about how circuits work.

 

The in-line amp mod has a Y cable with both male and female ends so that you can plug into the stock power PCB, which only has one JST plug. You're supposed to unplug the JST cable from the power PCB, plug that into the female end of the Y cable, and plug the male end into the stock power PCB. However, I had a power breakout PCB that allowed for multiple JST plugs. I never plugged into the female end of the mod's Y cable thinking it was unneeded due to the power breakout board. I'm now thinking I was wrong about that. Heheh. I'm hoping that diode did its job and I didn't fry anything else.

 

I also installed a new speaker but I don't think that was the issue. The only other thing I can think of would have been a faulty amp mod.

[rasputin]

So my question to you is - is a 'scratch button' feasible? Like a plain Sanwa momentary button, functioning in the same way as the scratch switch?

I have added a spring to a PT01 cutter a while ago. It basically does what You describe.

https://www.youtube.com/watch?v=62qH7_zEKYA

 

r

Edited April 16, 2018 by rasputin

[Guest rasteri]

E: After getting more creative with my googling I found that such buttons were often used before sharp-cutting crossfaders were introduced, they were even called 'transform' buttons since mashing them would produce transformer-like scratches like I thought. Seems to be rather common knowledge in fact so apologies for being such a dunce. I'm still curious how they could be wired into a PT01-S - especially since I still haven't read anywhere of hooking up two such buttons through an XOR gate to allow 'flipping' between opening/closing the audio with button presses.

You can wire the output of a logic gate directly into the VCA pin of the PT01S, I've done it and it works great.

 

Some discussion here -

 

http://www.digitalvertigo.co.uk/forum/index.php?showtopic=38093&page=21&do=findComment&comment=415933

 

and

 

http://www.digitalvertigo.co.uk/forum/index.php?showtopic=38093&page=21&do=findComment&comment=415978

 

Obviously that was to interface an innofader rather than your XOR gate idea, but the same principle could be used.

[Guest rasteri]

Sooo, installing that line amp .... I smoked D6. I'm hoping that's the only thing that got taken out. The thing is I don't see it on Rasteri's schematic. Anybody know the specs for D6 on a PT01 Scratch?

D6 on the board is D1 on my diagram, I just named it wrong (oops).

 

And as Henrik says it's to stop the voltage regulator from trying to charge the battery when you have both the AC adapter and battery connected.

 

I beleive it's a 1N4002, it's a bit small for a 1N4007. Not that it matters though (the 4007 is for higher-voltage applications but will still work just fine).

[Jam Burglar]

I ordered some 1N4004s so hopefully that will do the trick.

 

I'm going to replace that diode and unhook the mod before testing to see if I can get it working in its normal state, then move forward from there. I just hope the diode is the only thing I fried.

[SouperRad]

You can wire the output of a logic gate directly into the VCA pin of the PT01S, I've done it and it works great.

 

Wow that was incredibly helpful - and much simpler to integrate into a PT01 than I had imagined. One last question - am I correct in assuming that low-voltage to the VCA keeps the audio open and high voltage to the VCA cuts the audio? I would assume that the VCA from Innofader goes to low when it is in a 'cut' position, but that would just be assuming on my part.

 

Thanks again for responding - in addition to what I needed to order to perform the other mods, I went ahead and ordered a couple ICs to wire this up as well - just a dollar or so in parts, save for the buttons.

 

E: I answered my own question by unplugging the JDD fader and turning on the PT01 - plays just fine with the fader unplugged so I must have assumed correctly! Can't believe it took me this long to realize that I could figure it out myself!

Edited April 19, 2018 by SouperRad

[Jam Burglar]

Just wanted to thank Backtrack and Rasteri for the help. Replacing D6 did the trick. Turns out that not having both ends of that "Y" cable connected is what caused the diode to fry. Luckily that was the extent of the damage.

 

FYI the line-in AMP and new speaker are worthy mods. I used the Celestion AN2075 for the speaker. Noticable improvement over the stock speaker and the extra volume on the line in is great.

[SouperRad]

Just got done with my DVS mod. I've seen a couple versions of this mod but only one had documentation and it involved drilling and soldering directly onto the soundboard off the needle, so I came up with my own approach. I removed the relevant L/R audio pins from the 6-pin female JST plug and inserted them into their own 2-pin plug which I connected to the center posts on a DPDT switch. The two poles being a 3.5mm stereo jack and the needle audio (which I got by inserting two pinned wires back into the 6-pin female plug). I also kept both the switch and the audio plug on the top face of the PT01 - this way I don't have any extra wires crossing over from the top half to the bottom half.

 

So now I can route a DVS signal from the USB card to my iphone and still use the JDD fader in the PT01 by routing the sound back in through the headphone out.

 

Earlier in the week I installed the JDD digital start/stop switch, and a chinese mp3/bluetooth board exactly like the models used by ScratchToys. That install was a lot of fun - ~20 minutes of cutting into one of the steel plates with a dremel XD. The board fit so perfectly I couldn't believe it.

 

The endgoal now is to set up a Windows tablet that has enough juice to run VDJ8 with latency as low as possible (able to get a little over 1ms on my desktop). Then I could have deck A output to the stereo jack while deck B outputs to the bluetooth board - so I can have both pre and post fader channels from the same external device!

 

Next mod I'm pondering is a way to mount some of those bluetooth dicers and get the usb power from the Pt01.

 

 

I also breadboarded my idea for a multi-button 'fader' and the results are promising, but I'm going to hold off on that one until I'm done with everything else. Between work and everything else just getting these 4 mods in was exhausting, and I still have a plastic platter stabilizer to attach too XD

[PortableModManiac]

I have built two quite different PT01 in the past few months...

 

PT01 "Righthand":

 

(tonearm swapped with fader (Innofader Mini), the large white knob above the fader is the start/stop button, honeycomb platter)

 

...and the "LoFa Late Night":

(all rotary knobs replaced with linear pots, honeycomb platter)

 

For the "LoFa", I used a PWM module that has proven to work well, and added a pot/resistor circuit to it that enables to set 33 or 45, and a ± pitch. As a spin-off, I designed some "addon" solutions for the PT01 (or others). The linear version can be installed without soldering or drilling (cable is fed into the module through the old "pitch" opening):

 

 

 

This is some next level modding! I am attempting to add a Stanton STR8 tonearm to the PT01 USB and with the mount the stock tonearm goes in being part of the plastic casing I am reluctant to cut it out incase I don't pull it off and then the case is damaged and mounting any other tonearm is not going to be easy. I saw this and firstly was thinking wow, then I was wondering how you mounted the tonearm to the other side? Did you make a new mount? Or cut out the stock one?

 

Here's a link to the pics I have of the initial mod but I am now at the point where I am deciding whether to remove the mount or mount it on the other side. If you remove the mount is it easy to remake?

 

https://instagram.com/p/BiKWGnvH_jv/

 

 

Managed to upload some pics. I have removed the gimbal wiring etc and have tested with a headshell. I am thinking that to sink it just a little bit more that tonearm mount has to go... Any ideas?

Edited May 2, 2018 by PortableModManiac

[PortableModManiac]

For anyone who wants to have a go at replacing the tonearm I've made some notes.I think underhung straight tonearms (like the STR8-150 and Vestax PDX 2000 tonearms) are the way to go because they'll be more skip resistant and the manufacturing and maths is easier.You may have to shorten the tonearm tube slightly because the pivot point in a PT-01 is closer to the centre of the record. The maths you need to work this out are in page 765 of http://www.tubebooks.org/Books/RDH4.pdf- basically you have to solve the underhang equation for L instead of Dopt. Clue : L = (D - Dopt) (or you could just say fuck it and live with the slightly misaligned tracking, I bet it'd make no difference).You can get STR8-150 tonearm assemblies from sales@focusrite.com for £72.50 inc VAT + £5.00 shipping. IMO we're better leaving the dwindling stock of Technics and Vestax tonearms to people who want to repair actual turntables.

Sorry to dig up this old post but I saw the mention of a Stanton STR8 arm and trying to find any information or pics about mounting any other tonearm is an endless search that ends up with only my questions coming back to haunt me! Has anyone posted about the tonearm mount on the case? I can't find anything other than the fader position mod that shows the mount could be removed or remade. Any ideas for finding any examples of removing the tonearm mount or mounting a full tonearm bracket? I am going crazy debating whether to cut the case or not. I have been slacking for too long and am trying to get the mods done I have half started and stopped before I actually get anywhere and it's starting to look like a huge waste piled up taunting me.

[iexist]

Anyone try a solid cutz platter?

[PortableModManiac]

Anyone try a solid cutz platter?

I just installed one in a PT01 USB I'm working on. I haven't scratched with it yet but it looks and feels like it's worth the price. I have done the platter stabiliser rings and washers in my PT01 Scratch and I didn't really think much of it and it was a bit annoying to install. The solid cutz platter I have has the patterned holes in which makes installing the belt back on the easiest thing ever. The whole thing took seconds and no need for any other rings etc. If you are thinking about upgrading the platter I think it is worth the extra cost for something that is not just a crappy plastic thing that just takes ages to get right...

[iexist]

Is there a solution to have more torque when playing at a low RPM? i feel i can only get good scratching with the RPM on high. Tough to play on lower bpm beats.

[Jam Burglar]

Is there a solution to have more torque when playing at a low RPM? i feel i can only get good scratching with the RPM on high. Tough to play on lower bpm beats.

 

You can get one of those rubber charity wristbands and put it around the ring on the underside of the platter. That helps a little but it's not going to blow you away or anything. It does help though. The other thing is adjusting your style to push the record a little more to compensate for the lack of torque when you release the record. So, there's still room for improvement with the pitch mods as far as I'm concerned. Rasteri has some suggestions for fixing it in this thread but I haven't had the time or guts to go there yet.

[iexist]

 

Anyone try a solid cutz platter?

I just installed one in a PT01 USB I'm working on. I haven't scratched with it yet but it looks and feels like it's worth the price. I have done the platter stabiliser rings and washers in my PT01 Scratch and I didn't really think much of it and it was a bit annoying to install. The solid cutz platter I have has the patterned holes in which makes installing the belt back on the easiest thing ever. The whole thing took seconds and no need for any other rings etc. If you are thinking about upgrading the platter I think it is worth the extra cost for something that is not just a crappy plastic thing that just takes ages to get right...

 

Just got my new platter! Its so buttery!

 

 

Is there a solution to have more torque when playing at a low RPM? i feel i can only get good scratching with the RPM on high. Tough to play on lower bpm beats.

 

 

You can get one of those rubber charity wristbands and put it around the ring on the underside of the platter. That helps a little but it's not going to blow you away or anything. It does help though. The other thing is adjusting your style to push the record a little more to compensate for the lack of torque when you release the record. So, there's still room for improvement with the pitch mods as far as I'm concerned. Rasteri has some suggestions for fixing it in this thread but I haven't had the time or guts to go there yet.

Im currently using a wristband for the extra torque. Its helped a bit like you said. I appreciate the tip to adjust my style for the portable. Good advice!

[rasputin]

Actually, the "rubberband mod" is a cargo cult. The only thing it does is to alter the belt's gearing ratio.

What we perceive as "lack of torque" is actually the belt slipping at the motor pulley. Whatever You do to the platter pulley won't improve anything.

 

r

[Jam Burglar]

Actually, the "rubberband mod" is a cargo cult. The only thing it does is to alter the belt's gearing ratio.

What we perceive as "lack of torque" is actually the belt slipping at the motor pulley. Whatever You do to the platter pulley won't improve anything.

 

r

 

Have you tried modding the motor pulley with any success?