Jump to content

Technics with +/- 50%...


Guest Symatic

Recommended Posts

Guest Symatic

... could be made soon!

 

I have been talking to some guys in the USA, who provide first rate Technics servicing and upgrades and really know their shiz.

 

I enquired about a -16% mod they apparently did once, as they also offer a 78rpm mod and I was wondering how they did it after Backtrack came up with his ingenious Midi-in mod for the Vestax PDX-2000.

 

they started out saying it was possible but kind of permanent, and not simple at all.

 

But recently we've talked about the idea more and more and there could be a pitch slider / circuit board mod in the works which would mean ultrapitch Technics with a relatively simple mod.

 

So what do you guys think about it?

 

Would you like this mod?

 

how would you implement it?

 

any feedback would be greatly appreciated and would maybe contribute to speeding up development.

 

I'd love to see an ultrapitch technics and can imagine a fairly strong niche market for it as long as it wasnt hideously expensive!

  • Like 2
Link to comment
Share on other sites

umm, I'd definitely use it so long as it worked properly. However I feel like (completely based on my gut, and not science) that given the torque on 1200s is relatively low that it putting it -50% would give problems for scratching... like I'd think the platter would stop a lot when you're cutting but idk. If it worked how it's supposed to then yea it'd be a dream.

Link to comment
Share on other sites

umm, I'd definitely use it so long as it worked properly. However I feel like (completely based on my gut, and not science) that given the torque on 1200s is relatively low that it putting it -50% would give problems for scratching... like I'd think the platter would stop a lot when you're cutting but idk. If it worked how it's supposed to then yea it'd be a dream.

 

on the M5Gs the -16% pitch position works fine...but -50% im also not sure about either..but i would def buy a pitch mod if they were commercially avaiable..cant beat the low wow & flutter on a 12

 

The reason why i havent switched to Stanton 150s is cause i had 2 Super Oem Decks a month ago and both tonearms started feeling loose after about a week of cutting..i tried turning the top screws down but they were both really firm almost impossible to turn so instead of doing possible damage i decided to return them both to the seller..i guess ill always stay a Technics DJ.

Link to comment
Share on other sites

I have tried it out. My technics goes -30%. I have tried -50% and the technics cant really handle it. You loose tourqe! But its stabile. I can make a vid and show it if anyone wants to how it behaves

As a matter of fact Im looking into the ultra pitch thing. It can be done. My biggest concern with this is that you have to drill in the technics and that is a pain. Was looking into making a remote ultrapitch.

 

But if someone else is doing the same thing I might not proceed any further.

Link to comment
Share on other sites

I have never shared this really. Dont know why... Here goes.
When I only had technics at home (2 years ago) and my friend had a vestax I wanted the low pitch so I started to experiment with the technics pitch function. First I made mods to the actual pitch function lowering the resistance from/to the pitch controller chip. With this you can get down to really low pitch like -70% but it flutters like you are doing a hydroplane.
Then I found out that you can change the internal oscillator to make it go faster or slower. This is prefect stabile but makes your strobe go crazy cause its contolled by the oscillator.

So if you want to make your turntable go fast or slow you can do this cheap and easy mod.
This is pasted from a mail I sent to turntabletech cause we exchanged info. I wanted to know how the tourqe mod was done and they got this from me in exchange.
------------------

Here is how you do it. Its fairly simple. I have been trying different methods but this is the only one that is stabile in speed. I checked with Serato and it differs +- o.o1% while running.
Desolder the original crystal at X201 on the mainboard.
Solder in cables to a switch. I made a little drawing of it. See the attached c-switch.jpg
I only want my turntable to go slow so I only use the original crystal and another with lower MHz (2positions).
But of cause you can use a rotating switch with many positions and use more crystals to even get it to run faster.
Pitch range with the crystals I have tried.
This is not exact values (at all) cause I don't really remember, try it yourself.
4.9167...MHz +8% to 28%
4.1932...MHz (original) -8% to +8%
3.5795...MHz -21% to -3%
3.2768...MHz -10% to -30%
Keep the cables to the switch as short as possible to avoid oscillation issues. Very important!!!
Solder the crystals directly to the switch.
I attached another picture so you can see where I put the switch. Not the best position cause I had to carve out the rubber casing. But it close enough to X201.
To make this work you have to cut the orange cable running from the mainboard to the pitchfader. It disables center click zero point.
You maybe have to adjust the zero point after trying this.
------------------

 

This is fairly simple to do but to make a nonstepped ultrapitch demands that you have a variable oscillator. I found this easiest to do with a digital circuit. And thats where I am now. Im trying diffrent variations. I want to include a transmitter so you can have the "ultrapitch" in a separate device (like a remote) without having to drill in the turntable as "technics people" sometimes are non willing to change the apperence of a their classic. ^_^

  • Like 1
Link to comment
Share on other sites

You on a role Backtrack, really fresh...How about holding down the 33 and 45 buttons or double click etccc.

This would eliminate the drilling. I could never get good stability once the speed was at the low level...To erratic

and dots going crazy like you mention...Put me down for 2 if you get it going...Skip the remote crontrol stuff for

now ;-)...

 

 

This is how far i got back in the early 2000's...

 

 

580648_10151641930921052_161549341_n.jpg

Link to comment
Share on other sites

Guest rasteri

Fascinating! I didn't realise modifying the pitch would be as simple as changing out the crystal.

 

How are you planning to implement a digital pitch?

 

Looking at the service manual, it looks like the pitch is determined by a PWM signal from IC301. Perhaps you could replace IC301 entirely with a little PCB that has a microcontroller on it. It could use the ADC to determine the fader position and use that to calculate what PWM frequency to put out.

Link to comment
Share on other sites

Looking at the service manual, it looks like the pitch is determined by a PWM signal from IC301. Perhaps you could replace IC301 entirely with a little PCB that has a microcontroller on it. It could use the ADC to determine the fader position and use that to calculate what PWM frequency to put out.

The thing is that it starts to oscillate if you tamper with the 301 output to much. But like you said using a ADC from the original fader instead of a extra fader is the best option. There are some drawbacks with this also but it can be fixed with some clever coding (I hope).

Link to comment
Share on other sites

  • 4 months later...
Guest Symatic

Nice...Looks like they have put the whole motor control in a separate box.

2,995 USD....wow

 

damn, i thought that price was for the whole modded deck in the picture... but looking again i think thats just the box...... errrrrrr NO

 

sheeeeit

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...