<![CDATA[ChipMusic.org - Can't find the pitch resistor - Newbie in need of some advice]]> 2020-01-23T17:50:16Z PunBB https://chipmusic.org/forums/topic/20378/cant-find-the-pitch-resistor-newbie-in-need-of-some-advice/ <![CDATA[Re: Can't find the pitch resistor - Newbie in need of some advice]]> maybe you might have luck inserting another/different clock across X1/X2 too?

a la:

http://getlofi.com/gameboy-dmg-01-pitch-modification/

(or maybe you'll have luck making magic smoke!)

]]> https://chipmusic.org/Duck 2020-01-23T17:50:16Z https://chipmusic.org/forums/post/263038/#p263038 <![CDATA[Re: Can't find the pitch resistor - Newbie in need of some advice]]> oh. sorry, somehow missed the other post saying the same thing!

]]> https://chipmusic.org/Duck 2020-01-23T17:45:22Z https://chipmusic.org/forums/post/263037/#p263037 <![CDATA[Re: Can't find the pitch resistor - Newbie in need of some advice]]> Hi - the datasheet for that IC is online here;

https://www.datasheetarchive.com/pdf/do … erm=HT3494

it says it is clocked by a crystal oscillator in the chip, so (I think) there won't be a pitch bend in the way you're expecting.

Maybe you can work something else by starving it of voltage or something.

]]> https://chipmusic.org/Duck 2020-01-23T17:44:57Z https://chipmusic.org/forums/post/263036/#p263036 <![CDATA[Re: Can't find the pitch resistor - Newbie in need of some advice]]> Hi...i don't the more expensive vtechs have those adjustable coils? I doubt this one has though, i'd say theres a resistor and you've missed it somehow. Sometimes v-techs have smaller boards coming off the main board that have a black blob chip and the pitch resistor on them.

order pcb

]]> https://chipmusic.org/PansySharp 2020-01-23T16:54:17Z https://chipmusic.org/forums/post/263034/#p263034 <![CDATA[Re: Can't find the pitch resistor - Newbie in need of some advice]]> Hey!

Thanks a lot for the pointers and info!
Just experimenting with it seems like a fun and learning way of approaching it!
I'll try to use this project in that way and see what happens. If it breaks it breaks:)

Cheers!

]]> https://chipmusic.org/Callesw 2018-02-16T09:47:10Z https://chipmusic.org/forums/post/255505/#p255505 <![CDATA[Re: Can't find the pitch resistor - Newbie in need of some advice]]>

]]> https://chipmusic.org/Knife+Crimes 2018-02-15T22:28:02Z https://chipmusic.org/forums/post/255496/#p255496 <![CDATA[Re: Can't find the pitch resistor - Newbie in need of some advice]]> Not all sound toys have a 'pitch resistor'. Sad but true.

The Holtek HT3494 chip in the photo is the 'brain' of that keyboard. I found the datasheet here: http://www.datasheetspdf.com/pdf/760735/Holtek/HT3494/1 It uses a crystal oscillator (or what looks like a ceramic resonator, marked X1 in the photo) as its clock. You may have luck effecting the pitch by interfering with X1 or the pins it is connected to.

Keep modding but! Break some shit! Circuit bending is about exploration as much as anything.

]]> https://chipmusic.org/Knife+Crimes 2018-02-15T22:20:08Z https://chipmusic.org/forums/post/255494/#p255494 <![CDATA[Can't find the pitch resistor - Newbie in need of some advice]]> Hey guys!

I'm new to this forum, and super new to this whole world of modding stuff (and new to electronics in general). My only achievment so far
has been to add a pitch bend to a very simple toy synth. I had no problem in finding the pitch resistor on that one, by licking my finger
and poking around a little bit.

I am now trying to do the same thing on another, a little bit more advanced synth, but with no luck!
I'm using the same method of finding it, and I've been going over the board a lot of times. The synth is called "Music time keyboard 310".
Below you can see a photo of the circuit board. I'll gladly take more photos if needed!

I'm thinking that maybe some of you guys see something that I'm missing, or maybe point me in another direction:)
Cheers!

]]> https://chipmusic.org/Callesw 2018-02-15T14:15:10Z https://chipmusic.org/forums/post/255481/#p255481