LTC1799 on Alesis Hr-16

heat00hunter · October 26, 2009, 01:56:40 PM

Hi every body, i'm new on this forum.
My english is so bad, dont juge this please.

I have a question about the Ltc 1799.
I have a Alesis hr-16 and i want to know if it possible to put it on this for change the pitch??

Thanks to help me

Harold

heat00hunter · October 27, 2009, 01:45:08 PM

No idea?? $:-\$

Circuitbenders · October 27, 2009, 02:49:50 PM

Yes it is possible, do a search for 'alesis hr16 pitch' on google and a few videos come up with LTC1799 pitch controls. I assume its just a meatter of replacing the timing crystal, if the alesis uses one.

heat00hunter · October 28, 2009, 10:58:23 AM

Yes i know it's possible. I had see this vidéo and i ask to spunkytoofers for this tip. But he say this answer is on the alesis hr-16 service manuel. I don't know where to search. I have just see on this "the clock" on the P.11 pin 37 of the DM3AG's IC. You can download it here: http://www.broke-toy.com/HR16_HR16B_D1_D2.pdf
Thanks to help me!

Circuitbenders · October 28, 2009, 01:11:32 PM

I'm not really sure what you are asking here.

Theres instructions on fitting an LTC1799 on Get LoFi here http://www.getlofi.com/?page_id=1446

Without a schematic or an HR16 to look at i have no idea where you would find the timing crystal if there is one. I haven't done this before but it looks like you could always just cut the trace going to pin 37 of the DM3AG and wire the LTC1799 onto that pin.

heat00hunter · October 28, 2009, 01:58:54 PM

I built a lot of Ltc1799 i know how it work.
But for the alesis hr i dont know how to search on the pcb

.
And if you don't have one, you can't help me...

electoyd · October 30, 2009, 06:52:28 PM

Hiya
there is a blue crystal on the board, it is like a blue blob with two metal legs, i think its right next to the biggest chip in there. It kinda stands out when you look for it. You have to remove this and take the signal lead of the oscillator and attach to the circuit board where the side of the crystal that was controlling the clock signal was (easy to find out remove a leg at a time of the crystal and if it doesnt work there is your signal) The machine only needs a signal from one leg to work. I hope this makes sense, i've made it so i can flip back and forward between the oscillator and crystal. So i get normal or variable pitch. To be honest i always leave it on normal pitch when switching on or off, because these oscillators play about with actual speed the cpu and stuff work at as well. You cant use this pitch mod with midi. Any questions i'll try and answer them.

Gordonjcp · October 31, 2009, 09:55:26 AM

That would control the clock speed of the whole machine. Slowing it down would slow the rhythm down, too. Have a look for the clock pin on the ASIC, but be careful - the chip is very fragile.

electoyd · October 31, 2009, 03:27:02 PM

Gordon-i stand corrected but also thanks! the way mentioned by myself does indeed work also but as you say it does slow the whole machine workings down and i never switch the machine on when the osc is the clock and its mostly effective but does have quirks. But you have me interested, i've noticed the big asic chip. Would you need to bend up the clock input pin and then connect your osc output to that? thanks-ian

heat00hunter · November 12, 2009, 10:51:06 AM

I want to say thanks you, i will try it and post the picture.

Gordonjcp · November 12, 2009, 03:45:36 PM

Well, it would be hard to bend the pin up because of the package design, but you may be able to cut the appropriate track. I must admit I haven't really looked into it yet.

Doesn't the pitch slider in the tuning menu give you enough range? ;-)

heat00hunter · November 22, 2009, 07:25:11 PM

hi i'm come back, because i dont found this bleu blob,

Somebody can help me to found this on the pcb please...
My english is so bad and i see a lot of bleu blob.

Thanks you

Gordonjcp · November 22, 2009, 10:03:05 PM

The blue components are capacitors, usually for decoupling the supply rails. Other than that I'm not sure what you're asking...

heat00hunter · November 22, 2009, 10:34:03 PM

electoyd say: "there is a blue crystal on the board, it is like a blue blob with two metal legs, i think its right next to the biggest chip in there"
I want just know exactly where it is??
For add the Lct1799 on this blue crystal !!!

Gordonjcp · November 22, 2009, 11:36:15 PM

Ceramic resonator, down beside the 80C32 CPU with two wee brown disc ceramic caps flanking it. Can't miss it.