HT8950 nasty pitchshift pedal

[wormfooduk]

I am after a really nasty sounding pedal so i got a cheap voice changing kit from maplin. its a very common ht8950 + 386n based circuit the input should be ok but the output is for a 8 ohm speaker. Ive read page after page of people talking about moding this circuit for guitar and that it works but noones shown how they did it. I can make a pcb if someone has a different working layout? plus its a 5 volt circuit so i will need a voltage devider to bring the 9v supply down

[edvard]

http://www.generalguitargadgets.com/projects/20-modulationecho/124-dh-pitch-shifter

[wormfooduk]

I saw this one but theres quite a few posts that say it doesn't work well enough to bother with. is there any someone has built/likes?

[nick d]

             I did build this , based on a Maplin/Velleman kit , modded as the GGG schemo .  It works - sort of . Less than useless as a guitar effect - don't bother , save your solder !

[wormfooduk]

dam was hoping it would be good in a glitchy 8bit ish kind of way

[nick d]

                  Try UglyFace - much cheaper , very lo-fi , glitchy as hell , loads of fun !!

[Taylor]

I think the "one man's trash is another's treasure" applies well here. I've got a bunch of these chips and plan to build some of these circuits soon. I don't think it's safe to take someone's word on what's useful - for example, if you asked me what I thought of Tube Screamers, I'd say it's "less than useless as a guitar effect - don't bother, save your solder!" But of course one or 2 others may disagree with me on that. 

Not intended as a jab, and opinions are always welcome - I just don't think they can be seen as universally meaningful unless you know that you agree with the opining one on everything else.

If you want something really nasty sounding I think this circuit is exactly what you're looking for.

[Top Top]

I used to have a kit that I got from radio shack or a surplus store that was the same or very similar, maybe an older version of the same chip (it had all the same options, but don't know if it was the same chip). I played the guitar through it and it was good fun. If "good in a glitchy 8 bit ish kind of way" is what you are looking for, I don't think you will be too disappointed.

[anchovie]

Connect through an input capacitor to the AIN pin, don't connect anything between AIN and AO and connect a 15K resistor from VREF to AIN. This turns the input stage into a square-wave fuzz creator. Thanks to the rest of the chip, this searing lead sound will be coupled with a poorly-tracking harmoniser. The 386 isn't essential as the output signal will be at the rails, but might add extra squeal and unpredictability if required.

Perfect for giving the solo in "Owner of a Lonely Heart" a sonic wedgie.

[wormfooduk]

Taylor: i agree, just don't want to be pissing in the wind with this one.
anchovie: thanks for the tip "square wave fuzz" sounds great. im looking for nes ish sounds. a couple of my friends play 8bit console electronica live and i though id make them a nasty pedal to add to there live thing.

[nick d]

           You're right , Taylor . Bit of a gut reaction on my part . I hoped at the time that I would build something amazing as a present for someone , and felt let down by the result .
       I still have the parts to hand , and might well revisit this , perhaps with a little tweaking , who knows ? ( Mind you , UglyFace IS totally mental ! )  

[Nasse]

http://www.spelektroniikka.fi/kuvat/voicekytkiss.pdf another sick box perhaps, never tried it, there is layout too