[sdiy] favorite adsr?

[Stewart Pye]

Hi Tom,

Understood. I'll give it a go.
I'd be interested in seeing your DSPIC designs if you're willling to 
share them when you get them finished.

Regards,
Stewart.

Tom Wiltshire wrote:
> Stewart,
>
> I wasn't making any specific claims about my own PIC design. It's 
> pretty good, certainly, and for the price I don't think you can argue, 
> but it only has a 10-bit output. This means that for very slow 
> envelopes (10 secs) to critical destinations (like pitch or 
> highly-resonant filters) you can hear a little bit of digital 
> stepping. This disappears when you speed things up a bit. But in all 
> honesty, I can't claim that it's perfect. For a quick, cheap, simple 
> VCADSR that only uses a few components, it's pretty good, and you'd 
> mostly never know it's digital. Ultimately, I'd recommend you knock 
> one up on a breadboard and try it.
>
> I've built other envelope generators with 12-bit DACs and the stepping 
> disappears on these. My current designs are based on the 33FJ128GP802 
> chip that I was raving about earlier, and this has a 16-bit DAC 
> accurate to 14-bits. With a sample rate of 10KHz+ and some post-DAC 
> filtering this is entirely indistinguishable from analogue.
>
> Regards,
> Tom
>
>
>
> On 29 May 2009, at 12:56, Stewart Pye wrote:
>
>> Hi Tom,
>>
>> If you reckon it's as good or better than an analogue one, I'll try 
>> out your ADSR. I use AVR micros here but I'll program a chip at work. 
>> it certainly "looks" impressive on your website.
>>
>> Dan,
>>
>> If you want to try Tom's ADSR PIC, and you can't find someone to 
>> program it locally, I'd happily send you some programmed chips for 
>> the price of chips and postage from Australia (if it's OK with Tom).
>>
>> Cheers,
>> Stew.
>>
>>
>> Tom Wiltshire wrote:
>>>
>>> I'd be extremely sceptically about any claims made purely on the 
>>> basis of one technology or another.
>>> You can use CMOS switches or transistors of one sort or another in 
>>> an analogue ADSR, and I doubt you could generalise. Some will be 
>>> faster, some slower. Usually there is a trade-off between being able 
>>> to reach long segment times and being able to produce an extremely 
>>> short segment time. This is down to the charging capacitor required. 
>>> A big cap can give you very long times, but even with minimum 
>>> resistance will still take a few mSecs to charge.
>>>
>>> Myself, I gave up on analogue ADSRs some time ago. They use a lot of 
>>> components and are relatively complicated compared to a digital 
>>> solution, on top of which digital is more flexible (any curve shape 
>>> you like, for instance). There was a time back in the early days 
>>> when digital envelopes were pretty basic, used sample rates of 
>>> 100Hz, and got a reputation for being sluggish and not sounding 
>>> good, but that was years ago. It's easy to design a far better 
>>> envelope than appears in the Waldorf Wave, say.
>>>
>>> Finally, it is worth saying that any time under 1mS or so is just a 
>>> "click" sound anyway, so you might not find it that appealing.
>>>
>>> Regards,
>>> Tom
>>>
>>>
>>> On 29 May 2009, at 12:02, Dan Snazelle wrote:
>>>
>>>>
>>>>
>>>>
>>>> i am going to be testing out ADSR'S all weekend and i have heard 
>>>> (maybe wrongly) that transistor based ADSR's are quicker/snappier.
>>>>
>>>> is this true? any recommendations on circuits to try?
>>>>
>>>> thanks
>>>>
>>>> --------------------------------------------
>>>> check out various dan music at:
>>>>
>>>>  http://www.myspace.com/lossnyc
>>>>
>>>> (updated monthly)
>>>>
>>>> http://www.soundclick.com/lossnyc.htm
>>>>
>>>>
>>>>
>>>> http://www.indie911.com/dan-snazelle
>>>>
>>>> (or for techno) http://www.myspace.com/snazelle
>>>>
>>>> ALSO check out Dan synth/Fx projects:
>>>>
>>>> AUDIO ARK:
>>>>
>>>> www.youtube.com/watch?v=TJRpvaOcUic
>>>>
>>>> www.youtube.com/watch?v=BqIa_lXQNTA&feature=channel_page
>>>>
>>>> www.youtube.com/watch?v=V4nJPjGgOcU&feature=channel_page
>>>>
>>>> and soundtrack/design work:
>>>>
>>>> NEW: check out Dan's sound design from the 1998 award winning film 
>>>> SAFARI by catherine chalmers
>>>>
>>>> http://www.catherinechalmers.com/videos.cfm
>>>>
>>>>
>>>>
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>>
>>
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