[sdiy] There is no fun analogue chips anymore!

[Harry Bissell]

from the archives (search NE5517 for all posts...)

--- Antti Huovilainen <ajhuovil at cc.hut.fi> wrote:

> What are the main differences in the OTA core
> between 3280 and 
> 3080/13700/5517? (ignoring buffers etc)
> 
> Less CV feedthrough? Distortion?

13600 - Dual OTA with linearizing diodes and
controlled impedance buffer. Good buffer performance
at low bias levels, but a rapid change in bias could
feed through

NE5517 - Similar to 13600 with a different buffer
scheme... current mirror from Gm bias drives the
buffer. I saw little difference from the 13600
in evaluation. I'd consider it a sub. I did get
some odd bleedtrhough when it should have been cut
off. Not enough to consider it a serious bug, just a
curiousity.

13700 - Dual OTA with linearizing diodes and fixed
impedance buffer. Less CV bleedthrough in the buffer
for fast control signals, poor buffer performance at
really low Gm biases.

CA3080 - The classic single OTA with no diodes. 

CA3280 - Dual OTA with linearizing diodes fed from an
internal current source. No buffers. Very low offset
variation with Gm bias. Can use this as a control VCA
feeding mod signals to a VCO without tuning shifts
with
mod level... any other critical applications. Makes
the best VCA (low distortion and almost zero control
feedthrough of level shift.

H^) harry

----- Original Message -----
From: Dan Snazelle <subjectivity at hotmail.com>
To: Harry Bissell <harrybissell at wowway.com>
Cc: blacet at blacet.com, synthdiy diy <synth-diy at dropmix.xs4all.nl>
Sent: Tue, 26 Jun 2012 08:49:30 -0400 (EDT)
Subject: Re: [sdiy] There is no fun analogue chips anymore!

Can someone talk about the ne5517? Ive never used one....is it better than a 13700?

Sent from my iPhone

On Jun 26, 2012, at 8:42 AM, Harry Bissell <harrybissell at wowway.com> wrote:

> The dearth of 'analog chips' could be an opportunity to explore alternative designs, including (gasp) discrete.
> 
> I (along with my evil-twin Jim) lament the passing of the CA3280 (probably the best OTA ever) but we can still make
> do with the LM13700 and NE5517 when needed. 
> 
> Today, we have many components (in SMT) that can be exploited, making possible designs that if implemented in through-hole
> would have required a grand piano sized board.
> 
> I might say (OK I will say) that the era of SSM and CEM chips often resulted in 'me-too' synth designs that offered
> little change in sonic palette and only superficial differences in user interface. Look alike, sound alike...
> 
> There are always other ways to skin a cat (so to speak). Explore and grow :^)
> 
> H^) harry  (or am I the evil-twin ?)
> 
> 
> ----- Original Message -----
> From: blacet at blacet.com
> To: Tom Wiltshire <tom at electricdruid.net>
> Cc: synthdiy diy <synth-diy at dropmix.xs4all.nl>
> Sent: Mon, 25 Jun 2012 16:06:47 -0400 (EDT)
> Subject: Re: [sdiy] There is no fun analogue chips anymore!
> 
> You can still get the NJM13600 from Mouser (4000 in stock). This is a
> clone of the National part (LM).
> 
> The 2164 can be bought from Mammoth (1400 in stock).
> 
> Try some of those THAT ICs too!
> 
> Quityawhinnin'
> 
> 
>> On 25 Jun 2012, at 20:04, KD KD wrote:
>> 
>>> There is no fun analogue chips anymore!
>>> 
>>> It's all OPamp's, on and on and on and on!
>>> Not even ONE single new OTA!
>> 
>> When I heard that Analog Devices were withdrawing the SSM2164, I was in
>> such a mood that I might have been inclined to agree.
>> 
>> But it isn't true. There's all the THAT Corp stuff; various VCAs and
>> matched transistors, and you can *still* get the LM13700 (or whatever they
>> call it these days!) and then there's also the CoolAudio clones of a lot
>> of old stuff, including the SSM2164.
>> 
>> So ok, there might not be anything equivalent to the CEM3372 or SSM2047,
>> but there are *some* interesting analog chips around still.
>> 
>> Tom
>> 
>> PS, Jim: +1 for bringing the CA3280 back. It'll never happen, but I would
>> like to see a new linear VCA to go with some of the new V/dB ones. Hassle
>> THAT, maybe?
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> 
> 
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> -- 
> Harry Bissell & Nora Abdullah 4eva
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-- 
Harry Bissell & Nora Abdullah 4eva