[sdiy] There is no fun analogue chips anymore!

[Pete Hartman]

And I think that is exactly the difference in what I was reading.
There were no additional transistors in the circuit, and it
specifically talked just about being V -> I.  I also went back and
looked again after posting my question and saw that the current in
question was through a load that was an integral part of the feedback
loop...at which point that also made it clear it wasn't really talking
about the same thing.

I appreciate Tim's earlier answer as well... thank you both

Pete

On Tue, Jun 26, 2012 at 3:48 PM, Jim Patchell <patchell at cox.net> wrote:
> A Trans-conductance Amplifier refers to the fact that the amplifier has a
> voltage input and a current output.  So, a 741 (voltage in-voltage out amp)
> can be turned into a transconductance amplier with the clever use of feed
> back resistors.  However, what we refer to as an O TA also has an input that
> will control the gain (transconductance) of the amplier.  So, NO, in
> general, you cannot use a 741 to replace a CA3080.
>
> -Jim
>
>
> On 6/25/2012 12:43 PM, Pete Hartman wrote:
>>
>> This is a TOTAL newb question, but...  I've seen at least one
>> implementation of an alleged transconductance amplifier using a 741 as
>> the base (but not used in synths).  IF you can explain in a paragraph
>> or two, I'm curious why that sort of thing is not used more generally
>> given the relative scarcity of the dedicated OTAs.  And if my question
>> exhibits a level of ignorance that can't be addressed on list, then
>> feel free to ignore me (or send me links for research) too :-D
>>
>> Pete
>>
>> On Mon, Jun 25, 2012 at 2:36 PM, Jim Patchell <patchell at cox.net> wrote:
>>>
>>> Heck...I  would be happy if they would just bring back an OLD OTA! (like
>>> the
>>> CA3280).
>>>
>>> -Jim
>>>
>>>
>>> On 6/25/2012 12:04 PM, 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!
>>>>
>>>> Thank's for stealing 5 sec of your valuable time with this rant! :)
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