MOTM

How about adding an op-amp buffer on a daughterboard to handle the  
inputs? Would that help? You could customize the gain and input  
impedance to your liking. A MUUB-2 board would probably suffice.

On 7-Mar-08, at 7:38 AM, Mark wrote:

>
>
> Someone sent me the brilliant of normalling the inputs.  He connected
> In 1 to the switched lug 2, and In 2 to switched lug 3 on his 490.
> It is a less invasive mod than changing resistors on the board, and  
> the use of
> dummy plugs would provide the original function.
>
> Normalling the inputs in the above way, then the input impedance for
> one input would be 3K, and for two inputs it would be 10K on one
> input and 5K for the other.
>
> I'm thinking if I connect In 1 to the switched lugs 2 and 3, In 2 to
> the switched lugs 1 and 3, and In 3 to switched lugs 1 and 2, then
> the input impedance would be the same for any one or any combination
> of two inputs.
>
> Does anyone you see a problem with doing that, or have a better idea??
>
> Thanks :)
>
>
> On 3/4/08, Mark put forth:
>> On 3/3/08, loopcycle put forth:
>>> I'm still learning the 480, but it definitely changes character  
>>> depending on
>>> the input signal amplitude, just as the 440 does.
>>
>> That's true of most filters.  It is certainly true of Moog ladder
>> filters.  Which is why I think it would have made much more sense if
>> the 490 had only one input jack and an input level knob.  The 490
>> always seems to sound as though the input is not loud enough (and
>> MOTM mixers like the 830 and 890 have little or no gain).  So I'm
>> always patching in some sort of amplifier before the inputs.  Multing
>> the same signal to more than one input also works.  Which would be
>> the same as putting the input resistors in parallel.  While I could
>> change some or all of the input resistors to 5K, I don't think
>> lowering the input impedance of the module is such a good idea.
>> Would it be better to increase R5 to a larger value, or would that
>> cause other problems??  Any ideas??
>