[pabbi1]

Were that there was something like this in 40+ steps... other than Shallco, of course.

 

[fishski13]

i really like this attenuator calculator:
Stepped Attenuator Resistor String Calculator - Neville Roberts

if you're going through all the work of building an attenuator, i would recommend tweaking the attenuation curve to suit your gain needs. experiment with some resistor values and listen to your loudest mastered recordings and some of your less-so loud recordings. you will then have a better idea of total attenuation needed and not waste valuable positions on gain settings that of are little value to your listening needs, and allow more available steps for smaller attenuation steps for finer control. the above calculator is slicker than a cat's ass in this regard.

 

[pabbi1]

That is cool - too bad there are no _reasonable_ 40 position switches. I guess it is Shallco or Seiden. You'd think someone would take a swing at it on the mechanical side, but JT should be available again soon.

 

[AudioCats]

you can always do a relay-based board, using single pole 40 step rotory as control, or use two 24 step to make a 47 position.
Small telecom grade DPDT relays can be found for as low as 55cents each.

I just opened a blue computer grade rotory switch (the kind you find in a A/B parallel cable box, it is 6 pole 2 position but can be modified to 1 pole 12 position), and I am not impressed by the contact quality. A sealled relay should have much better contact than that.

 

[rogerlike]

Quote:

Originally Posted by digger945 /img/forum/go_quote.gif I have thought about just building an external one to go inline from source to amp. Something that could be used with several amps.

AFAIK This isn't such a good idea. Something along the lines of:

From source to attenuator is low-Z, great. After the attenuator you have high-Z, and as such the signal is more prone to noise pick-up, and capacitance effects (treble roll-off, worse imaging etc.).

Interconnects are going to have a higher capacitance relative to the internal wiring of the amp, and won't be shielded as well as the wires inside nice metal amp enclosure - *typically* for unbalanced coax interconnects.

That's what I've read anyway, in a discussion about using an external attenuator to save money on a B22 build.