Variable 600 T-pad values

[Potato Cakes]

Hello, everyone,

It's been a bit of rainy day and I need to recalculate values for the stepped T-pad using 2x24 switches that I plan on implementing in the UA176s I am building.

For reference I am calling Z+ in/out the points that connect to either side of R1+R1. You'll have to determine which pole will be R2 and R3 according to your preference. The wiring scheme that I came up with is this:


- Stop Pin at 1 and 21 (pole will not directly connect to Position 1)
- Z- in/out connects to pole of R2 Wafer
- Position 1 of R2 Wafer connects to middle of R1+R1 and also jumps to Position 22
- Z+ in connects to R3 wafer pole
- Position 22 of R3 wafer connects to Z+ out
- Take one of the R1 (600 ohm) resistors and connect the pole of R3 wafer and Position 1 of R2 wafer
- Take the other R1 resistor and connect Position 22 of the R3 wafer to Position 1 of R2 wafer

This should give you 40dB of attenuation with a 600R load. Please feel free to double check me.

Thanks!

Paul

 

[xazrules]

hi, i use this handy calculator https://www.custommmic.com/calculators/attenuator/

with the third diagram you can use a two way rotary switch and change the shunt resistor and the top one.

bye

 

[Tubetec]

Thanks for that Xarules  ,
Ive been looking for something just like that for ages ,
There are many many useful calculators for all sorts of electronic and sound applications out there , only thing is the are  spread the lenght and breath of the WWW.

I'll try a post in documents section up top,  'Handy calculators for circuit design' .
That way when anyone happens upon a neat tool that helps us less mathmatically wired  up individuals  we could keep it to hand .

 

[xazrules]

Hi Tubetec i'm very happy to try to contribute with my humble knowledge to this forum! you all are great and i learned everything and i mean everything here, never opened a book