thank you for your inquiry.
At first I want to wish you a happy new year !
The calculation is more important, the values in the table are not so exact.
here some for the current model, I think you have the version before 2009 ?
Also sonically it make nearly no difference if you have 320 or 360 or 470 Ohms,
the influence to the sound is very low !
Heres ome calculation examples for the actual model of Basis Exclusive.
Another calculation :
R1 = 47,000 ohms (fixed): 0.0000212
R2 = 2210 Ohms: 0.0004525 Dip 8
R3 = 1000 Ohms: 0.0010000 Dip 7
Sum = 1/ 0,001473 = 679 Ohms
That means Dip7,8 gives 679 Ohms
Another calculation for :
R1 = 47,000 ohms (fixed): 0.0000212
R2 = 1000 Ohms: 0.0010000 Dip 7
R3 = 470 Ohms: 0.0021276 Dip 6
Sum = 1/ 0,003149 = 318 Ohms
That manes Dip 6, 7 gives 318 Ohms
Another calculation :
R1 = 47,000 ohms (fixed): 0.0000212
R2 = 1000 Ohms: 0.0010000 Dip 7
R3 = 470 Ohms: 0.0021276 Dip 6
R4 = 220 Ohms: 0.0045248 Dip 5
Sum = 1/ 0,00767 = 130 Ohms
That means Dip5, 6, 7 gives 130 Ohms
Another calculation :
R1 = 47,000 ohms (fixed): 0.0000212
R2 = 2210 Ohms: 0.0004525 Dip 8
R3 = 1000 Ohms: 0.0010000 Dip 7
R4 = 470 Ohms: 0.0021276 Dip 6
R5 = 220 Ohms: 0.0045248 Dip 5
Sum = 1/ 0,00812 = 123 Ohms
That means Dip5, 6, 7,8 gives 123 Ohms
Its almost impossible to figure out how to get a value of 320 and 350 ohms unless
I play around with the formula over and over and over again.
Is there some way to gauge what numbers used together will yield a closer result to the value I need?
I want since years to make a complete table of usefull values, but that takes much time to set this up, so I never made it.
Also the gains switches can be combined to have near a gain in 1 dB steps, but who needs that ?
Also from my experience the difference in sound is not so sensitive to small changes in resistance, especially when over 500 Ohms.
So if you use 221 oder 150 make a small sonic difference, so why care too much for details.
Balanced
For balanced you have to make same at adjustment at both dip switches.
It has to be 350 / 2 means 175 Ohms at positive and neg Input.
175 pos and 175 neg = 350 Ohms.
Will be 221 Ohms and 1 K Dip 5, 7 at both dip switches
R/1 = 47,000 ohms = 0.0000212 +
R/3 = 1,000 ohms = 0.001000 + ( Dip 7 )
R/4 = 221 ohms = 0.004524 ( Dip 5 )
Total equals = 0.005546163; 1/0.005546163 = 180 ohms x 2 = 360 Ohms
Or some thing more exact with 10 k in addition :
Will be 221 Ohms and 1 K and 10 k Dip 5,7,10 at both dip switches
R/1 = 47,000 ohms = 0.0000212 +
R/3 = 10,000 ohms = 0.0001000 + ( Dip 10 )
R/3 = 1,000 ohms = 0.001000 + ( Dip 7 )
R/4 = 221 ohms = 0.004524 ( Dip 5 )
Total equals = 0.005546163; 1/0.005546163 = 177 ohms x 2 = 354 ohms
To the load resistance- that does not make such a big sonic difference.
Only when you change more than 30 % you may have a slightly noticeable difference.
So for 500 Ohms load you can adjust between 350 and 700 with no big difference.
Balanced
For balanced you have to make same at adjustment at both dip switches.
It has to be 350 / 2 means 175 Ohms at positive and neg Input.
175 pos and 175 neg = 350 Ohms.
Will be 221 Ohms and 1 K Dip 5, 7 at both dip switches
R/1 = 47,000 ohms = 0.0000212 +
R/3 = 1,000 ohms = 0.001000 + ( Dip 7 )
R/4 = 221 ohms = 0.004524 ( Dip 5 )
Total equals = 0.005546163; 1/0.005546163 = 180 ohms x 2 = 360 Ohms
Or some thing more exact with 10 k in addition :
Will be 221 Ohms and 1 K and 10 k Dip 5,7,10 at both dip switches
R/1 = 47,000 ohms = 0.0000212 +
R/3 = 10,000 ohms = 0.0001000 + ( Dip 10 )
R/3 = 1,000 ohms = 0.001000 + ( Dip 7 )
R/4 = 221 ohms = 0.004524 ( Dip 5 )
Total equals = 0.005546163; 1/0.005546163 = 177 ohms x 2 = 354 ohms
That means you have to put both dip switches left and right column
DIP 5, 7, 10 to ON to get 354 Ohms balanced.
And please lower the gain to what is necessary.
Too high gain is not good for signal to noise ration.
To the load resistance- that does not make such a big sonic difference.
Only when you change more than 30 % you may have a slightly noticeable difference.
So for 500 Ohms load you can adjust between 350 and 700 with no big difference.
Calculation for 500 Ohms :
R/1 = 47,000 ohms = 0.0000212 +
R/2 = 10,000 ohms = 0.0001000 + ( Dip 10 )
R/3 = 4,700 ohms = 0.000212 + ( Dip 9 )
R/4 = 2,200 ohms = 0.0004545 + ( Dip 8 )
R/5 = 1,000 ohms = 0.001000 + ( Dip 7 )
R/6 = 475 ohms = 0.002105 ( Dip 6 )
Total equals = 0.0038993774; 1/0.0038993774 = 256 ohms x 2 = 512 ohms
That means you have to put both dip switches left and right column
DIP 5, 6,7,8,9,10 to ON to get 512 Ohms balanced.
Best regards / Mit audiophilen Grüßen
Friedrich Schaefer
ASR Audio Systeme Friedrich Schaefer
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