(Original version)
The
Line Stage has options for different gains and output impedances. There are two
ways to get different gains and output impedances. First, the board is wired so
jumpers can be installed to change the transformer ratio. Second there are two
different transformers that may be used, the LL1674 or LL1676, which are
identical except for their winding ratios. Although there are several
variations, I had to pick one as “standard.” The “standard” version of
the Line Stage has 6.5dB of gain and an output impedance of 1000 Ohms.
Input
Options
|
Option |
Transformer |
Potentiometer |
Ratio |
Gain
* |
Input
Impedance |
Note |
|
1 |
LL1676 |
10KΩ |
1:1 |
0dB |
10KΩ |
|
|
1a |
LL1676 |
50KΩ |
1:1 |
0dB |
50KΩ |
|
|
2 |
LL1674 |
10KΩ |
2:1 |
-6dB |
40KΩ |
Standard |
|
3 |
LL1674 |
10KΩ |
4:1 |
-12dB |
160KΩ |
|
* The gain numbers above are in addition to a base of
+24.5dB.
Output
Options
|
Option |
Transformer |
Ratio |
Gain
* |
Output Impedance |
Note |
|
4 |
LL1676 |
2:1 |
-6dB |
4KΩ |
|
|
5 |
LL1674 |
4:1 |
-12dB |
1KΩ |
Standard |
|
6 |
LL1674 |
8:1 |
-18dB |
250Ω |
|
*
The gain numbers above are in addition to a base of +24.5dB.
Option Combinations
|
Options |
Total
Gain |
Input
Impedance |
Output
Impedance |
Note |
|
1
& 4 |
18.5dB |
10KΩ |
4KΩ |
|
|
1
& 5 |
12.5dB |
10KΩ |
1KΩ |
|
|
1
& 6 |
6.5dB |
10KΩ |
250Ω |
|
|
1a
& 4 |
18.5dB |
50KΩ |
4KΩ |
|
|
1a
& 5 |
12.5dB |
50KΩ |
1KΩ |
|
|
1a
& 6 |
6.5dB |
50KΩ |
250Ω |
|
|
2
& 4 |
12.5dB |
40KΩ |
4KΩ |
|
|
2
& 5 |
6.5dB |
40KΩ |
1KΩ |
Standard |
|
2
& 6 |
.5dB |
40KΩ |
250Ω |
|
|
3
& 4 |
6.5dB |
160KΩ |
4KΩ |
|
|
3
& 5 |
.5dB |
160KΩ |
1KΩ |
|
|
3
& 6 |
-5.5dB |
160KΩ |
250Ω |
|
Option Wiring
|
Option |
Cut
trace between pins: |
Add
jumper between pins: |
|
1,
2, 4, 5 |
None |
None |
|
3 |
6
and 10, 7 and 9 |
6
and 9 |
|
6 |
1
and 4 |
2
and 4, 1 and 5 |