The new Nordstrand Preamp is now shipping and will be available from dealers by mid August. Please contact your dealer for pricing and purchase information.
3B Preamp Specs
Overall gain is +/- 10db by a trim pot on the circuit board.
Bass +/- 12db @ 50Hz
Treble +/- 12db @4khz
Midrange +/- 12db @ 1k with no external capacitors.
Add two capacitors as indicated in the table to change the frequency.
Frequency |
200Hz |
300Hz |
400Hz |
500Hz |
600Hz |
700Hz |
800Hz |
900Hz |
1khz |
To outside lugs of mid pot |
68nf |
47nf |
33nf |
22nf |
15nf |
8.2nf |
5.6nf |
1.2nf |
N/A |
To gray leads from circuit board |
390nf |
190nf |
120nf |
82nf |
56nf |
47nf |
27nf |
12nf |
N/A |
We stock capacitors for the even numbered frequencies and will include one set with each preamp for a second frequency of your choice.
Battery life is estimated to be around 180 hours for an alkaline 9v. Adding a battery to make it 18v will give more headroom and longer life.