Hi,
I've got an old Sansamp Bass DI (not the bass driver with controls outside, the old one) which is running on a 9v battery, and i'd like it to run like everyactive DI, via 48v phantom power.
I've searched DIY forums here and there and can't find anything,
Could anybody help ?
thanks in advance
I've got an old Sansamp Bass DI (not the bass driver with controls outside, the old one) which is running on a 9v battery, and i'd like it to run like everyactive DI, via 48v phantom power.
I've searched DIY forums here and there and can't find anything,
Could anybody help ?
thanks in advance
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Sounds weird as ; 1 it's working on a 9v battery, 2 every active DI works on phantom power.
no ?
The insides of the original SansAmp are still fairly secret. There are several "recreations" but they do not all agree. They are mostly for the later model with more knobs.
The later model has a LOT of opamps (chips) and may be more power-hungry than a P48 can supply. P48-powered DIs have to be designed that way. This may not have been a design goal for the original SansAmp.
The later model has a LOT of opamps (chips) and may be more power-hungry than a P48 can supply. P48-powered DIs have to be designed that way. This may not have been a design goal for the original SansAmp.
the most common way to convert the 48V is to use pnp emitter followers, where the 6k8 resistor in the desk acts as emitter resistance. the collectors are feeding into a 9V zener (supply) , and the base bias resistors are calculated to have a voltage of say 15V dc at the output. you may have to use lower power opamps, for example MC33178. there is no dc isolation this way.
Hi Friedd,
Yep. I would 'forget about it'. You'd stand a lot better chance of adapting it to a wall wort @9V (if it isn't already -- sorry I don't know). There would probably be some diy help and/or circuits for that.
The problem is, that only a few 10's of mW are available from Phantom power -- even if you draw so much current that you hog it down to half voltage, something boards don't like. And it will start to generate a lot of noise.
Unless the designer undertook the challenge to keep power consumption to very low levels from the outset of the design, there's very little hope of achieving a satisfactory result.
Sorry for the unhappy news.
Regards,
Rick
Yep. I would 'forget about it'. You'd stand a lot better chance of adapting it to a wall wort @9V (if it isn't already -- sorry I don't know). There would probably be some diy help and/or circuits for that.
The problem is, that only a few 10's of mW are available from Phantom power -- even if you draw so much current that you hog it down to half voltage, something boards don't like. And it will start to generate a lot of noise.
Unless the designer undertook the challenge to keep power consumption to very low levels from the outset of the design, there's very little hope of achieving a satisfactory result.
Sorry for the unhappy news.
Regards,
Rick
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