[glynnw]

I have been thinking about the fact that everything in my system except the amp and PC is running off a wall wart, some pieces at abt 7V and the rest at 12V.  In my closet is a new large 74 amp-hour SLA battery and charger purchased for an abandoned amp project and a 12V Anthem linear power supply.  Before I just start inserting them into the system, is there any danger here?  Should there be some kind of additional interface? Can I run several pieces off of one supply? Is it easy to convert a 12V source to 7.5V?  Anyone with experience or any other comments, please chime in.  I am pretty much in the dark. 

Currently in system are the following candidates for external power supply upgrade:

SOtM USB card  - 6.5 to 9 V (from the manual)
USB Regen - 7.64*
Bottlehead DAC 12.51*
Tortuga Volume control - 12.06*
Music Reference small tube preamp - currently heard wired to 12V wall wart
DSpeaker Anti-Mode 2.0 Dual Core (too long a name)  - 12.09*

* measured from wall wart output cable

I have a Bottlehead battery supply on order and plan to use it with the DAC.

[G Georgopoulos]

You dont mention the current draw of each equipment...

[G Georgopoulos]

Is it easy to convert a 12V source to 7.5V?

You are very close to doing it with a chip linear regulator (LM317T) ,i cant recall from memory the drop out voltage,it is usually 2,5v or 3v anyway the Vin for the regulator should be equal or higher the drop out Voltage + Vout in your case is ok (12v... 4,5V above Vout)

To calculate the resistors values to set it at 7,5v and pin outs of the chip just google LM317T...too busy to help you here...

all the best...

[glynnw]

Here are the current draws available to me:


SOtM USB card  - 6.5 to 9 V (from the manual)   2A max
USB Regen - 7.64*     wall wart sez 2.93A, 22W max
Bottlehead DAC 12.51*
Tortuga Volume control - 12.06*
Music Reference small tube preamp - currently heard wired to 12V wall wart - Wall wart sez .33A max
DSpeaker Anti-Mode 2.0 Dual Core (too long a name)  - 12.09*   4.5W active, .8W standby

* measured from wall wart output cable

[G Georgopoulos]

Here are the current draws available to me:


SOtM USB card  - 6.5 to 9 V (from the manual)   2A max
USB Regen - 7.64*     wall wart sez 2.93A, 22W max
Bottlehead DAC 12.51*
Tortuga Volume control - 12.06*
Music Reference small tube preamp - currently heard wired to 12V wall wart - Wall wart sez .33A max
DSpeaker Anti-Mode 2.0 Dual Core (too long a name)  - 12.09*   4.5W active, .8W standby

* measured from wall wart output cable

oh ho,you seem to need large power supplies, the lm317t i mentioned can only manage 1.5A max
from the watts to find the current use this w/v=I
to increase the current of the regulator you need to use power transistors in the regulator see diagram bellow



for your requirements one transistor should suffice

i'm just steer you to the right direction,it would take many pages to describe how it works

make sure the plugpack/transformer can supply these high currents

all the best...





 

[glynnw]

Thanks - I don't really understand it all, but this gives me a place to start learning.

Thanks again,

Glynn