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Anyone have any idea if it is wise or possible to adapt an off the shelf phono stage (tom evans microgroove plus) from AC to battery, and if so how it might be done?
thanks
Follow Ups:
What is "tom evans microgroove plus"? And what is phono stage that you want to power by DC.
You see... there is probably nobody here who has done it on your model unit, but it may be 100 people who knows how to do it. We need to know what you want to power, a TT motor, preamp, separate preamp, preamp in receiver, or what? When you say "phono stage", it could be any of this things.
Apologies for lack of info. The Microgroove plus is a turntable phono stage with seperate power supply. So the battery power would be to power the unit amplifying the signal from the cartridge, which then leads into a power amplifier. The power supply itself is crucial to the performance of the unit.
tnks
edward
First you need to select what batteries to use. I assume you want rechargables. If you want to go with nonrechargable then just select enough batteries for proper voltage, disconnect exsisting power supply and there you go. Respect polarity, and make a switch to disconnect them when not in use. You can use relay powered by existing power supply, so when you cut power to unit, these batteries will be OFF too.
Rechargable batteries are more economical, ofcourse. First measure current draw for circuitry, then estimate how many max. hours you use unit on daily bases. Then select batteries with enough capacity to power this. (Ofcourse, you will match voltage ratings). Main problem with rechargables is that you cannot charge them while you are using them. So you should use relay powered by main power switch that will engage charging circuit only when unit's power switch is OFF. At same time relay should disconnect load on batteries. And when ON, relay should disconnect power to charging circuit. Charging circuit can be more or less complex. It will, basicaly, only affect how many charges you will get from batteries. No influance to sound, whatsover, as long as relay(s) connect and disconnect everything properly. Relay should be powered by DC to keep EMI low.
If you think you do not understand how to make this, take this directions to any good technician, and they will know how to make this.
So you need to achieve:
1. Rechargable battery power supply.
2. When main power is ON, relay disconnects power to charging circuit, and connects battery to preamp.
3. When main power is OFF, relay disconnect preamp from batteries, and connects power to charging circuit. Charging circuit must be reverse current protected, (1 diode is just perfect).
Relay that can do this should have 4 normal-closed, and 4 normal-open contacts. You may need 2 relays if one like this is hard to find.
If I didn't help you, I hope I, at least gave you good dirrection and idea.
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