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Will phono stage work if rechargeable battery replaces by wall-wart?

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Babyspark

New Member
Hi, To elaborate - I have an Angle Audio phono-stage which works of a 15v dc wall-wart. Inside the unit is a rechargeable 9v battery. Once the battery is charged it will run the unit in 'play' mode but when the battery voltage drops sufficiently it cuts out and has to be charged again. There is a toggle switch for 'charge' or 'play', it won't charge if in play mode. Normally there's no problem as I keep it sufficiently charged but sometimes it does suddenly die due to low battery voltage in 'play' mode.
I am wondering if I could just whip out the battery and connect a 9v wall-wart in its place to ensure it never dies on me. I appreciate there might be some slight degradation of sound quality but that may not matter to my aged ears.
Or is this too dodgy to try?
I appreciate readers have no knowledge of the circuitry, just looking for some comments/guidance. Thanks.
 

alec_t

Well-Known Member
Most Helpful Member
Don't see why that wouldn't work. If there's room, rather than remove the battery perhaps you could install a switched jack socket so that plugging in the 9V wall-wart would disconnect the battery.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Obviously the reason for the battery is to reduce noise and hum, using a battery powered preamp is a good way to do this.

Running it from a mains PSU 'may' be acceptable, you can really only try it and see - make sure to use a regulated supply though.
 

sagor1

Active Member
Many wall-wart adapters give higher voltages with less load. You have to match the voltage at a rated load. That is, if using only 100mA on battery, and you try to use a 9V 600mA wall-wart, its voltage may still be high like 12-13V at a low load level. That 600mA wall-wart will give 9V only at 600mA
That said, there are some "switcher" types of wall-wart adapters, and those are steady voltage regardless of load. You have to measure the voltages carefully while plugged in.
Another option is to build in a small 9V regulator circuit (3 parts), and feed it from the 15V charger. Since it won't be charging without batteries installed, you can simply run the device off the 15V wall-wart with a 9V linear regulator chip (LM7809)
 

Babyspark

New Member
Discovered a 9v regulated ac/dc transformer in my stash so made up a connector and connected it to the phono-stage in place of the rechargeable battery. Seems to work well with no discernible sound degradation; hopefully it will continue to do so. Thanks to all for above posts.
 
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