cambridge 640p

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slovell1

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cambridge 640p
« on: 5 Mar 2009, 08:55 am »
is it possible to upgrade the wall wart or get a better separate power supply for this unit?
thanks,  sam 8)

TheChairGuy

Re: cambridge 640p
« Reply #1 on: 5 Mar 2009, 04:03 pm »
Hi Sam,

On the wall wart (body), what does the voltage and amperage ratings say?

Most likely, this could be considerably improved by another/higher spec/regulated supply.  But it must be the same voltage and at least as much amperage for it to be bettered.

John

S Clark

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Re: cambridge 640p
« Reply #2 on: 5 Mar 2009, 04:26 pm »
It's 12V .5 Amp.  What would be the advantages of using a small 12v lead cell battery? I would imagine that with such a small draw, using a trickle charger, it could last for days without recharge and battery life would be at least a couple of years.

TheChairGuy

Re: cambridge 640p
« Reply #3 on: 5 Mar 2009, 05:14 pm »
Lead acid batteries need lotsa' storage caps between source and battery to better sonically even the cheapo wall wart that the Cambridge came with.  That's been my experience, at least.

A 12v power supply, preferably linear, with regulated 12v voltage and higher amperage would probably be a significant tweek for this phono pre-amp.

Old Radio Shack units like this http://cgi.ebay.com/Micronta-12-vdc-Regulated-Power-Supply_W0QQitemZ280317933283QQcmdZViewItemQQptZCB_Radios?hash=item280317933283&_trksid=p3286.c0.m14&_trkparms=72%3A1234|66%3A2|65%3A12|39%3A1|240%3A1318|301%3A1|293%3A1|294%3A50  typically end up under $25 and would be a boon to (both of) you.

To use it most easily, you'd snip the power lead from the wall wart part...leaving the correct connector to your preamp in tact.  Then, get down to the bare wires (tin them if you like) and insert into + and - output of the Micronta power supply. A cinch (but your wall wart is no longer operable...so be forewarned)

I have this exact power supply and it was quite a nice, cheap tweek on my 12v powered CDP I used until recently.

Regards, John