24V or 15V Power Supply for RA-1 Clone?
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Lil_JV

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I am gathering parts for a clone decided to just use an elpac power supply instead of batteries. Which voltage is more suitable? 24V or 15V?

Thanks in advance.

JV.
 
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Lil_JV

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Can someone please help! I am trying to get this order finished. I know the chip is rated to 18V and there are some tantulum caps before the V+ and V-. Basically I need to know if the amp can run on 24V or if it will fry the chip.

Thanks,

JV.
 
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guzzler

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i'd go the 15V for the RA-1, it's really meant for low-Z phones so a high voltage isn't really needed. The 24V supply will, however, probably be more useful in the long run

g
 
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Lil_JV

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So I would not fry the chip if I use the 24V? It would be good to be able to use it with other amps.

Thanks guzzler.

JV.
 
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Paragon

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If the chip is only rated for 18V, then don't put 24V across it.

What chip are you using?
 
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Lil_JV

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Ok, hold on. The + of one battery and - of another are supposed to be grounded in the original design. Could I just use a single supply and apply +15V to one side and -15V to the other and just omit the ground? Or do I need a dual supply?

JV.
 
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guzzler

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assuming you're using the NJM4556, it's rated 36V, ie +/- 18V, so the 24V supply would be fine. However, the arrangement of the batteries in the RA-1 means the ground is at the junction of the two. Unless you use a dual supply, you'll need to have some way of creating a virtual ground. IMO, you're no longer building an RA-1 clone when you do that, as many attribute some of the tonal characteristic of the RA-1 (just a well calculated CMoy, really) with that arrangement.

JV, a single supply doesn't give it +/-15V, it puts out 30V, the +/- have to be referenced from a ground you then create, and therefore are dependent on it, so you can't "omit" ground as you put it

g
 
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Lil_JV

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Ok thanks! So I will just go with a dual 12V supply then.

JV.
 
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