IMO, DCPreamp's "telephone pole" wiring is excellent. Bundling is a recipe for coupling signals and noise to places where you don't want them, and I don't particularly like using internal coax- it just adds unwanted capacitance and is hard to dress neatly.
I can't comment on sonic qualities of batteries, but having used a bunch of them for portable test equipment type applications, can say that not all batteries are created equal, or even close. Worse, an old battery will have way different performance than a new one (talking SLA mostly). I've had the best results from the round Gates cells- low Z and very long life. The Yuasa "blocks" and similar are ok when new, but seem to go bad after a number of years, even when properly maintained. More commonly, I forget about them, self discharge drains them, and then they have to go to the recycle station. Never fully discharge an SLA, as you may never get it back to normal again
I don't agree with a point made somewhere above about output impedance of regulators. You absolutely can lower the output impedance of a source by adding a regulator. Just as the inherent output impedance of an op-amp may be in the tens of ohms, adding feedback can lower it to milliohms at low frequencies. At high frequencies you still have to rely on capacitance to keep the impedance low. No implication about sound though, only measured Z
I can't comment on sonic qualities of batteries, but having used a bunch of them for portable test equipment type applications, can say that not all batteries are created equal, or even close. Worse, an old battery will have way different performance than a new one (talking SLA mostly). I've had the best results from the round Gates cells- low Z and very long life. The Yuasa "blocks" and similar are ok when new, but seem to go bad after a number of years, even when properly maintained. More commonly, I forget about them, self discharge drains them, and then they have to go to the recycle station. Never fully discharge an SLA, as you may never get it back to normal again
I don't agree with a point made somewhere above about output impedance of regulators. You absolutely can lower the output impedance of a source by adding a regulator. Just as the inherent output impedance of an op-amp may be in the tens of ohms, adding feedback can lower it to milliohms at low frequencies. At high frequencies you still have to rely on capacitance to keep the impedance low. No implication about sound though, only measured Z
What I want to know, is if is better to use a regulator, or maybe worse, with batteries. And what type of filtering would need to decrease the Z as low as posilble, I think with caps can be done.
If I put large caps between + and 0 and 0 and - rails, would get low impedanze? how much cacity? Need to ad any coil?
If I put large caps between + and 0 and 0 and - rails, would get low impedanze? how much cacity? Need to ad any coil?
Has anyone looked at the Elektor battery powered preamp published in 1997 (Ton Giesberts)? I built this 8 years ago - it uses 12 NiMH batteries, recharges when the power is switched "off" to the preamp, and when switched "on" the mains is disconnected and it runs on the batteries. From memory it doesn't use any regulators after batteries, just relies on +/- 7.2V from the batteries. I'm just replacing the batteries now as they are starting to die - not bad for 8 yrs.
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