Thank you! I thought as much, but I'm not qualified in electronics at all, let alone - enough to second-guess Nelson Pass.
Wouldn't 4000 be enough for this circuit even if it was fed with AC and these were the main smoothing capacitors? Assuming the current draw of 20 mA, as mentioned in the original B1 paper.
If that's the case and you want some gain, be sure to look at Wayne's BA2018 preamp.
I have both the b2, b1 rev2 and the korg b1.
Both the b1 buffer amps are more neutral and have no gain of course. More of a uncolored sound. B1 rev2 is more ruthless and sharper than the original b1 I think. But I need gain and they don’t perform well in my system. They sound, well, flat.
The b1 korg is far my lively and although the measurements say it’s colored it doesn’t sound that way to me. Just sounds juicier and richer. Perhaps more veiled than the buffers but I like it a lot.
A lot will depend on your amplifier, speakers and listening habits. All these circuits are relatively inexpensive and there is no “best”. There is only what is best for you. So I’d recommend trying both.
If you are using am power amplifier with a relatively high input impedance (<50k ohms) you can just try a volume pot in front of the amp to see if a no gain preamp will work for you. The B1 buffer does it's job well but if you don't need a low impedance into the power amplifier you can accomplish the same thing with just a volume pot. It may actually sound better.
Why better, if you don't mind explaining? Sure, B1 has THD of its own and it's not exactly 0, but it's low enough to not care - or so I thought.
Do you need a 100 ohm source like the B1 into an amp with say 100K ohm input like the f5? Probably not. A 10K volume pot will work and will not have input and output caps or active devices like the B1 buffer which can color the sound...
If you have a power amp with say a 20K input impedance you are going to have to use an active buffer to get the output impedance down.
But my main point is throw a volume pot in front of your existing system to see if you can live with no gain. Many of us, especially those of us using vinyl as a source, can not.
If you have a power amp with say a 20K input impedance you are going to have to use an active buffer to get the output impedance down.
But my main point is throw a volume pot in front of your existing system to see if you can live with no gain. Many of us, especially those of us using vinyl as a source, can not.
Probably. I think Nelson once said you could go down as low as 1000 or 1500, though don’t quote me (quoting him) on that
