I've been receiving some odd questions about the B1 of NP. Especially regarding the choice of input and output caps and the psu.
First, I would like to clear some things regarding the DCB1 and what the heck is it's difference from the B1. The DCB1 boards contain a symmetrical Salas shunt regulators which powers a B1 in a symmetrical fashion. This means that the gates and drains of the jfets are (or should be) near zero DC, hence, no need for the input and output caps, which are also coined as signal caps since our precious signal passes through them. Most audiophiles will start a war when it comes to choices of their signal capacitors, so why not just remove them altogether for peace and harmony?
In the DCB1, much hard work and brain power were used to concoct a way to remove these signal caps, and since these input and output caps came about due to the biasing of the input and the eventual raising of the source output to Vcc/2, a more elaborate way of powering up the DCB1 was derived wherein it will bias itself up and at the same time end up with zero DC on the input and the output. Enter the Salas shunt regulator, an innovative and clever psu design. Goodbye input and output caps.
So, if you have a regular B1 and use a single Salas shunt regulator to power it, then it is wrong to call it a DCB1 since the meaning of the "DC" in the DCB1 is Direct Coupled. Therefore, a B1 should not be thought of the same as a DCB1. Yes, they use the same ccs'd loaded jfet design but the B1 is powered asymmetrically and that the input gate is set at Vcc/2 to bias the jfet which in turn defines the necessity for an input capacitor. Consequently, the source of the upper jfet will also be about Vcc/2 and so an output capacitor is required to remove the DC voltage present at the output.
In the olden days, these input and output capacitors that are used for inter-stage amplifications were known as "coupling caps", and so the term "direct coupled" would mean the opposite or synonymous to an OCL output design.
Again, please do not mistake the DCB1 for a regular B1, the latter being famous amongst DIYers while the former is a more advanced version wherein more work and patience is required of the builder. Ultimately, the DCB1 is not a B1, and vice versa. You can power a B1 with a Salas shunt regulator and still not make it a DCB1.
I hope this clears things up for the interested parties, and I sincerely hope my PMs will be mildly de-congested.
Back to the underground...
