Boss Waza-Craft buffer: what's up with that?

[bool]

Try it. It can clean up some of hf noise but you need to scale the passives (biasing resistors) to be of sufficiently low-z to bring the curr.noise generated voltage down. It doesn't kill the midband noise; this one goes straight into the chugga-chugga...

[Jubz]

Hi.

I m wondering. A 2 transistors buffers + his associated components will take more PCB place than the opamp version, and this circuit becomes more complex because it aims to go close to opamp performance. Soundwise will there still be differences (character? mojo?) which makes worth it?

[Rob Strand]

Try it. It can clean up some of hf noise but you need to scale the passives (biasing resistors) to be of sufficiently low-z to bring the curr.noise generated voltage down. It doesn't kill the midband noise; this one goes straight into the chugga-chugga...

I'll have to play around with it.

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Needs a high-beta transistor.

[anchovie]

the coolaudio bbd's and clock chip

I found it mildly amusing that after having so many of their pedals cloned, Boss is now buying parts from Behringer!

[bool]

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Boss is now buying parts from Behringer!
...

Beer-ringer has obviously perfected the craft. No wonder after so much interactions of "reverse" R&D.
R&D is R&D after all.

[Rob Strand]

I was packing up the stuff from this thread and there's a few points I can add about the Waza pedals.

On the SD-1w  the buffer output which goes to the overdrive section is tapped off the source of the JFET ie. before the final BJT buffer.  Whereas the clean signal is tapped off the BJT buffer.    (So it follows the pattern of some of the Ibanez pedals where the clean signal has an extra buffer before the JFET switching.)

The DM-2w on the other hand uses the output from the second buffer for both the clean signal and the input to the effects circuit.

The internal buffers on the DM-2w, for example the buffers used on the Sallen and Key filters, are just the plain vanilla one transistor buffers.

In both the SD-1w and the DM-2w  the output buffer is a BJT buffer, like the older Boss pedals.  One change to the output buffers on the Waza pedals is the resistor in series with the signal line is moved to the output side of the resistor to ground.  This prevents creating an unnecessary voltage divider with the 100k to ground and minimizes signal loss.

The general set-up on the JFET switching uses 1uF electrolytic caps for all the signal coupling caps and 100k resistors to Vbias.  The standard Boss pedals used 47n caps and 1M, so the Waza circuits have dropped the low-frequency cut-off a bit.

[antonis]

I m wondering. A 2 transistors buffers + his associated components will take more PCB place than the opamp version, and this circuit becomes more complex because it aims to go close to opamp performance. Soundwise will there still be differences (character? mojo?) which makes worth it?

No other than current capability (second transistor could easily be a couple of Watts item) and personal design joy..