That Buffer is discussed at length by Dennis Feucht.
But a k389 with 46r as source resistors will have VERY LOW current capability.
It would need a very easy load (including parasitic capacitance) to perform.
It's just an attempt to know the kind of sound. BTW is powered with a standard lm317/337
They are supposed to be the same, though I heard that the Linear Systems ones aren't as quiet as the Toshiba ones.
Start with 10 Ohm ones.
It's doubtful if with such regulation you'd get the best SQ from any buffer…
Much better than LMs.
As a starting point. This is what JC suggested me.
Joshua, the weekend give me clear results:
1/ +-15V supply togheter 10R sounds better
2/ Changed 2SK170BL in place of LSK389, sounds better 2SK170BL
Now it's time to upgrade the PSU, I will keep you informed.
P.S. 2N4391 are on the way home to make the schematic "B" of Calvin buffer.
1/ +-15V supply togheter 10R sounds better
2/ Changed 2SK170BL in place of LSK389, sounds better 2SK170BL
Now it's time to upgrade the PSU, I will keep you informed.
P.S. 2N4391 are on the way home to make the schematic "B" of Calvin buffer.
Hi Felipe,
According to my expectations, since it's JC suggestion.
According to my expectations, since I heard that Linear Devices JFETs, in practice aren't as good as the Toshiba ones, though they are similar according to the Datasheet…
It's highly recommended, since the SQ of this circuit is highly dependent on the quality of the PSU.
If you can afford it, the Jung-Didden SuperRegulator is the best for such an application. However Salas Shunt is much better than simpler ones.
Through-hole ones? Where did you get them from?
According to my expectations, since it's JC suggestion.
According to my expectations, since I heard that Linear Devices JFETs, in practice aren't as good as the Toshiba ones, though they are similar according to the Datasheet…
It's highly recommended, since the SQ of this circuit is highly dependent on the quality of the PSU.
If you can afford it, the Jung-Didden SuperRegulator is the best for such an application. However Salas Shunt is much better than simpler ones.
Through-hole ones? Where did you get them from?
I bought from this seller because in the past the sourced me original parts.
2N4391 Transistor | eBay
Joshua could you post or link the Calvin buffer schematics that you will try?
2N4391 Transistor | eBay
Joshua could you post or link the Calvin buffer schematics that you will try?
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The Jung-Didden SuperRegulator are these?
Super Regulator V2.2 - Power Supplies and Accessories - Circuit Boards
Super Regulator V2.2 - Power Supplies and Accessories - Circuit Boards
I'm going to try 4 buffers, both buffers in each schematic attached, all through-hole.
In the first schematic, it's going to be 2SK170 BL or V and 2SK170 + 2SJ74 BL or V, +/- 15V, 10 Ohm sources resistors. When 2SK170 + 2SJ74, their Idss and sources resistors will be matches according to Euvl's suggestion (actually slight mismatch in Idss and sources resistors).
All 4 buffers will be fed from Jung-Didden SuperRegulator. This way I'll make sure that the SQ isn't affected by the circuit's sensitivity to the regulator's quality.
Since 1 of those 4 will be installed in my setup, it's good to have the SuperRegulator.
Indeed.
Attachments
In Buf 1, (the half on the left)
the output connection is tapped into the wrong position.
The tapping should below the source resistor, i.e. at the drain of the lower jFET.
If you look at Calvin's sch you will see that the outputs are tapped in at BELOW R3 and BELOW R103.
R5 and R6 are far too low.
use >10K and preferably >100k.
Calvin uses 100k for R12 and R112.
Then use the receiver to load the cable and buffer.
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