B1 with Korg Triode

HI broennimannrainer
Been listening to the Sansui AU-317 and the B1K. The Sansui is more laid back, smoother with more bass but not as defined at the low end. The B1K is cleaner, more air, more detailed and punchier. I'm not getting any midtone boost with my setup with the Nutube compared to the Sansui. More clarity is what i'm noticing mostly. Different feel- I like both amps. Listening with NCore 252MP and Goldenear BRX. Using the B1K with wall wart power supply and the SMPS DC Filter kit. Upgrading the power supply might improve things again.
Hi Gwam
Nice to read your review and to hear that you like both of the amps. The Sansui i more than 40 years old. I am quite sure you get a more defined low end when you change at least the power caps. They have become dirt cheap. Be careful about upgrading to linear power supplies. Usually they are very epensive and depending to the situation they might be better or worse than a switching power supply. Hear it for a week and then move back to the other supply. Maybe a heard advantage vanishes.
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As posted a couple of years now, I tried a huge laboratory regulated linear PS with the B1K.
Yes, here probably not the last say vs shunt regulators & Co, but well...

At the end A) not a big difference soundwise -note I had upgraded the PS caps on the B1K- and B) I prefered the sound of the SMPS with Mark's filter.

Bottom line for me: linear not worth the hassle here, if you wish to tweaw there are other bits starting with the bias. B1K works with SMPS perfectly and as intented... what else should I have expected from Papa LOL?

For more details re units or precisions re sonic difference, search my old posts in this thread

I hope this helps

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Hi Brijac,

Interesting, always glad to be proven wrong and discover another tweak.

Are you planning several of these devices? I can see on their spec sheet that max current is 50mA... I believe this is what the B1K requires (from memory), so no real margin here if any (if I am not mistaken) . I also expect quite an inrush current at start-up due to the PS caps, unless a slow start device is also planned? Or just all this gets on a modified B1K board that has all the PS parts taken out / does without the the existing RCR filter + diode reg and your new schematic around that chip replaces it entirely? That could reduce significantly the current need to get under 50mA, as quite a bit is burned there...

Just thinking out loud...

Good luck

Interesting, always glad to be proven wrong and discover another tweak.
Not really a matter of proving wrong or not, friend wants good linear instead of smps as he has an extra secondary, so i designed it as an addition to my smd version of b1k. Good thing is we can compare :)

I can see on their spec sheet that max current is 50mA.
TPS7A4701 is 1A load capable, which is heavily derated. I went for it instead of 150mA variant due to initial current rush, which can exceed that value, but i belive b1k nutube runs at around 70mA when it settles, haven't actually measured. So no worries there. I haven't modified filter, i left it as pops designed it out of respect and it sounding really good as is, it's just improved significantly by using modern smd components.

You can check it here, i posted it at post #8420
Did anyone ever publish a schematic making a balanced version using two B1s? (I scanned a bit of this thread but not all 428 pages). I am not enough of a circuit designer to make the design, although I like to think I could build it if someone did. I would like to make a balanced pre to go with an Aleph project I am working on.

Thank you.

Official Court Jester
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there is no such thing as balanced B1, simply because there is nothing to make basic blocks (SE buffers) married in balance

in short, what you can make - two SE buffer cells, each conditioning one phase of your balanced signal, and you have it

but - there is a trick - adding xformer after buffers, having as result that two phases of balanced signal are again/still married together on output of pre ........ even if- frankly- divorced for short time, being thrown through 2 separate buffers

so - either look at Iron Pre (Bal) and make your own ......... or buy one in Store (soon again) and make your own