RCruz, I just noticed you didn't use the TL431... I guess I'm just reading my own experience over again!
Why is it recommended to use the Fairchild transistors? What is wrong with the ON Semi ones?
They are out of production for one. Also the Vbe is different, so they require some adjustments. In listening tests the Fairchild transistors seemed to work better.
Here is my buffer from Keantoken the board is from Project16
I use unmatched ON Semi transistors , my offset is 0.1-0.2 mv.
i put total 3,7ΜΩ resistors for R12 .
i use 10uf cap before the buffer and 10ΚΩ and 50ΚΩ pot.Super quiet...
I use unmatched ON Semi transistors , my offset is 0.1-0.2 mv.
i put total 3,7ΜΩ resistors for R12 .
i use 10uf cap before the buffer and 10ΚΩ and 50ΚΩ pot.Super quiet...
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Hello nikosokey
It is a pleasure to see that my route was served, the only small problem is that the four capacitors of this circuit are small beings.
Achieving your copper engraving is perfect!
Regard's
It is a pleasure to see that my route was served, the only small problem is that the four capacitors of this circuit are small beings.
Achieving your copper engraving is perfect!
Regard's
I do not know if with Fairchild is better but I use CDIL and listening is very good.
Measures after trimming for dc offset=0.1mv-0.3mv +/-
Vbe Q4=672mv, Q2=670mv Q3=618mv Q1=615mv
on R2=56Ω=51.2mv
on R12=150Ω parallel to trim 100Ω=51.3mv
Vbe Q4=672mv, Q2=670mv Q3=618mv Q1=615mv
on R2=56Ω=51.2mv
on R12=150Ω parallel to trim 100Ω=51.3mv
The Kuartlotron webpage schematic gives instructions for changing resistors to accommodate Vbe. There is also a possibility it could be unstable, but I haven't seen it so far. You may get acceptable results without any changes, although your input transistors will probably be running low bias.
Thanks Kean
i will decrease the R1 nad R2 to 52Ω or 47Ω....and i will readjust the R5 trim ...
When i change the 15pf to mica cap i put 5pf the only available , the sound change for the best ,sound completely clean...now
the 25mv on multimeter are the output from my amplifier Golmund clone 9.2.
with SuperBuffer after my DAC AK4490.
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I'm currently playing around with a shuntreg kit I assembled and tried a couple of 'non-recommended' voltages to power the Kuart.
+/-14.3V sounds too in-your-face, too forward-sounding for my liking, though it did bring drive, flow and much better retrieval of lower level details. But the airiness for which I so loved the Kuart was lost.
Toning it down to +/-13V restored the earlier laidback presentation (with the LM317/337 PSU), while retaining much of the new-found liveliness, drive, flow, and better resolution, but more importantly, restoring the airiness.
I haven't got down to checking if the transistors are overheating, or if the DC offsets have gone up, but the sound is definitely more likable than before. Unfortunately with my existing transformer 13V is the lowest the shuntreg can provide. I also need to re-do the TP adjustment (of half Vcc).
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Sorry, but without reading back lots of pages, where does one find the boards??
Maybe Keantoken you'd want to put a link into ur sig page that goes to a page that links to the boards, or something along those lines?
I'm interested enough in the circuit to try some out! 😀
_-_-
Maybe Keantoken you'd want to put a link into ur sig page that goes to a page that links to the boards, or something along those lines?
I'm interested enough in the circuit to try some out! 😀
_-_-
Higher voltages will increase potential thermal mismatch and possibly cause thermal distortion. Furthermore the bias chain is made for +-10V so if you go much higher you won't be able to dial in TP. If you like the sound at a higher voltage, try deliberately putting TP 2V high or low.
I also put a link in the first post:
http://www.diyaudio.com/forums/anal...error-correction-superbuffer.html#post3823194