I assume it suits well your DAC. Is the total kit project up to some level that could rival serious brand name DACs?
Salas,
Thanks. I will buy them in the next a few days.
They will be used for Tx 18-0-18V that gives about 26V for CCS-shunt +/-15VDC up to 1A load.
Do you think they need heatsinks? If I buy the TO245 could I not use heatsinks?
I modelled it with PSU2 and it appeared that heatsinks may be required. But I have been using the much smaller 1N5822 diodes (no heatsinks) without a problem, although with lower current. I have never touched them to check how hot they ran though.
Regards,
Bill
Salas,
I am still planning to rebuild your low voltage version with the buffer. Last time when I built it I did not use remote sensing and at the time I did not have a scope. I was pretty happy with the result but I think I will do much better this time after learning much from building yours and Ikoflexers. Have you updated the schematic? Is the one I had still the latest version?
Regards,
Bill
I am still planning to rebuild your low voltage version with the buffer. Last time when I built it I did not use remote sensing and at the time I did not have a scope. I was pretty happy with the result but I think I will do much better this time after learning much from building yours and Ikoflexers. Have you updated the schematic? Is the one I had still the latest version?
Regards,
Bill
Constant current tends to bring up the heat higher than we should think for small differences of using more. Better get some smallish ones, or cut little copper or aluminum Pi folded makeshift ''wings''. If they don't touch anything else, they will transfer well by not using insulation pads on the TO-220 backs, even if tiny.
Sounds a good idea. As far as insulation goes, the back of them is the cathode. So insulation pads are needed if using aluminum, otherwise with small heatsinks they are not needed.
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I've yet tried a separate components, like AN or ML, but did a direct comparison with TEAC VRDS-50. I fed our DAC with TEAC's digital source and this is what I found: - compared to TEAC's dry and precision sound, this DAC is natural, liquid and musical, particularly "tube sound"; - DAC opens a better stage with impressive stereo image.
Further playing that with higher sampling source or SACD, like Sony DVD-S9000ES, you would find quite exhausting in the listening sofas.
???
Hello everyone
I plan to make Salas Shunt Regulator +/-24V DC for preamplifier.
Can be used 2SK246 or BF245(A or B) instead 2SK170? The reason is the price for the 2SK170, these others are 3 times cheaper than 2Sk170. Will the performance in terms of THD violate if you use a substitute?
Hello everyone
I plan to make Salas Shunt Regulator +/-24V DC for preamplifier.
Can be used 2SK246 or BF245(A or B) instead 2SK170? The reason is the price for the 2SK170, these others are 3 times cheaper than 2Sk170. Will the performance in terms of THD violate if you use a substitute?
Also, I have a question about 2SK170 transistors dissipate. Input voltage will be about 32V, voltage at drain is about 25V, 5mA(Id) multiplied by 25V is Pd=0.125W.That will give a large dissipation of TO92 housing, right? Should we increase the value of resistor so Uds about 10V and 15V across the resistor?
Hi Viktor, neither the 2sk246 nor the bf245 are good substitutes. Look at the datasheet if you want to find a substitute, so it should have a small Vgs(off). The reason is that the jfet should operate reasonably within the Vbe of the bjt that clamps it.
Hope this helps.
Hope this helps.
About your second question. The jfet does not see the entire 25V. No worries about dissipation, it is not a problem at all.
Q5 in post1 must be a low pinchoff voltage jFET, 2sk170 or equivalent.
Other versions of the regulator have changed R4 & R6 to jFETS used as CCS. In these locations bf244 or bf245 can be used. But check the pinout.
Other versions of the regulator have changed R4 & R6 to jFETS used as CCS. In these locations bf244 or bf245 can be used. But check the pinout.
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Your main concern is to use a no more than -0.7V pinch off NJFET under Vbe in the Vref. You may also lift that margin by using a resistor between the BJT and ground. BF245A in low Idss looks like it can go low pinch off, and is also fast for capacitance, it may even open up the bandwidth if used everywhere and even sound better, but its something you must experiment with, I haven't yet used it, don't know if it will create some oscillation tendency.
You may not understand, here is the schematic and you will see that the Uds is 25V.
An externally hosted image should be here but it was not working when we last tested it.
Your question on 2SK246 and +/-24VDC application would be referred to Salas, the designer of the circuitry.
0.125W isn't too bad. You can always back it off a bit with a small resistor between G,S. Something like 33R.
Yes, thank's ikoflexer.
I think that dissipation at 2SK170 is a little bit high for this version which i intend to use. I am thinking right now to increase value R3, about 3Kohm.In that case Uds will be 10V, dissipation is 10V*5mA=50mW, that is safe for TO92. Voltage at R3, if i use 3K will be around 15V. Is that OK?
I think that dissipation at 2SK170 is a little bit high for this version which i intend to use. I am thinking right now to increase value R3, about 3Kohm.In that case Uds will be 10V, dissipation is 10V*5mA=50mW, that is safe for TO92. Voltage at R3, if i use 3K will be around 15V. Is that OK?
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