Probably as you say, fake parts means what? More noisy or less reliable in the long run?
I had a Salas shunt before. To be honest, my golden ears are not as they use to be. I cant hear cheap vs good psu.
this is my 2nd BA-3. The first one I did, I used values for 12dB gain,
Gain is too low for some reason, going to stick with stock values.
Well rare, discontinued transistors (in this case the toshiba) 2sa970 + low ebay price usually means fakes...a different device rebaged. Could work but sound bad, could be worse. Big value caps can be a lower value or voltage rating. Lots of bad things happenwith cheap stuff from china. Especially on ebay. No offense to the chinese, I am one. Well, actually half. There are reputable sellers too. It's just there is money tobe made doing this stuff in China, and access to lots of cheaper parts to use for fakes. It wouldn't make much sense, labor-wise to do it in some other countries.
I've had both the lm317/337 and the superreg in my BA-3. Superreg is better. but it's not a night and day difference.
Watch your cap rating/tansformer rating, amount the reg needs to drop, etc. A shunt reg may want to drop a lot of voltage...a lm317/337 reg may want only a 3 or 5v drop. And the caps need to be rated for the input voltage.
I've had both the lm317/337 and the superreg in my BA-3. Superreg is better. but it's not a night and day difference.
Watch your cap rating/tansformer rating, amount the reg needs to drop, etc. A shunt reg may want to drop a lot of voltage...a lm317/337 reg may want only a 3 or 5v drop. And the caps need to be rated for the input voltage.
I near yah about ebay stuff.
I have tried HV Salas Shunt.
Btw, where did you get low voltage one?
I only see super reg on diyaudio store but its limited to 15v unless
Different op amp is used and then its experimental.
I used ad817. Its pretty easy to set up for different voltages...the math to get the voltages where you want them is a bit hard. Check the super reg thread. Basically a chip swap and a resistor change and you are good. I have not used the salas shunt...just lm317/337, super reg and batteries...batteries were with a jfet boz.
I still let P3 at the middle because i don't have distorsion analyzer. This preamp have good dynamic,great sound stage, and very detail. Listening for kind of instrument music, trio, ... really really good.
But for Voice, for me the voice is quite far from listening position. The singer is behind the all of the musicians so a little bit "unfriendly".
Does anyone have same of view?
I don't have 2sk2013/2sj313 so i used IRF610/9610 right now.
But for Voice, for me the voice is quite far from listening position. The singer is behind the all of the musicians so a little bit "unfriendly".
Does anyone have same of view?
I don't have 2sk2013/2sj313 so i used IRF610/9610 right now.
fiddling with P3 can change this, but without distortion analyzer it is difficult to find the way…
another problem fiddling with P3 changes the offset a bit and you have to refiddle the other pots…..
not so easy….
possibly your k2 is too high….
care for a sound card distortion measurement solution…. it is so interesting!
another problem fiddling with P3 changes the offset a bit and you have to refiddle the other pots…..
not so easy….
possibly your k2 is too high….
care for a sound card distortion measurement solution…. it is so interesting!
Sorry, what k2 mean?
I'm playing with soundcard and ARTA today and also feel very interesting. now i can see how 2nd harmonic distortion and 3rd harmonic distortion visible in spectrum graph, but i think need more time to play with it.
I used Creative Blaster Live 24 bit external, this seem not a very good sound card to do this job.
k2 means second harmonic….
a good value to start is to make k2 8-10db higher than k3.
So good luck in adjusting your sound and I find it so astonishing how different the same circuit can sound changing the harmonics.
And I think if your card can do 24 bit and 48kHz it is sufficient to get the required information.
Keep care not to overload the sound card.
Normally I adjust at the pre output 1V and with a pot or resistors I dampen the voltage to around 200mV.
Similar if you measure amps, I get down the 2.83V at a 8R resistor with a resistor network to 200mV to measure distortion at one Watt.
But maybe you know all this…..
a good value to start is to make k2 8-10db higher than k3.
So good luck in adjusting your sound and I find it so astonishing how different the same circuit can sound changing the harmonics.
And I think if your card can do 24 bit and 48kHz it is sufficient to get the required information.
Keep care not to overload the sound card.
Normally I adjust at the pre output 1V and with a pot or resistors I dampen the voltage to around 200mV.
Similar if you measure amps, I get down the 2.83V at a 8R resistor with a resistor network to 200mV to measure distortion at one Watt.
But maybe you know all this…..
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Thanks generg, Zen Mod for detail explain,
i'm not sure can catch up all the thing your mention here, since this is first time i used sound card to measure pre, amp. could you please have a picture about register network that for me (and maybe someone likes me) understand it more clearly.
Thanks for your kindly help.
Keep care not to overload the sound card.
Normally I adjust at the pre output 1V and with a pot or resistors I dampen the voltage to around 200mV.
Similar if you measure amps, I get down the 2.83V at a 8R resistor with a resistor network to 200mV to measure distortion at one Watt.
But maybe you know all this…..
i'm not sure can catch up all the thing your mention here, since this is first time i used sound card to measure pre, amp. could you please have a picture about register network that for me (and maybe someone likes me) understand it more clearly.
Thanks for your kindly help.
Simply google "soundcard probe".....
One possibility is here
Electronic Equiptment - DIY soundcard scope probe
By this circuit you can get the voltage at the outputs of the Pre or Amp down to let us say 200-500mV.
Most soundcards endure only voltages < 1V.
If you come near to 1V the soundcard distortions mix with your pre or amp distortion and you get ugly figures....
One possibility is here
Electronic Equiptment - DIY soundcard scope probe
By this circuit you can get the voltage at the outputs of the Pre or Amp down to let us say 200-500mV.
Most soundcards endure only voltages < 1V.
If you come near to 1V the soundcard distortions mix with your pre or amp distortion and you get ugly figures....
That soundcard probe works very well, I have made one and find it invaluable.
Remember with a preamp you need to have a load resistor on the output to give it something to drive, if I recall correctly I used 22K or something across the output and clipped the soundcard probe to that. Preamp was given a sinewave of sufficient amplitude to give a couple of volts output from the BA-3, and the soundcard probe then adjusted to give 1V to the soundcard input. That signal was then FFT with Electroacoustics Toolbox, and P3 adjusted looking at the relative height of the K2 and K3 spikes.
Remember with a preamp you need to have a load resistor on the output to give it something to drive, if I recall correctly I used 22K or something across the output and clipped the soundcard probe to that. Preamp was given a sinewave of sufficient amplitude to give a couple of volts output from the BA-3, and the soundcard probe then adjusted to give 1V to the soundcard input. That signal was then FFT with Electroacoustics Toolbox, and P3 adjusted looking at the relative height of the K2 and K3 spikes.
Thanks for your all guide, i will try to understand it all.
Today i tried to see how the preamp signal display on PC, and here is results.
LEFT channel
RIGHT Channel
Tried to adjust P3 and also see the k2,k3 change. but still not glue how the sound good relate to them. need to read more and more i though.
@6L6: i'm not attached register to preamp yet. will do for next measure.
after adjust the P3, DC offset will right very high ( ~1-1.5V), then i re-adjust DC offset, then k2,k3 also change, this make me confused.
Today i tried to see how the preamp signal display on PC, and here is results.
LEFT channel
RIGHT Channel
Tried to adjust P3 and also see the k2,k3 change. but still not glue how the sound good relate to them. need to read more and more i though.
@6L6: i'm not attached register to preamp yet. will do for next measure.
after adjust the P3, DC offset will right very high ( ~1-1.5V), then i re-adjust DC offset, then k2,k3 also change, this make me confused.