Will surely do it. See its really 16VAC off your wall, if more, use 35V cap for longevity. See to use good quality proper value load resistor for the cart (evaluate a couple, don't follow the manual's minimum blindly), and VERY good quality 0.47uF coupling output cap. Will be happy to know if it worked for you well enough.
P.S.
That is what the specific post 7809 cap multiplier filter in your circuit is supposed to do for cleaning its DCin (LT SPICE sim).
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Zfoils & Teflon are best IMHO, next, Dale & Mundorf. Cheaper, Takman MF & Obbligato. Plain, Beyschlag and Russian K42y.
Hi salas,
Is the gain set by the value of R1? if I wanted to reduce the gain to 10 dB what would be a suitable value?
Thanks
Craig
Is the gain set by the value of R1? if I wanted to reduce the gain to 10 dB what would be a suitable value?
Thanks
Craig
Av=-(gmRD) for no RS. About 32-35mS Yfs (gm) for each 7mA K170. Thus circa 50R with such IDSS fets. But don't run them over 8V across because extra noises creep up.
I have kindly been given 2 Rifa 0.47uF caps for the output C3 part number PHE 241H made in Aus, I believe they are quite old but NOS. anyone heard of them? Any comments
hi batty, the transparent ones? I did tried for C1 (1uF) on aleph J, bit mushy to my taste but sweet. for my simplistic NJFET I use K73-16, 0.47uF
I bought a set of 0.47uF ft-3 caps and some TX2575 resistors for Rload. Why is a 7809 used, most phono stages thrive on shunt supplies and being a MC-pre with it's tiny signals I thought a shunt is in the right place here. Guess I'm wrong here 😉
- so no output swing, therefore no shunt needed, no gain here to use a Salas 1.1 ?
Regards, Erik
- so no output swing, therefore no shunt needed, no gain here to use a Salas 1.1 ?
Regards, Erik
You can try whatever instead of the 7809 but leave the multiplier noise filter that comes after the 7809 there. That one defines the PSU Zo also. See not to have serious heat sources near the input JFETs.
Not as much as when feeding many different level stages and there is no further rail circuitry like filters here.
Hi Salas,
I have fired this up without success. I have measured some voltages on the circuit attachment. Fets are IDss 6.5mA What do you think? I have only fed signal from my cartridge as i dont have anything with such a low output. If the dc readings look ok i might make up a divider from the cd ouput as the next step.
cheers
Craig
I have fired this up without success. I have measured some voltages on the circuit attachment. Fets are IDss 6.5mA What do you think? I have only fed signal from my cartridge as i dont have anything with such a low output. If the dc readings look ok i might make up a divider from the cd ouput as the next step.
cheers
Craig
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Thanks Salas i'm embarrassed to have them in the wrong way.
After reversing I still can't get any sound through either of the amps though.
I used different fets this time matched at 8.5 mA IDss is this ok?.
This is a question on my skills with so few parts!!!
Does the 5.95v measured at the drains seem ok?
Measuring output resistance gave 224k input resistance was as per loading value.
Are the two fets in parallel to reduce the noise?
I made them on perf board so i will check the layout again.
Thanks for your assistance
After reversing I still can't get any sound through either of the amps though.
I used different fets this time matched at 8.5 mA IDss is this ok?.
This is a question on my skills with so few parts!!!
Does the 5.95v measured at the drains seem ok?
Measuring output resistance gave 224k input resistance was as per loading value.
Are the two fets in parallel to reduce the noise?
I made them on perf board so i will check the layout again.
Thanks for your assistance
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The voltage drops look logical. Would expect more but they still drop. Yes, paralleling is for less noise. It has been tried out recently with success by a member in the simplistic phono thread also. Maybe you can cooperate a bit for debugging?
http://www.diyaudio.com/forums/analogue-source/129126-simplistic-njfet-riaa-635.html#post2584529
http://www.diyaudio.com/forums/analogue-source/129126-simplistic-njfet-riaa-635.html#post2584529
Hi Salas, thanks for referring to that post, Hi Batty, hope's your simplistic will sing very soon & will you allow me to update my simplistic here?, seems this is a more appropriate thread, and not many people doing this type of simplistic recently