I built the phono stage on perfboard and I didn't have a PSU available so I used Alkaline batteries for a couple months.
Built the shunts and psu and listened. It was better. I don't think it was a case of expectation bias. I actually thought the batteries would sound better but I hate all the monitoring of voltages.
Certainly not a scientific test or A/B test.
On the other hand, I have tested batteries vs lm317 in the MC step up circuit. This was a true A/B test, dual mono batteries vs single lm317. Batteries won.
Built the shunts and psu and listened. It was better. I don't think it was a case of expectation bias. I actually thought the batteries would sound better but I hate all the monitoring of voltages.
Certainly not a scientific test or A/B test.
On the other hand, I have tested batteries vs lm317 in the MC step up circuit. This was a true A/B test, dual mono batteries vs single lm317. Batteries won.
Nice ; thanks for all the details.
Battery sounds as headache as well. considering the nice shunts Salas nicely spelled out for us 🙂
Hi, Salas I kindly ask how many volts I should set a simple power supply with the lm317, precise which circuit I built on a handmade pcb.Regards
August 2013 issue is the FSP document. For that one in most cases you must have B+ adjust range between 30V to about 34V. Its not absolutely fixed B+ spec since it helps adjusting the rail level for the test points correct indication. Because the JFETS differ somewhat in IDSS from build to build.
How to build it for MM gain or other gain says the guide in the paragraph "sensitivity" on page six.
How to build it for MM gain or other gain says the guide in the paragraph "sensitivity" on page six.
Hi Salas,
I am starting the fs build, been sitting here for to lang already.
I measured the 117's idss from the kit.
i have:
3.8 mA
4.3 mA
5.02 mA
5.3 mA
5.41 mA
5.52 mA
5.55 mA
5.72 mA
5.9 mA
6.25 mA
Could you tell me what the best locations for these are?
Also i am going to use it for a benz Ace M, i guess the load resistors in the build guide are good?
regards,
John
I am starting the fs build, been sitting here for to lang already.
I measured the 117's idss from the kit.
i have:
3.8 mA
4.3 mA
5.02 mA
5.3 mA
5.41 mA
5.52 mA
5.55 mA
5.72 mA
5.9 mA
6.25 mA
Could you tell me what the best locations for these are?
Also i am going to use it for a benz Ace M, i guess the load resistors in the build guide are good?
regards,
John
ACE M wants >240Ω and we have combinations from 100Ω up to 1k there already. Νο problem.
Use 5.52 & 5.55 for Q7s
5.02 & 5.3 as Q3xs
3.8 & 4.3 as Q5xs
5.72 & 5.9 as Q2x but with 47 Ohm R6x
Use 5.52 & 5.55 for Q7s
5.02 & 5.3 as Q3xs
3.8 & 4.3 as Q5xs
5.72 & 5.9 as Q2x but with 47 Ohm R6x
Thanks,
is it a problem to have the 3.8 & 4.3 as Q5xs so badly matched?
or should i buy some more and get a better pair?
regards,
John
is it a problem to have the 3.8 & 4.3 as Q5xs so badly matched?
or should i buy some more and get a better pair?
regards,
John
They are close enough for that place. They create bias for the error amp BJT in the same order. Doesn't need to be exactly the same because it doesn't differentiate its parameters enough at that tolerance. Its good enough they are low Idss and they won't be creating much dissipation on it as it has high voltage across.
i have 2 2sa970bl of 401 and 399 hfe
i have 2 bc560c of 595 and 596 hfe
what is better to use for q3y/z?
regards,
John
i have 2 bc560c of 595 and 596 hfe
what is better to use for q3y/z?
regards,
John
Looks like a good gain choice for that cartridge. The guide says 6.8R for 13mA IDSS and 9.1R for 14mA. Yours is 13.39mA so put a 8.2R I would say.