V check
Having a stash of V is better to be put in good use. If you can find some circa 15mA to match then you can make your phono in better input noise and interstage drive current. The RIAA values are slightly changed to be adapted and you will not need the 1Meg shunt resistor to R4 also.
For the RIAA - it is going to the 57db for my Shelter 901 - I have already matched some 170 BL at about 8.5mA, but I also have a stash of V's. I will measure some and see how many I can match.
Also waiting some teflon capacitors from the states.
Having a stash of V is better to be put in good use. If you can find some circa 15mA to match then you can make your phono in better input noise and interstage drive current. The RIAA values are slightly changed to be adapted and you will not need the 1Meg shunt resistor to R4 also.
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nicoch46,
I tried choke input, but got lower voltage with not enough margin to regulate for the shunt. I may put a small resistor after the diodes though.
George, try a small film cap (1-5 uF, what's handy) after the diodes instead.
That should be what nicoch intended when he mentioned you can try choke input or semi...
George, try a small film cap (1-5 uF, what's handy) after the diodes instead.
That should be what nicoch intended when he mentioned you can try choke input or semi...
I will do when I finish the rest of the RIAA. Now, I put a small resistor in front.
I would be fun to see if I can tell the diffence.
I know, and it helps small Xfrm too (not George's case anyway). It avoid too much stress to the choke and often helps to rise the voltage a bit.this caps is used to adjust the Vdc out or lower the buzz from cheap choke
Thanks for the advise Salas.
With V's it' s difficult to find matches, especially at 15ma. There are more at 11-13ma.
I have to buy now some resistor values that I' missing to complete the build.
This time I' m not going to use trimmers for the source resistors, and hope everything is going to be fine.
With V's it' s difficult to find matches, especially at 15ma. There are more at 11-13ma.
I have to buy now some resistor values that I' missing to complete the build.
This time I' m not going to use trimmers for the source resistors, and hope everything is going to be fine.
Franz was once saying the same and his V were stronger in the end... Double check the conditions. Are you using straight current mode DMM measuring and a 9V battery, or you add a resistor in series also, then you translate voltage drop? It can be dropping enough with V and changing the VDS passing lower IDSS.
Franz was once saying the same and his V were stronger in the end... Double check the conditions. Are you using straight current mode DMM measuring and a 9V battery, or you add a resistor in series also, then you translate voltage drop? It can be dropping enough with V and changing the VDS passing lower IDSS.
I am measuring with a staight current mode DMM and a 9v battery. I tested few again with a fresh battery and matching is the same, only absolute value is around 0.20mA more. Should I test all of them again? As I understand, this is the recommended method.
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