Ultrasimple mm/mc RIAA preamp 2

[Salas]

For BL, the finger touch ain't that critical, nor the warm up, because they have an almost zero tempco. The GR are very sensitive, but I don't think they are really around lately, nor preferable.
Just let your mA meter stabilize. The BLs are gonna rise the reading a little and then settle in a couple of minutes.

[RCruz]

Originally posted by salas
For BL, the finger touch ain't that critical, nor the warm up, because they have an almost zero tempco. The GR are very sensitive, but I don't think they are really around lately, nor preferable.
Just let your mA meter stabilize. The BLs are gonna rise the reading a little and then settle in a couple of minutes.

Thank you Salas

[jazzzman]

Thanks Nicoch46. Those PSUs look interesting (and not that expensive either). What would I use the pot for and how would I know if I needed it?

[nicoch58]

you have integrated amp or pre amp with pot?

my phono are connect to power amp and I put optivol between ...


Ps

Match: my 2sk170bl go up and down for more of 5minute....try your batch!

[jazzzman]

Nicoch46, I have an integrated amp with pot, so I guess I won't need the pot.

I also have a question regarding load capacitance.

I note in post 15 Mad_K mentions the need to have the proper load capacitance. (I can't figure out how you guys cut and paste prior posts in the thread.) Unfortunately, the information on my pickup is unavailable. But how do you change the load capacitance on the preamp? I would like to try a few configurations and see what sounds better.

[nicoch58]

You do not know if are MM or MC ?
MC 100r to 47k no caps
MM 47k try at last add 50-100pf polystyrene or silverMica
what input amp use ?

http://www.cartridgedb.com/

[jazzzman]

Thanks, mine is MM and according to your database it looks like it takes a 47k load. Exactly where do I put the additional capacitor, is it on the plus side of the input?

[nicoch58]

same as 47k , plus to ground .

madk have higth input caps for MM try without

but grab a MC denon dl160 or dl110.....

[jazzzman]

I am in the process of compiling the pieces to try this project and I am not sure about the power supply.

Can I use three 9volt batteries with a 24 volt regulator?
Would I put the 2200 cap between the batteries and regulator?

Also would I need a local bypass?
If so would I put one on the drain of each jfet?
What would be a good value for the bypass cap?
Thanks

[LucasAdamson]

Is there a kind electronics engineer out there that could me. I need to buy two matched pairs of 2SK170 GR (5mA) jfets, for use on an RIAA phono stage.

I can't seem to find them online, and would have a job matching them myself, so I thought I'd ask...

Many thanks
Lucas