Simplistic NJFET RIAA

[The Space Egg Corp]

I got 'lucky'...
...measured my RIAA's today...
...and got a bunch at 47.1/2n & a bunch at 15.4/6n...
...ordered the interstage from the 'old' schematic, by mistake ( dahggg ! )...
...oh well...is 100n NOT 47n...
...should be OK I guess ??

Cheers

Si.

[The Space Egg Corp]

Saw a funny listing on eBay...
it said :-

Ex-Soviet Military guitar-tone capacitors, for THAT 'Woman' tone.

Strange; I didn't think the USSR Army normaly issued any Epiphone Casino's !

Si.

[Salas]

Originally Posted by The Space Egg Corp

I got 'lucky'...
...measured my RIAA's today...
...and got a bunch at 47.1/2n & a bunch at 15.4/6n...
...ordered the interstage from the 'old' schematic, by mistake ( dahggg ! )...
...oh well...is 100n NOT 47n...
...should be OK I guess ??

Cheers

Si.

What old schematic, and which one you got in mind to do?

[luxury54]

sorry for bumping in this thread with my question but I downloaded the schematic of the RIAA stage and seems to me very tempting to try out;
however, I would also like to try it with my R2R tape deck as a play preamp and since I heard that the RIAA filter stage doesn't differ too much from the NAB filter stage used for 19cm/s tapes, I wonder if someone would know how to change the filter values of the RIAA equalization so that I'll be able to use it as a repro preamp also using NAB equalization standard?

Thanks

[atupi]

What would better for interstage cap: FT-1 0.022uf 2 pcs paraleled or a single FT-3 0.1uf ?

[RCruz]

Originally Posted by atupi

What would better for interstage cap: FT-1 0.022uf 2 pcs paraleled or a single FT-3 0.1uf ?

I would use a single 0.1 FT-3

[RCruz]

Originally Posted by Salas

How much VDC from 1K4's right side to capacitor and ground?

23.8V

[Salas]

If its about 10.5V across the lower buffer JFET, make it 1.8K so to drop about equal across the upper one. Not that is a real problem, but more elegant having the same dissipation.

[Salas]

Originally Posted by atupi

What would better for interstage cap: FT-1 0.022uf 2 pcs paraleled or a single FT-3 0.1uf ?

Single cap is more coherent, but if you have big bass reflex speakers and a bit light turntable maybe the lower value can cut more unwanted feedback energy. Evaluate.

[Salas]

Originally Posted by luxury54

sorry for bumping in this thread with my question but I downloaded the schematic of the RIAA stage and seems to me very tempting to try out;
however, I would also like to try it with my R2R tape deck as a play preamp and since I heard that the RIAA filter stage doesn't differ too much from the NAB filter stage used for 19cm/s tapes, I wonder if someone would know how to change the filter values of the RIAA equalization so that I'll be able to use it as a repro preamp also using NAB equalization standard?

Thanks

Preamp for reel-to-reel