Simplistic NJFET RIAA

[Salas]

Very close results on second implementation. VR1 to max clockwise and VR2 close to max clockwise. tp1-2 variations around 5 mV.

Your super close attention to match everything helped. The rest will be ambient temp delta when boxed up.

 

[Salas]

369 is Q1, first amplification fet.

Getting crowded. Choosed a 15 ppm 3 W ww for R13

That 15ppm R13 is a main reason you got very low drift TP. But high MC version is naturally less susceptible due to higher Rs anyway.

 

[Salas]

P.S. I hope those NOS like, red-brown C2x in the regs termination Zobel aren't MKT.

 

[stajo]

P.S. I hope those NOS like, red-brown C2x in the regs termination Zobel aren't MKT.

Nope. Panasonic 250 V polyproppers. Quite common in modern switching stuffz.

Boxing taking shape. Oii, I found this bunch of Epcos 25 V 10 mF 0.035 Ω ESR but they were to biggy 30 mm dia. Had been perf on the DCB1

I also now know that I can cut a fin or two on the Q1x:es. The were hardly lukewarm and I can get the boards closer.

 

[stajo]

P.S. I hope those NOS like, red-brown C2x in the regs termination Zobel aren't MKT.

PS. Dont you like MKTs? I love them, especially in filters and would not hesitate to test them in a riaa comp.

 

[Marra]

It looks to be coming along nicely.

 

[stajo]

It looks to be coming along nicely.

Yea thanx. Light blue is not my colour any day of the week but they sure soak the space. Had the worst workday so I feel like emptying a sixpack or 3 but maybe I plug it in for some disco later, we'll see

 

[Salas]

PS. Dont you like MKTs? I love them, especially in filters and would not hesitate to test them in a riaa comp.

More THD. Maybe complementary in some tube circuits.

 

[stajo]

More THD

Some nice THD in the mid is partyblasters.

https://www.youtube.com/watch?v=2s4slliAtQU;)

Should I just cut those candy cable RCAs?

 

[Salas]

Its your vintage TT. Me I would just deoxidize them and keep it original.

 

[stajo]

Hmm ok. So what do I replace them with? 50 ohm coax or tp's? I hate RCA

 

[Salas]

Something coax per channel with excellent shielding, flexibility, and no more than 100pF/m.

 

[stajo]

I have some Belden 75 ohm 56 pF/m. Would that do? http://www.belden.com/techdatas/metric/89259.pdf

 

[Salas]

Yeah, if 5mm diam video cable does not feel too chunky for you in the particular installation.

 

[Salas]

Those things usually go directly to the tonearm though and you got to check if there is same give if a suspension is involved, space to route etc. Investigate before break.

 

[stajo]

Thanks. Was just thinking of playing some punkrock before bedtime but now I'm to tired to do anything but watching 3 episodes of Time Team in a row.

So what cable to buy?

 

[stajo]

Forgot to upload

 

[Salas]

Lucky, there is a board. If it is on a suspended subchassis don't change them, they look in good condition. Just wire the four pin XLR at the other end.

 

[LucasAdamson]

I know a lot of people with SL1210 turntables change the cables, considering them not up to the standard of the rest of the wonderful deck. I used to love my SL1200. The arm is good too. I'm on a DIY Lenco these days though, with a terminator style linear tracker I've nearly finished.

 

[LucasAdamson]

This stuff is cheap and <97 pF/m, made from ultra pure long crystal oxygen free copper by the world leading professional cable manufacturer. It's all the good stuff without the snake oil.

Van Damme - Specifications - UP-LCOFC Hi-Fi Interconnect & speaker series