Simplistic NJFET RIAA

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Ricardo, why you will need all this component swapping freedom again after all those auditions? I mean, when Kent shows the PCBs you know what to use by now. Or you want to be changing in the future because of rest of the system changes and fitting again tunings?
 
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Ricardo,

For the time being, I suggest you get a simple perfboard like Nicoch says, and start getting used to P2P with the components you got. It will be nice practice. Don't be afraid. Prototyping it is, that is why they are called proto boards. And remember, less soldering points, components use their legs directly together, size changes can be accommodated easier. To tell you the truth, if the grounding is right, it always sounds cleaner enough than any PCB, maybe Teflon PCBs are near. OK there are things that don't lend for P2P, like digital stuff, way too complex, 200 leg ICs including, need certain decoupling smt components, certain trace dimensions and geometry, or complex high gain, high NFB analogue, but this RIAA is no rocket science. Its ''Simplistic''. Nice opportunity to get your feet wet.;)

Also it can look nice if made with nice symmetry. This reg was made by member Stixx for instance. He has shown it on my HV shunt thread. Is it ugly?
 

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Hi Salas

No.. it is not ugly at all.

As a matter of fact, my decision to use ready made pcb´s is recent... All the psu´s inside the CDP (and some sregs) are p2p. I use perfboard from velleman with "roads" of copper... not very good.

I will try the tinned ones.

Could you please post a pic of the underside of a p2p riaa ?
I learn a lot only by studying the soldering technics.

JFYI.... Took a while to settle but now the riaa is sounding big, clear and very dynamic. (The CDP can not compete with this soundstage and dynamics)

Ricardo
 
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Re: Russian 47nF cap size

kstlfido said:


Hi Ricardo (or anybody else)-

When you get the 47nF caps, could you post dimensions? I would like to allow for larger (within reason) components on the PCB.
Hi Kent

Today I received the K72P-6 0.047u Teflon caps.

These are uge (7cm form contact to contact) and 23mm diameter.

I do not believe I can place them in my actual riaa :eek: unless I use long leads (3~4cm)... Should I do it ?

Ricardo
 
Crickey! That thing IS huge! Longer than the 100n FT-3's!! I will probably not make space for that.

But, yes, I would assume you could stand it on one end and use a long lead. Hope they are not too heavy and apply force to the little copper traces. I would *think* sanding them on one end would be OK. Just don't wiggle it around too much! :D

I have had no time here and will not be able to get to the PCB design until next week. Tax time here in US, got to get my books prepared.

-Kent
 
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Just received some 680uFBGNx35v from Canada. the guys from FedEx asked me more money for the delivery and customs than the already high cost of the caps. And I already had payed for their services in the original invoice. It was my first and maybe my last order from overseas...:mad:

But I got a reward in the end... I replaced the 470uF 50v BG Std in the shunt output by one of the red caps and.....:violin: :hphones: :eguitar: :violin:

It seems the shunt marries perfectly with the BGNx.... wonderfull powerfull detailed bass and sweet trebble just five minutes after turn on.... imagine what it will be like in two weeks or a month.

Ricardo

PS:
Here is my first draft of the riaa.... Please guive me your comment and advise.... (It will be used for p2p).
 

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It is a very low noise cap.

I noticed an important reduction in noise. That brings out detail. I had the same feeling when I installed the geddon on the TT.... lower noise floor.... much more detail.

Ricardo

PS
When you have time, please comment on the drawing... I must be sure there are now flaws this time.