Simplistic NJFET RIAA

Thanks Salas. Yes I used the same recording setup - the on-board input on my PC's motherboard - nothing special. I'm waiting on some 300R and 400R Takman's for the load - apparently the cartridge is happiest at somewhere around that, I am currently using Welwyn RC55 100R. The PC recording does lose quite alot of dynamics and detail, but gives you an idea of what it sounds like, the seperation and dynamics are superb. It betters the modified RB251 I was using by quite a margin.

It wasn't as expensive as it sounds - the arm was around £250 in kit form and the cartridge was second hand at £600. I got promoted at work so the cartridge was my reward :)
 

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diyAudio Chief Moderator
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Thanks Salas. Yes I used the same recording setup - the on-board input on my PC's motherboard - nothing special. I'm waiting on some 300R and 400R Takman's for the load - apparently the cartridge is happiest at somewhere around that, I am currently using Welwyn RC55 100R. The PC recording does lose quite alot of dynamics and detail, but gives you an idea of what it sounds like, the seperation and dynamics are superb. It betters the modified RB251 I was using by quite a margin.

It wasn't as expensive as it sounds - the arm was around £250 in kit form and the cartridge was second hand at £600. I got promoted at work so the cartridge was my reward :)

Congratulations for your promotion. I have listened to your older files and you can achieve quite a range of balances, so yes, see with VTF, VTA, and loading to center it well. Although the transfer and replay on our PCs is not what you get from your speakers in your room, you could be offsetting factors we are not aware of, the files you posted are different enough between various set ups, giving an idea.
 
Is the balance just a little bit off center?
From the visualisations, it is really rolled off sharp on the high end.
I have only listened to Adele, but nice rig

I noticed that with the Adele recording. The Supertramp recording is better IMO, I see plenty of high frequencies in that recording. That is from a Speakers Corner pressing which sounds excellent to my ears.

The only issue is that I'm not far off overloading the line-in on my PC, there is a bit of distortion in the bass which isn't there listening direct.

My KEF 103/4's have very clean/tight bass so a touch more warmth at the low-end isn't unwelcome. The first thing I noticed with this Dynavector was how much more bass it produces than my other cartridges.
 
Preliminary RIAA layout

Hi Folks-

All my parts have arrived so I've started my RIAA board layout, attached. 3" x 4.5" (76mm x 114mm). Expand to see the grid (which is at 0.1" spacing).

As in the shunt layout, I tried to minimize connection length, which is a challenge with such large parts in the RIAA. But I believe it is a good, compact compromise. C1 & 2 Tex-Cap teflon; C3 is an FT-3. C7 is generic size (1" x 2.1") and should accommodate most caps. I caved in and got the precision Texas Components resistors for the RIAA. Shinkoh for R load; the rest are PRP.

The ground rail snakes around a little bit; ~5" in length. Some of the tracks are longer that I had hoped. But for the RIAA it should be OK?

I'd appreciate any feedback!

Thank you & Cheers- Kent
 

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diyAudio Chief Moderator
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As long as it is compact and there are no ground loops, don't worry. Separate encasement for transformer and rectification/main cap filter is a must. No AC low or hi power cabling entering the phono box in other words. Your chosen parts quality is proven for this CCT. Good luck finishing it, and we will be waiting for your photo report.
 
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I'll give Simplistic a try too.

My Goldring 1012gx has a sensitivity of 6.5mV. Thus a 37 db version for me, right?

The R-core I need is 28V (which is not that easy to find?) then. The load values stated by manufacture are 47,000 Ohm and 150-200pF. So the Rload should be 47K, but what about Cload?
 
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Thanks. Planning to put it in a separate box as advised. Together with SSLV1.1, most probably. But I've seen your build where double filtering was applied, and SSLV was in a same box. IS that correct?

OT. If anybody cares, selectronic gives 20% discount if you enter "2011" as a code. Until midnight only.
 
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Correct, me I am no perfectionist when building for myself. In roomy box you can compromise some little 50Hz spike from just the tacked away mains cable entering, and secondary wires. The R-Core itself behaves. No compromise is still two boxes.
 
riaa layout test

I've been checking my layout, attached. 3x4.5", nice and compact. Using turrets for easy soldering/unsoldering. Big space on upper left for output C. The Tex-Cap's will need to be trimmed; trimmer caps will ride on top of the tex-caps.

I have a question about the RIAA 'lytic caps. I know this subject is rife with subjectivity. I have some Nichicon Muse and Elna Simlic II's for the 470uF's. Do either of these have better build quality and/or reliability? If you wish to comment on their subjective qualities as well, fine.

Thanks- Kent
 

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