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Old 17th February 2009, 09:28 PM   #1041
RCruz is offline RCruz  Switzerland
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Well..... I am runing it at 12 oclock now but with the tremendous improvement in dynamics, I believe I can push it much higher without stress..... For now I am just listening ... openning nicely.. still some harshness in the highs.... (Mundorfs probably)... nevertheless, as is it is already a superb Riaa.

Ricardo
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Old 17th February 2009, 10:15 PM   #1042
Salas is offline Salas  Greece
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Not sure before it will burn for about 50 hours, but your big brown cap can get a further 300pF mica in parallel if you will still feel that your sound is a bit stronger in between 10kHz-20kHz.

Edit: You can also bypass the Mundorf with a 47nF K-40 if some harshness proves to be related to that capacitor.
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Old 18th February 2009, 08:41 AM   #1043
RCruz is offline RCruz  Switzerland
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Hi Salas

Do you mean I can add 300p to the 15.7 nF on the Riaa filter?

Ricardo
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Old 18th February 2009, 09:02 AM   #1044
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Quote:
Originally posted by nicoch46
HI kent my suggestion is to order two optvol if you want tray the lightspeed, fom me better use the series element as normal resistor ,and play with brand for fine tweak ...

you can tray for we?
Hi nicoh46-

I have already ordered matched LDR's from a chap offering them on the thread. I liked the shunt-series ldr approach. Also, maximus on that thread has a chip based controller (with IR remote capability) design and will be producing boards for sale.

Cheers- Kent
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Old 18th February 2009, 10:51 AM   #1045
Salas is offline Salas  Greece
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Quote:
Originally posted by RCruz
Hi Salas

Do you mean I can add 300p to the 15.7 nF on the Riaa filter?

Ricardo
Yes, exactly.
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Old 18th February 2009, 06:54 PM   #1046
RCruz is offline RCruz  Switzerland
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Hi Salas
Now the sound of the Riaa is really impressive.

Comparing it with the stock MM Riaa in the 101, the timbre of the instruments and the subjective frequency response seem very similar (meaning that I lost nothing).

But the comparison stops there.... Your design is faster, much more detailed and a lot more dynamic.

The distortion is lower and the schunt + Riaa is very silent in comparison.

All this after 48 hours and based on some low quality components. Now I will fine tune starting with the resistors, case, cabling and connectors.

Regarding the cable, The last pics you posted (dual mono psu) has a nice red coax... where can I get it ?

I found some silver plated copper screened wire:
Two types available. 7/0.2 - signal wire is 7 strands of 0.2mm dia. amd 19/0.2 - signal wire is 19 strands of 0.15mm dia. Overall diameter for 7/0.2 is 2.3mm and for the 19/0.15 is 2.7mm

What should I choose ???

Thank you for the wonderfull design and unconditional support.

Ricardo
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Old 18th February 2009, 08:39 PM   #1047
Salas is offline Salas  Greece
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Thanks. Google for Shinkoh resistors and Mogami coaxial cable. The tantalum resistors were found online from a UK store and the Mogami coax was found locally. Avoid any silver plating and keep the coax small in diameter IMHO.
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Old 18th February 2009, 09:58 PM   #1048
RCruz is offline RCruz  Switzerland
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Thank you so much Salas.
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Old 19th February 2009, 06:48 PM   #1049
RCruz is offline RCruz  Switzerland
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Hi Salas

Now the sound is really opening with uge dynamics. It is a total success but needs some tuning.

I notice some forwardness in the mid/high frequencies so I will try to bypass the 15.7n cap. Can I use 330 pF ?

Ricardo
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Old 19th February 2009, 09:36 PM   #1050
Salas is offline Salas  Greece
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Yes, it is suitable. It will drop the last octave a bit.
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