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Old 19th April 2010, 09:14 PM   #3591
Salas is online now Salas  Greece
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Yes.
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Old 19th April 2010, 09:33 PM   #3592
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Tomorrow I will do the measurements & I will let you know, thanks again for your kind patience with me.
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Old 20th April 2010, 07:51 AM   #3593
vgeorge is offline vgeorge  Greece
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As I am almost finished collecting parts for my second Riaa buit, got a little confused regarding R3 value. I am going to built the 56db version for my Sheleter 901 and R3 is stated as 43K, however doing my calculations here, http://www.kabusa.com/riaa.htm I think I should have a 47k R3 for the following values:
R3 = 43,06 and 42,95 takman carbon
R4 = 6,829k and 6,835k shinkoh
c2 = 47,05n and 47,01n Obligato // silver mica
c3 = 16,009 and 16,013 Russian silver mica // silver mica
(C2 and C3 can be adjusted to lower values)

Also thinking to try for C4 a Hovland instead of the usual FT-3(I have both, what do you think?
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Old 20th April 2010, 09:59 AM   #3594
RCruz is offline RCruz  Switzerland
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Hi vgeorge

You can not input Salas riaa values directly into kabusa.

Salas calculates the values by simulating the whole circuit.

Let me know R1 and R5 real values and I will see if you need any adjustments

What type of cap is the hovland ?
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Old 20th April 2010, 10:09 AM   #3595
vgeorge is offline vgeorge  Greece
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Hovland is this one: Hovland Company: Products: MusiCap Capacitors
They have good reviews usually.

R1 = 6,175k and 6,180k shinkoh
R5 = 1,009M and 1,010M Takman carbon

Thanks.
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Old 20th April 2010, 02:37 PM   #3596
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Some general rules IMHO about caps:

Best dielectic: 1st air, 2nd teflon & after the rest of materials.

Best kind: 1st foil, 2nd metallized.

Best conductors: 1st silver, 2nd copper.

Better take always the cap higher VDC rated, thicker dielectric & thicker conductors so less resistance & better spread.

I owned some Hovlands, are very good caps polypropylene film & aluminum foil, so very similar to Obbigatos that are also polypropylene film & aluminum foil, if same kind of materials choose if possible the higher VDC rated.

For C2 better use silver mica as suggested Salas

Last edited by merlin el mago; 20th April 2010 at 02:40 PM.
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Old 20th April 2010, 02:46 PM   #3597
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Default Test record measurements

I am really surprised, with DVM in ACmV mode Side One trck, 3,4 & 5 & Side Two track 5 always the DVM is changing the reading & not fixed AC voltage is measured
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Old 20th April 2010, 04:07 PM   #3598
Salas is online now Salas  Greece
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Can't keep relatively steady on 300Hz second side even? Try 2V AC scale.
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Old 20th April 2010, 06:47 PM   #3599
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DVM minimum AC scale is 200~V
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Old 20th April 2010, 06:50 PM   #3600
Salas is online now Salas  Greece
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Your DVM should be capable of measuring AC over some decent bandwidth and have some scale steps. Anyway does it show something at 200VAC scale when connected on outputs as you play the special tracks?
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