I was having some trouble finding everything for the ARTA Box, and I was wondering if someone would be kind enough to check these parts before I buy them?
Specs:
http://www.artalabs.hr/AppNotes/AP1_MeasuringBox-Rev4Eng.pdf
Reference resistor 27 ohm/10W - 0.27 Ohm 10W Resistor Wire Wound 5% Tolerance 016-.27
All resistors are 1%
8k2 - 8.2K Ohm 1W Flameproof Resistor 10 Pcs. 003-8.2K
910 - 910K Ohm 1W Flameproof Resistor 10 Pcs. 003-910K
710 - KOA Speer 715 ohm 100ppm Thru-Hole Resistor Metal Film 1/4W 1% MF14D-F BULK (Bag of 100): Amazon.com: Industrial & Scientific ?
1K - 1K Ohm 1W Flameproof Resistor 10 Pcs. 003-1K
Zener diode 4.1V / 0.5W - ?
RCA jacks (red/black) - Gold RCA Jack Solder Type with Nut Pair 090-278
Dual binding posts (red and black) - Gold Banana Jack Pair 091-1160
DPDT 6A switch - DPDT Mini Toggle Switch 060-338
SPDT switch - SPDT Sub-Mini Toggle Switch 060-355
Specs:
http://www.artalabs.hr/AppNotes/AP1_MeasuringBox-Rev4Eng.pdf
Reference resistor 27 ohm/10W - 0.27 Ohm 10W Resistor Wire Wound 5% Tolerance 016-.27
All resistors are 1%
8k2 - 8.2K Ohm 1W Flameproof Resistor 10 Pcs. 003-8.2K
910 - 910K Ohm 1W Flameproof Resistor 10 Pcs. 003-910K
710 - KOA Speer 715 ohm 100ppm Thru-Hole Resistor Metal Film 1/4W 1% MF14D-F BULK (Bag of 100): Amazon.com: Industrial & Scientific ?
1K - 1K Ohm 1W Flameproof Resistor 10 Pcs. 003-1K
Zener diode 4.1V / 0.5W - ?
RCA jacks (red/black) - Gold RCA Jack Solder Type with Nut Pair 090-278
Dual binding posts (red and black) - Gold Banana Jack Pair 091-1160
DPDT 6A switch - DPDT Mini Toggle Switch 060-338
SPDT switch - SPDT Sub-Mini Toggle Switch 060-355
Digikey has everything
CMF55715R00FHEB Vishay Dale | CMF715HFCT-ND | DigiKey
RS and Farnell also have them
For zener 3.3-4.7V works, i would keep it lower...
The only thing that i do not understand is WHY 715 ohm, someone before had it handy/tried to match his sound card input and get round number for the gain (no sense).
Anyway someone made it more complicated for the crowd, 820ohm- 1K will do!
The accuracy changes with input impedance of sound card used anyway and you have to calibrate that to be sure, then mic is off (in case of diy capsule) so you have to calibrate that with known calibrated mic...
The only purpose of that resistor is to protect input of the sound card in case you hook up something crazy to that input by accident or you measure insane SPL so your MIC preamp swings over 10V-+ (so diodes can clip, the input and not fry diodes and SC input in case the resistor is not there)...
All values are flexible you are going to have to do all the calibrations anyway...
Also about the 27ohm/10W, how bout using something smaller?
Other use 1Kohm which is in my opinion too high, output impedance of an amplfier driving the speaker will be closer up to the 1 ohm (in case of tubes, way below for solid state), and typical (realistic) loudspeaker currents used will be much higher.
I know that derived voltage in that case will be small and noise higher so i am greeting 27 ohm in Arta box, but will explore lower values (ESP labs uses 10 ohms for me initially 5.6/2W worked fine), and "small" current values, im going to try to measure most comon current used for typical audio reproduction (1W on speaker?) ...
Also using 10W res is overkill unless you're pumping way more loudness to measure T/S 2W will do...
CMF55715R00FHEB Vishay Dale | CMF715HFCT-ND | DigiKey
RS and Farnell also have them
For zener 3.3-4.7V works, i would keep it lower...
The only thing that i do not understand is WHY 715 ohm, someone before had it handy/tried to match his sound card input and get round number for the gain (no sense).
Anyway someone made it more complicated for the crowd, 820ohm- 1K will do!
The accuracy changes with input impedance of sound card used anyway and you have to calibrate that to be sure, then mic is off (in case of diy capsule) so you have to calibrate that with known calibrated mic...
The only purpose of that resistor is to protect input of the sound card in case you hook up something crazy to that input by accident or you measure insane SPL so your MIC preamp swings over 10V-+ (so diodes can clip, the input and not fry diodes and SC input in case the resistor is not there)...
All values are flexible you are going to have to do all the calibrations anyway...
Also about the 27ohm/10W, how bout using something smaller?
Other use 1Kohm which is in my opinion too high, output impedance of an amplfier driving the speaker will be closer up to the 1 ohm (in case of tubes, way below for solid state), and typical (realistic) loudspeaker currents used will be much higher.
I know that derived voltage in that case will be small and noise higher so i am greeting 27 ohm in Arta box, but will explore lower values (ESP labs uses 10 ohms for me initially 5.6/2W worked fine), and "small" current values, im going to try to measure most comon current used for typical audio reproduction (1W on speaker?) ...
Also using 10W res is overkill unless you're pumping way more loudness to measure T/S 2W will do...
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Is it supposed to be 27 Ohms or 0.27 Ohms?
Is it 910 Ohms or 910k Ohms?
Are you wanting qty 100 of the 710 Ohm ones?
I used to buy everything I could from either mouser.com or digikey.com (in that order).
Tip: Also definitely order their HUGE paper catalogs, which should be free. They can be extremely handy.
[Tree huggers need not flame me again, about saving paper or trees. You are all idiots, anyway. On second thought, please do respond, so I will know who the idiots are. (I dare you!)]
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