one more meta42 question
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mekanoplastik

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hi there....

im new here and i have a meta42 question....mmhuahua..yes.i am the nightmare newby who has no clue of electronics and barely writes English but loves to ask..



well.. here I go.,,.after lots of reading and much trying to understand the components for the meta42 I have came up with this... and some questions

Buffers: Intersil HA5002

C1: Solen poliprop 1 µF @ 250 V
C2,C3: 4* panasonic 820uF 16v (12mm)
C4: Wima MKS2 10uF/16V

V. Gnd: no

OpAmp: AD8620

R1: 1k
R2: 200k
R3,R7,R9: 47.5k
R4,R5: 475k
R6: 47.5k
R8: Jumpered

Wiring using cat5 wire.

the resistors values and everything else are based on opinions I gathered from forums and I assumed they were ok…

The power supply I will use is a 20$ 16VDC/1.56A regulated. (It works with 220v and 120v and I need that feature)

The potentiometer will be the cheap pana unless you guys say it is not mach for such a great and smart selection of components.


last one….. what are the Q’s on the boars??? do I need them to improve the sound??

I plan to use this amp with my d-303 and alessandros ms1 (I don’t have the ms1 yet but…I like planning ahead..) and I have the premonition that they will make a nice setup

Well..this is all from now ..thank you very much
 
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tangent

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Quote:

Buffers: Intersil HA5002


You're not going to be building on the META42 printed circuit board, then, unless you build some kind of adapter. The PCB only works with the Elantec buffers. If you're going to build on protoboard, then of course you can use any buffer you want.

Quote:

V. Gnd: no


I have no idea what you mean by this. Since you're using a single-voltage power supply, I should think "virtual ground = yes".

Quote:

R2: 200k


Are you using a 20K pot? If not, make R2 10x the pot's resistance, as the META42 article says to do. The only reason to use a low resistance on R2 is if you're using a bipolar-input op-amp and high resistances would cause problems. The AD8620 is FET-input, so you can use up to 1M here without even a slight worry.

Quote:

R7,R9: 47.5k


47.5 ohms, surely, not 47.5Kohms.

And as I say in the article, R8 and R9 are there to solve problems. If you populate them before you know you have a problem, you can get an amp that doesn't work as good as it possibly can. I say, jumper both of these positions to begin with. If in testing you have hiss problems with low-impedance headphones, only then should you consider putting some resistance in either position.

Quote:

R5: 475k
R6: 47.5k


You either got that from someone who hasn't actually built a META42 or you've pieced together these resistor values from those used in two different amps. You can't take the R5 value from one working amp and R6 from a different working amp and assume that they will work together. R6 should be at least 80x higher than R5.

If you're piecing together these resistor values without knowing what you're doing, you need to either stop and just pick one complete set of resistor values chosen by someone who does know what they're doing, or read and re-read the META42 article until you do understand what all of the values do and how they interact.

Quote:

Wiring using cat5 wire.


Surely you mean you're going to strip off the jacket from a length of CAT-5 and use the individual wires within. When you say that you're going to use CAT-5 like that, it implies that you're using the entire assembly, like you would for making DIY interconnects. When you break it up into individual wires, it isn't CAT-5 any more.

Quote:

what are the Q’s on the boars???


Try again.
 
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