chipamp lm4780 components

[garbage]

hi all

according to the chipamp lm4780 kit, the parts are as follows:

LM4780 Dual Mono Kit Contents
1 PCB set, consisting of 2 amplifier and 2 rectifier boards.
2 LM4780
6 22 kohm 0.5w compact metal film resistors
4 2 kohm 0.5w compact metal film resistors
4 680 ohm 0.5w compact metal film resistors
2 10 kohm 0.5w compact metal film resistors (mute)
4 0.1 ohm 3w Dale LVR3 power resistors (output)
4 2.7 ohm 2w Panasonic metal film resistors (zobel)
4 0.1 uf BC polypropylene cap (zobel)
4 1500 uF 50v Panasonic FC Capacitors
16 MUR860 On Semiconductor Diodes
4 10 uF Panasonic FC Capacitors

but on the pcb i'm not sure which goes where as there is no documentation yet.

can someone confirm the below?

i gather the following information from other threads:
R1 = 22k (feedback resistors)
R2 = 22k (feedback resistors)
R3 = 1k or 680R (for more gain)
R4 = 22k
R5 = 1k or 680R (for more gain)
R6 = 1k or 220R (series input resistors)
R7 = 1k or 220R (series input resistors)
R8 = 0.1R (output)
R9 = 0.1R (output)
Cz1 and Cz2 seems to be the zobel cap.
the holes parallel to Cz1 and Cz2 seems to be the zobel resistors.
C1 and C2 are the 10uF bypass caps or BG 4.7uF N caps.

thanks
garbage

btw, i've got my boards.

An externally hosted image should be here but it was not working when we last tested it.

 

[garbage]

0R1 accuracy?

have you guys measured the value of the 0R1 resistor?
i measured mine and got fluctuating readings from 0R to 0R8!!

these are the cheap coffin type resistors.

An externally hosted image should be here but it was not working when we last tested it.

 

[tiroth]

You can't measure such low impedances with a standard multimeter. You should run a known current through it and measure the voltage instead.

 

[carlosfm]

You can't measure such low impedances with a standard multimeter.

You can do it with a "standard" analog multimeter.

 

[tiroth]

What is this "analog" you speak of, good sir?

 

[carlosfm]

What is this "analog" you speak of, good sir?

Something like this:
http://www.gmc-instruments.com/english/produkte/metrahit1a.htm

 

[tiroth]

I was just joking

 

[wim]

Forget it Carlosfm, you can't measure such low resistances acurate with a standard multimeter (digital or analog) , only with very expensive multimeters, special mili-ohm meters or the methode posted by trioth.

Please escuse my bad knowlegde of this language.

 

[carlosfm]

I was just joking

I know.

Forget it Carlosfm, you can't measure such low resistances acurate with a standard multimeter (digital or analog) , only with very expensive multimeters, special mili-ohm meters or the methode posted by trioth.

You can.
It's one of the only things that make me sometimes use my old analog multimeter.
Check the link I posted, you can see this feature:

"Resistance measurement: 1 Ohm .. 1 MOhm (4 ranges)"

It just measures to 1MOhm, while my DMM measures to 200MOhm.
But it's in the low end of the scale that analog MM has it's advantages.

 

[wim]

carlosfm, for what i read in the documentation, resistance-measurements are with intern battery from 1,5 DC Volt.

Measuring 0,1 Ohm (thats what the post form Garbage is about) : I = 1,5V/0,1 Ohm = 15A!!! P= 22,5W!!!

The documentation says max. current for measure Ohms is 83 mA.

Or didn't i read the documentation well (possible, becouse i am a Dutch speaking person with only little knowledge of other languages, sorry for that)


Please your opinion??

 

[garbage]

thanks guys for your responses.

looks like i'll have to measure with a known current like tiroth suggested.

 

[soundNERD]

I'm going to have to agree with CarlosFM

My cheapo $5 digital multimeter always works fine, though I have to figure roughly 2ohms below what it says because of the resistance of the cables/ bananna plugs and alligator clips.

May not be precise enough for that though, but it does measure it. and the lack of preciseness is due to my homemade cables (I don't like the type you have to touch and hold to the wire since that uses two hands. The same two hands needed to use the fire extinguisher

 

[carlosfm]

On a (even cheap) analog multimeter you adjust for 0 ohms.