Hello, yesterday I bought dual analog VU display and now I have no idea how to connect it. I have ABIT NF7-s (on board sound card) and I don't know how "strong" is left and right output (how many V) cuz I don't want to burn display This is what manuals of display say: 40mV = -10dB 80mV = -5dB 100mV = -3dB 140mV = -1dB 200mV = 0dB 330mV = +2dB Now mybe I didn't buy right display for PC but the idea is to look very cool (led or two should do it). So... do I need any resistors or I just plug it in Thanx for all help
This might help linkyou have to copy the shortcut into the address bar. Relace R2 with a pot, i think its 10K but im not too sure, better asking cpemma or someone.
Thanx for that but i really can't make it out whats the output V from L/R channel. Is it 12V? Dunno. (I'm kind a n00b at this) And I dont have V-meter. Btw. this is my VU meter:
Ahh ha, i have a similar VU meter but still havent got around to wiring it up The circuit i plan on using is this here. i think the outputs on the motherboard is about 1V peak, this circuit is just a simple non-inverting amp to drive the VU.
There's one bit of info missing, and that's the meter resistance, which ought to be somewhere in the manual. At a guess, the maximum output of the soundcard line will be around 1V, but some are as high as 2V. A simple potential divider system to get 330mV will probably badly affect sound quality, so unless you can come up with a meter resistance value, I'd try a 4k7 or 5k pot in series with each meter input (could use 1 stereo pot), with input from the line socket to one end, output to the meter from the wiper, and wire those to your stereo speaker jack in parallel with the speaker wires. The soundcard output is set by your software volume control, so you can test at low volume to check safely. If the sound quality does suffer, which is quite likely with the relatively low-resistance load, you'll have to build an op-amp buffer as BjD suggests, the circuit he links is cheap to build & looks OK.
Thanx guys for all your help so far So... here it is: Internal resistance = 650 Ohms (did I write it right? ) Hmm... didn't know it will be so "hard". I know there r some "spliters" and with them 2 ppl with headphones can listen to music from 1 discman. So... if I use that... i give 1 plug to speakers and 1 plug to this VU meter. So then I could add just one resistor or something and that would be it. Would that work?
So, all you need is a resistor to waste the spare voltage, 330mV across the 650R is the same current as 1V across 1,970R, so (1970-650)=1320R added in series with the meter. Try a 1k5 (1,500 ohms), a 1/4W is OK. The overall resistance, around 2k, looks a highish load on the line output, so be prepared for some loss of sound quality. And use screened cable from the splitter to the meter or you may pick some noise up.
Thnax m8 for all your help. U the man Just one more thing: This is plug-in for speakers/headphons... and I dunno how to connect wires So... r 1 and 2 for left/right speaker ( + ) and is 3rd - ? [sry for bad pic... i did 10 and thats the best 1 ]
if you have necessary a good measuring use a trimmer of 2kohm or use two resistor in serial system 1200 ohm and 120 ohm.5%error.by
