A47

[jasonhanjk 0]

It should be if Gary don't change anything.

[Username 0]

Being such a newb, I want to ask what is the square that doesn't touch any point?

 

Second, what is bias?

 

Thirdly, I don't quite get the whole schematic.

[heady 0]

It should be if Gary don't change anything.

Well, I am a newbie in reading EE stuff but the data sheet did say 5V supply but two AA gives at most 3V, so how does Gary do it??

[jasonhanjk 0]

From the datasheet, minimum voltage is 2.7V but normal Nimh batteries gives 2.4V. So there maybe a slight non-linearlity at the opamp side. I would not know until I measure it.

 

Non-linearty normally gives rise to THD but hey, if the THD are mostly even, you guys will like it!!!

[Username 0]

 

My working A47, anxiously waiting for its jack and an ultra-bright blue LED. I don't quite like white.

[jasonhanjk 0]

I used Cmoy2 with 9V 170mAh battery powering EW9 for a total 10 hours.

[Firefox 0]

How long approximately will a 9-volt battery power a A47? Will it be comparable to a CMOY?

 

I am worried because of this phrase in the original A47 scrapbook on headwize:

"The resistor-divided 9V battery in the original spec it will not power it very well or for very long - maybe 2 hours. "

It depends on which opamp you use and your listening levels.

 

If you have moderately low listening levels and use opamps like the OPA213x or OPA2227, I'd say you can expect about 6 hours of battery life from a 170mAH 9v battery.

 

This is calculated with a 7.5mA quiscent current draw per dual-opamp and a 3mA output per channel.

Also, taken with 90% capacity for the 9v battery since NiCD batteries have a self-discharge of 10% in the first day and it's about 50% more for NiMH.

[Username 0]

Have anyone tried building a PA2V2 clone?