2x9V are required for driving medium to high impedance ( 100-600 Ohms) low sensitivity h/p. Regular h/p (16-32 Ohms) can work with CMOYs operating at +/-5V. Higher voltage cause higher thermal dissipation in opamps.
@thelegendaryblah
I agree with the dangers of dual battery setups, but rail splitter (with its limited current) is also prone to failure. And Objective2 amp (with its battery protection) is out of question due to budgetary constraint.In that case single battery, virtual gnd, capacitive coupled o/p is best soln. like Portable 9V Headphone Amplifier - RED - Page119
Regarding the rail splitter, there is a concern about the unequal life of the 2 batteries.
This may result in large voltage difference between V+ and V-.
Say, V+ may read 9 while the V- may read 7.8V.
It is interesting that a simple (and old)circuit like Cmoy can lead to much discussion.
It seems to me that uploading a file here is like learning rocket science~
This may result in large voltage difference between V+ and V-.
Say, V+ may read 9 while the V- may read 7.8V.
It is interesting that a simple (and old)circuit like Cmoy can lead to much discussion.
It seems to me that uploading a file here is like learning rocket science~
My colleague prefers 2 x 9V as it gives more headroom.
I have never used a Cmoy that I have no idea about the driving capability of it.
Or, on no ground to estimate whether one 9V or 2 x 9V is good.
Maybe, I need to build a p2p prototype... if time allows...
Let me clarify the objectives of this post.
There are 3 aspects of the present discussion:
1. discussion on the functions and hence circuit of the Cmoy;
2. techniques and rules for "good" PCB layout; and,
3. practical issue, e.g. making the PCb smaller and use small size caps, so that the PCB can be put inside a candy can, etc.
For some issues, people may come to consensus easily, whereas it is not so easy for other issues.
Anyway, suggestions and sharing of experience are welcomed.
There are 3 aspects of the present discussion:
1. discussion on the functions and hence circuit of the Cmoy;
2. techniques and rules for "good" PCB layout; and,
3. practical issue, e.g. making the PCb smaller and use small size caps, so that the PCB can be put inside a candy can, etc.
For some issues, people may come to consensus easily, whereas it is not so easy for other issues.
Anyway, suggestions and sharing of experience are welcomed.
Experimenting the layout:
1. put the battery and electrolytic caps near the switch to shorten power wires;
2. volume pot put to right;
3. put back the 10 resistor for reducing noise if any.
cons:
220 caps far away from output
some ppl say there is a ground loop, I am not sure.
imgur: the simple image sharer
1. put the battery and electrolytic caps near the switch to shorten power wires;
2. volume pot put to right;
3. put back the 10 resistor for reducing noise if any.
cons:
220 caps far away from output
some ppl say there is a ground loop, I am not sure.
imgur: the simple image sharer
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