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Meier Audio Quickstep (also Stepdance and 2Stepdance) Discussion and Impressions Thread - Page 182

post #2716 of 2748

oh btw, if I ever upgrade, it is if Meier comes out another even better amp, I really hope if he was able to reduce the amp size by much. That's considerably an upgrade to me :)

post #2717 of 2748
My only issue is the lack of charging circuit.
post #2718 of 2748
Quote:
Originally Posted by audionewbi View Post

My only issue is the lack of charging circuit.

amen, brother!

post #2719 of 2748
This is why i think if it as "my special occasion amp", 9 volt battery isn't really cheap but when i plug in the er4s and turn the knob on i forget all about it.
post #2720 of 2748

If you have to ask for a charging circuit, might as well as ask for Li-ion battery as that will really slim thing down a bit.

post #2721 of 2748
Quote:
Originally Posted by ClieOS View Post
 

If you have to ask for a charging circuit, might as well as ask for Li-ion battery as that will really slim thing down a bit.

It has a few large caps inside it ( i think they are caps), I guess he might have to redesign those parts as well. 

post #2722 of 2748
Quote:
Originally Posted by audionewbi View Post
 

It has a few large caps inside it ( i think they are caps), I guess he might have to redesign those parts as well. 

 

Caps are easy to deal with, just don't use big electrolytic and you can instantly slim the design down. Battery / power section is a much more tricky issue.

post #2723 of 2748

If anyone can do it will be the Dr himself, I wonder if he is working on few projects as I am typing this. 

post #2724 of 2748
Maybe the caps he uses sound best?
post #2725 of 2748
Quote:
Originally Posted by pietcux View Post

Maybe the caps he uses sound best?

 

They are power caps, not directly in the path of the signal (and thus don't directly affect the sound). Electrolytic is good choice for power caps, but there are suitable replacement as well.

post #2726 of 2748

They're there because he considered them best for the circuit despite whatever other options he had.

 

I wonder how much more battery life he could have given the amp by designing it to run off of a pair of AAs.  Then we could use Eneloops (or their Amazon rebranded variety).  My rechargable Tenergy 9V block doesn't have as much capacity as one of those, let alone a pair, and it seems that the LT1054 voltage converter/regulator doesn't use that much current itself, which I assume is what supplies the amp with the power that it runs on if it isn't just for the unique volume control.

post #2727 of 2748
Quote:
Originally Posted by Mad Max View Post
 

They're there because he considered them best for the circuit despite whatever other options he had.

 

I wonder how much more battery life he could have given the amp by designing it to run off of a pair of AAs.  Then we could use Eneloops (or their Amazon rebranded variety).  My rechargable Tenergy 9V block doesn't have as much capacity as one of those, let alone a pair, and it seems that the LT1054 voltage converter/regulator doesn't use that much current itself, which I assume is what supplies the amp with the power that it runs on if it isn't just for the unique volume control.

 

The choice of 9V is because 9V is high enough voltage to run most opamp properly and battery is generally considered a very clean power source, as long as you don't have to mess with the voltage by much. To use AA, anything less than 5V is not going to be enough (generally speaking), and 6V (4x AA)is borderline, while 9V (6x AA) is going to be heavy and bulky. If you are only going to use just one pair, you'll have to use a step-up circuit, which it creates noise / ripple that requires extra circuit to smooth down (which is the main reason why Dr. Meier has been avoiding step-up circuit all these time, I would believe). So if these extra circuits are unavoidable, then the smarter choice will be to go straight to Li-ion as it is far more efficient and higher capacity than NiMH of the same size. There are quite a few ways to get there, but unfortunately none without problem of their own.


Edited by ClieOS - 2/26/14 at 5:57pm
post #2728 of 2748
Quote:
Originally Posted by ClieOS View Post
 

 

... you'll have to use a step-up circuit...

 

That's LT1054's job.


Edited by Mad Max - 2/26/14 at 8:07pm
post #2729 of 2748
Quote:
Originally Posted by Mad Max View Post
 

 

That's LT1054's job.

 

If my measurement over the LT1054 (in StepDance) is right, it is not a step-up convertor but a step-down convertor / regulator actually. It takes either battery or DC input (from the socket), regulate it down to about 7V, then follow by a transistors based split circuit that creates a +/-7V supply rail to the opamp. It also explains why StepDance requires a regulated 15V adapter as LT1054's input rated only up to15V.

 

p/s: I would also think a step-down is more energy efficient than a step-up circuit. You might get more capacitance from a pair of AA, but boosting 3V to 7V will take more power than down regulating a 9V to 7V.

 

[See below] Cool, I stand corrected.


Edited by ClieOS - 2/27/14 at 4:38am
post #2730 of 2748

Hello guys,

 

the LT1054 takes the +9V powerline of the battery and creates an additional -9V battery. Thus the effective supply voltage is doubled. The opamps run at +/- 9V.

 

Cheers

 

Jan

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