[Voodoochile]

Oh I still think that the PS choice makes a notable difference in the PPA, just to a lesser degree than the META. The rail isolation and diff drive has to be helping out in a big way.

 

[Budgie]

If you do caps in series to get a higher voltage rating, you really need to place resistor voltage dividers across the caps to spread out the voltage properly. Otherwise the voltage will not spread equally across the string of series caps.

edit-
Like this-
http://www.oz.net/~coilgun/theory/capacitors2.htm

 

[fewtch]

Thanks guys, I don't really plan on turning a simple battery pack into what amounts to a full power supply...

(particularly for a $100 Creek amp). Before I did that, it would just be easier/cheaper to return to using Elpac linear regulated power from the wall socket.

 

[Steve Eddy]

Quote:

Originally posted by fewtch Thanks guys, I don't really plan on turning a simple battery pack into what amounts to a full power supply... (particularly for a $100 Creek amp). Before I did that, it would just be easier/cheaper to return to using Elpac linear regulated power from the wall socket.

Bah! No guts, no glory!

se

 

[puppyslugg]

Quote:

Originally posted by fewtch Thanks guys, I don't really plan on turning a simple battery pack into what amounts to a full power supply... (particularly for a $100 Creek amp). Before I did that, it would just be easier/cheaper to return to using Elpac linear regulated power from the wall socket.

It may not be worth your trouble with a $100 Creek, (though it's not really that much of a hassle)but the lesson here is: ps do make a diff. I believe you will also have the same issues with your Meta.


Koyaan I. Sqatsi:
Quote:

Bah! No guts, no glory!

LOL! Well said!

 

[Voodoochile]

Quote:

Originally posted by Koyaan I. Sqatsi Bah! No guts, no glory!

Or sometimes this:
"No guts, No glory, No more Creek!" {poof}

Once in a while it goes that way, so do proceed with caution... and the guts, of course! Sometimes glory will follow, and sometimes painful humility.

 

[puppyslugg]

Quote:

Originally posted by Voodoochile Sometimes glory will follow, and sometimes painful humility.

More like 'painful humility', for me.

 

[Steve Eddy]

Quote:

Originally posted by Voodoochile Or sometimes this: "No guts, No glory, No more Creek!" {poof}

Bah! I love the smell of phenolic burning in the morning. Smells like... VICTORY!

se

 

[fewtch]

Quote:

Originally posted by CarlJF One thing you can do, instead of using 9V batteries, is to use a AA-cells battery holder (see DigiKey BH48AAL to see what I mean). NiMh AA batteries have much more current reserver than 9V. Typically, they show a rating of at least 1500 mAh. I even found some which have 1700 mAh and rated at 1.25V. Whith those, using 2 eight cells holder will give you 20V DC with a 1700 mAh reserve. If you take the more general 1.2V batteries, you get 19.2V with 1500 mAh reserve. The main drawback being that that recharging 16 batteries isn't that fun...

I took your advice here and ordered sixteen AA-size NiMH batteries (Kodak 1700 mAh, 1.2v) and two 8-cell holders... will be using this with the custom Headsave Ultra I have on order.

Thanks for a great suggestion, and... recharging 16 batteries won't be that big a deal. I have a one hour charger that holds 4 AA batteries at a time, so the whole thing shouldn't take more than about 4 hours. I believe that fully charging two Plainview 9v NiMH would take about the same amount of time, maybe longer.

Total cost including shipping for the above was about $27 (there were some nice sales at www.thomas-distributing.com), cheaper than an Elpac WM080 and certainly cleaner power! Muchas gracias.

 

[ronslam]

Just curious why noone has mentioned sealed lead acid batteries as an alternative solution - cyclists have been using them to power their lights for years.

A couple of 12v batteries and a charger could cost around $60 which is a lot more than a wallwart, but should sound much better. There are 24v ones, too.

Some highend audio equipment (such as Rowland) add battery power as a very expensive option.

Any thoughts?
Ron

 

[PeterR]

I think SLAs really only make sense when you need a lot of capacity. I'm using a pair of 3.5Ahs for a Zen headphone amp, works great.

 

[tangent]

ppl once told me liquid acid batteries make noise when you move them. I imagine this speeds up the reaction which would generate extra electrons vs. the still state.

Gel cells would probably be okay, but I'd want to know more about them, such as their impedance vs. time or voltage.

 

[DCameronMauch]

I have been using four 12V 26AH SLAs for +-24V power.
But also have fairly decent +-24V wallwart too. Either
way, there is internal regulators provide +-16V to the
circuitry. So I use the WW to keep everything warmed
up, and switch over to the SLAs when I actually listen...
Only have to recharge the SLAs about once a month.

 

[fewtch]

Update to my original post -- I found a couple Plainview 9.6v NiMH in a drawer (better than the crappy ones I was using before that weren't supplying enough power) and have been using them with the Creek OBH-11 in the dual battery pack I made.

Unfortunately, they don't last long. The Creek is rated at 150mA and I thought it would use significantly less than this under normal operating conditions. Unfortunately that doesn't seem to be the case -- the 170mAh Plainviews last just a little over an hour on a full charge (then it's a 3-4 hour charging job to recharge both batteries again)... this isn't working.

Maybe I'll have to get another 16 'AA' size NiMH plus holder for the Creek, altho it probably isn't worth it for a secondary setup... I'll just use the Elpac WM080 wall wart. Shame, I really like the sound of the OBH-11 the best running on NiMH power (alkalines sound OK, but just lacking something... and too pricey to keep replacing them).

 

[tangent]

I recall measuring this amp at about 50mA draw. I also recall that the op-amps they use aren't exactly low-voltage types. What may be happening is that you're running out of voltage swing, not that the batteries are dead. Measure the voltage across the terminals when the amp starts clipping. If the voltage is still well above 6-7V per battery, you just need to add a bit of voltage to make this circuit happy. I don't recall if the circuitry inside can tolerate more than 24V. If it could, 3x9V would solve your problem.

Beyond that, you're looking at things like the PPA battery board, which starts getting expensive and complicated.