Drained batteries in an unused Quickie

[4krow]

 Regardless of what should make sense, I plan to install separate switches for a custom Q that I will be building sometime in the future. I have had the same battery issues noted above, so it is no problem for me just use a couple of Frankenstein switches for the job.

[aragorn723]

4Krow,

What else do you plan to do in your new Quickie?

Dave

[4krow]

 Dave,

 The list can get long and varied. Maybe I will shoot for the "ultimate Q". If so, then the battery compliment would have it's own enclosure and I would be able to use larger rechargeable batteries. I want to have some extra room in the chassis, only to make it easier for my less than delicate fingers. I almost always opt for the RCA connectors of my choice, as well as a stepped attenuator. That is where there is a turn in my thinking. The Q acts well as a buffer for source components, so the stepped attenuator would be more limited, acting less as a volume control and more about matching it's output to the gain of my integrated amp to begin with. In other words, the Q may be purposely limited at both ends of it's attenuation/gain.
 All in all, I usually find myself changing out almost every part of the kit for expensive and higher quality parts.

  Having said all of this, the BH kit one step up the ladder (can't recall the name, but it is DHT with an AC power supply), is calling my name.

[aragorn723]

4Krow,

That does sound like a fair amount of work to put together something like that.  The Smash looks pretty nice, I think the differences between that and the Quickie are that it has multiple preamp outs, different output tubes, ac power, and was around $400, so a pretty good deal overall.  Its still DHT too.  There might even be a few more inputs.

Dave

[boulos]

I've had three sets of Duracells drain down to below 7 (and yes some read negative) with the quickie turned off. I've taken the quickie out of the chain until I find a solution.  In fact, the 3rd set was while the quickie was disconnected from everything (and off).

Perhaps the easiest solution is not to use Duracell?

Another solution is lead-acid batteries. Would 3 of these or similar work well:
http://www.amazon.com/Tekonsha-2023-Sealed-Lead-Battery/dp/B007HGHUMG

Thanks!

[aragorn723]

That should work fine.  If you poke around the forum, quite a few people have wired up 12V powersonic SLAs to get 36V plate voltage for the Quickie.. Been thinking about doing that myself.  If you look around on amazon, they have bulk deals where you can get 3 powersonic SLAs together for $33 (which is pretty good).  Here is a link:

http://www.amazon.com/PS-1250-12V-5AH-Battery-VOLT/dp/B0089XPRYO

Dave

[boulos]

Great. Thanks Dave for the pointer!

[badman]

Also to be noted- NIMH tend to self-discharge, unless you get ones designed for longer shelf life. 

I spent the scratch to get these:

http://www.bhphotovideo.com/c/product/883815-REG/Powerex_MHR9VI_IMEDION_Ready_When.html

Which not only are high-quality, high capacity, low self-discharge, they also are 9.6v compared to the more common 8.4 for NIMH.  Given that we're operating the quickie at a relatively mild voltage to start with, a smidge of extra zoot is probably a good thing.

[Grainger49]

The low self discharge batteries are a great improvement over standard NIMH.  I did a quick search on Amazon for"low self discharge 9v" and found a number that come with a charger.

[badman]

I did a LOT of reading, and the Tenergy Centura are one of the best, and reasonably priced.  The reason I went with the (more expensive) Imedions is that they are 8 cells instead of the 7 as used in the tenergy, resulting in a nominal voltage of 9.6V rather than 8.4 per "9v" package.  7.2 is even more common (6 cells).  Given the relatively deep bias of the quickie relative to the supply voltage, I didn't want to give up any voltage so went with the 8 cell packages.  The resistive bias slides relative to the supply voltage stock so it's less of an issue since the stock design allows for some voltage deterioration, but if someone were to use a led cathode bias (which I have preferred in another simple plate-amp circuit), that low a voltage in the supply would mean the led bias on the cathode is relatively deep and would be better around 1v than the 1.57 of the preferred HLMP-6000 part (which has excellent low and stable impedance).  1.57 ought to do well (probably better than the stock resitive setup) at a higher voltage- less input headroom but should be improved linearity and current availability (which will drain batts faster, a non-issue). 

We shall see!  The stock kit is designed to be flexible WRT battery types, system connectivity, and battery discharge curves but if one optimizes for a higher, stable  operating voltage (perhaps even adding 1-2 more 9V cells) at a modest bias (trading input headroom for linearity and current), the linearity should be improved particularly with the PJCCS in place. 

That's what's great about an inexpensive high performer like this- customization to your specific wants/needs isn't something to be feared, worst case, you buy $1.50 worth of replacement resistors and throw 'em back in, if you couldn't cleanly remove the originals.