Is there a benefit to battery isolation with Quickie, QS

[frank bare]

I've been interested with the idea of a separate enclosure for batteries. I was curious if the batteries have any effect on the circuits of either the Quickie, QS amp, and if it would benefit. Also, would the wire length play an important role?

Thanks,
Bare

[4krow]

  Bare,

  The only benefit that I can see that you can place the battery pack out of sight. Depending on how long the battery run is, you may have to go up a gauge. As far as an effect on sound, I'm sure that there won't be any difference. I have built several Quickies, and the idea of a separate box appealed to me. If not that, then I built them where the batteries were at least, out of sight.

[Paul Joppa]

The stock Quickie and the Quicksand both include the power supply (batteries!) in the signal current loop, so the power supply imperfections do have an opportunity to impact the sound. The PJCCS substantially reduces that effect. Adding long lines between the power supply and the circuit offers another opportunity for imperfections to affect the sound. One way to change the equations is to put a capacitor across the power supply and inside the amp circuit, which lets the cap take most of the signal current, at least at frequencies where its impedance is less than that of the cable+power supply. Whether that's an improvement or not remains an open question.

So much for theory. Experimentation is the only way to find out.

[frank bare]

Thank you both for your reply.

It certainly remains then an open debate, as to any benefit of battery isolation. My first attempt at the PJCCS, I couldn't get it to work, due 'Im sure to soldering errors. Back to the drawing board... add a new PJCCS and see the benefit!

It's worth building a second Quickie, just to have as the experimenter pre-amp. One to listen to and one to compare any of the mods completed...that's a fun idea, right?


Bare

[4krow]

 The part that I enjoyed about building more than one Quickie was the fact that I could change things up, bringing the result to one that suited me best. This included a volume control that had Many stepped positions, different output capacitor choices, and a set of chokes used in place of the PJCCS (which, in the end, I preferred the PJCCS).

[Wanderer]

I don't see what remotely locating the batteries will do for you. HOWEVER if you have not built the PJCCS in your Quickie do that. Immediate sound improvement.
 

[frank bare]

Thank you all for the posts. I like the idea of a 2nd Quickie. And for sure, go for the PJCCS. I am determined to get this operational in the Quickie to hear the benefit.

Bare

[aragorn723]

The stock Quickie and the Quicksand both include the power supply (batteries!) in the signal current loop, so the power supply imperfections do have an opportunity to impact the sound. The PJCCS substantially reduces that effect. Adding long lines between the power supply and the circuit offers another opportunity for imperfections to affect the sound. One way to change the equations is to put a capacitor across the power supply and inside the amp circuit, which lets the cap take most of the signal current, at least at frequencies where its impedance is less than that of the cable+power supply. Whether that's an improvement or not remains an open question.

So much for theory. Experimentation is the only way to find out.

Paul,

Can you give us a "for dummies" version of where to install this cap/what value/type to use?  Sounds like an easy mod to try!

Dave

[Paul Joppa]

The positive high voltage supply goes to terminals 2 and 7 (follow the red wire from the stack of 9-v batteries to T2 and T7). Ground is at 5 and 10 (you can see those terminals attach to the ground of the RCA jacks).

Voltage rating should be at least 50 volts. I have no idea what capacitance to use; let's say between 10uF and 100,000uF. Electrolytic caps will have some leakage current which will eventually drain the batteries, but that's the only practical way to try really high capacitances. The first experiments should tell you whether there is an effect, and (if there is an effect that you like) how large a capacitance is needed to have that effect.