Quickie PJCCS voltage

[Alonzo]

I have a stock Quickie that I'm about to add the PJCCS upgrade to.  I've upgraded the battery pack to a 48V pack, will the PJCCS work with the +12v into the diode and transistor or will I have to adjust the resistors size (470 and 4K) to bring the voltage down to the 36v it was designed for? 
Alonzo

 

[earwaxxer]

I'm actually interested in this question as well...I would think it would work with the higher voltage. I also have about the same voltage with my LiPo pack. That would be my next tinker, to try the PJCCS. Any knowledgeable engineer that can way in on this?

I did do a quick comparison between my 30V NMH pack that I use for my t-amp and the 45-50V pack. I would say, just from a quick A/B take that the 30V sound through the 3s4 is very good, but there seems to be a subtle increase in drive with the 50V. Again, better headroom would be a way to describe it. I only listened at lower volumes, and did a very quick listen. My impression is that I liked the higher voltage better. I was charging my 50V pack at the time and I wanted to listen to some music. I could probably live with the 30V sound without notice if I didnt have the choice.

 

[Paul Joppa]

The PJCCS, unlike the original C4S, adjusts its current according to the available voltage. I made this change because ordinary alkaline batteries will lose voltage over their life, and I wanted the Quickie to run well even when the battery drops to 2/3 of nominal. It should work fine at higher voltages as well.

(The other change is that it is not a cascode, and does not have as high an effective impedance as the C4S. The main function of extremely high impedance is to improve the power supply noise rejection, which is of course not so important with a battery. The reason is that less compliance (voltage drop) is required, so it works better with a low voltage supply.)

 

[Hank Murrow]

The PJCCS, unlike the original C4S, adjusts its current according to the available voltage. I made this change because ordinary alkaline batteries will lose voltage over their life, and I wanted the Quickie to run well even when the battery drops to 2/3 of nominal. It should work fine at higher voltages as well.

(The other change is that it is not a cascode, and does not have as high an effective impedance as the C4S. The main function of extremely high impedance is to improve the power supply noise rejection, which is of course not so important with a battery. The reason is that less compliance (voltage drop) is required, so it works better with a low voltage supply.)

I am stunned sometimes at the incredible generosity of Paul Joppa in delineating his design reasons and process of design. I am an artist who shares everything, but Paul can match me and raise me in this!

Cheers...... it is a joy to read your posts, as well as to remember how helpful you have been in my search for 'The Music'

Hank in Eugene, and All-Bottlehead

 

[earwaxxer]

Thanks for the reply Paul...though I'm way too "green" to understand the second statement!

Eric

 

[Alonzo]

Thanks for the explaination Mr Joppa, I got the PJCCS in and measurements are correct but I flubbed something else up.  Now there's very low output from both channels regardless of the on/off switch position.  It's on the shelf for now until I get my Seduction investigated and corrected.  I will update (with photos) soon (unless the HDL -Honey Do List-) pops up.

 

[Alonzo]

I has been a GREAT DAY!!!!  After tearing my Quickie completely apart, 2 new switches and all the upgrades torn out, I happened to tilt it up during a sound test and got sporadic music.  It played perfectly when upside down.  Seems the - 9v battery connections had expanded from all my on/off test with batteries.  Tightend these up and now I have music, full system now playing:  turntable => Seduction => Quickie => 45 SET.  On top of that, got a refund check from my oral surgeon.  It has been a good day.

Now that I have some spare change, anyone know of a tube display shelf or holder, got tons of tubes sitting in RubberMaid boxes, it sure would be great to put them on a nice polished wooden holder so I can keep up with them.
Alonzo