How many battery connections are there in the Quickie?

[Jim R.]

Scheming -- always scheming on how to do things a little different and so they work nicely in the spaces I have.  One thing I'm considering right now is an external power pack, so I'm wondering how many total connections from the batteries to the circuit there are.  My guess is that there are 3 from the D cells -- a common center and two other poles, and 2 from the 36v supply, for a total of 5.  Is this right or do the D cells require two connections each?  This is the difference between a fairly cheap and easily available umbilical connector set (5-pin mini-xlr) or a more 6-pin option.  Though I suppose an octal socket and plug will also work, but I'd like to keep it a bit more compact and locakable if possible.

Thanks,

Jim

[earwaxxer]

the heaters 'D' cells have 4, the 36V have two. I 'beefed up' the 36V wireing but left the heater wires as cheap skinny stuff.

[Jim R.]

Thanks, Eric,

Guess I'll have to ponder this a bit more.

Thanks,

Jim

[ptempel]

Did you get the PJCCS upgrade?  If not, then I'd recommend it.  Have read that it can give up to 100 hours of battery life for regular alkalines.  Can't verify yet since I'm still on my first set.  It sounds better than the Adcom GFP-555ii preamp.  Will probably be putting it up for sale soon...

[Jim R.]

Yes, I ordered the pjccs right from the start -- though some folks have reported somewhat better than 100 hours with it and standard alkaline batteries.

As for the connections, I realized that they are directly heated so they should have separate supplies.

Thanks,

Jim

[Noskipallwd]

Hey Jim,
I replaced my nine volts for the first time yesterday, approx. 106 hours. I kept a close watch on that, still on the first pair of D-cells. Bought some nine volts in bulk at Costco the other day. If I can get that kind of battery life regularly then I'll be a happy camper. There is not much else in my house that has that kind of battery life. I am lucky if I get 10 hours on the HiFiman.

Cheers,
Shawn

[Jim R.]

Shawn,

That's still a lot of bedtime listening, which is where I will most likely end up using the quickie.

Thanks,

Jim

[earwaxxer]

Hey Philippe - That Adcom was a great inexpensive preamp as I remember. I never had one, but I remember it. How was the Quickie better? Is the Quickie stock?

[Paul Joppa]

For what it's worth, Duracell and others list 18 amp-hours for an alkaline D cell, which is 180 hours at 100mA. 9-v are rated 595mA-hours, so about 200 hours at 1.5mA per channel (average draw over the life of the battery).

Real-world tests seem to give a bit more than half the rating, I found 2 mentions of 12A-h for D cells and one of 300-500mAh for 9-v batteries. None of the tests are done at the low currents used in Quickie, and end-of-test voltages are all over the place. I figure the battery is dead when it drops to 2/3 of the nominal (1v for D cells, 6v for 9-v).

NiCd and NiMH hold a pretty constant 1.2v per cell until they die quite suddenly; that's a good voltage for quickie use.

[4krow]

When my quickie is complete, I will be using LI-ION 9V batts, and copper top alkaline for the heaters. I have the PJJS upgrade, so it will be interesting to see the outcome.

[Jim R.]

Paul,

Thanks for anticipating my next question about current draw :-).

--Jim

[Jim R.]

So, wonder if a dual 36v supply approach would work?  I found some NiMH 9v (actually 8.4) cells and a charger that can handle up to 10 of these at a time) but the max capacity rating is 250 mAH -- so I figure if I go with two sets of 4 -- one for each channel, that should give about the same life as standard alkalines, no?

Any concerns regarding doing this as far as the PJCCS is concerned?  Maybe I'd need a second PJCCS as well?

Don't worry, I've already decided to build this in the 8 x 10 format chassis as the output caps I plan to use are rather huge.

-- Jim

[Paul Joppa]

The only issue is you need another pole on the power switch for a dual-mono battery. (Paralleling batteries is problematical, in case you were thinking of it...) The PJCCS has two independent channels.

[earwaxxer]

Its funny about the voltage on the 3s4's. I have noticed that my Quickie still works with main voltage as low as 16V. Whether the tubes continue to amplify or not seems to be more dependent on the heater voltages. When those dip too low it stops.

[Jim R.]

Paul,

No paralelling here -- that's why I wanted to go with the dual mono supply idea, and as long as the channels on the pjccs are independent, it should be just fine this way.  So, this is what I'm a gonna do -- which is really good as I've already ordered the parts to do it. :-)  Not exactly cheap, but probably a lot cheaper in the long run and I wont be tossing batteries away all the time.

-- Jim