Quickie preamp

[Wanderer]

I have been reading and I thought you either use the pcjj or the chokes, are you saying to add both to it one at time or either or?

One or the other. You can use chokes or PJCC mod, not both at once.

They both increase the gain but the PJCC sounded "smoother" to me.

Your Milage May Vary   

[underdawg]

ok thanks ill stay with the pcjj then

[4krow]

Ok, maybe I'm just lazy, but I don't remember seeing a price for the chokes. Would be a simpler install, not that pjjs is a problem.

[4krow]

pjccs     sooooory

[Wanderer]

Ok, maybe I'm just lazy, but I don't remember seeing a price for the chokes. Would be a simpler install, not that pjjs is a problem.

Thread on the chokes here:
http://www.bottlehead.com/smf/index.php/topic,70.0.html

You source the Hammond chokes from an outside supplier. Not expensive.

As I said I find the PJCCS better but others prefer the plate chokes. Worth a try.   

[earwaxxer]

Here's the choke link
http://angela.com/hammondchoke156c.aspx

[galyons]

Batteries from radio shack industrial grade.

Now there is an oxymoron if I have ever seen one!!   

Quickies are fun and perform to an amazing level!  Radio Shack...not so much! 

Cheers,
Geary

[underdawg]

I was just trying to find reasonable batteries is all, and at least the shack changes the stock frequently.

[Paul Birkeland]

FYI - a 47uF-100uF at 6+V will work for the cathode bypass capacitors.

[underdawg]

why such a high value capacitor, normally I bypass power supply caps with .1 to 1 uf caps?

[Paul Birkeland]

A bypass capacitor implies that it's bypassing a larger capacitor. 

The capacitor across the cathode resistor is there to act as a short for AC on the filament, removing degenerative feedback that would otherwise be there.

The cathode bypass cap also stabilizes the bias point, though this becomes unnecessary with the PJCSS upgrade IMO.

The size of the cathode bypass cap must be sufficient to offer the same "short" across all audio frequencies and then some.  The 1000uF cap we put in the last Quickie was used because we already had it, the new Quickie uses a 150uF capacitor that we added to our inventory for the BeePre.

-PB

[Grainger49]

The above post is an example of Bottlehead's business acumen.  Stocking a new part costs money.  Until it is necessary you don't do it. 

[underdawg]

so based on 1000 uf and 150 uf, I assume since I just ordered one its coming with 150 uf caps, so I have some nice mundorf 390 electrolytics that should work ok?

[underdawg]

so based on 1000 uf and 150 uf, I assume since I just ordered one its coming with 150 uf caps, so I have some nice mundorf 390 electrolytics that should work ok?

The caps I have are bipolar 390ufd 63 volt, but I am not sure what side is the negative either, I feel stupid being in electronics 25 years and cant tell, tried to google but mundorfs site couldnt tell me.Anyone know if they will work and which side is the negative?

[Grainger49]

You mean there is no stripe on the Mundorf?