No you do not have to always use the power supply. However batteries will only last a few hours in a Series bass.  
 
Here is a link to the 1/4 inch jack wiring information. It can be used by your tech to rewire the 1/4 inch jack from stereo to mono. As an alternative you could use a 1/4 inch TRS (stereo) to TR (mono) adapter. The instructions for making one are here.
 
Keith

germansal..although I have limited experience with Si & II basses I do know you have to use the power supply cord as this has the stereo output on it.have you just purchased this bass, do you know anything about them?
Go to the FAQ & Must reads/FAQ for all info on series basses

thanks for your attention terryc
but i ve purchased the bass 16 years ago
regards

germansal,
I want to clarify that the bridge pickup did work at one time. While you were using it it started to make a noise and now does not work at all. Is this  a true statement? Were you using the power supply or batteries when it stopped working?  
 
Using the power supply what does the bridge pickup do? If you swap the bridge and neck pickup connections on the preamp does the problem move with the pickup?  
 
As I said in my first post to you, you will get faster assistance if you call Alembic directly. You could also send an e-mail but this can take longer due to the time it takes to send notes back and forth.  
 
Keith

i,ve send mails to mica for 5 days and nothing happened
thanks

and besides that i called from spain yesterday and nothing happened too

I received many emails from you starting on Saturday at the Helpdesk and my regular email. We rarely respond to emails over the weekend, so I'm sorry that this delay has caused you some stress. We also received an inquiry from the Spanish distributor I believe on your behalf.  
 
Here's the response I sent last night around 8:00pm our time. I've also resent it to your email address (note it is from the original Helpdesk inquiry on June 6):
 
Hi German,
 
The replacement pickup is $220 plus shipping to Spain. You will need to specify one connector type:
 
1. Coaxial
2. 2-pin
 
and one decoration type:
 
1. plain
2. engaved Alembic name
3. Alembic name stamped in gold
Only specify based on your original pickup, as the shapes have changed slightly over the years.
 
You should confirm the pickup is actually dead by moving the connector from the neck pickup to the bridge pickup on the preamp card. This will
confirm the problem is truly isolated to the pickup and that we will be sending you a part that will actually correct the problem you are
observing.
 
Also, are you testing with a 1/4 connector or the 5-pin/power supply combo?
 
-Mica, manning the Helpdesk
 
Alembic, Inc.
3005 Wiljan Court
Santa Rosa, CA 95407
707 523 2611 ph
707 523 2935 fx
phone hours 10-4 pacific time
 
(this message will be moved to the troubleshooting section)

my apologies germansal, I was under the impression you had just got your bass.
Good luck with getting it fixed.

No problem terryc peace dude
Fortunely Mica contact me today

Germansal..thank you for that, you should get yourself on here more often, we all have great discussions and offer help whenever we can.
We also gripe about the crap bands we have been in, discuss basses, amps, settings and all sorts of stuff.
We all maybe thousands of miles apart but we are all friends here.
Also get a pic of your bass on here too..we all like to see basses, we cannot get enough of them
And peace to you too(we need plenty of it)

if you want to see my bass and listen to it
check this link  
www.myspace.com/germansalvatierra
hope you all enjoy it
And God bless this basses

Nice classic late 70's bass..whatever it needs it will be worth every euro to get it done.

German,  
Hello and welcome. I like your tunes!
Mike

THANKS DADABASS2001

mica ,ive send you an email today,s morning
to order the pickup
check your mails
Thanks  
German