Running old Alembic Series 1 on battery power?

[bucephylus]

Yes, pics of the color code would be great. Also, I believe the batteries are wired series parallel, but having a close up pic of the battery wiring - and the wiring on the back of the 1/4" jacks - would be extremely helpful.

I truly appreciate you going out of your way to help me with this project! I am going to build 2 of the boxes so I have a spare.

Chris

We had a bit of discussion over on the Alembic Club Forum about several of these topics. i recommend combing through those posts. Most of the information is there. Jimmy Johnson was a primary participant (GREAT guy!).

https://club.alembicguitars.com/index.php?topic=28410.15

The short of it is that the +/- DC power for Ron's preamp can be anywhere between +9 / -9 VDC and +18 / -18 VDC.

+/- 9VDC, as supplied by onboard pair of batteries is bare minimum; which is why the 8.4VDC rechargeable batteries don't work, when inserted into the Series I or II bass.

But, for a belt pack, +16.8 VDC / -16.8VDC using two pairs of rechargeable would work just fine. See @FC Bass 's post a few before yours for an example. No idea how long such a belt pack would last; which is why I opted for the power bank route.

Here are some pics of the resistors I used. I'm not sure the value matters a whole lot +/- 20%; you just need to knock the signal amplitude down a bit. I used 15k. 20k might work just as well with a slightly lower output amplitude.

 

[crazycloud]

A +/- battery PSU isn't hard, but if you have the space Id go with 3 or 4 18650 batteries per rail as they're cheap to buy, same with chargers. But they take up a lot more volume than 4x9V.

 

[crazycloud]

The reason for the series resistors is to electrically isolated the N and B PU outputs from each other so that they sum rather than seeing the effectively zero output impedance of each stage and shorting. The drop in level isn't the primary reason.

 

[FC Bass]

Mine is in the practice room now and I won't be there for at least two weeks, but will take it with me next time and take some pics. Stay tuned


It's pretty simple and there's solid info above.

I estimate it's about 10 hours lifetime for four 9V Duracell batteries. The side LEDs on mine are a great indicator, when the LEDs get black dots in the middle it's time to change batteries. When it starts, there's about two hours left.

 

[crgny]

Mine is in the practice room now and I won't be there for at least two weeks, but will take it with me next time and take some pics. Stay tuned


It's pretty simple and there's solid info above.

I estimate it's about 10 hours lifetime for four 9V Duracell batteries. The side LEDs on mine are a great indicator, when the LEDs get black dots in the middle it's time to change batteries. When it starts, there's about two hours left.

Checking back to inquire if you've made it back to your rehearsal space to get some detailed pics of the battery power supply. I now have all of the necessary parts to duplicate the device but, admittedly, I am still a bit confused as to the proper series-parallel battery wiring and the number of contacts / wire connection designation for the 1/4" jacks (I picked up both standard and switching jacks, but not sure which to use).

In any case, it would be extremely helpful if you could send closeup, detailed pics of the internals - with the batteries in and the batteries out.

In advance, sorry for being a pest about this, but I want to make sure I get it right the first time.

Thanks!

Chris
crgny1 at gmail dot com

 

[FC Bass]

Thanx! I looked all over the place, but couldn't find where the quetion was asked

Hope this helps, it's as far as I dare to go... I think the green wire is suposed to be attached somewhere, looks like I lost the Stereo option for now. (both outputs give the pickups summed)

 

[crgny]

Fantastic - thanks for the very detailed pics! This should be enough for my electronics guy to duplicate the device.

Thanks again!