How to convert a passive Dingwall AB-I to an active pre-amp question?

sha975 · #1 10-14-2007, 01:21 PM

Anyone have any experience converting a ABI over from a passive pre-amp to a active pre-amp? I love the active sounding passive circuit in the bass now but I have a Aggie OBP-3 laying around and would love to hear how that sounds in it. I want to leave the 4-way rotary switch in with all of its options for the pickups and of course the volume can stay the same also.

I was reading where some of the AB-II come with an OB-1 and still has the bluEQube Switch. I also read something about a hybrid treble or something like that. Anyone have any idea on how to pull this off? Any wiring diagrams?

Dragonlord · #2 10-14-2007, 02:20 PM

First off, there is no passive preamp, there are passive electronics and there are active electronics, which means a preamp. Anyway, you could probably fit the preamp in the control cavity, but you would have to drill a few holes in the bass. It's something a tech should probably do if you don't have much experience with this stuff. Anyway, an easy way to try it out would be to try the Aguilar DB-924, which is basically the OBP-1 in a box. If you are in Europe I have one for sale actually. Anyway, this will let you know if you like the result before you drill any holes, so, if you decide it's worth it and you want to have the preamp onboard, you can proceed to do it - but I wouldn't drill a Dingwall if I wasn't sure about the result.

kyral210 · #3 10-14-2007, 04:13 PM

I can build you one! There actually very simple:

sha975 · #4 10-14-2007, 04:53 PM

Quote:

Originally Posted by kyral210

I can build you one! There actually very simple:

I already have the 4-way rotary switch (wired neck pu, series, parallel, bridge pu) and volume knob from the passive circuit already in the bass. The bluEQube Switch is also already in the bass. I think that all I need to do is probably get rid of the tone control and make a few other connections. Of course the preamp has to be wired. I'm familiar with wiring up a pre-amp and drilling holes etc. I'm just wondering how I would wire the OBP-3 with the 4-way rotary switch and the bluEQube Switch. I'm really just interested in wiring it with the 4-way rotary switch...I don't have to have the bluEQube Switch... I just noticed that ABII's come wired with a Active aggie Preamp and bluEQube Switch.

I'm just wondering if anyone has wired one up themselves or have the diagram on how to do so. I don't need a diagram on wiring the pre itself, I just need to know where the in and outs of the pre-amp need to go because of the 4-way rotary and bluEQube switch configuration.

Sheldon D. · #5 10-14-2007, 06:09 PM

Wiring in an OBP-3 will be a tight squeeze. You'll be best off running it off 9 volts instead of 18 to conserve space.

Really, I'd recommend the OBP-2 instead. With a stacked pot, you won't have to do any drilling and you'll have a comfortable amount of room in the cavity.

Here's a link to the wiring diagrams on Aguilar's site.

http://www.aguilaramp.com/support_wiring_diagrams.htm

Just sub the rotary output in place of the blend.

sha975 · #6 10-14-2007, 07:52 PM

Quote:

Originally Posted by Sheldon D.

Wiring in an OBP-3 will be a tight squeeze. You'll be best off running it off 9 volts instead of 18 to conserve space.

Really, I'd recommend the OBP-2 instead. With a stacked pot, you won't have to do any drilling and you'll have a comfortable amount of room in the cavity.

Here's a link to the wiring diagrams on Aguilar's site.

http://www.aguilaramp.com/support_wiring_diagrams.htm

Just sub the rotary output in place of the blend.

Sheldon,

so basically I can leave the volume and 4-way rotary exactly the way it is except for removing the wire off of the middle lug on the volume pot because thats were the input of the pre-amp goes right? And this is where I get confused because the bluEQube goes to that middle lug of the volume pot. It seems that there are wires leading from the BQ to the volume pot, tone pot and the jack.

Where do all those wires go if I plan on keeping the rotary and the BQ plus and a active pre? The jack already has 3 pronges so I'm assuming that it's already a stereo jack and I won't have to replace it right? I'm sure that I can junk the tone pot and replace it with the treble/bass stack. My main problem is that I have 3 wires coming from the BQ to the volume, tone and the jack. two of those lugs are to be utilized by the new pre-amp and the wire going to the tone I have no clue where it goes after I junk the tone.

To sum everything up, I need to know where I place all 3 wires coming from the BQ? Hope this isn't to confusing.