Aguilar Preamp Headup!

[Tewest86]

If anyone is hooking up an Aguilar preamp, I just want to inform you the the diagrams for the vol-blend is wrong. It took me days to fix the problem only to find out Aguilar drew it wrong. Follow the vol vol diagram which shows blue wire (output) on the outside prong and and input wire from blend (or straight from pickups) on the middle prong. If you follow their diagram for vol blend, you will have volume but no volume control. You will have constant volume all the time.

[FunkyMan]

Send this to aguilar!

[Tewest86]

All their vol-vol drawings are right. It's just the vol-blend ones. Technically, you use either outside prong for output but then you would have a weird volume control. Turning if counter-clockwise would turn it up instead of down. It works the same as the blend pot where the center prongs are the pickup inputs and the 2 outside prongs are output. (output to ground and output to preamp and/or volume pot)

[Aguilar/Dave B.]

Originally Posted by Tewest86

If anyone is hooking up an Aguilar preamp, I just want to inform you the the diagrams for the vol-blend is wrong. It took me days to fix the problem only to find out Aguilar drew it wrong. Follow the vol vol diagram which shows blue wire (output) on the outside prong and and input wire from blend (or straight from pickups) on the middle prong. If you follow their diagram for vol blend, you will have volume but no volume control. You will have constant volume all the time.

Hi Tewest!

Thanks for posting. I went over to Goran's bench and asking him to check the diagram, run a simulation, and finally to check the wiring in one of our basses. This was his response:

The wiring scheme shown in Blend-Volume configuration diagram is correct, and will provide the proper functionality of the Volume control.

At the full CCW position, the input of the OBP (connected to the center terminal of the Volume potentiometer) will basically be shorted to the left terminal (ground) – this setting will result in minimum (zero) output.

With Volume potentiometer at the full CW position, the input of the OBP will be shorted to the output of the Blend pot – there is no attenuation of the signal in this configuration. This setting provides maximum output.
The wiring scheme shown in Blend-Volume configuration diagram is correct, and will provide the proper functionality of the Volume control.

At the full CCW position, the input of the OBP (connected to the center terminal of the Volume potentiometer) will basically be shorted to the left terminal (ground) – this setting will result in minimum (zero) output.

With Volume potentiometer at the full CW position, the input of the OBP will be shorted to the output of the Blend pot – there is no attenuation of the signal in this configuration. This setting provides maximum output.

Here are some common problems that may apply in this case:

1. Tiny wire strands touching the wrong terminal. These can be as thin as human hair, so you have to look really close.

2. Wires that have broken, but the insulation makes it look like they are still connected. A gentle tug usually makes them come loose.

3. Broken pots. Very common. There must be 50 ways to break your potentiometer.

4. Preamp wiring errors: Wiring diagram shows rear view of potentiometers arranged in a certain way. If your potentiometers are arranged differently and/or positioned in such way that terminals are facing each other it could be tricky to translate what is shown in the wiring diagram to what’s inside of your bass.


Hope this is helpful!

Best,

Dave B.

[Tewest86]

Ok. Thanks. Let me try a different volume pot.

[Tewest86]

Is the blue wire input to volume pot from preamp or output to preamp?

[mmbongo]

I posted this same thing about a year ago

I never could get anything using Aguilar's diagram, so I followed the digram at StewMac which worked like a charm.

[Aguilar/Dave B.]

Originally Posted by Tewest86

Is the blue wire input to volume pot from preamp or output to preamp?

Hi,

Blue wire is input to the preamp. Preamp is after Pickups, blend, volume pot. Honestly...this is a pretty basic diagram; but I can see how this might be confusing. Feel free to call us or write Marco for assistance. techsupport@aguilaramp.com

Happy Holidays,

Dave B.

[SGD Lutherie]

Blend pots are not all the same!

What you want to do it to set the blend at the center detent, and then take a meter and read from the center to each outside terminal on each deck.

One side will be close to zero, or a few ohms: that is your hot side.

The other will be close to the value of the pot: that is your ground side.

Here's the reading from a 500k Bourns blend pot on the StewMac diagram:



This is for an M/N taper pot. Some are the reverse of this. You should prefer an M/N taper over an A/B taper, which does not give full volume at the center.