Trim pot question

[rv_bass]

I have a Series instrument and in order for me to get both pickups to be the same volume, I have to set the bridge trim pot maxed all the way and the neck pickup only a little over half way.  Is this typical?  If not, is there a way to adjust something so that the trim pots have equal influence over the volume (Gain) of each pickup? 


In the photo, the neck pickup volume trim pot is on the left, and the bridge is on the right.  The settings shown provide equal volume for both pickups.


Thanks!

[KR]

Fret the outside strings at the 20th fret and set each pickup height measuring 3mm between the bottom of the string and the top of the pickup. Do this 3mm setting for --both-- pickups. After setting the pickups like this, maxx both trim pots. The bass pickup will inherently be a little louder because of greater string excursion at the bass pickup position under the strings. If the volume difference with this setting is still huge: unplug and re-attach the offending pickup at the preamp card and see if it's a connection issue. BTW 3mm is a very good pickup height setting for many basses, active or passive. Also, Alembic pickups are the same wind/strength for neck and bridge positions, so raising the bridge pickup closer to the strings is common in order to make it compete well with the neck pickup with its position picking up the broader string swing. Setting the neck pickup at 3mm, and the bridge pickup at 2mm will help a lot and is common. Always measure pickup height while fretting at the 20th fret.

[rv_bass]

Thank you, KR, I will do as you say tomorrow and report back.

[KR]

Cool. Sounds like a pickup height issue. Bridge pickups are set higher during most bass setups. All mine are set like that.

[mario_farufyno]

Maybe this is due to the fact strings move less near the bridge, or related to PU height?

[mario_farufyno]

oops, thanks KR

[KR]

You're just backing me up--lol

[rv_bass]

I checked the pickup heights this morning.  Bridge is at 3mm (can’t raise it any more) and neck is at 4mm.  I‘ll check the wire connections tonight and also try switchIng the pickup connections to see if the issue is replicated on the neck pickup using the bridge pickup connection. 

[KR]

RV, that pickup height is pretty good; nothing wrong with that. That's the setting I have on a couple of my basses. Maybe swapping the pickup connectors at the card will be an indicator. As usual I would recommend cleaning the 5-pin connector at both ends just for yucks, using alcohol.

[rv_bass]

I switched the connections for the two pickups, seems to provide the same result.  I guess the neck pickup Position is just stronger for the reasons you stated above.  I now have it set at max for the bridge and 3/4 for the neck.  I’ll adjust as needed with the two volume controls and the master volume.


Just wondering, are the blue and yellow boxes on the board associated the “electronics upgrade”?


Thanks

[KR]

RV, I assume so, about the upgrade. Ask Mica or see who weighs in about all this...I think your bass is probably within range electronically. On my MSB the Bridge pickup outputs really strong, making me favor the Neck trim a little more to balance the tone for my taste. If your bass is a LSB I would think the Neck pickup position would speak stronger as it's even farther from the bridge than a MSB Neck pickup is. The farther the pickup is from the bridge the stronger it will sound. Also, you can try physically swapping the pickup positions; maybe your neck pickup was wound a touch hotter.

[lbpesq]

Yellow looks like a capacitor, blue looks like a trimpot.  That's my guess, FWIW.  Also, Alembic pickups in a Series are individually adjustable.  There is no requirement that they are supposed to be adjusted identically.

Bill, tgo

[rv_bass]

Thanks KR and Bill, this all makes sense.

It’s a LSB and I can get the two  pickups pretty close with the trim pots set as they are.  That gives me a neutral starting point.  Then as Bill notes, I can adjust the volume knobs individually for the mix I like, then use the master to adjust the overall volume of the mix.  Then it’s off to Alembic bliss! 

Thanks for the help!   

[KR]

RV, I just modified my post suggesting swapping the physical positions of the pickups as the neck unit may be wound just a touch hotter.

[edwardofhuncote]

Rob, I can't remember where it is, but somewhere there is a post to a thread where the blue trimpot is mentioned. The sticker covers the slot to keep you from adjusting it, which makes me think it was associated with the RF upgrade.

Gimme' a little bit and I'll remember the right word to search. 

*pictures on this thread- http://club.alembic.com/index.php?topic=23588.msg236296#msg236296 and FC confirms what I thought. This isn't the post I was thinking of, but it gets you there.