Converting a SBMM SUB to passive electronics

[Guest MoJo]

Before I throw myself to the lions on the Ernie Ball forums and get burned alive for suggesting such a thing, has anyone here removed the pre-amp and converted an SBMM SUB to passive electronics? If so, how did it go and how did it sound?

Thanks

[KiOgon]

I've done a few kits for - and I'm sure the owners were well pleased.

Must be some mention of in my feedback😎

[Guest MoJo]

9 minutes ago, KiOgon said:

I've done a few kits for - and I'm sure the owners were well pleased.

Must be some mention of in my feedback😎

I have a look later

[KiOgon]

I found one from Tom - can't believe how long ago!

tom1946

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Posted April 25, 2015

Just received a kit and pickup from John and it's transformed my MM SUB, can't believe the difference this has made, thanks so much for a superb loom too.
The quality of John's kits is exemplary, very fast delivery too.

rock on John

•  

[gary mac]

Last week, I converted a customer's active Squier Jag to passive. Completely transformed it, from an horrid boomy mush to clear articulate Fendery goodness.

Sorry a bit of a thread hijack but just making the point that sometimes the manufacturers don't get it right and that simple can be best.

[Paddy515]

I owned an active USA Sub and a passive USA SUB version at the same time. Now only own the passive version and use it for every gig. Really growly without being over-harsh. Love it.

[Paul S]

I have an EBMM Sterling 5 and had it converted to passive, much prefer it now.  Plus it is lighter with the guts out, too  

[Guest MoJo]

16 hours ago, Paul S said:

I have an EBMM Sterling 5 and had it converted to passive, much prefer it now.  Plus it is lighter with the guts out, too  

PM’d you Paul

[Paul S]

Nothing in my inbox, sir.

[Bassalarky]

The one in my avatar pic is passive (wired parallel) and I think it sounds great.p It's not actually a MM bass, but very similar. I like simplicity so it has only a volume control, couldn't be happier with it.

[Andyjr1515]

On 05/11/2019 at 15:06, Paul S said:

I have an EBMM Sterling 5 and had it converted to passive, much prefer it now.  Plus it is lighter with the guts out, too  

That's going back a bit now, Paul

 

@MoJoI spotted this because I had a vague recollection of there being an output strength issue with the EBMM pickup when converting the bass to passive.

Now - I must say - the Ernie Ball and Music Man sites are very, very light on the technical (I suppose they don't want people fiddling with their admittedly excellent products) so I have no idea if this also applies to the SBMM version.

If you want the full blow by blow, the thread is here:

https://www.basschat.co.uk/topic/294193-paul-ss-sterling-5/#comments

The issue was compounded by Paul's request to add a powerful Aguilar P-pickup into the equation but the MM pickup had an exceptionally low resistance (from memory less than 3kohm).  I believe that it is basically a noiseless single coil and has a dummy coil to counteract the hum but that is only going from a hint on their website.  Nevertheless, I had to wire the MM in series (it is in parallel when running through the active EQ) and that got the output to a level where a blend arrangement could be used to balance the two pickups in the middle position of the three way switch.  

I'm sure it was a bit of an offense against the original EBMM pickup design concept but, I have to say, it sounded brilliant! 

 

The SBMM might be completely different in all respects but the wiring convention to put the EBMM into series turned out to be:

Red is hot
White and black joined
Green to ground

 

Hope this helps

[Guest MoJo]

34 minutes ago, Andyjr1515 said:

That's going back a bit now, Paul

 

@MoJoI spotted this because I had a vague recollection of there being an output strength issue with the EBMM pickup when converting the bass to passive.

Now - I must say - the Ernie Ball and Music Man sites are very, very light on the technical (I suppose they don't want people fiddling with their admittedly excellent products) so I have no idea if this also applies to the SBMM version.

If you want the full blow by blow, the thread is here:

https://www.basschat.co.uk/topic/294193-paul-ss-sterling-5/#comments

The issue was compounded by Paul's request to add a powerful Aguilar P-pickup into the equation but the MM pickup had an exceptionally low resistance (from memory less than 3kohm).  I believe that it is basically a noiseless single coil and has a dummy coil to counteract the hum but that is only going from a hint on their website.  Nevertheless, I had to wire the MM in series (it is in parallel when running through the active EQ) and that got the output to a level where a blend arrangement could be used to balance the two pickups in the middle position of the three way switch.  

I'm sure it was a bit of an offense against the original EBMM pickup design concept but, I have to say, it sounded brilliant! 

 

The SBMM might be completely different in all respects but the wiring convention to put the EBMM into series turned out to be:

Red is hot
White and black joined
Green to ground

 

Hope this helps

Thanks for that Andy. 3k is exceptionally low for a bass humbucker IMO. I think you have to retain the parallel wiring option to get the classic 'Ray' sound. From what I can recall when I owned a full fat US Stingray 5, the series wired tone is darker with less attack. Food for thought, I may leave well alone, for the time being

[Andyjr1515]

28 minutes ago, MoJo said:

Thanks for that Andy. 3k is exceptionally low for a bass humbucker IMO. I think you have to retain the parallel wiring option to get the classic 'Ray' sound. From what I can recall when I owned a full fat US Stingray 5, the series wired tone is darker with less attack. Food for thought, I may leave well alone, for the time being

As Paul says in the original thread, it produced a really good sound in this instance but yes - probably, in general.  Trouble is, presumably the concept is very low output with the EQ amplifying the sound to give the classic MM tones.  If so, going passive is going to be a bit of a compromise whatever.

But - and it's a big but - the SBMM might be completely different.  I fitted a MM lookalike for someone another time and that was pretty high output - more like 10k. I suppose you really can't make assumptions.

Let us know how you get on.

Andy 

[Paul S]

5 hours ago, Andyjr1515 said:

That's going back a bit now, Paul

Isn't it!  3 years ago, seems like yesterday.  I was hoping you'd chime in, I couldn't find the original thread!

[Jimothey]

Sorry for a bit of a hijack but @Andyjr1515 I’m looking to do this to my 6 string bass the pickups outputs are around 12k each so do you think I could just scrap the preamp and convert to passive without any problems??........😀

[Andyjr1515]

54 minutes ago, Jimothey said:

Sorry for a bit of a hijack but @Andyjr1515 I’m looking to do this to my 6 string bass the pickups outputs are around 12k each so do you think I could just scrap the preamp and convert to passive without any problems??........😀

I'm no expert, but I would have thought so.

What's the bass?  In most/many cases with basses, the pre-amp is actually just a powered EQ and the pickups themselves are passive.  

[Jimothey]

38 minutes ago, Andyjr1515 said:

I'm no expert, but I would have thought so.

What's the bass?  In most/many cases with basses, the pre-amp is actually just a powered EQ and the pickups themselves are passive.  

It’s a Washburn XB600 (the one I did the build thread about) my plan is just to replace the existing electrics with 2V and 2T pots instead 

I’ll just give it a go and see what happens........👍

[Andyjr1515]

44 minutes ago, Jimothey said:

It’s a Washburn XB600 (the one I did the build thread about) my plan is just to replace the existing electrics with 2V and 2T pots instead 

I’ll just give it a go and see what happens........👍

I'm pretty sure that will work just fine

[Jimothey]

48 minutes ago, Andyjr1515 said:

I'm pretty sure that will work just fine

Cheers mate..........👍

[dannybuoy]

The Joe Dart signature bass is basically a passive Stingray/Sterling. I also very much like my Sandberg Basic in passive mode. Especially with flatwounds!

Edited November 8, 2019 by dannybuoy