My "new" 1982 Yamaha BB1200S

[hypercarrots]

Hi Kenstee,

I'm looking for help:

My BB1200S came with EMG pickups and preamp. Former owner did send me the original BB1200S preamp, but no original pickups. I'm gonna replace the EMG's with vintage style alnico's and restore the original preamp.
I also have a BB2000S which appeared to have the same LC87452 Yamaha preamp. It's missing some caps, resistors and one of the C2240 BL transistors, so it's not working.
The BB1200S has a 3 band EQ, and the BB2000S has a 2 band EQ. But when I tried the BB1200S preamp on the BB2000S bass it worked perfect.
I'm trying to repair the incomplete preamp, I hope you can help me out with a schematic, or one of the service manuals for either BB2000S or BB1200S [LC87452 Yamaha BB1200S/BB2000S preamp]
Thanks, anyway.

kenstees last post was in 2014

 

[Bass Boy 1200S]

kenstees last post was in 2014

Yes, I should have noticed. This was my first post, not so smart indeed. Yust beginning to learn how things work on TB.
I'll try again, with a more suitable post and see if I can find some help with my preamp.

Thanks Hypercarrots.

 

[RobTheRiot]

@Bass Boy 1200S Welcome to TB!
Takes a little while to find your way around, but once you do there's so much great info and so many great people here.
Unfortunately I can't help with your question, but if you post it in the Pickups/Electronics subforum im sure someone will be able to help!

 

[Bass Boy 1200S]

@Bass Boy 1200S Welcome to TB!
Takes a little while to find your way around, but once you do there's so much great info and so many great people here.
Unfortunately I can't help with your question, but if you post it in the Pickups/Electronics subforum im sure someone will be able to help!

Thanks RobTheRiot.
With Hypercarrots and you helping me to find the right direction, I already start to feel at home.
I'll try the Pickups/Electronics subforum. Thanks for you help!

 

[hypercarrots]

Thanks RobTheRiot.
With Hypercarrots and you helping me to find the right direction, I already start to feel at home.
I'll try the Pickups/Electronics subforum. Thanks for you help!

Yamaha BB1200S Pre-amp circuit

 

[Bass Boy 1200S]

Perfect, exactly what I need to do the job.
I even had a hard time reading the value's of the excisting parts, and had no Idea about the ceramic cap value's at all. This makes live a lot easier.
Great!

Thanks again, Hypercarrots.

 

[LK Harwood]

They are great aren't they! A P-Bass on steroids. One suggestion..Even if you're a die-hard rounds guy do consider at least trying D'Addario Chromes on it. With the preamp engaged, you can make it sound as bright as new roundwounds but with no string squeak. I didn't believe it either...until I tried it. I'm hooked.....

Another TB'er gave me some great advice for the preamp settings when I got mine: "Bass-all the way up, Mids-neutral, treble-all the way up. Depending on how your rig sounds, you can tweak them slightly. Sometimes I back off from those default positions just a tiny bit-- lows if the bottom is overwhelming, highs if it sounds too harsh, and mids to get a slightly more glass-like tone. For a more vintagey tone I'll back off the highs to neutral, and turn the mids all the way up. For true vintage tone, you can just flick the toggle to turn it off, and then there's just a single tone knob for passive mode. It's a really marvelous pre-amp, very well-voiced."

I've got a pdf of the service/parts manual for it. Shoot me your email address in a PM and I'll send one to you if you want.

Do you still have that PDF file? I have 2 BB1200s' and I recently got a BB1100s but the preamp isn't working. The 1100 sounds great passive but I was really looking forward to having a bolt-on with that amazing preamp.
Thank you

 

[tanr26]

They are great aren't they! A P-Bass on steroids. One suggestion..Even if you're a die-hard rounds guy do consider at least trying D'Addario Chromes on it. With the preamp engaged, you can make it sound as bright as new roundwounds but with no string squeak. I didn't believe it either...until I tried it. I'm hooked.....

Another TB'er gave me some great advice for the preamp settings when I got mine: "Bass-all the way up, Mids-neutral, treble-all the way up. Depending on how your rig sounds, you can tweak them slightly. Sometimes I back off from those default positions just a tiny bit-- lows if the bottom is overwhelming, highs if it sounds too harsh, and mids to get a slightly more glass-like tone. For a more vintagey tone I'll back off the highs to neutral, and turn the mids all the way up. For true vintage tone, you can just flick the toggle to turn it off, and then there's just a single tone knob for passive mode. It's a really marvelous pre-amp, very well-voiced."

I've got a pdf of the service/parts manual for it. Shoot me your email address in a PM and I'll send one to you if you want.

Hi I know its been 12 years since your post but I just got a BB1200s that shows traces of previous work done in the electronic cavity. I set my eq quite high, about 75-90% most of the time. When i flick the passive switch the difference in output is so unbalanced that its like turning the volume from 10 to 2. Is this normal? Does the eq boost that much output? Or should be less extreme? I also find the tone knob to have only a subtle effect on the tone in passive mode ( i know it doesnt work in active mode). Thank you in advance for your help. Cheers

 

[tanr26]

kenstees last post was in 2014

Ahh should have gone through the whole thread before posting