phil_the_bassist Posted July 7, 2009 Share Posted July 7, 2009 So, my MMSR5's preamp has sh*t itself and thus I need a new one. Rather than beg EBMM to send me a new SR pre, I'm now looking into the options available to me in the world of Aftermarket Preamp Goodness. My initial idea was to get a SeymoreDuncan/Bartollini/Nordstrand high output MM replacement pup, and put that in with a John East MM-preamp, so I can get a real hot MM sound with active/passive and all the benefits that come with using JE equipment ...I've now had a thought, what about the ACG filter based pre? Why limit my bass to The Stingray Sound? Why not allow all the options of the ACG/JE filter based preamp? So, what do you guys think? Quote Link to comment Share on other sites More sharing options...
GreeneKing Posted July 7, 2009 Share Posted July 7, 2009 I'm biased I have owned 2 ACG01's and fitted and used about half a dozen ACG02's. I did create a thread where I described how they work and how that they allow you to craft a tone rather than simply tweek it. Not everyone is a fan and if you're not prepared to re-learn your tone production then maybe it's not for you. The range of tones is immense and I just leave my amp flat when using the ACG basses. Its a powerhouse of tone in your bass. Quote Link to comment Share on other sites More sharing options...
henry norton Posted July 7, 2009 Share Posted July 7, 2009 I think the ACG has polarised the options a bass player has. Alembic asides, it used to be you tweak your tone externally (via effects or changing amp settings), and/or use a range of basses to give you a broad range of sounds. I don't think the ACG will be a direct replacement for a rack of instruments but it's intuitive and flexible in a way 'old fashioned bass, mid, treble isn't, and given time, there are alot more useable sounds to be had. I'm happy with two basses and a v-amp but if I could only have one I'd probably install an ACG pre. Quote Link to comment Share on other sites More sharing options...
obbm Posted July 7, 2009 Share Posted July 7, 2009 I've looked into all aspects of SR5 pre-amps including what you are suggesting. Just to repeat what I've said many times before, the coil switching function is an integral part of the EBMM pre-amp and uses the first two stages of the op-amp. Take away the EBMM and install something else and you'll have to decide which of the three selections you want to hard-wire. The alternative is to replicate the EBMM circuitry on a new PCB and interpose it between the pick-up and the new pre-amp. By rewiring and reconfiguring the pick-up from 5 to 6 wires and completely rewiring the selector switch you can do it but then you lose the switched gain adjustment that compensates for different levels when coil switching. I know I've been there and done it. Tread carefully. Quote Link to comment Share on other sites More sharing options...
steve Posted July 8, 2009 Share Posted July 8, 2009 (edited) could you not get the MM pre repaired? - not that I'm trying to dissuade you from the acg pre Edited July 8, 2009 by steve Quote Link to comment Share on other sites More sharing options...
phil_the_bassist Posted July 8, 2009 Author Share Posted July 8, 2009 [quote name='obbm' post='535257' date='Jul 7 2009, 10:54 PM']I've looked into all aspects of SR5 pre-amps including what you are suggesting. Just to repeat what I've said many times before, the coil switching function is an integral part of the EBMM pre-amp and uses the first two stages of the op-amp. Take away the EBMM and install something else and you'll have to decide which of the three selections you want to hard-wire. The alternative is to replicate the EBMM circuitry on a new PCB and interpose it between the pick-up and the new pre-amp. By rewiring and reconfiguring the pick-up from 5 to 6 wires and completely rewiring the selector switch you can do it but then you lose the switched gain adjustment that compensates for different levels when coil switching. I know I've been there and done it. Tread carefully.[/quote] so which bit/where abouts is the op-amp? I've googled it and i was merely informed it was a basic preamp...does this mean its the first stage of the EBMM pre? Will this only be a concern if I don't change both the pickup and preamp? Quote Link to comment Share on other sites More sharing options...
phil_the_bassist Posted July 8, 2009 Author Share Posted July 8, 2009 [quote name='steve' post='535373' date='Jul 8 2009, 08:18 AM']could you not get the MM pre repaired? - not that I'm trying to dissuade you from the acg pre[/quote] And where's the fun in that! I'm gonna explore other options to get my ray working then I'll have a half dead pre to play with at my leisure Quote Link to comment Share on other sites More sharing options...
obbm Posted July 8, 2009 Share Posted July 8, 2009 [quote name='phil_the_bassist' post='535377' date='Jul 8 2009, 08:24 AM']so which bit/where abouts is the op-amp? I've googled it and i was merely informed it was a basic preamp...does this mean its the first stage of the EBMM pre?[/quote] This is the stock SR5 pre-amp. It uses a 4-way op-amp. The first two stages provide a form balanced input for series and single coil modes. This is the way they eliminate any extraneous noise and hum. In parallel mode they just use a single input. If you follow the circuit through then you will see. The two other stages are the eq control. The whole lot, including the pots are mounted on the single PCB with flying leads to the 4-pole switch. If you wanted to use a different pre-amp and retain coil switching then you would need to trace out and build a copy of the input stages of the MM pre-amp. then connect that to your pre-amp of choice. [quote name='phil_the_bassist' post='535377' date='Jul 8 2009, 08:24 AM']Will this only be a concern if I don't change both the pickup and preamp?[/quote] Not really as all the replacement pick-ups for SR5s are wired to allow direct connection into the stock SR5 pre-amp. If you did away with coil switching and hard wired in parallel or serial then you could just drop in any pre-amp. I used an Aguillar OBP3 in mine for a while but it was just wired in parallel mode. I waited 4-years for an MM SR5 pre-amp to come up on Ebay. I strongly recommentd that you send it back to EBMM and get it fixed. Even if you don't use it, it will have a good resale value. Alternatively you could give it to me. If you want to play around then why not buy my Sub 5. It would give you hours of amusement I'm sure. Quote Link to comment Share on other sites More sharing options...
Spartacus Posted July 8, 2009 Share Posted July 8, 2009 [quote name='phil_the_bassist' post='535377' date='Jul 8 2009, 08:24 AM']so which bit/where abouts is the op-amp? I've googled it and i was merely informed it was a basic preamp...does this mean its the first stage of the EBMM pre? Will this only be a concern if I don't change both the pickup and preamp?[/quote] The SR5 pickup has 3 coils including a dummy for humcanceling. The SR% preamp and switch includes circuitry that selects buffers and balances the coils to match volumes and stay hum free. So if you lose the preamp youll have to rewire the pickup and replace the switch to keep the pickup selections. If you change both pickup and preamp youll stilll have to replace the switch to keep pickup selection because its an intergral part of the preamp circuit. Usual way to do that is with a 3way on/on/on double pole triple throw switch which will leave your pickgard with a slotted hole unless you do what obbm suggests and somehow get the switch and buffered front end of the preamp replicated. Quote Link to comment Share on other sites More sharing options...
phil_the_bassist Posted July 8, 2009 Author Share Posted July 8, 2009 Thanks for the diagram and explaination Dave, I can see what you and Spartacus are saying now! It's a lot to think about...perhaps I'll just tAke your Sub off your hands then Quote Link to comment Share on other sites More sharing options...
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