Heimrich

@NancyJohnson What you say about setup being a combination of multiple factors and a trial-and-error process is absolutely clear and correct, and once again I thank you and the forum for the great infos you provide...So if I got it right, the sequence should be: 1. Remove the strings and aim for a neck as straight as possible (checking it with a ruler) 2. Re-string (is that what you mean when you say "once you're tuned up"?) the instrument and check how it goes, tightening the truss rod if necessary (when you say "a bow of 1mm or 2 over the length of the neck" do you mean with the strings on? Isn't it too much? Maybe you mean 0.10/0.20mm?) Sorry if I keep bothering you but I'd really love to learn how to be able to fix the problem myself without taking it to the luthier or, at least, if that's not possible, to get a full knowledge of what the problem is...

@NancyJohnson very interesting video, that's definitely a work beyond my poor skills... Seems like I'm going to plan a visit to the luthier 😊 Ehm.... Forgive me for another dumb question but... When you say "to ensure the neck is straight", do you mean completely straight after removing the strings and eliminating the tension they generate? Watching the video I'm assuming that in order to be considered perfectly straight the neck must not be under any tension at all, neck relief is only to allow the string to vibrate properly...What if the neck is bowed even without the strings but just a bit (let's say 0.15, 0.10mm)? Couldn't it be considered as "normal" relief once the strings are on? Or must the neck be absolutely straight without the strings to be considered ok and not bowed/damaged? Sorry, thanks for the patience!

@NancyJohnson Mmm.... No, I don't think I have the skills (or could acquire them in a reasonably short time) to do the job myself... I think I will take it to the tech who already did some repairs on another bass of mine. I haven't check the list of luthiers but... I live in Italy, near Rome... P. S. I know that judging by some pictures is not easy at all, but do you think those are frets needing some work? Because if not, I'm probably back to the starting point about my setup problems... Thanks

I've finally had some time to check the frets properly, and I think I've found at least a few of them in not perfect condition...As a checking system I've followed @NancyJohnson and @Grangur suggestions, I took a metal string action ruler (this one https://it.dhgate.com/product/string-action-ruler-for-guitar-bass-string/388035345.html) I put the bass in horizontal position and I moved the ruler by groups of three frets at a time, using the fret in the middle of the group as a pivot. Holding the ruler at the extremities and slightly moving it to see if it rocked, I've found it does on several frets, oscillating up and down and producing an audible "tik" on the frets left and right of the "pivotal" one....The ones that seem to me the worst are the 6th, 7th, 9th and 11th, each on different points (6th towards the high strings, 7th and 8th next the low ones, 11th in the middle...) To give you an idea of the situation I attach some pictures of the frets, can you please give me your opinion on their status? Thank you again😉

@Chiliwailer No no, you're not sounding arrogant at all, I really love to learn from people way more experienced than me.... @NancyJohnson If i take the strings off, is it better to let the neck settle for a while before checking it or can I do it right after removing the strings? Another question (I know I'm probably sounding dumb...) isn't a too straight neck at risk of generating the same problem of buzzing at the end and near the nut (judging by the second picture)? I understand there's probably no "rule of thumb" (pun not intended 😁), but what would be a reasonable relief for an action around 2mm or less (say, 1,7...)

Many thanks to all of you for your suggestions, this evening I will try to deep in a little further with the "neck -checking" and definitely try to spot uneven frets... @Silvia Bluejay, @Grangur You're right, without seeing the bass it's hard to tell, I'll see if I can take some good (or at least decent enough) photos of the fretboard.... @Chiliwailer about the truss rod being too loose, I'd like that would be the case, but I kept the relief between 0,30 and 0,25....Should I go lower than this? Isn't it low enough or at list in the "normal" range? @NancyJohnson the bass is a bolt on

I've tried by raising the action up to 2,5 mm (my goal would be to keep it at 2 mm max, even less if possible and I think instruments like Warwicks should allow that...) but the problem remains, maybe it attenuates a little bit but it's still there... I also noticed that it's impossible to lower the strings less than 1,5mm even lowering everything at max (saddles, bridge, just-a-nut...). I can bring the E down to 1mm but the G remains at 2mm even detuning it! (as I said in the first post neck relief should be OK, it's 0,20mm) At this point I think I'll take it to a tech, but I'd like to know what do you think the problem is... Thank you

I haven't tried it yet, but as far as it seems the nut works, If I screw/unscrew the hex grubs it moves up and down as it should, on both sides...height is about 0.30 mm as specified in the warwick vid...

Yes, just-a-nut.. One thing I noticed following the Warwick setup video is that I cannot lower the G string enough to make it "barely touch the frets" as the tech in the video says... https://youtu.be/-NEXH61OCJY

Hi guys, as the title says looks like I'm having a fret buzz problem I can't solve... The bass is a second hand '98 German made Warwick Thumb bolt on 5 strings and so far I couldn' t reach a good set up. I followed the setup guide by Warwick on YouTube but the problem seems to be the neck buzzing on different areas at the same time, specifically the 4th fret (all the strings but the D in particular) and from the 17th to the 21st on the B, E and A (absolutely un-playable, can hardly hear the notes). There's a little buzz at the 3rd fret but nothing even remotely comparable to the "hive" produced at 4th.The frets from 6th to 16th are perfect and easy to play on all the strings, same as the 1st fret (no buzz at all on all the strings) Neck relief is at 0,20 mm, the action is 2 mm at the 12th fret (and I'd like to keep it that way) As far as I know, the frets next to the body should buzz when there's too much relief and viceversa, what puzzles me is that given the simultaneous buzz upper and lower I can't find out where to intervene... Considering that the bass is 22 years old and I've bought it less than two years ago, I was thinking if it could be a problem of worn out frets on some areas of the neck... Before I take it to a tech, could it be the cause of the problem? If not, what could I do myself before asking for the help of a professional? Thanks a lot!

I've sent an email to H.P.Wilfer of Warwick, he kindly and patiently send me a long and exaustive explanation. Not only he confirms the bass has not been modified in any way, he confirms as well what Doctor J wrote some posts above adding, in his own words: "Yes, Corvette $$ has Passive MM PU´s + active 2-Band El. Passive PUs are not connected to electricity. If he goes into passive mode with a pull-push pot (bypass), passive pu's continue to work as usual. The PU signal does not go through EQ but directly from the PU's to the socket. EQ is still connected to the battery but not active because the signal does not go through the EQ. EQ Treble / Bass function is off. Vol and Balance Poti continue to work as usual. With Thumb Bass, the function is the same as with Corvette $$. The only difference is that Thumb Bass has active PUs. A preamplifier is built into active PUs, which always requires power to function. That is why active PUs are always permanently connected to electricity."

Thanks, so you too confirm that the EQ is the part that is bypassed when I pull the switch

Thank you so much, that basically supports what I thought, by pulling the knob I disengage the EQ but the pickup preamp is still powered* thhrough the red wire hence the definition of "active anyway"(for lack of better word) *of course keeping the battery in :-)

Yes, if I remove the battery the only way to get a signal is to bypass the active eq, I think what Doctor J wrote a couple of posts above is the best explanation of why this happens. Now that you're telling me I think I've seen the YouTube videos you're talking about... A couple of days ago I took part to a discussion on another forum about the "real" nature of active pickups, specifically the MEC J type active ones in Warwick Thumb bass...It seems like there's a bit of confusion (or at least I AM a bit confused) about how the passive pickups/active preamp and the active pu/active preamp system works, the differences betwen them...Someone said that "if you disengage the active pre of a Thumb, what you're left with are the pickups, which are passive". That to me contradicts the Thumb specs as declared by Warwick itlself ("active MEC J pickups, active electronics"). Using as examples two Warwick models: Corvette $$: passive pickups, active preamp. If I pull the knob, I disengage the preamp (thus the treble/bass eq), what's left is the passive pickups, the volume and the pu balance. Thumb: active pickups, active preamp. Disengaging the preamp (this time I mean keeping the 9v battery), if I got it right, the pickups remain active, so they are still powered by the battery, the only thing to be bypassed is the preamp (same treble/bass eq as the Corvette)...Am I right on this? If not, how does it actually works? And, most important, why Warwick would call those pickups "active"? If it was true that "if you disengage the active pre of a Thumb, what you're left with are the pickups, which are passive", why bother to call them "active"? Sorry, I didn't want to be long-winded ;-)

I see....Can I ask you what did you google? Is there some specific discussion you found (something like "active pickups working without battery")? I'm asking because I've searched a lot on the web before getting here on basschat but I haven't been able to find anything definitive about that...

Thanks a lot, that's very interesting...So when we say "active pickups are dead silent without a battery" it's not completely true, at the end of the day the passive pickup principle of the string mechanical vibration producing magnetic energy that is then transformed in electric energy still applies...Just to be sure I get it right, the preamp is the treble/bass knob? Or there's a preamp inside the pickup (like EMGs) AND the active treble/bass EQ?

Thank you so much! So I'm not the only one, that's exactly what happens whit mine...I have to increase the gain and master on the amp but yes, it's still usable. As vfar as I know that shouldn't be possible in an active pu/active preamp design...My concern (in my ignorance) is that it could depend on some sort of...bad shielding (for lack of better word) somewhere in between the instrument and the amp I will definitely send an email to H.P. Wilfer as BassBunny suggests. After all, no one is more qualified about Warwicks than him :-)

Hi everyone, I'm new and I apologize if this is in the wrong section....I’d like to ask if someone could please help me to find out if my bass has been modified in some way. I bought my ’99 Thumb BO 5 second hand in a shop and unfortunately, they couldn’t give me any info about the former owner of the instrument. As far as I know, the J/J MEC pickups in a Thumb BO bass are active, with an active preamp…That was confirmed by H.P. Wilfer who kindly answered an email giving me all the specs about the instrument via the serial number. On the due premise that I have very little knowledge about electronics, wiring etc., I’m trying to use some time during this forced quarantine to fill such a gap and clarify some doubts. A couple of days ago I came across some discussions on the web about the “real” meaning of active vs. passive (how the term “active” is sometimes misunderstood, how a bass with passive pickups but active preamp has to be considered active…you surely know the debate much better than me), as far as I know in an active/active configuration such as the Thumb bass both the preamp AND the pickups are powered by the 9v battery, so if I disengage the preamp pulling the volume knob the preamp doesn’t work anymore but the pickups do, right? If I’d remove the battery, being the whole system active, the instrument should cease to function and no sound should be heard… That’s where the problem lies. I actually removed the 9v battery, I plugged the bass into the amp, I pulled the knob and with my surprise, it plays! Isn’t this what happens with the passive pickups? Always based on my very basic knowledge, in a passive pickups/active preamp instrument if I remove the battery the preamp deactivates but the pickups, not needing an external current, keep working… I know it probably sounds like a dumb question but...is it possible that my bass has been modified/rewired to make the pickups work like passive? Or maybe does the instrument gets somehow current from the amp through the cable (amp is a Little Mark II that so far never gave me any problem, no hisses, noises, power drops...)? I attach some pictures of the electronics cavity, can you tell me if you see something wrong? As far as I’m concerned, it seems to me like the two battery wires have been cut and reconnected (there’s a sort of plastic/rubber wrapping on part of them). If any modification actually happened, is it possible to reverse it and put the instrument back to its original active/active configuration? How? Thanks

Hi everyone, I'm Emerico, a bassist from Rome...I've always gravitated around blues, rock, hard rock, metal...My gear consist in a Warwick Thumb BO 5 (I'm asking for some help about this instrument in another post...), a Spector Euro 5 LX and a Warwick Corvette $$ 5. My amp is a MarkBass Little Mark II, I used to have a MarkBass 4x10 but nowadays I rarely play live so I use IRs (MOOER Radar, Poulin LeCab...)