Kongo Posted October 7, 2012 Share Posted October 7, 2012 (edited) Hey guys. I'm having issues with the output on my bass since changing the pre-amp. Allow me to give a low down and then any advice will be taken on board. :-) So, I decided to change the pre-amp on my LTD F105 from the G&B 2-band to a Spector TonePump. I love these pre-amps and figured as this LTD is the only 2-band they do, why not experiment. It's brand new straight from Spector themselves. Now then, I took the old pre-amp out, it has a lot more wires than the TonePump, i.e. the usual "white" and "black" where one wire that split into two. Other than that, just more wires that go to it's own treble and bass pot, which were also removed as the Tonepump comes with pre-wired bass and treble. I got the wiring diagram from the Spector site on wiring a volume/blend combination, traced all wires to make sure this G&B pre-amp wasn't piggybacking anything and when all was said and done, taking it out and putting the Tonepump in would be straight forward. At least I thought so. I took it out and got to putting the Tonepump in. Everything was connected. I was getting a signal so I thought ok, lets go test. Tightened everything up, plugged it in and...such a weedy sound came out. Even with the EQ fully boosted. These also come with a trim pot, so I made sure the output on the pre itself was up, and it is. No difference. Time was not on my side so I came back to it the next day. I re-soldered a couple of joins just in case. Tightened everything back up again. The output is a bit better, it's audible now but still weak. It doesn't even engage my compressor on it's most sensitive setting it's that weak. Also there's a slight distorted breakup in the low end, not the nice kind you get from these pre-amps, this is unwanted distortion, like a cheap fuzz box. If it helps, I've also noticed crackles if I move the wires and the volume pot seems to make a "swoosh" sound when I turn it. I'm thinking perhaps a ground issue but I can't trace it for the life of me. One last thing, the battery was new (Duracell) but just in case I changed it to check and it's still the same, so it can't be that either. Is it perhaps loosing juice somewhere? Any help will be appreciated. Thanks. :-) Edited October 18, 2012 by Kongo Quote Link to comment Share on other sites More sharing options...
MarkBassChat Posted October 7, 2012 Share Posted October 7, 2012 TonePump is a preamp with a very strong signal. If you get weak signal, there must be some wiring mistake. Check it again with the wiring diagram. The trick is that every single wire has to be connected properly, not 99% of them . If you cannot do it on your own, find someone in the neighbourhood who can fix it. Mark Quote Link to comment Share on other sites More sharing options...
Stacker Posted October 7, 2012 Share Posted October 7, 2012 That sounds to me like the pre-amp is being bypassed completely. Are any of the EQ controls doing anything? Check your battery connection first: if that's not being engaged then the pre-amp won't work. Quote Link to comment Share on other sites More sharing options...
paul_5 Posted October 7, 2012 Share Posted October 7, 2012 If you've got a weedy output (technical term) and you've changed the battery then I'd look at the wiring as Mark suggested. It may be that one of the wires isn't fully connected, but it may also be due to phasing issues - check that the two wires from your pickups are going to the right places on the Pre, otherwise no amount of soldering will rectify the problem. Quote Link to comment Share on other sites More sharing options...
ahpook Posted October 7, 2012 Share Posted October 7, 2012 a swooshing sound on the volume pot might indicate that you've got some DC across the pot. Quote Link to comment Share on other sites More sharing options...
Kongo Posted October 7, 2012 Author Share Posted October 7, 2012 Hey dudes, thanks for the replies. Lemmie give some feedback. [quote name='MarkBassChat' timestamp='1349595180' post='1827967'] TonePump is a preamp with a very strong signal. If you get weak signal, there must be some wiring mistake. Check it again with the wiring diagram. The trick is that every single wire has to be connected properly, not 99% of them . If you cannot do it on your own, find someone in the neighbourhood who can fix it. Mark [/quote] That was my thoughts exactly. Having play a Spector Euro I did research into what made them tick, other than the wood. The TonePump interested me and my research lead to finding that its output is very hot (so much so later ones, such as mine, have an output trim pot). Although I can't rule it out, I highly doubt the pre-amp is faulty. It must be my wiring. I followed the diagram to a T and all the joints are solid, AFAIK. That being said, I can't tell a cold joint from a normal one. Maybe I had one of those? But I've done it twice now. I think I should just see if a local can sort it out. Anyone who understands this kind of thing should be able to do it but a local repairer who rewired my friends guitar should be a good bet. Hope he's good with pre-amps. [quote name='Stacker' timestamp='1349597058' post='1827984'] That sounds to me like the pre-amp is being bypassed completely. Are any of the EQ controls doing anything? Check your battery connection first: if that's not being engaged then the pre-amp won't work. [/quote] The EQ controls work, at least at the output level it currently is putting out. But yes, they definitely work. :-) [quote name='paul_5' timestamp='1349597143' post='1827985'] If you've got a weedy output (technical term) and you've changed the battery then I'd look at the wiring as Mark suggested. It may be that one of the wires isn't fully connected, but it may also be due to phasing issues - check that the two wires from your pickups are going to the right places on the Pre, otherwise no amount of soldering will rectify the problem. [/quote] I've been thinking phase perhaps. I wired pickups in before where the output was weak...Hmmm but then there were no funny issues. A thing to think of, however. [quote name='dave.c' timestamp='1349610991' post='1828208'] Are they passive pickups or active pickups that require power to them? If they are active and have no power then you will get a weak output from them. [/quote] It's an LTD F-105, it has ESP SB-5's in the bridge and neck, they are passive. I was gonna look into EMG 40DC's but after all of this I think if I do, it's going straight to someone who can wire, which will just up the cost. :-( I think after all of this it's best to take it to someone...This is a cost I did not foresee but the bass is worth it. If anyone can think of someone local to myself who could be of help, please let me know. :-) Quote Link to comment Share on other sites More sharing options...
Darkstrike Posted October 8, 2012 Share Posted October 8, 2012 Something very similar happened to me this weekend, installing a Aguilar OBP-3, right down to the crackling wires, though I had no blend. In my case, it was the volume pot itself that was wrecked(possibly overheated when soldering), once I swapped it out for another one I had handy, everything was perfect. Quote Link to comment Share on other sites More sharing options...
mart Posted October 8, 2012 Share Posted October 8, 2012 [quote name='Kongo' timestamp='1349652382' post='1828822'] ... If anyone can think of someone local to myself who could be of help, please let me know. :-) [/quote] Isn't basschat member (and mod) Icastle round your way? I'd get in touch with him and see if he can recommend someone - or even help you himself, as he's very knowledgeable and very helpful. Quote Link to comment Share on other sites More sharing options...
GregBass Posted October 8, 2012 Share Posted October 8, 2012 I think lettsguitars - also a BC member - is based somewhere around Leicester. Quote Link to comment Share on other sites More sharing options...
Kongo Posted October 10, 2012 Author Share Posted October 10, 2012 Thanks. I'll have a look. I'd rather someone on here who knows and is passionate about bass than someone who could, but isn't familiar. Example any electrician could follow the diagram, but they won't know the correct sound it should produce when it's done. Not expecting for free either, they'd be paid. I want my pride and joy sounding better than it did, not worse. :-( Quote Link to comment Share on other sites More sharing options...
Kongo Posted October 10, 2012 Author Share Posted October 10, 2012 [quote name='Darkstrike' timestamp='1349655971' post='1828838'] Something very similar happened to me this weekend, installing a Aguilar OBP-3, right down to the crackling wires, though I had no blend. In my case, it was the volume pot itself that was wrecked(possibly overheated when soldering), once I swapped it out for another one I had handy, everything was perfect. [/quote] I have considered that but the pot didn't get hot afaik. (sorry for double post, on phone on the move). Quote Link to comment Share on other sites More sharing options...
KiOgon Posted October 11, 2012 Share Posted October 11, 2012 Hi Kongo, I would happily have a look at it for you but I'm way down South. Not the sort of thing to be sorted without hands on I fear. Good luck in finding someone local, Cheerz, John Quote Link to comment Share on other sites More sharing options...
Kongo Posted October 11, 2012 Author Share Posted October 11, 2012 [quote name='KiOgon' timestamp='1349949508' post='1832523'] Hi Kongo, I would happily have a look at it for you but I'm way down South. Not the sort of thing to be sorted without hands on I fear. Good luck in finding someone local, Cheerz, John [/quote] I did think you'd know, I've seen many a post about these solderless kits you do (which I may require sometimes) but figured your distance would be an issue. Travel or shipping would be too much. But this reminds me in looking around who's local. :-) Quote Link to comment Share on other sites More sharing options...
Kongo Posted October 18, 2012 Author Share Posted October 18, 2012 (edited) Sorted it guys. :-) I sat and stared at the wiring diagram today until it appeared. The blue and black wire going to the volume pot were the wrong way round. :-/ How did I do this? Well, so it now seems the pan pot is also wired backwards...But I didn't touch it this time because I noticed it's meant to be that way. The ground etc were all correct so I left that alone and instead just swapped the blue and black wires instead...it works! I was using the previous wiring as a guideline and was thrown off by it. No more swooshing from the volume pot (So whoever said it was some DC going through was correct) and the output is...well when I 1st plugged it in I plucked the E-string and sh*t myself. My amp also decided to activate it's safety and disabled itself temporarily haha. So in other words, it clipped like a mother! I've turned the trim pot to 40% output, yes 40%! Now it's output is similar to what I'm used to, but still has that TonePump edge to it and with a bit of treble and bass dialled in it sounds so damn sweet, even with these month old strings. Thanks for the help, guys. My confidence is back and this mod is 100% successful. Now...maybe time to add active pickups! X-D Edited October 18, 2012 by Kongo Quote Link to comment Share on other sites More sharing options...
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