Hello,
it is me again with some additional news. After the last change I got relative fast that even with the correct 5-string pickups (NOT the known-as-faulty-ones, at first I had a model with those)) the B-String and also the G-String were thinner as expected. Not very strong, but for me nevertheless a noticeable difference. So I asked me why.
What Pickups are build in ? If you compare to standard five string pickups from Seymour Duncan or EMG with soap bars, you see the 4-string types are 3,5" (89mm) while the 5-string types are 4"(102mm). But our 5-string Thunderbird has 3,5" pickups. Those 3.5 pickups are given with a max string space of around 68mm. That fits - but what does this mean ? The G- and the B-String are at the ends of the bar then. With a 5-string pickup you get a magnetic field of nearly 80mm, that means also the outer strings are lying pretty in the magnetic field, not on the edges.
The question for me is, why uses epiphone such a strange measure for the t-bird pro V string ? The older t-birds have wider pickups, around 96 mm. This could also fit for a five string. But in the newest generation the pickups became smaller instead....... very bad idea.
The other thing is, it seems my pickups are microphonic. The hum is noticable, even in passive mode and too much for humbuckers.
Finally I decided to throw them away. The bass itself really has a nice tone. I ordered a set of Seymour Duncan passive 5-String soapbars SSB-5.
At work I have a friend who did the necessary routing for me. It is very very narrow, but it fits. The wood still has 2mm reserve on each side now :)
The sound now is complete different of course - even with the old bad original strings the B now is really fat, also the G is not thinner anymore. That is the V-String T-Bird Pro as it should have been from the beginning. Really a pity to make such a weird construction (electronic, pickups) , as the base idea of the t-Bird pro was really great.
Of course no hum anymore. I guess I will try the old active electronics later, but for now I am complete happy with the Seymours in passive mode (2x500k A, 1x250k A, 1x0.047 uF).
Best regards
Sigi