Hohner the Jack Bass schematics

[dunkelfalke]

Hello forum

my bass is dead
I bought the thing used, the active electronics never worked but I still could use it as a passive base. Now it doesn't work anymore because some wires came off (the bass electronics were partly resoldered by the previous owner, and he made a really ugly job doing it).

So, has anyone got the original wiring schematics or maybe some could draw new wiring schematics with a new, modern and better sounding preamp for me which makes the bass work even better as before?

The bass has got three pots, one of them is a dual concentric one, the other both are B500 kohm ones. an active/passive switch and a red led which works when the bass is active.

Thanks in advance

[dunkelfalke]

noone?

[D2o]

Dunk,

I'm not finding much on the wiring for this bass - sorry. Does the diagram shown in this link apply to your bass?

basschat.co.uk/index.php?showtopic=44498

Good luck,
D2o

[dunkelfalke]

Yes, that seems to be it, many thanks!

Unfortunately, the photo which shows the active control, is very low resolution, I cannot see exactly where to solder the wires to (got not only one wire floating free but five of them)

[D2o]

You are welcome.

Just eyeballing the dimensions, I wonder if you can take a guesstimate? Maybe worth a try.

Cheers,
D2o

[dunkelfalke]

That could be difficult, while the wiring diagram was dead on, this one isn't exactly the same as mine:

I've got only one concentric pot, two normal pots and a switch. This one is for two concentric pots and two switches.

Since the actual wiring diagram is exact, maybe someone could draw a fitting active control circuit with a preamp? Shouldn't be too difficult with that many geniuses here ;D

[D2o]

It'll have to be sumone else! ;D

Unfortunately, the "Mod God" title I've been saddled with is totally misleading and should be changed to "Order of Kyle Member".

Hopefully, sum other gai or another may be able to take a guess. Scant info on that ...

hmm, just had a thought that didn't really pan out ... I thought maybe I'd get lucky finding something similar while poking around the EMG site's wiring section a bit. Nope ... oh, well.

Good luck,
D2o

[newey]

DF-

This guy has an article about modding his:

www.alanratcliffe.com/gear/thejack/index.shtml

He says "Unfortunately, the active tone control circuit was noisy and ate batteries, so it had to go." He removed his and went passive.

On yours, you indicated that it wasn't working in active mode before it died completely due to wires being disconnected. Do you have any reason to believe that the active circuit board will work if rewired? Were all the wires to that board intact before it died completely?

If it was fully wired and not working (and given what Mr. Ratliffe had to say), you might save yourself a lot of grief by starting afresh on the active circuit. If there's a problem on the board itself, it may be a bear to locate and fix.

Hohner doesn't seem to have any schematics on their ewbsite, but perhaps if you email them they can point you in the right direction:

www.hohnerusa.com/index.php?1781

[dunkelfalke]

Altough I am a good Hohner customer (two Revelations and this Jack Bass) they tend to ignore my mails

Yes, I also thought about starting with a fresh circuit (and contrary to that guy I love active pickups).

Active mode never worked before because the wiring itself was in a real mess. The previous owner tried to rewire some things and his wiring sucks even more than mine back when I started at Guitarnuts (and that tells a lot).

[newey]

Yes, I also thought about starting with a fresh circuit

Then, the question is: Buy one or build one?

If you've never populated a PCB, you might be better off buying a pre-fab one and avoiding a lot of DIY headaches.

I bought one for guitar from guitarfetish, but haven't installed it in anything yet. It would probably work fine on a bass as well - makes your output low impedance and adds a bit of gain- cost me $20 USD. I imagine there are other similar units out on the web.

The wiring diagram would then probably follow in a logical fashion from whatever install instructions you receive with such a unit.

Pre-made units have also given some thought to miniaturization- anything you build is likely to occupy more space, so if cavity area is limited, that's another reason to go pre-made.

[dunkelfalke]

I did both. Probably my first post at Guitarnuts (back then still at John Atchley's site was about a preamp I soldered together which didn't work well enough.

Also tried out those things from Guitarfetish - they are nice for a guitar, but probably not for a bass.

Space isn't an issue at all.



this circuit should be fine, but I don't know how to adapt it to my case, am not sure about the split voltage, the split tone, which opamp to take, the resistor values and so on.

[newey]

JohnH is the one to ask about component values for that sort of thing- shoot him a PM.

You're well beyond my depth on this. But you now have a plan!

[dunkelfalke]

I do. But then again I have found a cheap (25 euros + shipping) bass preamp, fully wired with blend pot, two tone pots and a volume pot.

Difficult to decide.