Author Topic: Info request - mysterious Series I (Read 1200 times)

the_mule · « **Reply #15 on:** June 04, 2004, 08:16:47 AM »

Hoi Adriaan, yes, I have looked everywhere, used the reference pages for every possible location, but the serial number seems to be lost because of the modification John and Mica described before.

And yes again, I'm very serious about the pawn shop and the price I paid. I was very lucky to hear about it hanging there before anyone else seriously interested AND willing to pay the price (it's dead cheap for a Series I, but still a lot of money for many people) could get a hold of it.

I'm not sure about the core wood being mahogany though, in real it looks much more 'chocolate-ish', at least compared with the mahogany body of my Orion.

BTW: here's an 'intimate' picture of the electronics cavity. You can see the number '1937' written in blue/purple. Unfortunately the bridge pickup doesn't work. I have tried the 4-way (?) pickup selector switch that was still lurking in the dept, but no luck there. Some questions for other Series I owners: Does this cavity look reasonably undisturbed to you? Should I be able to solve the problem of the failing bridge pickup without sending the bass to Santa Rosa by the looks of this? I will certainly show it to Edwin van Huik, maybe he's able to locate the problem and solve it quite easily...

dela217 · « **Reply #16 on:** June 04, 2004, 08:52:12 AM »

Just some of my thoughts on this bass......

To me it does not look like your average small standard. It seems that the tailpiece and bridge are further back in the body. This bass could be a long scale, which would explain why the strap button on the back of the bass was moved.

There is also a handwritten number on the PF6B circuit card. These numbers are the serial number of the card (I think) and will not be the same as the bass, but in the neighborhood.

If you are not using a power supply, this bass may be one of the ones that was wired as stereo and not mono. So, if you plug a standard cable in, you will only get one pickup. A good way to test both pickups is to swap the wires on the circuit board. I would move the connector with the red dot on it to the position of the one with no dot. By the way, the one with no dot on it should have a blue dot on it. It must have been peeled off.

I think you just need a power supply.

I would but the pickup selector to it's proper position.

I think the bass is an 80 or 81.

Michael

the_mule · « **Reply #17 on:** June 04, 2004, 09:37:13 AM »

Michael, thanks for your imput, really interesting and very helpful. Maybe the 'damage done' isn't so serious after all! BTW: the number on the circuit card is also '1937'.

To me the bass surely feels like a short scale (lower string tension). My Orion is 34, my EvH is 32 and this bass feels really different. But, only the 'A-files' can tell for sure!

I already wondered about those red connectors. Should they come off quite easily? I don't want to break anything. To test both pickups, should I switch the red one with the blue one, or just leave the blue one off?

Hmmm, a power supply for sale isn't something you see every day. I'll be on the lookout for one of those then... Anyone?

bsee · « **Reply #18 on:** June 04, 2004, 09:41:29 AM »

A tape measure will tell you the scale as well, no need to rely on the card.

effclef · « **Reply #19 on:** June 04, 2004, 09:54:05 AM »

Mule - measure from the nut to the 12th fret, and then double it. 34, 32, or 30.5 is probably what you'll come up with.

Interesting that the pickup selector is still there, stuffed inside the cavity.

The positions should be: off, bridge, both, neck.

The connectors are just slip-on ones and should be easy to take off and swap over. The center cord comes from the dummy humcanceller in the middle and that stays where it is.

One thing that hadn't been suggested: make sure the trimpots (the screwdriver adjustments which you see on the back plate) for the pickup volumes are up. That could be why one doesn't work, if it is not the pickup itself, or the 1/4 jack being stereo as was suggested. I think that would be the two OUTSIDE adjustments. The two inside ones are for cancelling out the hum.

EffClef

the_mule · « **Reply #20 on:** June 04, 2004, 09:55:03 AM »

Just to prevent me from making a mistake: scale lenght = distance between nut and tailpiece?

the_mule · « **Reply #21 on:** June 04, 2004, 09:58:00 AM »

Wow, this topic is really going faster than I can write, sorry about that!

adriaan · « **Reply #22 on:** June 04, 2004, 10:20:14 AM »

Scale is the length of the string that vibrates, so between nut and bridge.
34 = 86,3 cm
32 = 81,3 cm
30.75 = 78,1 cm
Because the bridge saddles are adjusted for intonation, the proper measure is from the nut to the 12th fret (which by definition is halfway) and then you double the outcome.

adriaan · « **Reply #23 on:** June 04, 2004, 10:24:11 AM »

By the way, mahogany can have different shades. This mahogany is about the same shade that my Epic has.

the_mule · « **Reply #24 on:** June 04, 2004, 10:38:55 AM »

EffClef, how does the adjustment of the trimpots work? Up = out (turning anti-clockwise) or the other way around?

effclef · « **Reply #25 on:** June 04, 2004, 10:56:09 AM »

I am not sure, but if you stay away from the two toward the middle, you'll be OK for now. They only turn a little less than ONE TURN, not multiple turns. Anyway, with whichever pickup works sounding in the amp, turn one and then the other outside one and you'll find which one matches.

I am guessing, however, that it's wired for stereo at the 1/4 jack, and that the real issue is that if you use a mono cord, the long ground shell on the plug is shorting one pickup output to ground when you plug it in. If you have an electronics store nearby, go find an adapter: stereo plug to mono jack. So the end which plugs into the bass will be stereo, and it will tie the proper neck and bridge signals together to make a mono output jack for your mono cable.

However, this will only work if the pickup selector switch is in the BOTH position. Turn it all the way clockwise, then back off one notch.
At that point, if both pickups are working, you should hear both of them added-together-in-mono.

EffClef

dela217 · « **Reply #26 on:** June 04, 2004, 11:16:32 AM »

Another thing to do for diagnostic purposes is that you can plug a set of stereo headphones in the jack and see if you can hear both pickups. One in each ear!

the_mule · « **Reply #27 on:** June 04, 2004, 11:18:21 AM »

Thanks, I know what to do, try & maybe buy this weekend!

dela217 · « **Reply #28 on:** June 04, 2004, 11:19:58 AM »

If you bass is wired stereo, Alembic can supply a schematic to convert it to mono and your troubles are over. But I would still recommend a power supply. The series basses use batteries quickly.

811952 · « **Reply #29 on:** June 04, 2004, 11:55:19 AM »

The power supply is a rather simple-to-construct item if you don't *need* to have the real deal. I think it's plus 9 volts and minus 9 volts to the bass, with unbalanced stereo audio back down the cable. I believe I saw a schematic posted here somewhere a few months ago, and I'm sure Dave Houck probably knows which thread. You could build one or have one built to get you by until you could acquire the real thing, and I'm sure Edwin probably knows where to scrounge one on your side of the world. I think these things are only supposed to last a maximum of 35 or 40 hours on a pair of batteries (batteries essentially being for emergencies), so it really is worth getting a power supply. Once again, nice bass. Looks like a mahogany core to me, and short or medium scale at longest. As for the pots on the back, if I recall I run mine (Left to Right) full - centered - centered - full. The center two are for the negative-feedback hum-canceller circuit, and while you will find yourself tweaking them a bit occasionally, mine usually end up pretty nearly dead-center. It appears that they function more like a balance control between the appropriate pickup and the hum-canceller than purely as a hum-canceller level pot. And yes, plug in a pair of stereo headphones and you should hear wonderful, pure, stereo Alembic joy...

John