Older DS-5 question

[edwardofhuncote]

Awesome, thank you Jimmy J... just try reading the manual, right!? I'll give it a rip. 

Thanks All.

[JimmyJ]

Aside from the overall innovation of having an external power supply for our instruments, the actual hardware part of that PSU isn't anything too wild.  The preamp boards can operate on anything from +/- 9v (batteries) to +/- 18v (DS-5) or maybe even more.  I've made several purpose built PSUs running at +/-15vdc which have been solid operators for years.

On the audio side, Alembic's lo-z opamp output signals allow for some very creative signal routing and manipulating. 

Here are a couple pics of my modified DS-5s.  Excuse the home-made looks.  Ha!  Plus the insides of one which may not have any original parts left.  HA!

Jimmy J

[David Houck]

Cool pics Jimmy!

[David Houck]

As an aside, that's a nice looking '73 at Gregory's Reverb link.

[mica]

Yes - dad confirms you need to summing resistors to make the Y cable. This is probably a DS-1 unit, or an early DS-2 unit. The one that is in the Reverb link above dad say had VERY few made with that decoration. He also said that drilling that sheet metal was very difficult.

I know DS-3 and DS-4 units exist, but I've never actually seen one! The revisions came quickly, and so there were very few units of them made. 

[edwardofhuncote]

Thanks Mica, and Mr. W.   

There are at least three similar, but not quite identical units in the Series I Showcase threads. They are a little bit hard to pick out, since they aren't really the subject of the posts, but I had a pretty good idea my box was akin to them. I'll follow-up sometime on that cable.   

[garyhead]

Aside from the overall innovation of having an external power supply for our instruments, the actual hardware part of that PSU isn't anything too wild.  The preamp boards can operate on anything from +/- 9v (batteries) to +/- 18v (DS-5) or maybe even more.  I've made several purpose built PSUs running at +/-15vdc which have been solid operators for years.

On the audio side, Alembic's lo-z opamp output signals allow for some very creative signal routing and manipulating. 

Here are a couple pics of my modified DS-5s.  Excuse the home-made looks.  Ha!  Plus the insides of one which may not have any original parts left.  HA!

Jimmy J

Jimmy.....in that bottom photo........Is that a Rabbit's Foot in the lower half? 

[JimmyJ]

Ha!  Well that DS-5 has brought me some good luck.  But no, it's an old style in-line fuse holder like the one below, velcroed in place.
Jimmy J

[jon_jackson]

Jimmy, I'm puzzled about what the fuse in the above photo of the in-line fuse holder is designed to protect...
Jon

[JimmyJ]

Jon,
Yeah, I know that looks weird (!!) but that's how they used to be manufactured and sold.  The internal ends of that wire are crimped onto the fuse clips so it's meant to be cut and inserted into the circuit.
Jimmy J

[edwardofhuncote]

...To keep everything legit you want to use summing resistors instead of a simple 2-to-1 Y-cable.  The idea is to avoid connecting the output of one channel directly to the output of another which might irritate your op-amps...  The schematic posted in the thread above shows 20k summing resistors.  If for some reason your DS-5 is permanently wired in stereo you can also make a simple summing cable with resistors in it to do the job...

So, if it isn't much trouble to build, it seems like this is what I'd like to do here. I have tested a couple different scenarios to make sure the box is actually working correctly, including Jimmy J's idea of simply connecting 1/4" leads from both the B & T jacks to both 1 and 2 inputs on the F-1X, which automatically summed them; this makes everything work exactly as it should... switching on my bass returned to normal, access to either individually, or both pickups. (or standby, of course)

If I go out to play somewhere though, I'd need a way to adapt the two 1/4" outputs marked B & T, to a signal my amplifier input can accept, and won't confuse my Series I as to what's happening down the line. (I still can't get my head around this... how does it know, and why does it care?) I do have a local pro-audio shop that can probably/definitely handle this if I can't, but as is painfully obvious - I haven't the first clue what to tell them I need here.

Is there a picture or a diagram somewhere I could provide them with, to make such a thing? Foremost in mind, it has to be something that works reliably and won't mess up my bass. On that subject... I guess I'd know if I had done any harm by now, by using the consumer-grade Y-adapter I had... it doesn't seem to have hurt anything, just didn't work right. (see post #1) I have found another use for it, since then.

Thanks Again, All.

[JimmyJ]

Hey Greg,

Here's a crude schematic of a summing Y-cable.  It's pretty simple and anybody who can make cables for you should get the idea.  The resistors can be either in the plugs (as drawn) or in the in-line jack, wherever there is room. 

If you're thinking about this for use when rehearsing or jamming with somebody else's gear, it might be simplest for you to use the 1/4" output from the bass.  And the next question is ... does your bass's 1/4" jack have the mono mod or is it a stereo jack?  Because if it's stereo, the same situation would apply there. 


Jimmy J

[dela217]

This guy makes the summing cables:

http://bayoucables.com/index.php?main_page=index&cPath=4

[edwardofhuncote]

Thanks a lot Jimmy J. and Michael D... appreciate it fellas. 

[edwardofhuncote]

It's worth posting the rest of the story I guess... at least the part of it I know about.

Turns out this box is actually a DS-1 or maybe an early edition DS-2, though I am not sure what the technical details differentiating those are. This one is stamped on the back of the case, 27, using (I think) the same stamps that were used to stamp serial numbers in the headstocks of the instruments at that time. (note the size and font of the 2 and 7 stamps in the serial numbers) At one time it also had a painted or decaled number on the front that had faded to nearly illegible by the time I got this thing. I finally found some vinyl transfers that were pretty close to correct, and replaced them. After cleaning up the metal case a little, (whatever metal they made these boxes from, it tarnishes severely... is it nickel-plated maybe?) Finally, for a little class, I added a brand-new full color Alembic logo sticker to the top.

The backstory; I got this thing a little while back when John McVie surplused some gear... very soon afterward, I discovered he had gotten this box from a Club Member here several years before, perhaps to enjoy the cool numerical coincidence of having a power supply with the same number as his #73-27 bass. Maybe I'll get a chance to ask him sometime. So anyway, mine now... nothing magical here, it's just a cool old handmade box from the early days at Alembic, and a history that includes at least three other Alembics...

...but for now, DS-1 #27 is now assigned to duty with Series Bass #77-621... fits right in the upper pocket of the old blue case.