Author Topic: DS-5R Stereo - Mono (Read 1157 times)

jon_jackson · « **Reply #15 on:** February 23, 2010, 05:49:45 AM »

Art, I just sent you 4 photos. Thanks for your help. I'll try to learn how to do this.
-Jon

artswork99 · « **Reply #16 on:** February 23, 2010, 05:57:00 AM »

Note from Jon: This is the best image I could get of the 5-pin connector wiring. The 1/4" jack is just above, where the tip of the pencil is pointing. There is one brown "orphan" wire from the 1/4" jack (at the pencil tip, just above the bright yellow wire) that just stops. There is also a brown wire on the ribbon connector that stops at about the same length, but I don't know if that is coincidence, design or wire failure. At any rate the 1/4" jack works fine.

(Message edited by artswork99 on February 23, 2010)

JimmyJ · « **Reply #17 on:** February 23, 2010, 12:20:11 PM »

Art, thanks for relaying the pics. Here's my theory (a-hem!)...

The unused wire on the bass's internal ribbon cable is normal although I can't really explain (nor see in the picture) your other orphan.

Jon, can you confirm for us that the DS-5R works correctly in stereo mode? As in, the neck PU comes out of the bass jack and the bridge PU out of the treble jack? If that's true then I think we can say your bass and cables are fine.

Furthermore, the shot of the DS-5R shows the amazingly solid Alembic factory wiring we know and love with the possible exception of the resistor running from the 1/4 jack to the switch. (Art, are you able to zoom to the switch/resistor/jack for us?) That resistor should at least have insulated leads... And it needs to be the same value as the other resistor clinging to the side of the switch or it won't sum properly. Replacing that resistor with a lessor value could lead to your symptoms....

Just a theory!

Jimmy J

(Message edited by jimmyj on February 23, 2010)

artswork99 · « **Reply #18 on:** February 23, 2010, 01:16:21 PM »

Jimmy,
Thanks for bringing that up... Good eye, you are so correct in seeing that there is no insulation on that resistor which would be so unlike Alembic. I did a re-solder on my 5-pin connector over the weekend and they even insulate the ground wires within the connector. Even the bends on that resistor look unlike their work.

JimmyJ · « **Reply #19 on:** February 23, 2010, 01:33:47 PM »

Yes, very odd. Except for the missing insulation it all looks correct and not obviously disturbed. The two resistors even look like the same components but we can't read the values. Mismatched values is still my guess...
Jimmy J

jon_jackson · « **Reply #20 on:** February 23, 2010, 03:01:14 PM »

Jimmy, the I think the answer to your question is yes, although I didn't use two different amps to check.

When the DS-5R is used with the two patch cords, both into an amplifier input, and the DS-5R Stereo / Mono switch is in stereo, both neck and bridge pickups are heard through the amp, as selected by the bass P/U selector switch: Neck, both or bridge.

Using the same setup, but then flipping the Stereo / Mono switch to mono, only the bridge treble pickup comes through the amp. In this condition, moving the bass selector switch to neck pickup results in no sound.

Although I can't do it tonight, I could try the experiment again tomorrow night using separate amps to ensure that there is complete separation between the neck / bass and bridge / treble outputs. I ran the the patch into two inputs on the same amp, [one input is damped by 15db, so I could tell which DS-5R output was operational due to the volume difference]. However, my notes show that either the bridge or neck was available from the DS-5R bass / mono output (depending upon bass selector switch) while only the bridge was available from the treble output jack. Since it was about a week ago when I did the test and my original note of only neck was coming from the DS-5R bass output was crossed out and replaced with either bridge or neck, I'm now not sure and think I need to repeat and confirm before saying definitively.
-Jon

JimmyJ · « **Reply #21 on:** February 23, 2010, 03:38:00 PM »

Hey Jon,

OK, things may still be alright...

When you set the DS-5R's switch to mono you should only use the single bass or mono output jack leaving the treble jack(s) disconnected. So the test is, in stereo, connect a single cable from the treble output to your amp's input, you should hear only the bridge pickup in two of the four positions of the bass selector switch. Now (turn the amp down) move that single cable to the bass output (turn the amp back up) and you should hear only the neck pickup in two selector switch positions. Now, while still connected that way just flip the switch to mono and the sound from both pickups should be there.

Let us know!
Jimmy J

pacificshine · « **Reply #22 on:** February 23, 2010, 04:20:17 PM »

Jon,
If you validate that everything works correctly in ?Stereo? mode on the power supply, then I think from the description of the symptoms it appears that you have a bad bridge P/U summing resistor or an open circuit (switch contact?) when the switch is set to Mono, so the result is that only the bridge P/U signal passes through the summing circuit. I checked the DS5 / DS-5R schematic and it confirms that in Stereo mode the two P/U signals pass individually through the Mono/Stereo switch and on to their respective 1/4 jacks and the resistors are not in the circuit. The resistors in the schematic are 20 KOhm but other similar values should also work OK. I can't tell from the photos what value these resistors are but if you have access to a multimeter you should be able to solve this mystery. Also, when the switch is in Mono and no patch cords are plugged into the 1/4 jacks, you should be able to validate this resistance by measuring from the ?Mono? out ?? jack tip to its two corresponding 5 Pin jack contacts: From Mono / Neck Out to Pin#2 and also from Mono / Neck Out to Pin#3 on the 5 pin jack. Both resistances should be the same or around 20K.

poor_nigel · « **Reply #23 on:** February 23, 2010, 07:59:50 PM »

After seeing the picture of the funky resistor, I decided to panic and open mine and check it out. Behold! I did not get the same results as Jon. I get lights on the unit and LEDS, but no sound what-so-ever. No configuration or switching produces any sound. They should have different problems, as they are not even made with the same components.

poor_nigel · « **Reply #24 on:** February 23, 2010, 08:21:42 PM »

I was thinking of offering Jon my spare and I would just wait for the repaired one from Alembic to show. I have an extra, no problem - Wrong answer. I sure am glad I did not, or who knows when he would get to play his bass as it was intended to be heard. What are the chances of two out of three DS-5R's being glitched from the same batch sold to a single client? I will say that upon closer examination of the box mine came in, it was opened and sealed again. The unit looks untouched. So I do not think it has been tampered with. There are points to the five-string bass where I think quality was dropped and I was going to just bring the bass to Santa Rosa this fall and I am sure it would get taken care of. I guess I will be bring this along with it. Are these bad luck basses? I wonder if the third unit works?

I do not have any real reason to be peeved right now (though I obviously am), as I do have a working one. However, after getting stuck with a $550 shipping fee for the bass and this unit (which took a well over a month to get here), I am in no mood to pay a penny more in shipping to get what I paid good money for. I will be very curious to see how Jon's unit works out. I hope it is something simple and he is up and running properly soon.

JimmyJ · « **Reply #25 on:** February 23, 2010, 10:31:53 PM »

Thomas,
Check to make sure that the ground wire is properly connected to the 5-pin jack (right side of your top pic). I believe it should be soldered to the chassis ground lug of the jack and then continue from there to pin-1. Your bass LEDs would light if they saw the + and - voltage but you would get no audio without proper ground. Just a guess.
Jimmy J

poor_nigel · « **Reply #26 on:** February 23, 2010, 11:49:59 PM »

Hey Jimmy:

Since it is just an audio signal problem, I can track it down with a multimeter. I'm sure you're right that it is a bad ground. I was actually more upset by the fact that I was using my vacation time to mess with it than the fact it is not functioning. My job is extremely stressful, so I really value what little vacation time I get. I still cannot get over the odds of two units from the same buy being glitched. Alembic electronics are very expensive, but they are also very reliable - go figure . . .

jon_jackson · « **Reply #27 on:** February 24, 2010, 05:25:37 AM »

This gets more and more strange. I'll try some of the posted suggestions tonight and/or tomorrow and report back. I've got a multimeter but anything beyond measuring resistance is outside my competency...

pacificshine · « **Reply #28 on:** February 24, 2010, 07:53:37 AM »

Jon,
Here a simple experiment you can do that will tell you whether you have an open circuit in the Neck P/U signal path in ?Mono? mode on the power supply (you can actually do this without pulling the unit out of its rack or opening the case):

1)Turn power to DS-5R off (or unplug from AC)
2)Connect a mono 1/4 cord to ?Mono Out? on DS-5R. Leave other end open.
3)Connect your 5 pin cable to DR-5R. Leave other end open.
4)Put DS-5R switch on ?Mono?
5)Measure resistance from tip of ?? plug to pin 3 on 5 pin connector (female end)
6)Measure resistance from tip of ?? plug to pin 2 on 5 pin connector (female end)
7)Both readings should be the same (about 20 K Ohm).
If you put the DS-R5 switch in ?Stereo? mode and perform the same test you?ll see that the resistance drops to zero when you measure from ?? plug tip to pin 2 on the 5 pin connector. If you move your ?? plug to the Treble jack on the DS-5R you?ll see the same zero resistance if you use pin 3 on 5 pin connector (bridge P/U output).

The ground wiring on the 5 conductor cable uses the shield (braided jacket) that connects both to the metal body of the plugs and also to pin 1. That can also be verified with a multimeter. I once went through all these tests when I suspected something was wrong with an older DS-5 but turned it out to be an operator error.

Let us know how it goes. If the system works in stereo mode then you know the 5 pin cable is good and it must be the summing circuit. Also, a bad ground should affect both channels.
--Alan

cozmik_cowboy · « **Reply #29 on:** February 24, 2010, 08:19:37 AM »

Jon, if I'm following all this correctly, you're plugging both DS5-R outputs to your amp & toggling between stereo & mono. Stereo works fine, but mono does not. If this is the case, the first test you need to run is unplug from the treble jack, switch to mono, & see what happens. This is how it's supposed to work, so if you don't get both p/ups that way, then start looking for an actual problem.

Peter