| Author | Message | ||
| count
Member Username: count Post Number: 87 Registered: 10-2003 |
Just got my hands on a five pin cable. (FINALLY!) But it was a little bummed to find out that my DS-2 doesn't switch to mono if I only plug in a jack to the bass output of the box. Any suggestions how to rewire it to be mono-capable.? | ||
| count
Member Username: count Post Number: 88 Registered: 10-2003 |
Anyone..? | ||
| jimmyj
Senior Member Username: jimmyj Post Number: 460 Registered: 8-2008 |
Nicolai, I've never heard of a DS-2, do you mean DS-5 ? (Not sure what "DS" stands for but I presume the "5" refers to the 5-pin connector, otherwise we would be on about DS-8 by now...) Anyway, the 1/4" output marked "bass" and "mono" on the standard DS-5 was a normal jack. But the one marked "treble" incorporated a switch which would be thrown when a plug was inserted. I believe this was the "13e" variation (though I can't remember for certain): http://www.switchcraft.com/Drawings/13e_cd.pdf So if you only plugged into the "mono" jack the two signals coming from pins 2 & 3 of the 5-pin connector would be summed to that jack by way of two 20k-ohm resistors. But when you plugged into the "Treble" jack the switch (somehow) broke that summing circuit and connected pin-2 to "bass" and pin-3 to "treble" for stereo outputs. I can't remember the circuit exactly but if your PSU has no summing resistors I would suggest a "mono" switch would be the easiest mod to make. If you ONLY wanted mono you could even hardwire the resistors straight from pins 3&4 directly to the "tip" of the 1/4" jack. Maybe you could open it up and post a pic for us? (Don't touch anything inside - those caps might be charged!) That would give us a better idea of what's going on. Jimmy J | ||
| room037
Senior Member Username: room037 Post Number: 483 Registered: 9-2003 |
Hello, Nicolai has very old series bass (SN is around 40) preowned Tilan Porter . DS-2 comes with it that I think. The pictures of inside is best way. Eiji | ||
| growlypants
Junior Username: growlypants Post Number: 50 Registered: 3-2011 |
You mean Tiran Porter, of Doobie Bros fame? | ||
| room037
Senior Member Username: room037 Post Number: 484 Registered: 9-2003 |
Yes, TIRAN PORTER ! Sorry for my mistake. Eiji | ||
| count
Member Username: count Post Number: 89 Registered: 10-2003 |
I made a Y-summing cable today, with two 18Kohm resistors. One end has a mono plug, with the two signal cable soldered to the tip, and the ground to the sleeve. The other two (separate ends) each hace a 18Kohm resistor soldered in series on the tip, and the (common) ground is soldered to the sleeve. When I have both jacks connected I can only hear the treble/bridge pickup, but as I disconnect the jacks respectively I can hear the opposite pickup. WTF..........?? (Message edited by count on June 27, 2013) | ||
| jimmyj
Senior Member Username: jimmyj Post Number: 461 Registered: 8-2008 |
Nikolai, The description of your Y cable sounds exactly correct and it should work - provided your "DS-2" is actually operating in stereo. Can you confirm that the bridge pickup signal comes out of the "B" output jack and the neck pickup comes out of "A"? And the resistor plugs of your Y-cable should be plugged into those two jacks ("A" & "B") while the mono "sum" (no resistors) is plugged into an amp input? And the bass is only connected to the power supply by the 5-pin cable - nothing in the 1/4" jack, right? Once again I'll ask if you could possibly post a picture of the inside of your power supply so we can see how the 1/4" jacks are wired? That would help us solve this puzzle. Because of the long history of your bass you never know what may have been modified along the way. But figuring this out will be worth the effort! Jimmy J | ||
| count
Member Username: count Post Number: 90 Registered: 10-2003 |
Here are some pic of the DS-2. Serial number 10 btw. ;)    | ||
| jimmyj
Senior Member Username: jimmyj Post Number: 462 Registered: 8-2008 |
Wow, thanks for the pics. That's a historic piece of gear! And indeed, no mono option whatsoever, love it! But you know, thinking back ... a Fender Bassman (and an Alembic F2-B) had two input jacks per channel, right? There was already a resistor summing network built in, I believe. So the original concept would have been to plug the "bass" output into the amp's A-channel and the treble output into the B-channel giving you individual gain and tone controls for each pickup. But if you preferred you could simply plug the two short cables in to the two A-channel input jacks and they would have been summed internally. Now back to Nikolai's puzzle. The next thing we need to know is, with your bass connected using the 5-pin cable does the neck pickup signal appear at the "bass" output jack and the bridge pickup at the "treble" jack? A purest might say "oh no you can't modify that piece, it's a collector's item". But I say "function over ... history" and I would add a mono switch and an LED. Kinda like below: (Please don't be put off by my horrible graphic!) The less intrusive mod would be to replace the "treble" jack with the switching version mentioned above and wire it like the later DS-5. No front panel changes that way. But first, let us know if the pickup outputs are coming out of the correct jacks. Jimmy J  | ||
| dfung60
Senior Member Username: dfung60 Post Number: 586 Registered: 5-2002 |
This is an interesting problem. The wiring in the box looks unusual. It should work with blend cable, but generally won't work well. The treble output only has the hot wire connected from the 5-pin, and no ground, so if you plugged the Bass and Treble outputs into separate amps, there wouldn't be any output on the Treble channel. With your custom cable, since you tied both grounds together, it should work. The problem you're experiencing sounds like the resistor value is too small (it's similar to the problem you'd see if you didn't use the resistors). They should be brown-gray-orange and some other band (the fourth band doesn't matter in this case). Just about anything with an orange band in the third position should be OK. David Fung | ||
| xlrogue6
Advanced Member Username: xlrogue6 Post Number: 266 Registered: 8-2002 |
The only problem with using both channels simultaneously on blackface and silverface Fender amps (most of them, anyway) is that the channels are out of phase with each other--not a huge problem, but there will be a "sour spot" (to coin a phrase) where you'll get phase cancellation when both channels are set for near identical output. If that's an issue, the both jacks of a single channel approach would be the mono option to use. | ||
| jimmyj
Senior Member Username: jimmyj Post Number: 463 Registered: 8-2008 |
I didn't know about the phase issue on Fender amps, that would not be ideal... David, it appears there never was anything soldered to the treble jack's "sleeve" lug so it must be relying on the front panel to provide "chassis" ground to that output. That should work unless there is corrosion where the jacks are mounted, but it all looks clean and dry - like new actually! You're right, it could be the value of summing resistors causing his odd Y-cable results... Jimmy J | ||
| keith_h
Senior Member Username: keith_h Post Number: 1879 Registered: 2-2005 |
As Jimmy says the 1/4" runs signal ground through the chassis and not the lugs. It is the same on my DS-5. Keith | ||
| count
Member Username: count Post Number: 91 Registered: 10-2003 |
Seems I'm gonna have to double check the resistors I put in then.. Pretty sure they were 18K, but they might be just 18. That would explain it then! Regarding modifying it: Completely out of the question. ;) At least drilling holes etc. I could but in a new switchcraft jack, but when I get my second GK 800rb up and running again I'll only be using it for stereo setup. The y-cable will do the job until then though. | ||
| edwin
Senior Member Username: edwin Post Number: 1586 Registered: 5-2002 |
Nitpicky point: only some Fenders suffer the polarity issue between channels. The Bandmaster, Showman and some Bassmen don't have this trouble. Amps with reverb and some Bassmen (with an extra tube stage) do. It's the reverb stage (which has an extra tube) and the extra tube stage on some Bassmen that flip the polarity. I've wired up my Alembics in stereo through my Showman and it sounds pretty good, more or less like the F2B. | ||
| lembic76450
Advanced Member Username: lembic76450 Post Number: 334 Registered: 5-2002 |
I have seen there statements about channels being out of phase on numerous forums. For years I jumped the channels 1 and 2 on my Bassmans, Showmans, and my F2B without problems and with a great summing boost. Thanks Edwin, for clearing up this confusion. (Message edited by lembic76450 on July 01, 2013) | ||
| count
Member Username: count Post Number: 92 Registered: 10-2003 |
Just checked my resistors. They are indeed 18k (Brown, grey, orange, Gold) I'm out of suggestions/options to be honest.. | ||
| jimmyj
Senior Member Username: jimmyj Post Number: 465 Registered: 8-2008 |
Nikolai, Please confirm that with only the 5-pin cable connecting the bass to the DS-2 (nothing plugged into the bass' 1/4" jack) that the bridge pickup sound is coming out of the "Treble" jack and the neck pickup is coming out of the "Bass" jack. The "Treble" and "Bass" outputs should each pass audio in 2 of the 4 positions of the pickup selector switch: Off, Bridge pu, both, Neck pu. For example, the "Treble" jack should only have sound in the "Bridge pickup" and "Both" positions of that switch. Make sense? Let us know what you discover. thanks, Jimmy J | ||
| count
Member Username: count Post Number: 93 Registered: 10-2003 |
I will doublecheck that this afternoon. I don't have anything else connected to the bass while doing this no.. | ||
| count
Member Username: count Post Number: 95 Registered: 10-2003 |
Allright, something has to be wrong with the cable. Tried every possible combination of cable/PU-selector/etc. using the volume pot of each PU to check which one was giving me a sound: Summing cable connected: Bass-pickup is the only one giving me signal. Summing cable having one cable disconnected gives me sound from the other (correct) one in the correct settings. Just for fun I connected a normal jack to each of the outputs (treble/bass) gave me the exact same result. There's got to be some issue with the summing. Wrong resistor value? Does it need to be larger/less? I have the PF-5 (early) electronics, don't if that's got any influence though.. | ||
| jimmyj
Senior Member Username: jimmyj Post Number: 466 Registered: 8-2008 |
Nicolai, You wrote: "Summing cable having one cable disconnected gives me sound from the other (correct) one in the correct settings. Just for fun I connected a normal jack to each of the outputs (treble/bass) gave me the exact same result." If I understand you correctly, using standard 1/4" cables the "bridge" and "neck" pickup outputs are correctly sending out of the "Treble" and "Bass" output jacks? This is GOOD! And yes, it points to your summing cable as the culprit (I'm sorry to say.) The description of the cable you constructed sounds exactly correct and should have worked. I don't mean to state the obvious but this Y cable can only be used in one way - the individual plugs with resistors must be plugged into the DS-2 and the plug which has two cables coming out of it must be plugged into the amp. Any other combination won't work correctly. The goal is for the two outputs to connect to the amp via one resistor each. If you used 20K resistors the audio signal from the neck pickup would pass through 20K-ohms of resistance on the way to the amp. And the output of the bridge pickup would also be 20k away from the amp. BUT the two pickup outputs would be separated by 40k-ohms and thus would not adversely effect each other. Also, it is not easy to fit anything extra inside a 1/4" plug (even one resistor) and keep the circuit from shorting. You could check for shorts with an ohm-meter. If you don't have one just unscrew the plug's outer shells and look closely for shorts. If it all looks good, try connecting it all with the shells off (loose on the cables). It could be those shells causing shorts. Keep trying, you've almost got it! Jimmy J | ||
| count
Member Username: count Post Number: 96 Registered: 10-2003 |
I used crimping sleeve. (Think that's what it's called, this plastic tube you heat up, which in turn shrinks over the wire) Think I'm gonna have to try with higher resistance resistors. Any input from the mothership....? | ||
| count
Member Username: count Post Number: 98 Registered: 10-2003 |
Just changed out the 18k resistors with 33k's. Oh my god, it works. It works so good...! | ||
| davehouck
Moderator Username: davehouck Post Number: 11122 Registered: 5-2002 |
Congrats!!! | ||
| jimmyj
Senior Member Username: jimmyj Post Number: 469 Registered: 8-2008 |
Hoorah! Nice going! Jimmy J |
