Author Topic: DS-2 Powersupply mono (Read 474 times)

edwin · « **Reply #15 on:** June 30, 2013, 08:17:01 PM »

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 · « **Reply #16 on:** July 01, 2013, 06:21:28 AM »

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 · « **Reply #17 on:** July 03, 2013, 05:53:22 AM »

Just checked my resistors.
They are indeed 18k (Brown, grey, orange, Gold)

I'm out of suggestions/options to be honest..

JimmyJ · « **Reply #18 on:** July 03, 2013, 09:05:34 AM »

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 · « **Reply #19 on:** July 04, 2013, 01:04:31 AM »

I will doublecheck that this afternoon.
I don't have anything else connected to the bass while doing this no..

count · « **Reply #20 on:** July 06, 2013, 10:01:54 AM »

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 · « **Reply #21 on:** July 06, 2013, 04:18:28 PM »

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 · « **Reply #22 on:** July 07, 2013, 01:09:04 AM »

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 · « **Reply #23 on:** July 12, 2013, 10:29:59 AM »

Just changed out the 18k resistors with 33k's.

Oh my god, it works. It works so good...!

David Houck · « **Reply #24 on:** July 12, 2013, 12:45:51 PM »

Congrats!!!

JimmyJ · « **Reply #25 on:** July 12, 2013, 03:32:36 PM »

Hoorah! Nice going!
Jimmy J