Topic: Two devices of 1 tekkeon?

[H₂O]

There are a few issues that can arrise when running 2 DC devices off one power source:

1. Grounding Loops (already discussed) - when one device has a different grounding or negative voltage - this can cause current to flow in the wrong direction and potentially add noise or damage equipment - To resolve this you need to use a ground isolating DC-DC converter (typically a fly back converter) or build one yourself with the right controller and xformer. 

2. Ripple Noise - if one device has a noisy power supply and the other device does not have a very robust filtering network then noise may be induced on the other device.  - To resolve add filtering between sources (can be added indirectly by a Voltage Regulator or DC-DC Converter in between).

I would be willing to bet that what Ted's box is filtering is the Ripple Noise indirectly and not isolating a ground loop as ground isolation can be expensive especially at current levels to power a deck or pre-amp.
 

[page]

So I have a tekkeon on the way.  My question is can I build a spliter to run my v3 & pmd661 off of one tekkeon battery at the 6v setting?  Also can I run the pmd661 off of the 5v USB out on the tekkeon?  I will know soon enough when it's in my hands but just wanted to know if anyone has tried these possibilities.

Opps, the PMD-661 is a 5v Device.  Still would like to know if you can run two devices of the same voltage of of one battery with a spliter cable.

What's the mA draw on the pmd? (why not use the USB out if the PMD will function on 1mA) which would solve the problem. (ala V3 & MT2 off of the single battery)

Just checked this thread now...

The PMD661 itself is rated for 5 VDC at 1.4A which is 1400mA. 

The AC Adapter unit that Marantz included is rated for 5V at 1.5A which leaves room to spare.

I have run with a hacked USB to Marantz plug before but will stick to the Tekkeon cable to eliminate any potential limitations that could pop up from USB spec current limitations.

poo, that's too high then. So either split the big cable or get a second battery. bummer.

[audiosf]

Would the Tekkeon MP3750 work fine with a SD USBPre 2 and a Tascam DR680?

[jibooer]

That will certainly work, however keep in mind that the capacity is 4100mah at 12v which isn't an incredible amount of run time. http://www.tekkeon.com/products-mypall-specs.html. However, the extended power pack is available which could double your capacity. The usb power will draw a bit too.

[jibooer]

I can confirm that running a UA-5 9v out tekkeon + 5v USB running a PMD-661 (24/48,coax) gives me over 7 hrs on a single, and over 15 hrs on a double, with no line noise that I can discern. The GAKusb makes it happen.

Well that worked for the UA-5, but...I was experimenting last night with my new  Naiant Bigbox and tried running it via DIN-3 to a Tekkeon and 5v USB to a R-09HR with terrible results. The noise was ugly. I tried it this with two different Tekkeons as well. I also tried it with different voltages, and high and low power from the Naiant, but still sounded like crap.  Whether or not it is Ripple or Ground loop noise is unknown to me, but it ain't a good sound. Just thought I would share this finding with ya'll.

Separate power sources eliminated all problems, and I think the 20v option (low power) on the Naiant running the Tekkeon on a low setting like 6v will yield some killer recording times.

[jibooer]

Thanks Jon! Much appreciated! Suffice to say that I don't have any qualms about isolating the Naiant's power source, especially after hearing that god-awful racket.

Nonetheless, it is still good to know that it could be possible to run the Naiant and another device off the same battery provided that proper cabling is used.

[jibooer]

Point taken.

Furthur testing has been done, the original scenario was repeated (Tekkon 9v DIN-3 to Naiant and 5v USB to r-09hr), but this time, I ran line-in XLR to my pmd-661 which was running on internal AA's at the same time. I got the same noise on the devices. When the USB cable was removed from the equation, noise was gone.

Well, as far as this thread is concerned, maybe someone else can chime in who has had issues like this.

[Fried Chicken Boy]

Would the Tekkeon MP3750 work fine with a SD USBPre 2 and a Tascam DR680?

I think acidjack runs this exact setup from time to time.  Check with him to confirm.

It sounds like the Edirol is the device injecting noise then.

Like the R-44, I think the R-09/HR has reversed polarity on the DC input.  Would that, in itself, cause the noise?

I have run a Korg MR-1(5V) off of the USB side and simultaneously run a mixpre on 9v off of the swichable side many times. This, I believe, also keeps them isolated. I would think you could run any 5V device off of the USB side and run whatever else off of the switchable side.

Just stumbled across the following blog post/article (link below) about using a Tekkeon to power a MixPre and Zoom H4N at the same time.  Since the H4N runs off two AA batteries, I'm sure this can be applied to any other deck that also does: Sony M10, Edirol R-09/HR, Tascam DR-2D, etc.  And the author gave a shout-out to taperj and linked to TS.com, too.

Rewire a Tekkeon battery to power MixPre and Zoom H4N