Topic: Samson Mixpad 4 current draw?

[groovetube66]

Does anyone know the current mA draw of the Samson Mixpad 4?  I can't find anything in the manual or on the web.  I would like to make a good rechargeable battery pack for it.  The battery compartment requires 2-9v for main power and another 9v for phantom.  The AC adapter (which I don't have, wish I did) says it is providing 15vdc (+) at one pin, 15vdc (-) at another, and 32v (+) at another for phantom.  A friend told me this:

The manual seems to hint that the bigger mixers will work from +/- 12VDC. Probably anything near 12 or 15V would be OK to power the mixer.  And depending on what kind of microphone you use and its phantom power requirements you might be OK with 18V but some absolutely require a full 48V. 8 AA cells in series makes about 12VDC.  Two of those and you have +12 and -12 VDC which could be wired to the 5 pin DIN +12 to Pin 1 and - 12 to Pin 2 and the common of both battery strings to Pin 3 and 5 GND.

Does this sound accurate?

Thanks.

[taperted]

Its getting around the multi pin plug that is a problem as well. I had one and we never figured it out so i got rid of it. Good luck. Blessings!!
~ted

[taper420]

Output on my ac adapter says +/- 15 Vdc, 0.12A, +32Vdc, 25mA
You have the mixpad so I'm sure you can see the pin schematic which is from left to right:
1. +15V
4. -15V
2. GND
5. +32 V
3. GND
It uses a standard midi plug.
If your succesfull with this please let me know...it'd be great to have an alternative power supply for this thing.
I tried rechargable 9 volts once and they didnt even make it through the first set. Right now I have lithiums in there and they seem like the most reliable cost effective way to go right now....they cost about 10 bucks a piece and I've used them for about 5 shows so far and there levels are hardly even touched...no phantom of course....FWIW i think the mixpad only supplys 18 volts of phantom even when its plugged in.

[groovetube66]

I will let you know.  If I can't get it right I'll probably just re-ebay it.  I bought a UBB1002 Behringer last week but haven't used it and was thinking of taking it back.  But at least it has the AC adapter.  I don't have the adapter for my Mixpad so without a good battery solution its usefulness is extremely limited.  In fact it might be time better spent figuring out a battery pack for the Behringer.  It requires 2-9v and 1-9v for phantom - same as the Mixpad.  But I need to look at the adapter and see what voltages it likes and current draw.

[taper420]

I'm not sure if you care, cause there both pretty much in the same league, and I have no first hand experience with the 1002, but I don't hear very good things about Behringer. On the other hand I have used the mixpad for years and I love the results. Though I haven't compared it with anything else yet, I've been told that the mixpad has pretty decent preamps for the price point... can't say the same about the 1002. Also depends what your using it for .... I rarely have AC power available when I'm taping, sounds like you do..... have you tried finding a replacement adapter? Also, you know you could just rig up a 9 Vdc connection to the two battery terminals and that should supply the power your looking for. You know those ratshack multi-tip power supllies? Allot of them will allow you to set it to 9 volts and they have tips with nine volt battery terminals instead of adapter plugs. Good luck.

[groovetube66]

I'm wondering - since the Mixpad 4 takes 2-9 volts for power and 1-9 volt for phantom, couldn't I rig up a couple of rechargeable rc batteries or sleds to connect to where the 9 volt batteries go inside the battery holder?

The 15 volt bit seems weird to me.  Is it getting converted to 12 volt inside?  If so that would make things easier.  I could just hook a couple of 12 volt rc batteries.

[Nick's Picks]

ive never seen such a fucked up powering schematic.

ditch that thing, imo.

[groovetube66]

I just got confirmation from Samson's tech support - the Mixpad 4 will run off a 12 volt configuration just like the 9 and 12 will.  They show how to do this in the manual.  Cool!

[taper420]

Thats good news
the manual is here: http://www.samsontech.com/products/relatedDocs/mixpad4_owners_manual.pdf
The battery diagram is on page 34-35. Let me know how you hook it up using one battery....it seems like the manual says you need three.

[groovetube66]

I was told to run it off of one battery (for main power) I would need to get a dc-dc converter which could turn unipolar dc into bipolar dc.  I am not an engineer and didn't know there were two types of dc current.  The Mixpad needs bipolar current.  I think to do this with one battery the battery would need to be 24v.  I am checking into this and will post what I find out.

[groovetube66]

Ok, here is the deal as it was hammered out by myself and an engineer friend of mine.  I am shooting for 12 hours runtime.  I am not worrying about phantom for now.

- First, one 12 volt rechargeable - 6AH.  It could be a SLA or other rechargeable.  The plus and minus from the battery go into

- a dc/dc converter which will up the 12v to 15v and create bipolar current (15v+, 15v-, and ground).  Astrodyne part ASD05H-12D15
http://datasheet.astrodyne.com/ASD05H.pdf

- some sort of case

- Wire the output from the Astrodyne to a 5 pin Midi plug to go into the Samson.

- I'm buying the parts this weekend and will take pics etc. as I get it assembled.

[taper420]

sweet .... +t