[corndog71]

I would most definitely be willing to add anything on running it on Battery power...

Could you tell me what the power supply board dimensions are?  HxWxD

[wgscott]

I'm going to try to assemble this thing "for real" this weekend, and will take some photos.

Maybe a wiki with some documentation might help.

[praedet]

I will get you the full PS dimensions in about 30 min, but I know it is 5 1/4" L and 3 1/8" wide for sure.  It has a heat sink underneath that is less than the height of the stand-offs, so I will just measure the height above the board...

Also, what do you all think about wiring up a switch?  Running the battery supply and the SDS board, both boards have switches.  I was planning on doing a switch on the PS so that it does not have any current in it when off.  Thoughts?

Part 2, I have a DPDT On-On switch.  How do I wire it

Here is the board.  I will take a better pic but it has both a location for a remote signal and a place to solder in wires instead of the switch...

http://classdaudio.com/products/power-supplies/12v-dc-switching-power-supply-500-watt-car-audio.html

Ted

[corndog71]

Also, what do you all think about wiring up a switch?  Running the battery supply and the SDS board, both boards have switches.  I was planning on doing a switch on the PS so that it does not have any current in it when off.  Thoughts?

Part 2, I have a DPDT On-On switch.  How do I wire it

Here's how I wired my DPDT switch.  The easiest way to figure it out is use your meter.  The middle terminal is your input and the upper or lower terminals are the output depending on which way you throw the switch.  The unconnected terminal breaks the connection cutting off power to the power supply.

In your case you could get a simple SPST switch and mount it next to the Powercon connector.  I know from my car audio days it's better to break the negative connection first with a battery.  Then you don't have to worry about messing up the circuit boards with unnecessary soldering.

[praedet]

Awesome, thanks!  For whatever reason, Trung wired up both sides of the switch where the other side appears to send power to the remote on switch on the PS board, and the first side is wired like yours to the on/off on the PS board...

[corndog71]

Awesome, thanks!  For whatever reason, Trung wired up both sides of the switch where the other side appears to send power to the remote on switch on the PS board, and the first side is wired like yours to the on/off on the PS board...

Ah, I see.  That makes sense as this power supply was designed to work in car audio.
I'm not sure if all of that was necessary but I can see why he did it that way.  The simplest way is to simply break the connection between the battery and the power supply.  To be fair I'm not familiar with the details of your power supply board.

[corndog71]

I hope I'm not confusing things here.   Are you referring to your battery powered amp or another one?  I keep going back to your pics of the battery powered amp.  I just saw the cable with the in-line switch and wondered if this is used for the amp.  If so then you're already good.  Looking at your amp it looks like a pretty straighforward build and what I would do.

Oh, and to clarify, in my picture you're seeing the red and black leads of my transformer. 

EDIT Again:  I just noticed the little toggle switch at the front of the amp.  Now I get what you're saying.   Ok, so now that I'm no longer confused, what I wrote before about breaking the connection between the battery and the power supply is still correct.  That is if that remote turn-on connection is optional like it is on the amp board.  If you don't need to use it then just use that cable switch to break the negative side of the incoming power wires.

[wushuliu]

Tweak first, then solder when you are happy with what you hear. Please let us know, so we can learn from all of your costly and demoralizing mistakes.

Seriously, you have nothing to lose by testing first until you are satisfied.

Agreed. I've learned this the hard way.

[wgscott]

So, I brought it in the house to give it a preliminary test before assembling it for real...


Overview. Note the matching Nova case.


Power supply.


Amp board hooked up to the Nova's pre-Amp RCA out.

The sound is quite good from my first test. 

[praedet]

Well, I learned a LOT over the last 2 days.

1. If you plan on removing the various connectors on the boards, see if Tom will ship the boards without them.  Removal is not trivial, and then getting everything back exactly right is also non-trivial.

2. Get a larger chassis then you need!  If you are going to make leads as short as possible, and hardwire to the board, you need room.

3.  Make sure you dry fit EVERYTHING before drilling holes for stand-offs.

4. Figure out what everything does before you wire it up

Anyway, the amp is moved into it's final chassis.  I used solid silver (22 AWG) for the RCAs and solid copper (14 or 16 AWG) electra cable for the speaker wire and power.  I replaced the pots with resistors and hardwired everything.  Lastly I put the wiring in place for the switch.

Things that I messed up/sucked.  The Neutrik Powercon.  Had I put the board into place with the powercon before drilling holes for the stand-offs, I would have realized that the place I chose for the board was TOO close to the back.  Oh well, a trimming of the powercon worked, but made it impossible to mount the powercon inside like I wanted, and made it VERY hard to solder wires under the board.

Solid wiring is REAL hard to work with when it is connected in multiple places.  REAL HARD...

So, I wired up the switch like I thought it was supposed to be (I was copying another person's battery PS wiring)  I had wires running to the switch location on the board, so when the switch was thrown they would form a circuit.  I also ran a wire from the positive hot wire, to the switch, and then to the remote signal turn on.  Again, when the switch turned on, it was supposed to send a signal.  FOr whatever reason, if ANY wire was hooked into the remote signal on the boar, the PS was ALWAYS on, no matter what switch you played with   Needless to say, I am now only running the switch wires, and they work

Anyway, I have quickly verified that the amp does in fact play, but I still haven't played it to check the resistor and wiring change out as I am working on the faceplate...

Here are some pics of the inside.  If you are wondering about the speaker hook-ups, they are Electra Tube connectors.  They are pretty cool

Ted

[corndog71]

Now THAT is a sweet looking amp!  Inspiring too as that is pretty much what I want to build later this year.  I was also considering putting 3 of those into one box for one hell of a 6-channel amp!

[praedet]

Thanks, and get a BIG box for 6 channels!

[TrungT]

Ted
Very nice 

[praedet]

Thanks, you are my hero!

[wgscott]

What is the advantage of removing those blue terminal block things?  Can you use a thicker wire?  I'd like to use 12 gauge if possible...

[corndog71]

If you're going to use thicker wire then you would be better off keeping the terminals.  But really, 16awg is plenty large enough to deliver the current.

[praedet]

Truly, it is a better connection...

But, if I had the board sitting in front of me again with those on, I son't know that I would remove them.  I would ask for one without them

[Jeff G]

Hey guys,
A quick update-
this is my first electronics project (SDS 254) and i think it's really a good one for the novice. In terms of sound, I'm very happy with the amp. I am working toward a nicer 2 channel system and morphing my HT setup. The current rig is an Onkyo 805, modula MT mains, a Paradigm center and various surrounds. I have an IB sub with 2 15s. My front end is a SB with a MHDT paradesia plus dac. I feel like it opened up after a few hours use but that could be my imagination. I am currently building a pair of Dennis Murphy/Paul Kittinger MTM design using the Seas ER-18. Can't wait to hear what it does with these (ordered some figured madrone today!!)

The ClassD was a significant improvement over the Onkyo internal amps- no big surprise. Much more meat to sound, more headroom, better image, cleaner mids, etc. Can't wait to get the Onkyo POS out of the way altogether. Next project (after the current one ) is to build the Dodd or Pass buffer. All will be right with the world. Great project and an absolute no-brainer for the $$$. The thought of battery power seems like a PITA but I am sure it sounds great. We'll see-

Thanks for the security blanket of the forum!
Jeff

[corndog71]

The thought of battery power seems like a PITA but I am sure it sounds great. We'll see-

It's really not that bad.  With a smart charger like the CTEK US800 you just hook it up and forget about it.

[wgscott]

I think the potentiometers supplied are this:

Pot; Cnd Pl; Rest 10 Kilohms; Bushing Mount; Linear; Pwr-Rtg 0.5W; Shaft Dia 0.25in
Mfr. Part#: 575SX1A48F103SS

http://www.alliedelec.com/search/productdetail.aspx?SKU=7532264

So, if I want to replace these, I presume I need something that is 1/2 Watt and 10 kOhm.  I thought for audio one wants a log rather than linear response?

Also, any verdict on that purple wire?  It says it is wired to the transformer grid, so I presume I want to ground it, but I don't want to do anything stupid.

I assembled it within the shell housing now and am listening to it as I design and order face-plates.  I am thinking of something along these lines, with 4 potentiometers/gain control (if I bi-amp) in front.  What I am posting below corresponds to a bi-amp configuration. I haven't yet decided whether I will do that or not, but it makes a good "worst case scenerio". I just about have enough room in the Nova chassis to do that, with two amp boards positioned at the rear, and the transformer in the front left, and the power supply board on the front right.

If I have two amp boards, that means 4 gain controls. I'm considering putting those on the front, where they would be accessible, and then a window, like the Nova's tube window, to peek in at the LEDs on the amp boards and power supply. I think that would be much cooler than ugly LED lights mounted on the front. I don't know if I'll put their logo on, but I did it in the mock-up.

Please suggest improvements!