[Vedder323]

Sorry it took so long but I wrote a full review for the SDS-470. I have had the amp for 2 weeks and love it more and more each time I listen to it.

http://www.audiocircle.com/index.php?topic=104385.new#new

[matt_garman]

I had similar issues using 2 SDS470 units with 2 SMPS800R in a 1U enclosure. The right channels kept hissing after about an hour of play. This was definitely an issue with the chassis and not enough ventilation. I noticed your unit was confined in a small chassis as well but slightly taller than 1U. I tried a larger heat sink (larger outriggers) but this was not the problem.

I added a 12 volt fan inside my case and the anps run cool now.

I sent 1 amp back to Tom due the overheating and the one he replaced it with did the same things.

I think if you created more air flow in your chassis the problems will go away.

Right after I posted about the issue, Tom replied.  He said, The temp difference is because there are different power supplies on the amp and in different places.  After I told him that my case has no vents except on the top, he said, I think that's the problem.  You need some more ventilation.  Can you drill holes in the bottom possibly under the amp and power supply?.

I won't have a chance to do that until at least next weekend.  But I'll give it a try.  There's not a huge rush for me to do this, since I'm not having any actual audio problems (but the temps do scare me a bit).

I agree, I bet a fan (even a low-RPM one) would make a huge difference in temperature.  The only problem is, my case is so small, I don't know where I'd put one.  My project turned out to be a bit more ambitious than I expected. 

At any rate, I concur with what everyone else has been saying: these amps sound wonderful.  Originally I said I didn't hear much of a difference between it an my QSC RMX2450.  But now that I've gone back and forth between the two amps, there is definitely a difference, which clearly favors the SDS-470.  The most notable difference to me is instrument separation and definition; this is most pronounced on classical music.  The second most notable difference is bass, which just seems better, especially on bass-centric music like trance.

[mboxler]

Getting Excited, Tom is testing my amp before shipment... 

Think the 470 will have any trouble man handling my Gallos? Tom thinks the amp will smack em around and have them begging for more...

Cant wait!

Now, to preamp or not to preamp, that is the question!

Hi Vedder323

I received my case kit with all connectors for my SDS-224.  As usual...no instructions.  I was wondering if you had the above picture in a much higher resolution that you could e-mail me?  I'm assuming the case power switch is connected to the amp, and I'm really confused how to hook up the balanced and unbalanced connectors thru the switch to the amp.  I'm hoping a better picture will answer a lot of questions.

maboxler at msn dot com

I'll contact Tom if you can't help.

Thanks in advance.

Mike

 

[tubesurf]

I know it is in this huge thread somewhere but I cannot find it again - does anyone know the Molex connector part number used to replace the pot with a fixed resistor?   I know some just use the connectors with the kits but I want to save those.   Thanks.

[bigdirty]

Planning to put my pair of bridged sds-224 in a better enclosure. Any thoughts on the merits of a dual chassis (amp/PS) vs mono block design?

lovin the info in this thread, thanks guys

big

[mboxler]

Planning to put my pair of bridged sds-224 in a better enclosure. Any thoughts on the merits of a dual chassis (amp/PS) vs mono block design?

lovin the info in this thread, thanks guys

big

Hey big

Do you already have two trannys/power supplies?  Two monoblocks would be NICE!  Anyway, I just received my SDS enclosure with components direct from ClassDAudio (already had the SDS-224, too lazy to build a nice case). 

http://classdaudio.com/amplifier-kits-1/parts-components-1.html

These are really nice, but only for one amp.  I'm not sure if Tom is planning on expanding his enclosure line to include multiple amps, but it sure looks like he's busy with new products.  Anyway, if you have the parts already, the bare cases may work for you. Comes with Neutrik connectors and single speaker connects (holes about an inch apart, not .75).

Mike

[bigdirty]

Hey big

Do you already have two trannys/power supplies?  Two monoblocks would be NICE!  Anyway, I just received my SDS enclosure with components direct from ClassDAudio (already had the SDS-224, too lazy to build a nice case). 

Yes, running a dual mono in a hammond case atm. not satisfied with the hammond, looking into the par-metal 20 series.

Im leaning towards the mono block build. just looking for some thoughts on the pro's/con's of each.

[walkern]

The Molex connectors I used were not a perfect fit and had to be filed a bit (the locking system on them was different than Tom uses), but are snug and won't fall out.  Mouser part number for them is: 538-10-11-2033, and you'd also need crimp terminals for them that will attach to the legs of the resistors (that must be soldered IMHO) - Mouser part number 538-08-50-0114.  There is a photo of how the resistors look in the connectors on page 108 of this thread

I know it is in this huge thread somewhere but I cannot find it again - does anyone know the Molex connector part number used to replace the pot with a fixed resistor?   I know some just use the connectors with the kits but I want to save those.   Thanks.
[/quote

[tubesurf]

Walkern - Thanks for that.

[walkern]

Least I could do... this thread is really LONG!

[vinylb]

I'm expecting my SDS-470 kit and the SDS enclosure with parts tomorrow. Anybody have any idea on how to wire the balanced/unbalanced connectors and switch?

thanks in advance

[mboxler]

I'm expecting my SDS-470 kit and the SDS enclosure with parts tomorrow. Anybody have any idea on how to wire the balanced/unbalanced connectors and switch?

thanks in advance

I just "finished" my enclosure.  Like most of my projects, I got to a good stopping point, and plan on finishing the rest later (ya...right!).  Tom sent me 8 or 9 pictures of the inside of the enclosure.  This one may help you.  I will be interested in your take on the wiring.  If you need all the pictures, PM me with your e-mail, and I'll forward you the whole folder. 

Mike

[vinylb]

Thx Mrboxler, pics always help Did yours come pre-wired at all?  From what I can see red is live, orange is ground, both wires for balanced and unbalanced are connected to same screw-in connections but how is the toggle switch wired?

[Barry_NJ]

From looking at the pic, the unbalanced wires go to the balanced connector, than from the balanced connector to the board. I believe that the toggle is actually wired to the board as there is some circuitry on the board to compensate for the balanced vs. unbalanced signal.

[mboxler]

Thx Mrboxler, pics always help Did yours come pre-wired at all?  From what I can see red is live, orange is ground, both wires for balanced and unbalanced are connected to same screw-in connections but how is the toggle switch wired?

No wires at all!  Since I only use the unbalanced, I did not install the switch or the unbalanced connectors (although I have them screwed onto the case so I won't loose them, and I plan on dealing with this later). 

Having said that...

Tom's tech wired the balanced connectors to the amp (+ - G), then daisy chained the + and G from the balanced connectors to the unbalanced connectors.  That's why you see only three wires per channel screwed to the amp.  (I've attached another picture that may be clearer).  You could just as well wire each connector to the amp, but 5 wires may get a little tight. 

The switch replaces the jumpers on J1 and J2.  I found it odd that only two of the three pins were used (2 and 3, I believe).  I can't remember if no jumper indicates balanced mode...I lost the original instructions.  When you get the kit, you will notice a bare side on the threads of the switch.  I e-mailed Tom if the bare side should go up...he didn't say yes or no.  Judging by the picture, you only need to deal with the top two pairs on the switch, and pins 2 and 3 on the amp. Sorry, I'm at work and am going off memory as far as pin numbers.  This is where I got tired and confused.  Using a multi-meter, it seemed as though this combination would not match the lettering on the back of the case.  I'll be interested in your take. 

This may not help.  If you are still confused, I'll e-mail Tom for clarification. 



   

[mboxler]

Sorry...can anyone verify the amp setting for balanced input.  I'm assuming it is no jumper on J1 and J2.

Vinylb...I'll open my case tonight and double check a couple of things.  I'll also try to post some things I ran into, so you don't have to go through some of the brain damage I did!

Mike

[vinylb]

Got an email from Tom, he says for balanced input remove jumpers J1 & J2 completely (this is for the SDS-470 board).
Pins 2 & 3 on jumpers J1 & J2 are to be shorted and used only for unbalanced. Moving to pins 1 & 2 for J1 & J2 will reverse polarity.

I also received instructions about the wiring of the balanced and unbalanced which is confusing, to me at least.

Barry_NJ i think you right, unbalanced is wired to balanced and balanced to connectors....at least thats what its starting to look like.

But I still dont get how the toggle works unless the live goes to it first ? but then you would need 2 lugs on it or two toggles?

Any input you have to prevent me from making mistakes would be very beneficial and truly appreciated.

[mboxler]

Got an email from Tom, he says for balanced input remove jumpers J1 & J2 completely (this is for the SDS-470 board).

I also received instructions about the wiring of the balanced and unbalanced which is confusing, to me at least.

Barry_NJ i think you right, unbalanced is wired to balanced and balanced to connectors....at least thats what its starting to look like.

But I still dont get how the toggle works unless the live goes to it first ? but then you would need 2 lugs on it or two toggles?

Any input you have to prevent me from making mistakes would be very beneficial and truly appreciated.

I just e-mailed Tom too...he's probably wandering why the same questions.

The toggle is wired directly to J1 and J2, pins 2 and 3.  When the toggle is in the RCA position, the top pair of connectors on the toggle are "ON", simulating the jumper.  In the XLR position, the connectors are "OFF", simulating no jumper. 

Hope this helps.  I'll try to clarify as you go.  Like I told Tom...I can see things from a novice's point of view.  Yes, wire from amp to balanced connector, then daisy from balanced connector to unbalanced connector.  The toggle switch is not a part of this wiring.

Mike

[vinylb]

Ah ok so the toggle acts as a jumper - that makes sense. Are jumpers/molex connectors, included in the kit?

As for the IEC and fuse, is that all internally wired so we just connect transformer to hot, live and ground connector on IEC?

[mboxler]

Ah ok so the toggle acts as a jumper - that makes sense. Are jumpers/molex connectors, included in the kit?

As for the IEC and fuse, is that all internally wired so we just connect transformer to hot, live and ground connector on IEC?

No...the molex connectors are not included (I haven't found out what the part number would be).  Now you know why I'm considering avoiding the toggle switch altogether.  If I need to switch from/to balanced, I'll remove the cover and jump/unjump (is that a word) pins 2 and 3 by hand.

The fuse is part of the IEC; however, the fuse is not supplied.  I got my 6.3 250V 20mm slow blow fuse at RadioShack.  Not sure what amp fuse you require.  While you are there, you will need the female flag disconnects for the IEC to transformer connection (the caps on the power supply force you to make a quick turn out of the IEC).  Model: 64-3088 | Catalog #: 64-3088.  I used the blue ones...the red ones were too small.  First problem I ran into.  The disconnects were still too big, and pressed up against one of the PS caps.  Took me a while to figure out a solution.  I used a dremmel tool to grind down the excess plastic (about 1/8") off the part that connects to the IEC.  I also loosened the nuts holding the PS and moved it as far from the IEC as possible, then secured it.  This combination gave me a 1/16" gap between the disconnects and the Cap (WHEW!).   I did not have a proper cripping tool for flag disconnects, so I soldered the wire to the disconnect.  If you have the right tool, you are probably okay.  If not, I'll take a picture of a "modified" "soldered" disconnect and post it.

Breath!

I went from a wood board to this "nice" case.  Grounding becomes very important.  1)  Run a short wire from the ground tab on the IEC to a dedicated nut on the back of the chassis.  Tom connected to a nut holding the IEC to the chassis.  I believe in never using a nut that is shared with another component.  Besides...that was a really sharp bend.  I ended up drilling a new hole above the IEC, grinding off the powder coating to bare metal, and running the ground wire to that dedicated nut.  Bad news...the top of the chassis hit that nut (F&*$).  I had to cut a peice off the chassis cover (not noticable, again, I can take a picture of this, of course you can simply connect to the IEC nut and avoid this altogether.  I happen to feel better with my solution).

The ground wire from the tranny can connect to one of the screws that holds one of the feet to the chassis.  Grounding done!  Connect the neutral and hot wires from the tranny to the IEC, wire the tranny to the PS,  and power it up.

You will need a break at this time.

I'll let you ponder this.  When you get the kit, a lot of this will make more sense, and a lot more questions will pop up.

Again, I'll help as best as I can, or Tom, if you prefer.

Mike