Christmas in September...sort of.

[Radian]

Forgive me audio gods for I have been sinning.

With a little creativity, I've been running my HT subwoofer in direct defiance of the AES using pro-level gear in the form of a modified K2 amp fed from a DCX2496. The items were not being used at the time for their intended purpose as PA equipment, so instead of spending money for the correct gear to accomplish this, I relegated them to duty in my HT. It worked, but wasn't what I would call convenient . Talk about lighting a cigarette with a cruise missile.

The 38 pound modified K2 idles at 200W when there's no signal present making it a more effective space heater than the TV. The PEQ on the DCX had to be setup or adjusted adhoc using a test CD and SPL meter. On top of that, there's the classic HT start-up sequence that runs like a pilot's take-off checklist: 1. Source-check 2. Receiver-check 3. Crossover-check .....sit down to watch movie, cue opening scenes...GF chimes in before I can even open my drink, "Where's the bass?", @#%#$ "Oops, thanks sweetie." 4. Amplifier - check

Recycling funds by liquidating a pair of surplus speakers has allowed me to finally purchase some consumer level gear that's a little more at home in the home. DCX gets replaced by the SMS-1, and the K2 gets replaced by a Dayton SA-1000. Everything is now sharing the same interconnects, the same color, less heat, RTA for tinkering, and finally it's all on a 12V trigger.

Using the remainder of those funds, I also picked up a new DEQ2496 during GC's labor day sale, so now I have the appropriate gear for another PA rig. The SMS-1 included an RTA mic, stand, and big 'ol cord that is compatible with the DEQ.

[SeisTres]

I tried doing that when I first go my sla's built as I was itching to use them. But, after two days of having to power everything up and power everything down and having my xls's being cumbersome and imposing, along with running 25' pro cables everywhere, I simple said "screw this" and waited a month until I made the order from PE for the t-amp. Granted, it's still not as convenient as I would like to be since I lost the little project box that was going to be the main volume, but it is 100x better than running my driverack for home audio, that's for sure.

[Drey Chennells]

nice! Can you rate the performance of the Dayton amp please? How do you like the sms-1?

[Radian]

You bet!! When I get it all dialed in and listened to, I'll post some remarks of the combo and pictures of the SA-1000 innards.

I was ready to grab the O-Audio BASH 500 and was eye-balling the Audyssey SubEQ, but then I'd have have to design & fabricate a box for the amp. The Dayton already had that in spades and used the same topology (even though the manual doesn't specifically say so) making it quite flexible in it's own right. The Audyssey is integrated like it wasn't designed with the tinkerer in mind, and it harbored a truly bloated price tag for what it was / is IMHO. The user still has to provide their own laptop for example. Got a sweet deal on the SMS-1, and it came with a mic I could actually use for more than just dialing in the software, a Velodyne-badged Behringer ECM8000 / Dayton EMM-6 clone. It works equally well plugged into the DEQ or as an announcement mic for PA. FTW

[Radian]

So what's in a Dayton SA-1000? Parts Express has good pictures of the fancy exterior, but here's some big photos of what makes it tick.

[Radian]

Got everything wired up.
Not so hot right out of the gate. When running the sweep signal out of the SMS-1...nothing came out of the sub. I had to turn my receiver way up...then I'd finally hear some bass; too much because now everything was cranked. I'd turn the volume down only to hear a whole bunch of garbled crap coming out of the sub that went away after 3 seconds or so, then no output again. WTF?


So I removed the SMS-1 from the chain and tried just the SA-1000 by itself. Sounds great! It is however much more sensitive to ground loops than I had anticipated. Anytime the Blu-Ray player is fired up, I get hum from the sub. It's coming through the HDMI cable and making its way to the sub amp. The amp itself is not inherently noisy. In fact, it's output is dead silent. It's just very susceptible to signal chain issues. When I hook up my walkman CD player directly to the amp...it plays cleanly, no hum or distortion. I'd be inclined to use toslink between the BD player and the receiver, but then I'd loose out on the max bit rate audio available through the HDMI cable. We'll see. I'll pick up a line-level isolation transformer. Blocking the loop at the amp input, I believe it'll cure the issue as that seems to be the only source. The cable box is not the problem (unplugging all of those connectors didn't change a thing), everything is plugged into the same circuit with polarized plugs (can't flip them around), and lifting the safety ground on the amp was only good for a ~2 dB spl drop (verified by meter) in actual the noise from the sub at max gain. Signal path from the receiver to the SMS-1 to the SA-1000 is less than two feet.

The SMS-1, on the other hand, has issues that require further investigation. I'll be taking it to the lab for testing before I give Velodyne a call. This was a brand new sealed unit, so it shouldn't be doing any thing like it's doing. It appears to have an input threshold issue. Once the input gets to a certain level, then the output kicks on. While the output is on, it's heavily distorted. Kill the input, the distorted output continues for bit, then all stop again. We'll see. Picture's worth a thousand words. I'll get it on a O-scope and see what's up. Worst case, it'll have to get it sent back to Velodyne for repair.

So for now the SA-1000 is running solo and doing a fine job. I'll let you all know what comes about as things progress. In contrast, the DCX / K2 combo had none of these issues.

[Radian]

Got the SMS-1 hooked up to the scope at the lab. Couldn't duplicate the garbage signal this thing generates when hooked up to my system. Nice clean sine waves. Gonna call Velodyne tomorrow. The PEQ and RTA function work as advertised, however it generates some kinda nasty "digital grit" in the output signal. Sounds like something quietly brewing coffee in the corner of my room that's definitely digital in nature, it lingers after I kill the input signal. All of my signal sources (CATV, BD player, and optical-in) generate the same output problem. Probably would have never noticed it with a normal subwoofer. Can't hear it so much when somethings playing through, but when I mute it or there's a sudden quiet part in a movie... More to come.

[Drey Chennells]

others have had a similar issue with their sms-1 fyi.

I'm trying to find a link back to that discussion, it was actually in the last few days I came across it. It was the first I've heard of any issues with that unit..

[Radian]

Went back to the lab and grabbed a better scope to work with. Wouldn't you know it, I was able to catch the gremlin in the act. Got a hold of Velodyne CS on the phone today and got an RMA. It's under warranty, so I'll see what they come up with for a fix.

[Radian]

Got a Jensen SUB-1RR line level audio isolation transformer in the mail tonight. Plugged into the back of the amp, pulled the ground lift (removed the cheater plug) and Viola! Fixed. Blu-ray without any more hum.

SMS-1 is on its way to Velodyne for analysis. I'll update when I get the unit back.

As far as the SA-1000...it's a sweet amp for the dough. I'm still getting used to how cool this thing runs. Efficient cab + efficient amp = very little, if any, heat. At the end of a night of movie watching, it was still nearly cool to the touch. It's nice. Just like most any other Dayton product, it gives me the impression that I got my money's worth. The onboard PEQ, X-over, and High Pass filter allow me to run it quite well in the absence of DSP. It certainly has no problem driving my subwoofer. From my investigations, I would venture to say this is the most feature rich, high power, consumer-grade subwoofer amp on the market today.

Thumbs-up!

[Radian]

The saga continues. The replacement unit I received from Velodyne does the same thing. I recorded a HQ video of the phenomena for your enlightenment / entertainment. Their Customer Service department is sending me yet another unit. We'll see if that exhibits the same behavior.

[Drey Chennells]

Got a Jensen SUB-1RR line level audio isolation transformer in the mail tonight. Plugged into the back of the amp, pulled the ground lift (removed the cheater plug) and Viola! Fixed. Blu-ray without any more hum.

SMS-1 is on its way to Velodyne for analysis. I'll update when I get the unit back.

As far as the SA-1000...it's a sweet amp for the dough. I'm still getting used to how cool this thing runs. Efficient cab + efficient amp = very little, if any, heat. At the end of a night of movie watching, it was still nearly cool to the touch. It's nice. Just like most any other Dayton product, it gives me the impression that I got my money's worth. The onboard PEQ, X-over, and High Pass filter allow me to run it quite well in the absence of DSP. It certainly has no problem driving my subwoofer. From my investigations, I would venture to say this is the most feature rich, high power, consumer-grade subwoofer amp on the market today.

Thumbs-up!

Awesome. So christmas wasn't a total bust ; ) I've enjoyed the same incredibly low cool operating temp conditions with the Sunfire cinema sig amps I've used with the tracking downconverter power supply. Years after BCarver developed these, and costing a premium, it's really cool to hear that as I've been looking at these, curious as to how they'd do overall and the reasonable price. What's it driving again please? Any regrets getting the chassis version?

[Radian]

What's it driving again please?

I've got it driving a DIY tapped-horn right now.

Any regrets getting the chassis version?

None what so ever.

Eleven years ago I got my paws on my first powered sub, a Yamaha YST-SW150. I had it installed in the rear corner of my listening room and I found out real quick how much it sucked having the amp on-board the sub. Pushing a line level signal through 30 feet of unbalanced cable = very little signal on the other end, and it was a noise magnet.

Ever since then, the idea of a component amp really appealed to me. This one is really nice. It isn't a Krell or a Butler, but that's not my style anyhow. If I ever need 30 dB of gain down the road, I'll just dust off one of the K2's again. I'll probably have a "real" HT rack by then anyhow.

The Dayton has a sleek look to it. It won't win an art award anytime soon, but it looks a helluva' lot nicer than a plate amp IMHO. In my install, it tucks away cleanly underneath my receiver. It's light weight (for me) so I can pick it up and turn it around to get at the back when I need to, which has been quite often lately, given the SMS-1.

Only caveat once again is that it will most likely need an isolation transformer, don't be surprised if it does. If I did some spark chasing around the board, I could most likely target the grounding issue inside the amp, but the Iso-Max was a very straightforward work around.

*edit* I've since gone back to using an optical toslink connection out of the Blu-ray in lieu of HDMI for the audio signal with great results. I am no longer in need of or using the isolation transformer to combat hum.

[bean438]

Dumb question I am sure, but how can it be a great amp if it hums without the isolator?

Shouldn't you be ok if you make sure everything is plugged into the same electrical outlet?

[Radian]

It's running without the isolator right now..no problemo

Shouldn't you be ok if you make sure everything is plugged into the same electrical outlet?

Not necessarily. Individual component outputs can be sources of noise as well. My Blu-ray player / receiver combo is a great example of this.