Measuring Amplifiers - Page 8

Your welcome! It is fun for me now that I do not do it for a living anymore

Sounds like a plan. You might want to pull some extra 20 amp circuits to the location of the amplifiers. I have found that running at full wattage you can only put 2 of them on a 20 amp circuit. I currently have 2 of them on a 20 amp circuit that also has a light and a digital clock on the circuit and on very deep, loud bass notes the lamp will dim and the digital clock will reset itself to 12:00! Show us some pictures when you have it installed.

I have a DCX2496 and a DEQ2496 that I am getting ready to use in a project myself shortly. Watch the gain settings in the DCX!

Ahhh, but you have Arvo's that I am starting to build! Maybe meeting halfway, no that won't work, ummmm, lemme' think about this!

I will be glad to test any amplifier. I know that lots of people use both of those amps so it would probably be of interest to others that come around here. Not sure how we would work it out but I am sure it could be.

Joe:
That sounds like a plan. I have worked with the Oaudio and it seems OK. It worked well with an AE15 in a ported box that ssabripo and I made. But I am real impressed with the Rhythmik gear. I have heard crackyflipside's (Chris) 12" unit and it sounds very, very good. I would tend to go with the Rhythmik. No solid scientific reason, just gut instinct from what I have heard.

This question can lead to the snake oil boutique power cord discussion which can go crazy. I took a common sense approach. If you want to bypass the SJE connector built into the back of the amp and make your power cord 'permanent' so that it cannot be unplugged, yes, it will be according to numbers a better connection than a pluggable connection. Will it be an audible difference? Highly unlikely.

I went so far as to buy Belden power cords that come under the 'Volex" name and are available at www.carlton-bates.com. Model 17604 is 3 cond, 14 gauge power cord. I then cut the end that plugs into the amplifier and replaced them with Schurter brand connectors. The cords are around $8-$9 each and the connectors are $4-$5 each. Shipping will kill you if you order one at a time.

So to answer your question, I tossed the flimsy power cords but kept the input connectors on the amp. Now realize that all of this doesn't mean squat if you are hooking this up to a 20 amp circuit with a wall plug rated at 15 amps and the internal house wiring is 14 gauge. I bought 20 amp Hubbell hospital grade outlets and wired 4 dedicated circuits with 10 gauge wire and run no more than 2 amplifiers per circuit. All my low level equipment is powered by a 2.5kw Balanced Power Transformer to cut down on noise.

In the end, does it make a difference? I believe all the little tweaks I have done to my power system add up to an audible difference. If you take each one by itself, they help and build a good foundation. Hope this helps.

Chuck

Yeah, average current draw running the amp wide open at full power "playing music" is a little less than 10 amps. Using a steady state 1000 Hz sine wave I was able to pull 17 amps. I just read your thread about mounting the amps in the closet. Make sure you have room for the air to circulate behind it! You might need to force feed some air behind the amps with a large auxiliary fan.

I actually have a reason to pull it out of the rack and use it in another scheme I am cooking up. But it is so heavy. If a really strong guy with an interest came over one afternoon, it would be much easier!

Tonight for your listening pleasure we have an 'OAudio 500' BASH plate amplifier. I would like to thank JoePerri for sending me his brand new amp to test. Thanks Joe! I will have to say from the start that I like this plate amplifier. It can be bought for $229.00 + $10.00 shipping from www.oaudio.com and packs a lot of punch for the price. This was the plate amplifier that was used in ssabripo's first DIY subwoofer that we built together. That being said, here are some specs and test results.

Controls


Close up controls


Rear PC Boards


Closeup Rear PC Boards

Now here are the specifications and the tests.

Specifications page 1


Specifications page 2


Test results


Oscilloscope and current reading at full power

Let's see..... the first thing I'll hear is 'It doesn't even meet specifications' and 'Those aren't great numbers'
and 'It doesn't have flat frequency response.'

You're right. It also only weighs less than 10 pounds soaking wet and costs $239.00 delivered. If you look at the controls, you will find features that don't exist on comparable PE plate amps. The quality of assembly and components used are very good. Yeah, it's made in China and OEM'ed to OAudio but it has good quality and decent specs.
It has a soft clip circuit that reacts when a steady state sine wave (or music) is applied and brought up to full power slowly. I could crank it up quickly and watch it peak without clipping but I could not get it to run at a steady 80 Hz at full power. You could see the waveform being 'adjusted' electronically. Now, for a 500 watt plate amp, this is a good thing. You can see from the current reading in the last image that I am drawing 4.94 amps. The fuse is rated at 5 amps. (I got tired of buying fuses and just put the current meter in line to monitor the draw.)
The fact that I have heard this amp work in a well built cabinet with a great 4 ohm 15 inch driver is what I base a lot of my praise for the amplifier on. This amp was run right with sherv's old SVS Ultra and it bested that sub easily. So, even though it only gets close to meeting specs, it has some power behind it. And it's efficient. For a plate amp, this is one of the better ones. Thanks again to JoePerri who shipped this to me from California so that I could test it.

Chuck