No, their +-57v. I was using a cheap meter for the voltage test as my good meter was being used for the current draw measurement.
I did some new tests today using a better meter. I used a monster car audio sub that I had stored in a closet from when I used to think car audio was cool.
First, let me note that none of the new test reached clipping. My DAC's output is 1.5v and I could not make the amp clip, so I assume the line levels in the receiver are quite a bit more than that.
The sub is dual 2ohm and was played in free air at 40hz. I used a single 2ohm coil because I knew from experience the impedance would rise about another 2ohms or so.
The first test was one channel driven. No protection was tripped with this test and clipping was not reached.
Results: 42V @ 9.5A = 399watts @ 4.42R
The second test was 2-channels bridged. I did this via KXdrivers from the source PC by inverting the phase of one channel. Over-current protection was reached at 1v and 0.5 amps above the test results, clipping was not reached.
Results: 51V @ 11.5A = 586.5 watts @ 4.43R
You can see from the last test you can't get much more power bridged before the over-current kicks in. You can adjust the over-current threshold on the board by changing some resistors, but I'm not sure if the board itself can handle more current flow.
I was pretty amazed to say the least. All that class-d power for $90, unreal.
The RB-TA3020 eval board sells for around $450 at profusionplc. The moto amp board is basically 2.5x RB-TA3020's and only cost $90 AND it comes with a power supply.
I'm off to buy 2 more of these things. I can't really afford it, but I can't afford to pass up a bargain like this either.
The Eval Board detailed the bridging of a stereo amp using an inverting OP Amp on the input...did you use it in your test? How exactly did you bridge? Did you see the supply caps? Are they 63V rated? Did you have an opportunity to take some pics?
Are these still for sale for $69? I could not find anymore...
So +/-50V?? That is so cool...so according to your numbers, that power supply approaches 1.2KVA, right? I would think that torroid alone is worth $150 alone...holy crap.
I need TWO MORE!!!
Are these still for sale for $69? I could not find anymore...
So +/-50V?? That is so cool...so according to your numbers, that power supply approaches 1.2KVA, right? I would think that torroid alone is worth $150 alone...holy crap.
I need TWO MORE!!!
Just bought ONE MORE....I will most likely need to sell off a few of my other amps (TA2020, TA2024, UCD180, ZAPPulse, 4 different Gainclones, Etc)...Too bad I cannot sell some Tripath Stock to fund this hobby (underwater by a few thou...)
The stripped and bridged TA3020 will work real nice with a dual-series connected Magnepan MMG's. I plan on having two sets of MMG's...each MMG pair per channel connected in series and hinged together like the Typani series of years ago. These speakers and the bridged amp should be the last of my "search" for the ultimate el-cheapo DIY system...
Theres a few nice Par metal amp chassis out there that can house the 5 channel amp boards...
More later
The stripped and bridged TA3020 will work real nice with a dual-series connected Magnepan MMG's. I plan on having two sets of MMG's...each MMG pair per channel connected in series and hinged together like the Typani series of years ago. These speakers and the bridged amp should be the last of my "search" for the ultimate el-cheapo DIY system...
Theres a few nice Par metal amp chassis out there that can house the 5 channel amp boards...
More later
I inverted the signal of one channel through software on my PC. After you invert the signal all you have to do is use the + of both channels. For me this was much easier than wiring up an opamp.
The supply caps are 71v 10,000uf. Theres only one cap per rail even though theres room for 2 on the supply.
I've been so busy I haven't had a chance to take pics. When I do, I'll post them along with the way I have everything wired up.
The first test I did was only one channel @ 4.42R, tomorrow I'll do another test with both channels driven and see if the power supply can keep up.
This whole thing puts my 6-channel AMP1-B setup to shame. I spent almost $500 and over 25 hours on that project and only get about 50wpc. I wish I would have found this deal before I built them.
I just ordered 2 more and theres 5 still listed.
http://cgi.ebay.com/ws/eBayISAPI.dl...50019607938&rd=1&sspagename=STRK:MEWN:IT&rd=1
The amp board, supply, and trafo should all fit perfectly inside this case.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7624530988&rd=1&sspagename=STRK:MEWA:IT&rd=1
The supply caps are 71v 10,000uf. Theres only one cap per rail even though theres room for 2 on the supply.
I've been so busy I haven't had a chance to take pics. When I do, I'll post them along with the way I have everything wired up.
The first test I did was only one channel @ 4.42R, tomorrow I'll do another test with both channels driven and see if the power supply can keep up.
This whole thing puts my 6-channel AMP1-B setup to shame. I spent almost $500 and over 25 hours on that project and only get about 50wpc. I wish I would have found this deal before I built them.
I just ordered 2 more and theres 5 still listed.
http://cgi.ebay.com/ws/eBayISAPI.dl...50019607938&rd=1&sspagename=STRK:MEWN:IT&rd=1
The amp board, supply, and trafo should all fit perfectly inside this case.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7624530988&rd=1&sspagename=STRK:MEWA:IT&rd=1
Yes, I saw that case...looks great and should do fine...
So you are using a usb dac as input to amp?? For a stereo bridge setup, you are splitting the DAC output pair (to four) and inverting one output set to third/fourth channel, and connecting both left/right speaker outs on channels 1/3 and 2/4 to the speakers? Are you using any resistors on the speaker outs so they don't "fight" each other?
When you run two channels @4ohms (bridged or not), I think you will runout of power and Overload before you get anywhere around 200wpc...but post you findings here...
Can you give me dimensions of the amp board? I think it was about 17" long, right??
So you are using a usb dac as input to amp?? For a stereo bridge setup, you are splitting the DAC output pair (to four) and inverting one output set to third/fourth channel, and connecting both left/right speaker outs on channels 1/3 and 2/4 to the speakers? Are you using any resistors on the speaker outs so they don't "fight" each other?
When you run two channels @4ohms (bridged or not), I think you will runout of power and Overload before you get anywhere around 200wpc...but post you findings here...
Can you give me dimensions of the amp board? I think it was about 17" long, right??
I have a soundblaster audigy card connected to 3 stereo optical outs. This is for future plans, right now I only have one DAC. It takes two channels to make a mono signal for bridging so this was just a temporary test setup. If I wanted stereo I would need two DAC's.
There's no resistors or anything needed. Here's a link to how to build a bridging module that explains the whole thing.
http://sound.westhost.com/project14.htm
I have plenty of faith this thing can do 200 watts stereo into my 4.4ohm test subject without tripping. The question is how much more than that can it go. When I did the bridge test the load was just over 4ohms, so the amp was really seeing a stereo 2ohm load at almost 300 watts per channel before over-current.
The amp board is 14.5"x6, supply is 8"x5", and toroid is 5".
I'm off to work now, I'll post more findings when I get home in the morning.
There's no resistors or anything needed. Here's a link to how to build a bridging module that explains the whole thing.
http://sound.westhost.com/project14.htm
I have plenty of faith this thing can do 200 watts stereo into my 4.4ohm test subject without tripping. The question is how much more than that can it go. When I did the bridge test the load was just over 4ohms, so the amp was really seeing a stereo 2ohm load at almost 300 watts per channel before over-current.
The amp board is 14.5"x6, supply is 8"x5", and toroid is 5".
I'm off to work now, I'll post more findings when I get home in the morning.
Do you have the bridging adapter? From the link, it almost looks more like paralleling rather than bridging.
For what little I know, bridging involves sending the output of one amp to the input of a second amp, and I did not see that in the link...again, looks more like parallel setup - and in parallel setup, you don't have a halving of the impedance like in bridging (again, for what little i know)
Anyway, I would like to see how you did your bridge setup...if it is simply inverting a second channel to the amp, and then hooking up the speakers using the positive terminals of the two amp channels...hmmm, I need to think it through better before I blow something up...
Since I am dealing with 4 ohm speakers, the bridging doesn't really fit for me since I would have a 2 ohm load on the amp - I am most likly going to modify the crossover on my MMGs to Bi-Wire, and then use four of the amps to power the two speakers...
For what little I know, bridging involves sending the output of one amp to the input of a second amp, and I did not see that in the link...again, looks more like parallel setup - and in parallel setup, you don't have a halving of the impedance like in bridging (again, for what little i know)
Anyway, I would like to see how you did your bridge setup...if it is simply inverting a second channel to the amp, and then hooking up the speakers using the positive terminals of the two amp channels...hmmm, I need to think it through better before I blow something up...
Since I am dealing with 4 ohm speakers, the bridging doesn't really fit for me since I would have a 2 ohm load on the amp - I am most likly going to modify the crossover on my MMGs to Bi-Wire, and then use four of the amps to power the two speakers...
No, I havn't built a bridging adapter yet. The schematic for the adapter might be a little confusing because it uses an op amp on each channel instead of just one like in the tripath data sheet. I'm not sure why two are used, because the signal just pretty much passes through the one without any change and the other one inverts the signal.
Here is another example of bridging that shows just a single op amp. This is meant to show how "tri-mode" bridging works, but just disregards the tri-mode part, the bridging principle is the same.
http://sound.westhost.com/bridging.htm
I see no problem with doing 4 ohm bridged. I managed to get nearly 600 watts bridged into 4 ohms before tripping the over-current. I'm going to try and find a few op amps and bridge both stereo pairs. I will test this configuration into 4 ohms and let you know how it goes.
Here is another example of bridging that shows just a single op amp. This is meant to show how "tri-mode" bridging works, but just disregards the tri-mode part, the bridging principle is the same.
http://sound.westhost.com/bridging.htm
I see no problem with doing 4 ohm bridged. I managed to get nearly 600 watts bridged into 4 ohms before tripping the over-current. I'm going to try and find a few op amps and bridge both stereo pairs. I will test this configuration into 4 ohms and let you know how it goes.
I was doing some more testing today and found out this amp does not like musical peeks. When powering a 4 ohm load the musical peeks trip the over-current protection at levels far below where I was doing the sine tests.
Its not that the amp is lacking the power, its just that the over-current threshold is set low. If your not afraid of SMD soldering, the fix for this shouldn't be too hard. When I get some time I'm going to try and raise the over-current limit.
Her is a pic of the amp board.....
http://i8.tinypic.com/24ycwmb.jpg
And here's the supply....
http://i7.tinypic.com/24yd3bt.jpg
Its not that the amp is lacking the power, its just that the over-current threshold is set low. If your not afraid of SMD soldering, the fix for this shouldn't be too hard. When I get some time I'm going to try and raise the over-current limit.
Her is a pic of the amp board.....
http://i8.tinypic.com/24ycwmb.jpg
And here's the supply....
http://i7.tinypic.com/24yd3bt.jpg
I just checked the over-current threshold resistors on the board and they are 15k. The same resistors in the datasheet and on the tripath eval board are 20k, so that definitely explains whats going on.
I'm not too good at math, or electronics for that matter, so I'm not sure what kind of difference 5k makes. I have two 20k resistors left over from an AMP3 project, so I'm going to experiment on the center channel and see if I can raise the trip limit.
Wish me luck (I'm a newb and need it).
I'm not too good at math, or electronics for that matter, so I'm not sure what kind of difference 5k makes. I have two 20k resistors left over from an AMP3 project, so I'm going to experiment on the center channel and see if I can raise the trip limit.
Wish me luck (I'm a newb and need it).
theAnonymous1,
Very cool pics! Thanks. I'm still waiting on my third moto to arrive. Which of the amps in the pic supplies the Front L & R speakers? I want to try to upgrade the sound of the Front channels only. I'm going to keep the receiver's together after the upgrades. I really like the smooth operation with the remote . I have two rooms where I can use a moto. I plan on getting a fourth. That will give me two extra's to do whatever else with.
What do you think I can do to the front channel amp to improve the sound? I'm in no hurry, so take your time. This thing could be unreal. I have done some light soldering on stuff, but I need help with what to do!
This is fun, I'm going to set up moto number two in my office where I do my T-Amp listening, then I can switch between the two.
Thanks in advance for the help!
Very cool pics! Thanks. I'm still waiting on my third moto to arrive. Which of the amps in the pic supplies the Front L & R speakers? I want to try to upgrade the sound of the Front channels only. I'm going to keep the receiver's together after the upgrades. I really like the smooth operation with the remote . I have two rooms where I can use a moto. I plan on getting a fourth. That will give me two extra's to do whatever else with.
What do you think I can do to the front channel amp to improve the sound? I'm in no hurry, so take your time. This thing could be unreal. I have done some light soldering on stuff, but I need help with what to do!
This is fun, I'm going to set up moto number two in my office where I do my T-Amp listening, then I can switch between the two.
Thanks in advance for the help!
One last thing for the night. A pic of the resistors in question....
http://i7.tinypic.com/24yol51.jpg
Tripath07, The set on the left is the front, middle is center, and right is surrounds.
The number one improvement I can think of is the input caps. They are the cheapest looking 2.2uf electrolytic caps I have ever seen. Replacing them should be priority #1.
They are the caps in the pic at the top corners of the chipset heatsinks. You can see on the center channel that there is only one on the upper right because there is only one channel on that chipset.
http://i7.tinypic.com/24yol51.jpg
Tripath07, The set on the left is the front, middle is center, and right is surrounds.
The number one improvement I can think of is the input caps. They are the cheapest looking 2.2uf electrolytic caps I have ever seen. Replacing them should be priority #1.
They are the caps in the pic at the top corners of the chipset heatsinks. You can see on the center channel that there is only one on the upper right because there is only one channel on that chipset.
Let's not forget the spring clips...they gotta go big time...does it look like the speaker out clip set on end of amp board will come off without too much effort?
What Anonymous has said about the peaks is true, when I think about it, it the amp would overload and shut down when a bass peak was hit...
I hate soldering SMD components...but it that's what it takes...
What Anonymous has said about the peaks is true, when I think about it, it the amp would overload and shut down when a bass peak was hit...
I hate soldering SMD components...but it that's what it takes...
The whole spring terminal block should come off without too much trouble. Theres not much room to put binding posts though. They would fit, but you would have a heck of a time tightening and loosening them.
A better option might be banana jacks like these......
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=091-1160
Hey, maybe I can mod and resell these things!! Better input caps, over-current limit raised, and banana jacks at the rear.
A better option might be banana jacks like these......
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=091-1160
Hey, maybe I can mod and resell these things!! Better input caps, over-current limit raised, and banana jacks at the rear.
Along with that 20kOhm Resistor (Rocr) for the overcurrent, the spec sheet also has that 220pf cap (Cocr) in parallel with it...does i t look like it is there too, or does it need replacing too?
You could always just wire the 5 way binding posts to the board and putting the whole shebang in a new chassis - that is what I was planning...
You could always just wire the 5 way binding posts to the board and putting the whole shebang in a new chassis - that is what I was planning...
The cap is there, but its value has no effect on the current limit.
Data sheet info for Cocr....
"Over-current filter capacitor, which filters the overcurrent signal at the OCR pins to
account for the half-wave rectified current sense circuit internal to the TA3020. A
typical value for this component is 220pF. In addition, this component should be
located near pin 31 or pin 33 as possible. "
Basically, all your looking at is replacing six 15k resistors with 20k or higher resistors. Theres two per chipset.
Data sheet info for Cocr....
"Over-current filter capacitor, which filters the overcurrent signal at the OCR pins to
account for the half-wave rectified current sense circuit internal to the TA3020. A
typical value for this component is 220pF. In addition, this component should be
located near pin 31 or pin 33 as possible. "
Basically, all your looking at is replacing six 15k resistors with 20k or higher resistors. Theres two per chipset.
Thanks, theAnonymous1 & John65b! When I get moto #3 I may pull off the case and look around. I'm sure I will need more help with the input caps, and other stuff.
theAnonymous1, I'm really glad to hear the input caps are really cheap! That means there should be a nice improvement in sound quality!
theAnonymous1, I'm really glad to hear the input caps are really cheap! That means there should be a nice improvement in sound quality!