i want to pay 🙂 when can i pay?
-joe
See post #135
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I'll start accepting payments when I have a fully functional working PCB that is fully tested. Once that's done, I'll post a list here with people's totals and start accepting Paypal payments.
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I'll keep you all posted on any progress.
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Sorry to change late but if it's possible could you put me down for a total of 6 boards and 6 kits instead of just 6 boards.
Thanks
Thanks
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I have started thinking about the chassis. My plan i to make a 3 channel amp (stereo + sub) driven on one SMPS assuming that opc and Cristi finds a nice solution.
The problem in my case is cooling and power requirement, because i will probably go with the 100W option (~40VDC main rail?) if ocp makes measurements and tests on that. But i'm not sure that my speakers will be on 8 ohms so extra power in the supply would be nice. I don't listen to high volume so it might work without any problems if i'm lucky, even if i have three channels on the same supply.
modushop.biz
This is the chassis im looking at currently, the price is nice and my plan is to put the two stereo channels on one side and the sub channel + SMPS on the other. Will this structure and layout have enough heat dissipation to run passive? I really want to avoid fans or other noisy cooling.
The problem in my case is cooling and power requirement, because i will probably go with the 100W option (~40VDC main rail?) if ocp makes measurements and tests on that. But i'm not sure that my speakers will be on 8 ohms so extra power in the supply would be nice. I don't listen to high volume so it might work without any problems if i'm lucky, even if i have three channels on the same supply.
An externally hosted image should be here but it was not working when we last tested it.
modushop.biz
This is the chassis im looking at currently, the price is nice and my plan is to put the two stereo channels on one side and the sub channel + SMPS on the other. Will this structure and layout have enough heat dissipation to run passive? I really want to avoid fans or other noisy cooling.
Why not use a plate amp on the sub?I have started thinking about the chassis. My plan i to make a 3 channel amp (stereo + sub) driven on one SMPS assuming that opc and Cristi finds a nice solution.
The problem in my case is cooling and power requirement, because i will probably go with the 100W option (~40VDC main rail?) if ocp makes measurements and tests on that. But i'm not sure that my speakers will be on 8 ohms so extra power in the supply would be nice. I don't listen to high volume so it might work without any problems if i'm lucky, even if i have three channels on the same supply.
This is the chassis im looking at currently, the price is nice and my plan is to put the two stereo channels on one side and the sub channel + SMPS on the other. Will this structure and layout have enough heat dissipation to run passive? I really want to avoid fans or other noisy cooling.
I have started thinking about the chassis. My plan i to make a 3 channel amp (stereo + sub) driven on one SMPS assuming that opc and Cristi finds a nice solution.
The problem in my case is cooling and power requirement, because i will probably go with the 100W option (~40VDC main rail?) if ocp makes measurements and tests on that. But i'm not sure that my speakers will be on 8 ohms so extra power in the supply would be nice. I don't listen to high volume so it might work without any problems if i'm lucky, even if i have three channels on the same supply.
This is the chassis im looking at currently, the price is nice and my plan is to put the two stereo channels on one side and the sub channel + SMPS on the other. Will this structure and layout have enough heat dissipation to run passive? I really want to avoid fans or other noisy cooling.
I really like these cases but I'm making my own.If your running them at low power then I think they will be acceptable.
This will be used for my computer and with some luck the sub won't be required depending on the speakers. Still i want a clean amp at reasonable price, and to just buy one extra channel is equivalent to the price of a plate amp and i doubt that the sound quality (theoretical at least) is the same.Why not use a plate amp on the sub?
It is also about simplicity, just to solder one extra channel and drill a few holes to get a top quality amp doesn't sound like a bad deal. What are the main reasons to use a plate amp instead in your perspective?
Thanks, i have also been looking at these cases for some time because i like the clean look and they are fairly cheap compared to any other 19" case i have found.I really like these cases but I'm making my own.If your running them at low power then I think they will be acceptable.
They have two options, 300mm and 400mm depth so i can get another 100mm of heatsink on each side to increase the power dissipation a bit if required. I hope this is enough otherwise it could be possible to manually mount another heatsink on the backplate or internally if the holes are enough to provide any ventilation without fan.
Hi Guys!
Sorry for not popping in lately, I've been working hard to get the boards finished up and sent off.
They are officially done, and I'll be generating the Gerbers over the weekend. That means the order will be placed Monday, and I will be getting a 1 week turn on the board which puts me about a week behind the original schedule. Sorry for the delay, but I really wanted to make some more measurements on the balanced input amplifier before sending off any boards.
sooo... the low input impedance on the - terminal shouldn't be a problem, and the only downside will be reduced gain if you happen to have a very high output impedance source driving the amp. CMRR is around 87dB and it remains unaffected by source impedance. Distortion is also unaffected.
I tested with both a 50 ohm source and a 1000 ohm source, and performance was identical with the exception of gain which went from about 27dB to about 18dB when the source impedance goes from 50 ohms to 1000 ohms. That means the balanced input scheme gets the green light, and anyone planning to use the amplifier in this fashion should be good to go.
I've also revised the ground scheme to give a little more flexibility without impacting performance. The end user will have a few options with 0R resistors depending of how they plan to implement supplies.
I also measured with a regulated front end, and as you would expect, most of the 60Hz + harmonics noise is drastically reduced or eliminated. Again, I strongly suggest using a separate regulated supply for the front end if you want the best possible performance. I attached an RCF 10" midrange directly to the outputs with the regulated setup (it's 103dB 1W/1m) and I couldn't hear anything with my ear right against it. That sort of performance is exceedingly rare from any power amplifier.
Measurements attached.
Q&A time...
454Casull:
Not really, other than adding a resistor in series with your load. If you want a current output amplifier, this is probably not the correct choice.
coolfox007:
I put you down for 3 full kits (which include the boards) which is what you asked for a few pages back. I know you later asked for four kits, but I don't have enough PCB's.
Pleas confirm that 3 full kits is what you want.
IanAS and maxw:
You guys are still on the waiting list. Ian, you were bumped in favor of someone who wanted full kits. You'll be bumped again for maxw since he too is looking for full kits. I don't mean to be unfair, but preference is given to full kits orders.
Boscoe:
A month is fine, but please don't leave me high and dry when the time comes. I've adjusted your order to be 6 boards and 6 kits as you requested.
ouimetnick:
Prices are listed on the first page of this thread. You're looking at $156 for all the boards and parts for a stereo pair. The GB is currently full but I can put you on the waiting list.
Qrikard:
Very nice cases! The price is pretty fair too. That should be perfect for a stereo 100W/ch setup. Do they have a C/W rating for the sinks?
Cheers,
Owen
Sorry for not popping in lately, I've been working hard to get the boards finished up and sent off.
They are officially done, and I'll be generating the Gerbers over the weekend. That means the order will be placed Monday, and I will be getting a 1 week turn on the board which puts me about a week behind the original schedule. Sorry for the delay, but I really wanted to make some more measurements on the balanced input amplifier before sending off any boards.
sooo... the low input impedance on the - terminal shouldn't be a problem, and the only downside will be reduced gain if you happen to have a very high output impedance source driving the amp. CMRR is around 87dB and it remains unaffected by source impedance. Distortion is also unaffected.
I tested with both a 50 ohm source and a 1000 ohm source, and performance was identical with the exception of gain which went from about 27dB to about 18dB when the source impedance goes from 50 ohms to 1000 ohms. That means the balanced input scheme gets the green light, and anyone planning to use the amplifier in this fashion should be good to go.
I've also revised the ground scheme to give a little more flexibility without impacting performance. The end user will have a few options with 0R resistors depending of how they plan to implement supplies.
I also measured with a regulated front end, and as you would expect, most of the 60Hz + harmonics noise is drastically reduced or eliminated. Again, I strongly suggest using a separate regulated supply for the front end if you want the best possible performance. I attached an RCF 10" midrange directly to the outputs with the regulated setup (it's 103dB 1W/1m) and I couldn't hear anything with my ear right against it. That sort of performance is exceedingly rare from any power amplifier.
Measurements attached.
Q&A time...
454Casull:
Out of curiosity, is there any way to increase the output impedance on the amp while leaving all else the same? In effect, to make it current drive rather than voltage drive?
Not really, other than adding a resistor in series with your load. If you want a current output amplifier, this is probably not the correct choice.
coolfox007:
I put you down for 3 full kits (which include the boards) which is what you asked for a few pages back. I know you later asked for four kits, but I don't have enough PCB's.
Pleas confirm that 3 full kits is what you want.
IanAS and maxw:
You guys are still on the waiting list. Ian, you were bumped in favor of someone who wanted full kits. You'll be bumped again for maxw since he too is looking for full kits. I don't mean to be unfair, but preference is given to full kits orders.
Boscoe:
A month is fine, but please don't leave me high and dry when the time comes. I've adjusted your order to be 6 boards and 6 kits as you requested.
ouimetnick:
Prices are listed on the first page of this thread. You're looking at $156 for all the boards and parts for a stereo pair. The GB is currently full but I can put you on the waiting list.
Qrikard:
Very nice cases! The price is pretty fair too. That should be perfect for a stereo 100W/ch setup. Do they have a C/W rating for the sinks?
Cheers,
Owen
Attachments
Looking good Owen.
Should be fine running from my MiniDSP then. (4V rms, 560 ohm balanced out)
Hopefully Cristi comes up with a good SMPS solution......
Should be fine running from my MiniDSP then. (4V rms, 560 ohm balanced out)
Hopefully Cristi comes up with a good SMPS solution......
you'll be on the waiting list for the next run, yes you are waaaay late; the gb closed a couple of weeks ago
looking good opc!! i guess i'll be fine with my near zero outputz then =)
looking good opc!! i guess i'll be fine with my near zero outputz then =)
ive looked through the thread i think every page just now and cant seem to find that table opc posted with expected power vs supply voltage vs load impedance. can someone link me?
The links are at the bottom of the first post.
http://www.diyaudio.com/forums/atta...e49830-lateral-mosfets-class-ab-worksheet.pdf
http://www.diyaudio.com/forums/atta...e49830-lateral-mosfets-class-ab-worksheet.pdf
hahaha wot? 😱 i had a (obviously foggy) memory that it wasnt in the first post so didnt even look there. probably i didnt think so because i already knew about this project a couple weeks in advance.
thanks
thanks
Thanks for making me aware of the existence of that nifty "little" chip. Having gone through the datasheet, I really love how NS deviced the MOSFET driver stage. I'm going to have a go at it in the simulator with a discrete arrangement, although I have no doubt that a discrete version would perform worse - the bias diodes for the shunt transistors in each driver rail sit on the same slab of silicone and are tightly thermally coupled. If one's to try this in a discrete setup one can't omit this thermal coupling.
I know that I'm late to the party. I've been planning to do a MLE49830 project, but just found this thread today. Please sign me up for 4 kits. What post describes the payment procedure?
Congratulations on a fine project.
Congratulations on a fine project.
nice
hi Owen, nice & very neat design
Hi Guys,
There's a new addition to "The Wire" series of projects I've been working on lately.
It's push-pull amplifier based on the LME49830 front end which drives a pair of ACD101NDD and ACD103PDD lateral mosfets. It's immensely versatile in that you can run essentially any rail voltage from about +/- 10V up to about +/-90V on the mosfets and get anywhere from 1W to 400W of output depending on the load and the rails. This is an amp that can be tailored to any situation.
You can also run the amp in class A, class AB, or class B if that's your thing.
For the input, you can run either fully balance, or with just one 0R jumper it can be configured for SE input. You can run the amplifier AC or DC coupled. There are separate supply options for running the LME49830 on higher rails than the mosfets which improves efficiency and allows for a good regulated supply for the front end. Alternatively, with a pair of 0R jumpers, you can run just a single +/- supply for both the LME and the mosfets.
The board is small enough to fit pretty much anywhere, and all you need to provide is the power supply and the heatsink! I've even got an optional regulated supply board for the LME section.
I've attached the schematic, the Excel worksheet to calculate power outputs and rails, along with the layout and a BOM.
The PCB will be a 3 layer design with a ground plane in the middle and signal routing on either side. The LME has its own heatsink and the two mosfets are mounted on a user supplied sink off the end of the board. The board measures 2.45" by 1.6" and has all the required mounting points.
I will also be running a kit with this that includes all of the parts required to build a complete amplifier. All the user will need to supply is the main heatsink and the power supply.
PCB's are going to be $12 per channel, and a full kit including all 0.1% thin film resistors, and the best caps available for this application will be $78 per channel. I've attached the price list for the amplifier kit which contains all the details.
There will be 50 boards made available, and it will be first come first serve. Please post here if you're interested in a just a board, or a board and a kit, along with how many of each. Any technical question are welcome as well!
Measurements to follow!
Cheers,
Owen
hi Owen, nice & very neat design
I know that I'm late to the party. I've been planning to do a MLE49830 project, but just found this thread today. Please sign me up for 4 kits. What post describes the payment procedure?
Congratulations on a fine project.
Unfortunately the group buy is already closed, see for example this post, so you will have to go on the waiting list. Owen has the details of course, but FYI.
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