Regarding power requirements for BatoMM it does not differ from any other amplifier.
One "good" difference (as all bridged amps) is that amplifier sink power from booth rails of power supply at same time and GND is almost unnecessary (no major current flow trough GND).
It is a good practice to made separate secondaries (same thing for SMPS and classical transformers) for each amplifier/channel and all ground traces to sum in single points.
As long as you don't have current flow trough signal GND you are OK
LLC SMPS by Macola is still in development. It is bit complicated to build and even more to design, so all of us here waiting for that to be done.
As Macola promised, it will have over 20KHz of FB response (compared to many SMPS designs that hardly have few kHz) and I just can imagine how that SMPS with BatoMM will sound.
One "good" difference (as all bridged amps) is that amplifier sink power from booth rails of power supply at same time and GND is almost unnecessary (no major current flow trough GND).
It is a good practice to made separate secondaries (same thing for SMPS and classical transformers) for each amplifier/channel and all ground traces to sum in single points.
As long as you don't have current flow trough signal GND you are OK
LLC SMPS by Macola is still in development. It is bit complicated to build and even more to design, so all of us here waiting for that to be done.
As Macola promised, it will have over 20KHz of FB response (compared to many SMPS designs that hardly have few kHz) and I just can imagine how that SMPS with BatoMM will sound.
@koko5 In short, R28 can't be removed as that resistor have function in FB network. It's noise contribution is minor, probably below noise floor of LME.
One thing I forget to mention is regarding speaker protection circuit.
On our (Serbian) forum we have discussion about that and the conclusion (also recommended by author) is that speaker protection circuit is NOT NEEDED.
LM3886 have all required protection in it (SPiKe™, several order faster then usual relay based protections), even those if something goes totally wrong and leads to destruction of LM, specific internal construction will save our speakers as thin wires which connect silicon chip with case contacts will act as fuse!
Another problematic thing with external protection circuit is related to remote feedback contacts and to be honest I don't see the way how all that can be simply realized.
One thing I forget to mention is regarding speaker protection circuit.
On our (Serbian) forum we have discussion about that and the conclusion (also recommended by author) is that speaker protection circuit is NOT NEEDED.
LM3886 have all required protection in it (SPiKe™, several order faster then usual relay based protections), even those if something goes totally wrong and leads to destruction of LM, specific internal construction will save our speakers as thin wires which connect silicon chip with case contacts will act as fuse!
Another problematic thing with external protection circuit is related to remote feedback contacts and to be honest I don't see the way how all that can be simply realized.
Yes, I am still planning this design.
I have been side tracked lately with a few other projects as well.
One of the issues i had was that I had missed placed my OPA1664's that I needed to test, so I had just ordered some more.
I also have another quad opamp that I got that I may use for the Servos of the individual poweramp stages as well.
Meanwhile I am in desperate need of a good small reference amp as well since I don't have anything except my huge poweramp's (+300 watt).
I will give this circuit a try as is.
I have everything to build it now anyhow.
Since I just want something small and compact for now I was thinking about using some LM1875's in place of the LM3886's.
I have a pwersupply of perfect size for such a power range (33Vdc 4-6amp).
It came from an old Diablo Printer what a beast that thing was if you have ever seen one.
And, I just got the LM1875's as well.
It will be for use to power my small desktop Sony speakers as I have nothing but headphones to listen to at this time.
And, it will be used as a utility amp for testing of other drivers and such as well.
As long as the THD performance is better than a stock circuit version as spec'd with out the composite design, that is all that matters to me.
It should be better than any of the smaller poweramp's (old stereo's)that I do have, as they all need one channel be repaired anyhow.
Larger power versions with the LM3886's or LM4780's will come later as I have a couple of huge transformers out of some old mainframe computers.
One is from an old DEC PDP 11/70, it has 6 winding's that are perfectly suited for use with the LM3886's.
These will power my final ESL setup as it has been planned for some 10 years now!!
Keep On DIYin'!!!!
jer
P.S. Welcome to the forum yu3ma!!!
We are very glad for you to have given your insight on this design!!!
I have been side tracked lately with a few other projects as well.
One of the issues i had was that I had missed placed my OPA1664's that I needed to test, so I had just ordered some more.
I also have another quad opamp that I got that I may use for the Servos of the individual poweramp stages as well.
Meanwhile I am in desperate need of a good small reference amp as well since I don't have anything except my huge poweramp's (+300 watt).
I will give this circuit a try as is.
I have everything to build it now anyhow.
Since I just want something small and compact for now I was thinking about using some LM1875's in place of the LM3886's.
I have a pwersupply of perfect size for such a power range (33Vdc 4-6amp).
It came from an old Diablo Printer what a beast that thing was if you have ever seen one.
And, I just got the LM1875's as well.
It will be for use to power my small desktop Sony speakers as I have nothing but headphones to listen to at this time.
And, it will be used as a utility amp for testing of other drivers and such as well.
As long as the THD performance is better than a stock circuit version as spec'd with out the composite design, that is all that matters to me.
It should be better than any of the smaller poweramp's (old stereo's)that I do have, as they all need one channel be repaired anyhow.
Larger power versions with the LM3886's or LM4780's will come later as I have a couple of huge transformers out of some old mainframe computers.
One is from an old DEC PDP 11/70, it has 6 winding's that are perfectly suited for use with the LM3886's.
These will power my final ESL setup as it has been planned for some 10 years now!!
Keep On DIYin'!!!!
jer
P.S. Welcome to the forum yu3ma!!!
We are very glad for you to have given your insight on this design!!!
I have just found a link to a PDF version of the long lost copy of Electonics Now Novemeber 1992 !!!
It is the issue that has an article on the Composite power amplifiers.
I have/had this issue somewhere, but I have failed to be able to find it the last few years.
Here it is in its entirety for all to enjoy again!!!
https://ia601701.us.archive.org/15/...s_1992-11/Radio_Electronics_November_1992.pdf
The original 70watt amp version that uses 4xLM1875's is the one I have been wanting to adapt to use the LM3886's for many many years!!!
Cheers!!!
jer
It is the issue that has an article on the Composite power amplifiers.
I have/had this issue somewhere, but I have failed to be able to find it the last few years.
Here it is in its entirety for all to enjoy again!!!
https://ia601701.us.archive.org/15/...s_1992-11/Radio_Electronics_November_1992.pdf
The original 70watt amp version that uses 4xLM1875's is the one I have been wanting to adapt to use the LM3886's for many many years!!!
Cheers!!!
jer
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Sorry, I wasn't trying to sway from the topic of this thread.
I was just excited that I had rediscovered the article that got me interested in such designs over 20 years ago.
I have been searching for that link for a few years now, after I already knew that it existed and that I had seen it before.
I understand the concept of the remote feedback as it is used in regulation circuits, but the rest of the design is just a composite amplifier configuration.
I do plan on making it very soon and most likely with the LM3886's.
Since I just found that article I will try those designs for use with the LM1875 too, although it is quite limited in current capability.
I will try the Remote feedback technique on it as well and see if it makes any noticeable difference.
I don't think that it will make much if any difference in my situation were my 12ga. speaker cables are no more than 3 feet long.
The composite design itself will make the greatest overall improvement.
I just ordered some AD8599's and some AD4898-1's too try with it as well as they have an extremely low Vos as well as very low distortion and noise.
http://www.analog.com/static/imported-files/data_sheets/AD8597_8599.pdf
http://www.analog.com/static/imported-files/data_sheets/ADA4898-1_4898-2.pdf
FWIW
jer
I was just excited that I had rediscovered the article that got me interested in such designs over 20 years ago.
I have been searching for that link for a few years now, after I already knew that it existed and that I had seen it before.
I understand the concept of the remote feedback as it is used in regulation circuits, but the rest of the design is just a composite amplifier configuration.
I do plan on making it very soon and most likely with the LM3886's.
Since I just found that article I will try those designs for use with the LM1875 too, although it is quite limited in current capability.
I will try the Remote feedback technique on it as well and see if it makes any noticeable difference.
I don't think that it will make much if any difference in my situation were my 12ga. speaker cables are no more than 3 feet long.
The composite design itself will make the greatest overall improvement.
I just ordered some AD8599's and some AD4898-1's too try with it as well as they have an extremely low Vos as well as very low distortion and noise.
http://www.analog.com/static/imported-files/data_sheets/AD8597_8599.pdf
http://www.analog.com/static/imported-files/data_sheets/ADA4898-1_4898-2.pdf
FWIW
jer
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No problem, It's all Good !!
I can't wait to give it a try anyhow!!!
I am very curious about the feedback part.
I have thought about such methods for quite some time.
I will start laying out a board shortly.
I have to find the 200 to 400 watt version I had already started but I will finish that one at a later time.
I have a rather unusual construction method planned out for that one.
jer
I can't wait to give it a try anyhow!!!
I am very curious about the feedback part.
I have thought about such methods for quite some time.
I will start laying out a board shortly.
I have to find the 200 to 400 watt version I had already started but I will finish that one at a later time.
I have a rather unusual construction method planned out for that one.
jer
Very nice project!
I have had a similar project without remote sense but with different approach:
https://docs.google.com/file/d/0BzbIeQI27LjoV21seUw4MG5jQWs/edit
I have had a similar project without remote sense but with different approach:
https://docs.google.com/file/d/0BzbIeQI27LjoV21seUw4MG5jQWs/edit
Hello mzperx,
after a few class D projects, especially with TPA3255, I am now going back to the 'roots'. Not because these amps are bad, no simply to get the opportunity to compare directly.
And that's how I found your nice project here!
Nice job, I especially like the layout, very compact and neat!
What do the measured values look like, do you have an option to measure?
best regards
Matthias
after a few class D projects, especially with TPA3255, I am now going back to the 'roots'. Not because these amps are bad, no simply to get the opportunity to compare directly.
And that's how I found your nice project here!
Nice job, I especially like the layout, very compact and neat!
What do the measured values look like, do you have an option to measure?
best regards
Matthias
Yes !
Working here as test and breackup gig at 70w - 60vpp : oberton 12nsw600
and here the awful ( working!) xfrm : https://www.diyaudio.com/forums/subwoofers/346086-oberton-12nsw600-2.html#post6093663
Got component for 3 more, and pcb. But now with family, home, dogs... I got others ways to spend my time ;-)
Working here as test and breackup gig at 70w - 60vpp : oberton 12nsw600
and here the awful ( working!) xfrm : https://www.diyaudio.com/forums/subwoofers/346086-oberton-12nsw600-2.html#post6093663
Got component for 3 more, and pcb. But now with family, home, dogs... I got others ways to spend my time ;-)
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There are more than 1000+ builds of BatoMM around the world, after 1000 we stopped counting ...
Almost 2MIL views on our local (private/dev) forum just BatoMM thread, almost 5000 thread replies just for that particular amplifier ...