So I've decided to check out some of these audio amps. I'm going to try Peter Daniels design/kit, and probably Brian's gainclone design/kit. Then, since there's such a lack of published technical audio data on most of these kits (THD, S/N ratio, etc), do some subjective (*blech*) A/B testing.
What I'm a little freaked about is the power supply. These huge coils just bother me for some reason (I'm used to PC electronics at best). One of the big reasons is that my eventual goal is to create a multi-channel (around 12-maybe 20 channels!) amp. The weight of the coil-based power supply(ies) would be enormous (I'm hoping for at least 100W per channel). Just as an FYI, this is all eventually heading towards an active crossover system I can use with multiple speaker builds to test/try as I build them (using something like the Behringer 2496 as the very flexible external xover). I'm even hoping to add capabilites like those provided by let's say the Speakercraft 1265 (12 channels by 65W each, whcih I use for external zones outside my main listening area) like channel bridging, allowing up to 3-4 "virtual channels" via switching individual channels to a particular "mega channel".
Now, I've read a lot of stuff about linear power supplies providing significantly better sound quality and even to the point that SMPS would create such junk sound output that they aren't even considered in the "audiophile" world (which I'm always suspect of).
So now I start seeing (here and/or elsewhere) talk about using SMPS for audio amps. Anyone done any A/B testing on whether or not they affect the typical sound parameters like THD, S/N ratio, etc? I know this type of information is very hard to come by in the (particular amp) diy world, but I have hope.
Or, do I need to just do it all on my own and do some subjective listening with my personal "reference" stuff (7.1 setup using Paradigm 100's for front/center/right and Polk di/bipoles for sides and rears, oh and a decent 300W subwoofer)?
If this is the case (in lieu of "published specs" based on a given smps power supply and using it with various diy amps), can somebody recommend smps kit(s) that I might look at (I'm not comfortable building any of this stuff from scratch) to consider using and if any of them may or may not be better suited for use as audio power supplies?
Or am I just nuts and I won't be saving anything (weight, space) by using the big ol' coils?
Thanks,
terry parker
terryparker@myself.com
What I'm a little freaked about is the power supply. These huge coils just bother me for some reason (I'm used to PC electronics at best). One of the big reasons is that my eventual goal is to create a multi-channel (around 12-maybe 20 channels!) amp. The weight of the coil-based power supply(ies) would be enormous (I'm hoping for at least 100W per channel). Just as an FYI, this is all eventually heading towards an active crossover system I can use with multiple speaker builds to test/try as I build them (using something like the Behringer 2496 as the very flexible external xover). I'm even hoping to add capabilites like those provided by let's say the Speakercraft 1265 (12 channels by 65W each, whcih I use for external zones outside my main listening area) like channel bridging, allowing up to 3-4 "virtual channels" via switching individual channels to a particular "mega channel".
Now, I've read a lot of stuff about linear power supplies providing significantly better sound quality and even to the point that SMPS would create such junk sound output that they aren't even considered in the "audiophile" world (which I'm always suspect of).
So now I start seeing (here and/or elsewhere) talk about using SMPS for audio amps. Anyone done any A/B testing on whether or not they affect the typical sound parameters like THD, S/N ratio, etc? I know this type of information is very hard to come by in the (particular amp) diy world, but I have hope.
Or, do I need to just do it all on my own and do some subjective listening with my personal "reference" stuff (7.1 setup using Paradigm 100's for front/center/right and Polk di/bipoles for sides and rears, oh and a decent 300W subwoofer)?
If this is the case (in lieu of "published specs" based on a given smps power supply and using it with various diy amps), can somebody recommend smps kit(s) that I might look at (I'm not comfortable building any of this stuff from scratch) to consider using and if any of them may or may not be better suited for use as audio power supplies?
Or am I just nuts and I won't be saving anything (weight, space) by using the big ol' coils?
Thanks,
terry parker
terryparker@myself.com
Hi terry,
I have had good experiences with Vicor smps modules ( www.vicr.com ). Interesting note: the founder of Vicor had the same concerns as you and started to develop modules for his private audio projects. Now his company is one of the largests in the world in smps business...
Just for kicks, I built an LM3886 gain clone with a pair of 150W Vicor modules that sounds great, but is really over the top. Those two modules could easily power a couple or more of those amps.
Jan Didden
I have had good experiences with Vicor smps modules ( www.vicr.com ). Interesting note: the founder of Vicor had the same concerns as you and started to develop modules for his private audio projects. Now his company is one of the largests in the world in smps business...
Just for kicks, I built an LM3886 gain clone with a pair of 150W Vicor modules that sounds great, but is really over the top. Those two modules could easily power a couple or more of those amps.
Jan Didden
i've used one off ebay, several of them actually... done several experiments using the sellers recommended mods. on unit i used, voltage rails higher, but works excellent. had sold off experiments to friends and they all commented about the quickness and cleanness out the sound. another liked the toroid implementation i'd made him more - but it was also a bridge config rather than single chip implementation (gainclones) that suits his speakers differently.
from diy building side... i liked the ease of grounding, no touchy 60hz hum to battle with.
i personally like them for given applications. have only tried with clones so far, but may try some to drive some greg ball ska amp boards.
i'd like to learn more about actually building them and stronger, more current, smps modules.
from diy building side... i liked the ease of grounding, no touchy 60hz hum to battle with.
i personally like them for given applications. have only tried with clones so far, but may try some to drive some greg ball ska amp boards.
i'd like to learn more about actually building them and stronger, more current, smps modules.
smps with greg ball ska amp
Funny you should mention that, it wasn't on my previous list, but I think it's a contender for my project as well. Currently, because of the lack of published specs on diy amps, it looks like going to have to build a few, then try them out with difference power supplies, find the best combination, then start the Motherload Project (multi-channel diy amp).
Anyone happen to know of any existing multi-channel (5 or more) diy amp projects / kits?
Funny you should mention that, it wasn't on my previous list, but I think it's a contender for my project as well. Currently, because of the lack of published specs on diy amps, it looks like going to have to build a few, then try them out with difference power supplies, find the best combination, then start the Motherload Project (multi-channel diy amp).
Anyone happen to know of any existing multi-channel (5 or more) diy amp projects / kits?
vicor vcpr smps - which ones?
I went to their site and it is impressive and certainly daunting. Can you recommend particular models "blocks" as they call them, that work well with a particular diy amp? Problem is, I'm having some trouble converting the diy-amp project/kits requirements defined by toroidal transformers vs. the specs used to described smp's. Usually seems like apples and oranges when comparing values, so makes it hard to pick smps to substitute for a coil transformer main/secondary specs. Any help?
I went to their site and it is impressive and certainly daunting. Can you recommend particular models "blocks" as they call them, that work well with a particular diy amp? Problem is, I'm having some trouble converting the diy-amp project/kits requirements defined by toroidal transformers vs. the specs used to described smp's. Usually seems like apples and oranges when comparing values, so makes it hard to pick smps to substitute for a coil transformer main/secondary specs. Any help?
janneman said:
vicor smps's
Yeah, I've been over at their site a lot trying to figure out a way to make it work. They have a lot of very neat stuff. Very small configurations with low heat dissipation and emi filtering modules. The problem is, as you've just indicated, they aren't cheap at all, from what I can see.
My "ballpark" number for quality amperage wattage is $1 per watt (cheap) to $1.5 per watt (good average). That's for used quality or diy quality. New, you can double those figures. But $800 for 300W of diy is way out of what I would consider acceptable. Dangit, 'cause I do like their stuff, it'd be perfect for a multi-channel amp config. (I do this same kind of thing with RAM and hard drive storage, almost treat it like a commodity -- see where the $ per MB is and use that as a barometer for "deals").
Don't know if a group buy would lower costs or if anyone else is interested. I'm surprised nobody is looking at taking something like Peter Daniel's stuff and making a multi-channel amp out of it (like a speakercraft, allowing you to bridge to different output sets, etc.). I wish I had the electronics background to bring it all together, but I'm working on it.
Yeah, I've been over at their site a lot trying to figure out a way to make it work. They have a lot of very neat stuff. Very small configurations with low heat dissipation and emi filtering modules. The problem is, as you've just indicated, they aren't cheap at all, from what I can see.
My "ballpark" number for quality amperage wattage is $1 per watt (cheap) to $1.5 per watt (good average). That's for used quality or diy quality. New, you can double those figures. But $800 for 300W of diy is way out of what I would consider acceptable. Dangit, 'cause I do like their stuff, it'd be perfect for a multi-channel amp config. (I do this same kind of thing with RAM and hard drive storage, almost treat it like a commodity -- see where the $ per MB is and use that as a barometer for "deals").
Don't know if a group buy would lower costs or if anyone else is interested. I'm surprised nobody is looking at taking something like Peter Daniel's stuff and making a multi-channel amp out of it (like a speakercraft, allowing you to bridge to different output sets, etc.). I wish I had the electronics background to bring it all together, but I'm working on it.
I also used vicor modules in my amp.. the only thing was that i had to screen the modules with a metal sheet because the amplifier circuitboard was too close.. (the amp is really small)
But i think they're really really good.. i have four 100watt 28volt modules, that works pretty well for me..
But i think they're really really good.. i have four 100watt 28volt modules, that works pretty well for me..
thomaseliot said:
That's too much! A pair of 150W 2nd generation DC-DC converters run just above 100$ each (I think in Europe they are 112$ for 1-24 pieces). That means you add a rectifier bridge directly off the mains and a hold-up capacitor (a few 100uF at the rectified line voltage, 450V in Europe) and a few 1000uF at the output and you're done.
Jan Didden
Actually, giving it more thought...
I think Jan's configuration probably makes a lot more sense, particularly for a multi-channel amp.
Jan, care to draw up a quick (for U.S. market electrical values -- 110v, etc) schematic of what this would look like? I'm looking to build a 10 channel (or so) amp with 100-150W per channel (hopefuly adding the ability to bridge amp's to 2-3 sets of outputs). The new Denon AV receiver (a mere $6000) allows you to do this, and even via software config -- allowing you to assign amps to channels and bridge amps, etc., all via software config -- as a diy version I would be looking at a simple switch next to each amp input for "Ouput 1,2,3" or some such. Also, my Speakercraft 12x65 , whcih I use for running external and "outside the main listening area" ceiling and outside speakers (all controlled through wall-mounted volume controls) is another, more basic example of what I'm trying to get to.
I'm looking for the same type of thing via a diy setup, with very good sound quality and higher wattage per channel (I'm targeting 100-150 so I can get 200-300 for large mains via bridging of bi-amping). Mainly this is to convert my main listening area (using Behringer 2496 xover/eq system) from passive to active and allow me greater speaker "component level" flexibility as I build my own speakers.
(BTW, I did demo the Denon and it was cool, a lot of fun, and sounded fantastic, but outrageously priced IMO).
I think Jan's configuration probably makes a lot more sense, particularly for a multi-channel amp.
Jan, care to draw up a quick (for U.S. market electrical values -- 110v, etc) schematic of what this would look like? I'm looking to build a 10 channel (or so) amp with 100-150W per channel (hopefuly adding the ability to bridge amp's to 2-3 sets of outputs). The new Denon AV receiver (a mere $6000) allows you to do this, and even via software config -- allowing you to assign amps to channels and bridge amps, etc., all via software config -- as a diy version I would be looking at a simple switch next to each amp input for "Ouput 1,2,3" or some such. Also, my Speakercraft 12x65 , whcih I use for running external and "outside the main listening area" ceiling and outside speakers (all controlled through wall-mounted volume controls) is another, more basic example of what I'm trying to get to.
I'm looking for the same type of thing via a diy setup, with very good sound quality and higher wattage per channel (I'm targeting 100-150 so I can get 200-300 for large mains via bridging of bi-amping). Mainly this is to convert my main listening area (using Behringer 2496 xover/eq system) from passive to active and allow me greater speaker "component level" flexibility as I build my own speakers.
(BTW, I did demo the Denon and it was cool, a lot of fun, and sounded fantastic, but outrageously priced IMO).
tlparker said:
I've found that the specifications on the national semi website can be achieved with careful layout -- very careful layout --
I have used SMPS for discrete designs -- occasionally you will see 48V telecommunications grade Sorensen switching supplies on EBay.
Here's an example of what can be done with the bridged LM4780 -- (I decided that I didn't want to go into physics as the labs were so boring -- now look what I have done !!!) Note the difference between the proto-type boards and those with some slight changes in layout done for production -- National takes great pains to show you the way on their websites and they actually take their amplifiers on the road for critical listening tests.
An externally hosted image should be here but it was not working when we last tested it.
Sorensen -- make or buy?
http://cgi.ebay.com/Sorensen-23-25v...5QQihZ011QQcategoryZ58286QQrdZ1QQcmdZViewItem
http://cgi.ebay.com/Sorensen-23-25v...5QQihZ011QQcategoryZ58286QQrdZ1QQcmdZViewItem
Exactly
To go even further, I've got a stack of Carver amps (been plucking "deals" off Ebay and will start selling them back off to Ebay/Audiogon in the fall), mostly with balanced inputs, level controls, and watts out the wazoo since most were for "production" use (bands, auditoriums, etc.). If I wanted something really big and ugly, but would do the job for excellent watt/$ price, I could go that way (and I still may).
To go even further, I've got a stack of Carver amps (been plucking "deals" off Ebay and will start selling them back off to Ebay/Audiogon in the fall), mostly with balanced inputs, level controls, and watts out the wazoo since most were for "production" use (bands, auditoriums, etc.). If I wanted something really big and ugly, but would do the job for excellent watt/$ price, I could go that way (and I still may).
I want to know details, how the SMPS300RE from Connexelectronic operates. Therefore I need the datasheet of the used SMD IC, that is to find between the transformer and the both large electrolytics go to the image under
https://hifiduino.files.wordpress.com/2012/04/300re.jpg
unfortunately the type number isn't to read for me.
Thank you for calling the type of this SMPS IC.
And a second question: which two kind of wires for the transformer windings and which kind of transformer core are in use ?
https://hifiduino.files.wordpress.com/2012/04/300re.jpg
unfortunately the type number isn't to read for me.
Thank you for calling the type of this SMPS IC.
And a second question: which two kind of wires for the transformer windings and which kind of transformer core are in use ?
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