tryonziess,
It appears you are referring to two separate projects in your last post. I think I get the last two.
If you missed it, this project is a system to bi-amp/tri-amp a home studio speaker system. The boards with the four rectifiers are the MyRef-C V1.2 builds for the tweeters. The BPA-150s are intended to push the mid drivers.
The volume is controlled by a dbx-234 active crossover that provides direct output to low/sub amplifiers. I have two Hefler DH-120 amps if I go separates on the bottom, or a Bash 500 watt sub amp if I use the "low sum" option available on the dbx unit.
I have built several speakers with passive crossovers through the years, but always wanted to try both an active crossover and tri-amping.
I have no idea how this system will perform, but yes, "this stuff is a lot of fun"
It appears you are referring to two separate projects in your last post. I think I get the last two.
If you missed it, this project is a system to bi-amp/tri-amp a home studio speaker system. The boards with the four rectifiers are the MyRef-C V1.2 builds for the tweeters. The BPA-150s are intended to push the mid drivers.
The volume is controlled by a dbx-234 active crossover that provides direct output to low/sub amplifiers. I have two Hefler DH-120 amps if I go separates on the bottom, or a Bash 500 watt sub amp if I use the "low sum" option available on the dbx unit.
I have built several speakers with passive crossovers through the years, but always wanted to try both an active crossover and tri-amping.
I have no idea how this system will perform, but yes, "this stuff is a lot of fun"
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I ordered 12 new LM3886 chips from Avnet yesterday. Should be here by Friday. I am going to assemble a new BPA300 from some partially assembled boards I had been working on. I try to get the little SMD items in first they are a bear to get in nice and straight. Then put together a slightly buffered pre with transformer balancing. Nelson Pass published some schematics of a small buffer with JFETS for the Lightspeed attenuator.
If I could ever get a properly matched set of LDR's I would pursue that. I have never been able to get them matched out properly. I have a nice relay attenuator from Dantimax which should work.
Some of my other projects are on hold since the dollar will not buy anything overseas without stretching to the limit a small hobby budget. The price of neodymium magnets has gone up 7 fold in a year and a half just like copper and gold.
I wish some of the other several hundred members would publish their projects here. I know for a fact that 300 of these boards were sold. All of that diversity gives the rest of us ideas to draw from.
Tad
If I could ever get a properly matched set of LDR's I would pursue that. I have never been able to get them matched out properly. I have a nice relay attenuator from Dantimax which should work.
Some of my other projects are on hold since the dollar will not buy anything overseas without stretching to the limit a small hobby budget. The price of neodymium magnets has gone up 7 fold in a year and a half just like copper and gold.
I wish some of the other several hundred members would publish their projects here. I know for a fact that 300 of these boards were sold. All of that diversity gives the rest of us ideas to draw from.
Tad
Uriah, who sells two LDR kits has developed a rig that finds the optimum matches from a large batch. He also ships the readouts of each individual piece.
You can purchase LDRs anytime to build a Lightspeed or to build my new LDR Attenuator "A Lighter Note". Email me. diyldr@gmail.com
You can purchase LDRs anytime to build a Lightspeed or to build my new LDR Attenuator "A Lighter Note". Email me. diyldr@gmail.com
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chrapladm,
Someday. What is wrong with today. I have been doing this for quite a few years and still do not have a grasp on what is really going on. Sometimes they work and sometimes they do not. Assembling, designing and laying out all of the parts is relaxing and you may even learn something along the way. It is a nice clean, nonpolluting hobby that takes up very little space and you can do all of it at home. You may not find many people that you come in contact with dayly that share this type of interest, my experience anyway, but the finished item will make you proud of your own accomplishments.
As goes to where to start I think this chipamp section is as good as any. There is a massive amount of Chipamp stuff here and elsewhere on the net. I personally like this little BPA amp layout since it is a clone of such a tremendously expensive commercial market item. You can construct a nice stereo set for under 250.00 dollars. Just read through the material and you will see how many folks like the sound. Extremely accurate and precise.
A few starter items soldering gun, magnifier, not too expensive volt/ohm meter and a well lighted area to work. Tweezers and assorted hand tools.
Tad
Someday. What is wrong with today. I have been doing this for quite a few years and still do not have a grasp on what is really going on. Sometimes they work and sometimes they do not. Assembling, designing and laying out all of the parts is relaxing and you may even learn something along the way. It is a nice clean, nonpolluting hobby that takes up very little space and you can do all of it at home. You may not find many people that you come in contact with dayly that share this type of interest, my experience anyway, but the finished item will make you proud of your own accomplishments.
As goes to where to start I think this chipamp section is as good as any. There is a massive amount of Chipamp stuff here and elsewhere on the net. I personally like this little BPA amp layout since it is a clone of such a tremendously expensive commercial market item. You can construct a nice stereo set for under 250.00 dollars. Just read through the material and you will see how many folks like the sound. Extremely accurate and precise.
A few starter items soldering gun, magnifier, not too expensive volt/ohm meter and a well lighted area to work. Tweezers and assorted hand tools.
Tad
chrapladm,
I also think the BPA amps are a good place to start and one can get excellent results. Just wanted to add the BrianGT offerings from Chipamp.com are also good entry points. That's where I started and was able to build a dual mono amp ($90 for complete kit) plus $44 for two transformers. As with all LM3886 designs, the sound was far beyond my expectations.
Jump in and have fun.
I also think the BPA amps are a good place to start and one can get excellent results. Just wanted to add the BrianGT offerings from Chipamp.com are also good entry points. That's where I started and was able to build a dual mono amp ($90 for complete kit) plus $44 for two transformers. As with all LM3886 designs, the sound was far beyond my expectations.
Jump in and have fun.
+1
For a multichannel solution, I would spend a bit more in enclosures and build 3x stereo amps. That way you get 3 differents amps, so you can make one of them beefier for the subwoofer, for example. And you can use them as 3 different stereo amps given the case you don't need it as a multichannel.
I had been always intrigued by making my own amp but I am more of the mechanical type of guy verse electrical. I can figure most things out but just have to ask lots of questions is all.
I had been looking at building a T-amp from 41hz and wanted something crazy only to figure out that I would need to spend an arm and a leg.
Most of my speakers have always been power hungry types of speakers. SO then I found out that fullrange drivers can actually give me what I want and I wont need mega watts.
SO then the making my own Krell mono block came back into my mind. HAHAH
Anyways seeing all these builds on here has got me thing maybe I could build something that I would be proud of also.
I was thinking that I could build something that would be used when I am not watching movies and just music listening(2ch). Then eventually try and work on getting the rest of the channels driven by the same power source. Has anyone already built a 5 channel or multiple mono amps for their Home theater?
When we say chip amp we are talking about the 2020 or something else? I only know the stuff on the 41hz website.
I have a pretty good soldering iron , cheap multimeter and some bright lights. SO there is a start.
I will wait to ask more questions. Thanks
Regiregi22 thanks for that I didn't see your comment on the multi channel until I asked again. I would only worry about the 5 channels and not the subwoofer. I will have huge subs and will be using MASSIVE amounts of power. SO I was just going to use a clone amp (Lab Gruppen FP14000) for my subs. Unless I want to make some sort of 1000 watt x 4 amplifier(or Passlabs X1000.5)hahaha
But I dont feel like trying that one so lets just stick with the easier 30 watter amps.LOL
Challenges are fun though
I had been looking at building a T-amp from 41hz and wanted something crazy only to figure out that I would need to spend an arm and a leg.
Most of my speakers have always been power hungry types of speakers. SO then I found out that fullrange drivers can actually give me what I want and I wont need mega watts.
SO then the making my own Krell mono block came back into my mind. HAHAH
Anyways seeing all these builds on here has got me thing maybe I could build something that I would be proud of also.
I was thinking that I could build something that would be used when I am not watching movies and just music listening(2ch). Then eventually try and work on getting the rest of the channels driven by the same power source. Has anyone already built a 5 channel or multiple mono amps for their Home theater?
When we say chip amp we are talking about the 2020 or something else? I only know the stuff on the 41hz website.
I have a pretty good soldering iron , cheap multimeter and some bright lights. SO there is a start.
I will wait to ask more questions. Thanks
Regiregi22 thanks for that I didn't see your comment on the multi channel until I asked again. I would only worry about the 5 channels and not the subwoofer. I will have huge subs and will be using MASSIVE amounts of power. SO I was just going to use a clone amp (Lab Gruppen FP14000) for my subs. Unless I want to make some sort of 1000 watt x 4 amplifier(or Passlabs X1000.5)hahaha
But I dont feel like trying that one so lets just stick with the easier 30 watter amps.LOL
Challenges are fun though
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I would also look into the Audiohm Optocouplers.
They have integrated the LED emitter and the LDR into a single close coupled package.
They are available in a couple of different styles.
Silonex Inc.: Products: Audiohm Optocouplers
Look at the NSL-32SR2.
It has a 1M Ohm dark resistance but only a 40 ohm bright.
This should be manageable with some tweaking.
They have integrated the LED emitter and the LDR into a single close coupled package.
They are available in a couple of different styles.
Silonex Inc.: Products: Audiohm Optocouplers
Look at the NSL-32SR2.
It has a 1M Ohm dark resistance but only a 40 ohm bright.
This should be manageable with some tweaking.
chrapladm,
Heck I am a Detroit Diesel technician and have lots of fun with this stuff. Go for it. Your mechanical skills will be put to the limit drilling and tapping 4-40 screws in nice and sticky aluminum. Also, comes in handy on the cabinet designs. Some folks do not know where to begin when cutting aluminum on a table saw.
Tad
Heck I am a Detroit Diesel technician and have lots of fun with this stuff. Go for it. Your mechanical skills will be put to the limit drilling and tapping 4-40 screws in nice and sticky aluminum. Also, comes in handy on the cabinet designs. Some folks do not know where to begin when cutting aluminum on a table saw.
Tad
Passdiy.com seem to show quite a few examples of users builds and they all looked nice from the gallery. Shine7.com also had some nice pics along with his builds.
The chipamp website I was not having any luck looking at much. Most of the links were not working. Some worked and I saw some details about the kits but I didn't even know what kit did what. When I went to click on the links of the pics it sent me to a used domain. D/K
What is the amplifier freq. response of most of these BPA300s? How low do they go?
Just wondering about how low they go for knowledgeable reasons for a sub amp. I could atleast draw a recipe for the sub amp while I tackle the smaller amps.
How much power can be generated from a single LM3886?
I maybe be off in understanding but all the amps I am seeing on the shine site keep doubling for more power. I saw an amp that had 6 LM3886's per channel but never saw the rated power for 8 or 4 ohm.
The other bad thing about learning about some of these builds and not knowing enough is that I start to read....lots and lots of info and get slightly confused but the biggest problem is the wifey isn't to happy about it. Cant help finding something interesting and then seeking endless information from good old google and forums like this.
The chipamp website I was not having any luck looking at much. Most of the links were not working. Some worked and I saw some details about the kits but I didn't even know what kit did what. When I went to click on the links of the pics it sent me to a used domain. D/K
What is the amplifier freq. response of most of these BPA300s? How low do they go?
Just wondering about how low they go for knowledgeable reasons for a sub amp. I could atleast draw a recipe for the sub amp while I tackle the smaller amps.
How much power can be generated from a single LM3886?
I maybe be off in understanding but all the amps I am seeing on the shine site keep doubling for more power. I saw an amp that had 6 LM3886's per channel but never saw the rated power for 8 or 4 ohm.
The other bad thing about learning about some of these builds and not knowing enough is that I start to read....lots and lots of info and get slightly confused but the biggest problem is the wifey isn't to happy about it. Cant help finding something interesting and then seeking endless information from good old google and forums like this.
chrapladm,
I myself would not use any chipamp to drive a sub-woofer. This is my opinion and may be crushed by many others. I think the LM3886 chip does it's best job from 300 to 500 hertz and UP. It really shines in the voice, guitar, piano range.
For sub-woofer duty a nice stable Pass Labs clone with mosfet outputs would or is my first choice. I am using a Leach clone with 10 BJT transistors on my lower end. It is stable and has plenty of grunt and runs cool. Do not get me wrong here. The LM3886 will drive very low frequency it is just my choice not to subject the small die area to extreme overheat situations like may be encountered with a sub.
If you choose one of the Chipamps from a website out there on the net make sure they will respond to questions. Also, make sure it is a true amplifer and not a toy that makes noise.
Rod Elliot's site offers PCB's for a variety of amp projects. His stuff is extremely stable and he is adamant about making things simple and over engineered. He has a PCB for a really nice mosfet amp and he offers his own forum to answer build questions. My only dislike is how many hoops you have to jump through to purchase something. No paypal or credit card directly on the web.
Make sure if you do build to learn all of the little tricks to prevent oscillation and outside interference, ie like twisting the power wires and using proper grounds. Nothing is more discouraging than powering up and there is all this distortion. Most stuff just needs to be neatly wrapped up and it will function nicely. Also, invest in a couple of light bulb sockets and bulbs for power input load protection on first power up. Less than 5 bucks total.
Tad
I myself would not use any chipamp to drive a sub-woofer. This is my opinion and may be crushed by many others. I think the LM3886 chip does it's best job from 300 to 500 hertz and UP. It really shines in the voice, guitar, piano range.
For sub-woofer duty a nice stable Pass Labs clone with mosfet outputs would or is my first choice. I am using a Leach clone with 10 BJT transistors on my lower end. It is stable and has plenty of grunt and runs cool. Do not get me wrong here. The LM3886 will drive very low frequency it is just my choice not to subject the small die area to extreme overheat situations like may be encountered with a sub.
If you choose one of the Chipamps from a website out there on the net make sure they will respond to questions. Also, make sure it is a true amplifer and not a toy that makes noise.
Rod Elliot's site offers PCB's for a variety of amp projects. His stuff is extremely stable and he is adamant about making things simple and over engineered. He has a PCB for a really nice mosfet amp and he offers his own forum to answer build questions. My only dislike is how many hoops you have to jump through to purchase something. No paypal or credit card directly on the web.
Make sure if you do build to learn all of the little tricks to prevent oscillation and outside interference, ie like twisting the power wires and using proper grounds. Nothing is more discouraging than powering up and there is all this distortion. Most stuff just needs to be neatly wrapped up and it will function nicely. Also, invest in a couple of light bulb sockets and bulbs for power input load protection on first power up. Less than 5 bucks total.
Tad
Tad are all these LM3886 chip amps still great for full range 20hz-20Khz at least?
After checking out Rods site I think I will be using some of his boards for some other builds also. L/T circuit and other.
And what type of power is available from a Pass lab clone?
That being said I dont think I will be able to build the subwoofer amps but should be able to build some small power amplifiers with High degree of sound quality.(50watts)
Looking at some of these subwoofer amps with high power ratings(2000 watts) I think I should leave that to the professionals. What wattage are you getting from your Leach clone?
AND what is everyone using their BPA 300 to power speaker wise?
I know I shouldn't need many watts with my future AN fullrange speakers but not sure. Thats why I was thinking 50 watts. Although I have been told 5 watts can be LOUD. I am used to using in efficient speakers so always having 150 watts a channel for just the 5 channels has been my philosophy.
And for subs I have always learned I should need about 3db of headroom in my amp selection so that has always made the number of watts pretty high.
But now I can think more refined since I will be using more efficient speakers and now can focus more about quality watts.
Bcmbob do you have a build thread on your multi channel amp? Or is it in this thread somewhere?
After checking out Rods site I think I will be using some of his boards for some other builds also. L/T circuit and other.
And what type of power is available from a Pass lab clone?
That being said I dont think I will be able to build the subwoofer amps but should be able to build some small power amplifiers with High degree of sound quality.(50watts)
Looking at some of these subwoofer amps with high power ratings(2000 watts) I think I should leave that to the professionals. What wattage are you getting from your Leach clone?
AND what is everyone using their BPA 300 to power speaker wise?
I know I shouldn't need many watts with my future AN fullrange speakers but not sure. Thats why I was thinking 50 watts. Although I have been told 5 watts can be LOUD. I am used to using in efficient speakers so always having 150 watts a channel for just the 5 channels has been my philosophy.
And for subs I have always learned I should need about 3db of headroom in my amp selection so that has always made the number of watts pretty high.
But now I can think more refined since I will be using more efficient speakers and now can focus more about quality watts.
Bcmbob do you have a build thread on your multi channel amp? Or is it in this thread somewhere?
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Build thread starts here and continues on following page.
http://www.diyaudio.com/forums/group-buys/137430-bpa300-round-2-a-115.html#post2710763
Something to keep in mind - the LM3886 is rated around 68 watts. With attenuation only one can achieve medium volume with inefficient speakers. That was my situation. When a preamp or buffer is added a volume level far beyond most people's needs can be coaxed from a single LM3886. As mentioned earlier in this thread, parallel chips contribute primarily to the ability to drive lower impedance loads and are not necessarily a method to produce more raw power. That's why matching all components in a system is a primary concern.
By the way, in the 60s a store named Stereoland in Detroit had a demo where a 3 watt amp could drive you out of the room. They used some super efficient Warfdale speakers the size of a small refrigerator.
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My system utilizes a Pyle pro electronic crossover. The sub and bass go to 4 12 inch speakers with 7 foot sonotubes filled with old pillow foam. Everything else goes to my custom line arrays. I have 20 4.25 inch magnesium/aluminum speakers in each column. All of this stuff is in my shop no room in wifeys den.
If I can get some neodymium magnets cheap I plan to construct some 48 inch ribbon speakers and power them with my new toooooob amp. A fellow member valvetude has a remarkable thread about his ribbon speakers. It is awesome the work he put into those things.
At this moment I am not utilizing a chip type amp in my system. I just like to build the things. Antek has transformers so cheap it is a shame. For all I have heard the LM3886 can provide full range audio at some quite respectable levels. I just can not get hold of how that much heat is going to get transferred at higher power levels hence the discrete approach.
Also, my speaker columns are not the easiest beast to drive.
Tad
If I can get some neodymium magnets cheap I plan to construct some 48 inch ribbon speakers and power them with my new toooooob amp. A fellow member valvetude has a remarkable thread about his ribbon speakers. It is awesome the work he put into those things.
At this moment I am not utilizing a chip type amp in my system. I just like to build the things. Antek has transformers so cheap it is a shame. For all I have heard the LM3886 can provide full range audio at some quite respectable levels. I just can not get hold of how that much heat is going to get transferred at higher power levels hence the discrete approach.
Also, my speaker columns are not the easiest beast to drive.
Tad
Tad,
Thanks, that sounds like a very interesting system and similar to what I'm trying to build. My rig should be complete this weekend and I'll report on heat output. I bought a cheap ($29) laser thermometer from Harbor Freight just for that propose..
P.S. valvetude's ribbons look exciting.
http://www.diyaudio.com/forums/plan...-w-tl-loaded-extremis-hybrid.html#post1249637
Thanks, that sounds like a very interesting system and similar to what I'm trying to build. My rig should be complete this weekend and I'll report on heat output. I bought a cheap ($29) laser thermometer from Harbor Freight just for that propose..
P.S. valvetude's ribbons look exciting.
http://www.diyaudio.com/forums/plan...-w-tl-loaded-extremis-hybrid.html#post1249637
Bcmbob 68 watts would be plenty for speakers. Even my budget SLA's would be screaming. I had a dual opposed seal sonotube for awhile with 3400 watts going to it. But thats now sold.
That ribbon project looks like a fun one. Way out of my league but fun.
Would you need a big 3U or 4U for a 5 channel amp utilizing the LM3886?
Couldn't remember how big your case was going to be with the DBX.
That ribbon project looks like a fun one. Way out of my league but fun.
Would you need a big 3U or 4U for a 5 channel amp utilizing the LM3886?
Couldn't remember how big your case was going to be with the DBX.
LM3886 projects can be very small. This is the BrianGT with amp board at 2 7/8" x 1 3/16" and the PS board at 2 7/8" 2 5/8". One PS can supply two boards if space is small. A full 7 of a 7.1 system can fit in a standard 17" chassis. Draw it out on a piece of paper.
The bi-amp rig will come in around 17" w/ 11" d/ 9" h. with amp layer + transformer layer + dbx crossover. Will add ears for rack mounting.
The bi-amp rig will come in around 17" w/ 11" d/ 9" h. with amp layer + transformer layer + dbx crossover. Will add ears for rack mounting.
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