ALl,
Please help me decide. I need amp for my DIY sub. I shortlisted two:
1) get DIY 4780 kit from audiosector which looks very good and costs around $73.
2) Sony xplod car amplifier for almost same cost. Advantgae is that this is available locally (I am in India) while kit needs to be ordered Internationally.
My question, is that major difference in quality in either approach? Is it worth the trouble ordering, building rather than buying off the shelf car amplifier. I am in India.
Many thanks
Please help me decide. I need amp for my DIY sub. I shortlisted two:
1) get DIY 4780 kit from audiosector which looks very good and costs around $73.
2) Sony xplod car amplifier for almost same cost. Advantgae is that this is available locally (I am in India) while kit needs to be ordered Internationally.
My question, is that major difference in quality in either approach? Is it worth the trouble ordering, building rather than buying off the shelf car amplifier. I am in India.
Many thanks
You're probably better off just buying an off the shelf amp. I feel if you're going to build an amp and you don't already have a lot of experience at it, it's going to be a while before it's completed and able to be used in the car. You may also run into problems while building it.
I'm looking into building one and can already see the kits are a fair price but I can order high end components from mouser and save a good amount of money.
Looks like the PCB's are the best way to go, granted you can pickup the components locally.
Check out Brian's site though, his kits are the cheapest and he seems to be the number one source on the net.
http://www.chipamp.com/orders.shtml
I just bought a cheapo Kingwood 4 channel, bridgeable car amplifier with low pass crossover, bass frequency range and bass gain control.
It's about 1,000 watts RMS and I can bridge it into 4 ohms to match my woofers' impedance.
Car amplifiers are almost always 2 ohms unless you're able to bridge them or it of course says otherwise. The point is, I got it for $60 with shipping and it actually looks really nice.
The top is made to look like a chrome op amp.
You're better off dumping the money into an off the shelf amp and build the gainclone for a special project. I've seen guys build the gain clones with as little as 9 parts which really makes them tempting since your build cost would probably max out at 30 USD once you added the power supply, housing and connectors...possibly less.
You could run it straight off the car battery but you wouldn't get much wattage out of it compared to with a transformer.
This is the main page:
http://www.geocities.com/rjm003.geo/rjmaudio/diy_gc.html
Check out the 9 part count version:
http://www.geocities.com/rjm003.geo/rjmaudio/images/gc_brd.gif
Here is the classic version:
http://www.geocities.com/rjm003.geo/rjmaudio/images/gc_lm3875a.gif
If you do decide to build a gainclone, be sure to use at least 10,000 uf caps instead of the 1,000 uf. Everyone says it's horrible with the 1,000. The bass just won't be there. Some people go 15,000 or even 20,000.
You can get away with wiring it point to point which makes it very appealing to the newly budding diy artist.
I just may go low tech and point to point wire mine. I intend to use it in a guitar amp and want to have the lowest part count possible.
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I'm looking into building one and can already see the kits are a fair price but I can order high end components from mouser and save a good amount of money.
Looks like the PCB's are the best way to go, granted you can pickup the components locally.
Check out Brian's site though, his kits are the cheapest and he seems to be the number one source on the net.
http://www.chipamp.com/orders.shtml
I just bought a cheapo Kingwood 4 channel, bridgeable car amplifier with low pass crossover, bass frequency range and bass gain control.
It's about 1,000 watts RMS and I can bridge it into 4 ohms to match my woofers' impedance.
Car amplifiers are almost always 2 ohms unless you're able to bridge them or it of course says otherwise. The point is, I got it for $60 with shipping and it actually looks really nice.
The top is made to look like a chrome op amp.
You're better off dumping the money into an off the shelf amp and build the gainclone for a special project. I've seen guys build the gain clones with as little as 9 parts which really makes them tempting since your build cost would probably max out at 30 USD once you added the power supply, housing and connectors...possibly less.
You could run it straight off the car battery but you wouldn't get much wattage out of it compared to with a transformer.
This is the main page:
http://www.geocities.com/rjm003.geo/rjmaudio/diy_gc.html
Check out the 9 part count version:
http://www.geocities.com/rjm003.geo/rjmaudio/images/gc_brd.gif
Here is the classic version:
http://www.geocities.com/rjm003.geo/rjmaudio/images/gc_lm3875a.gif
If you do decide to build a gainclone, be sure to use at least 10,000 uf caps instead of the 1,000 uf. Everyone says it's horrible with the 1,000. The bass just won't be there. Some people go 15,000 or even 20,000.
You can get away with wiring it point to point which makes it very appealing to the newly budding diy artist.
I just may go low tech and point to point wire mine. I intend to use it in a guitar amp and want to have the lowest part count possible.
.
@DrFrankenstein, Thank you for your inputs.
I forgot to mention that I am building Sub for home theater use. Since there is no so moderate price plate amplifier available in India, I am opting for car amplifier or kit.
Although I do not have much audio experience, I have enough electronics experience and hence I may not have problem building kit if I get better quality. But if all remain same, I can opt for off the shelf car amplifier since it is available locally.
Btw, car amplifier I am opting is Sony XPLOD XR-552 in bridge mode (available for approx $70 in india).
Sub is build using sealed enclosure.
Look forward for suggestions.
Thanks
I forgot to mention that I am building Sub for home theater use. Since there is no so moderate price plate amplifier available in India, I am opting for car amplifier or kit.
Although I do not have much audio experience, I have enough electronics experience and hence I may not have problem building kit if I get better quality. But if all remain same, I can opt for off the shelf car amplifier since it is available locally.
Btw, car amplifier I am opting is Sony XPLOD XR-552 in bridge mode (available for approx $70 in india).
Sub is build using sealed enclosure.
Look forward for suggestions.
Thanks
Just to get the story straight, are you planning on using this amplifier in your home or in your car? If you care going to use it in a car, then you should NOT try and build a chipamp without having a fairly good knowledge of the PSU needed for it to run off of 12V DC. Here is a pretty good run down of the required PSU which is NOT simple. If you need this for car audio, I suggest the Sony amp as the best choice. If you are using this for home use and can use a standard transformer, I would use the audiosector kit.
OK knowing the purpose of the amp helps a lot.
Now I would say just build the gainclone amp and with your experience, you shouldn't need a kit. The 9 part count gainclone I linked you to sounds good from what I've been told.
If you use the LM3886, you'll be able to get about 70 watts RMS out of it and the only part that will cost you much will be the power transformer. The entire project probably wouldn't cost you more than $40-$50 USD.
The Sony amp will end up being in the $100 USD price range because of the cost of a decent power transformer.
Those are the approximate costs for us in the USA. I will be building the 9 part count gainclone and have a lot of scrap parts floating around. I might be able to get away with building it at little or no cost. Not sure if you have parts floating around but I'm suspecting so since you have a lot of electronics experience. I truly am still in the amateur stages but am fairy knowledgeable. My building experience is still minimal.
Now I would say just build the gainclone amp and with your experience, you shouldn't need a kit. The 9 part count gainclone I linked you to sounds good from what I've been told.
If you use the LM3886, you'll be able to get about 70 watts RMS out of it and the only part that will cost you much will be the power transformer. The entire project probably wouldn't cost you more than $40-$50 USD.
The Sony amp will end up being in the $100 USD price range because of the cost of a decent power transformer.
Those are the approximate costs for us in the USA. I will be building the 9 part count gainclone and have a lot of scrap parts floating around. I might be able to get away with building it at little or no cost. Not sure if you have parts floating around but I'm suspecting so since you have a lot of electronics experience. I truly am still in the amateur stages but am fairy knowledgeable. My building experience is still minimal.
An additional comment:
The gainclone circuit is NOT the chipamp you should be using for a sub amplifier. The bass response is less than ideal due to the relatively anemic rail capacitors used. I would instead use much beefier rail caps and use a modified version of the BPA200 found in the National data sheets. This will give you plenty of smack and tight low end response that is lacking in the gainclones.
If you would rather not use a 4X chip setup, I personally use Linkwitz's take on the LM3886 set up with the 110uf N.P. cap for Ci. This circuit does a great job of effectively targeting the chips for bass reproduction and definitely gives great impact that I do not get with the standard gainclone circuit. Though it is not sold in kit form, it is very simple to wire using protoboard (I have not tried P2P). I use about 5k uF per rail per chip using an unregulated PSU, which is in line with Linkwitz's recommendation. One of these chips is NOT enough to effectively drive a sub at "Home Theater" listening levels, but it is a good start and should be enough to favorably compare to the Sony.
The gainclone circuit is NOT the chipamp you should be using for a sub amplifier. The bass response is less than ideal due to the relatively anemic rail capacitors used. I would instead use much beefier rail caps and use a modified version of the BPA200 found in the National data sheets. This will give you plenty of smack and tight low end response that is lacking in the gainclones.
If you would rather not use a 4X chip setup, I personally use Linkwitz's take on the LM3886 set up with the 110uf N.P. cap for Ci. This circuit does a great job of effectively targeting the chips for bass reproduction and definitely gives great impact that I do not get with the standard gainclone circuit. Though it is not sold in kit form, it is very simple to wire using protoboard (I have not tried P2P). I use about 5k uF per rail per chip using an unregulated PSU, which is in line with Linkwitz's recommendation. One of these chips is NOT enough to effectively drive a sub at "Home Theater" listening levels, but it is a good start and should be enough to favorably compare to the Sony.
Im not sure a chipamp is the best way to go for powering a sub? And also its going to end up costing a bit more then $75. You still need to ship it to inda and buy a transformer and any connectors. So figure a minimum of $125. Im not sure whats availabel in India, but you may want to look on ebay or second hand shops for something like an old NAD amp like the 2150 which uses nice 150w Sanken output transistors and can be bridged for 150w
Nad 2155
There are alot of other powerful well built amps from the 80's that can work very well for powering subs and can be had very cheap. Nad, Rotel, Adcom, Hafler.....etc Since your expereinced with electronics you may even find a real bargain on something that needs a repair.
Nad 2155
There are alot of other powerful well built amps from the 80's that can work very well for powering subs and can be had very cheap. Nad, Rotel, Adcom, Hafler.....etc Since your expereinced with electronics you may even find a real bargain on something that needs a repair.
You do make a very good point, especially considering that a rather nice sub amp can be had for about the cost of a chipamp after housing and PSU components are considered (I have that Bash amp in my HT sub and it works just fine for me). The rub here, if I am correct, is availability. If this is indeed the case, many of the options you mentioned (while indeed nice) will not be possible for yusuf to fine.imperfectcircle said:
I have seen a number of chip-based sub amps here and have built one myself. Though they do not have the raw power often found in many other sub specific amps, they do indeed serve the purpose and do it well at moderate volume levels. It not be the "best" way, but it is a way, and it works well for a moderate price.
I have to DITTO that. I have the same sub (BASH 300S). Superb performer. And more power than I need! I've also made an LM3886 based sub amp and was very happy with it. But, realistically, money and hassle, it doesn't come close to the Bash.
But, I DID enjoy the challange. So it's up to you again.
But, I DID enjoy the challange. So it's up to you again.
dfdye said:
Swapping the 1,000 UF caps with 10,000 or higher takes care of the bass punch issue, basically a pretty off the shelf mod I mentioned early on. All the guys I've talked to swear by this swap up and the results.
I also recommended simply going with the 9 part count build and point to point wiring. Even in India, that's going to be a really cheap build granted you can get the power transformer for a decent price. You can cram it into a pretty small case and it's it's metal, it will also serve as the heat sink.
He's going for cost effective, I suspect most of you are going high budget in your heads. Going with the point to point, 9 part count build and a cap and coil 12 dB crossover, he'll have one heck of a sub system for about $50 USD, not this $125 most of you speak of. As it is you can get the chips pretty cheap. Order them as samples from National Semi Conductors and the only thing you'll pay for is shipping. There's also a handful of companies that will send out caps and coils as samples and they'll send you any value and voltage you want, I've got a bunch of them.
..$125 + ?
Not if you're moderately resourceful.
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Just to put in a bit of perspective, it was I who recommended Yusuf to post here.
He's left out some bits of information, whch I'd like to fill in.
This is a sub he will be using at home, based off a JBL car sub driver. The other driver he was using was this one:
http://www.peerlessaudio.com/products/drivers/subwoofers/main3.asp?pname=14
After modelling this one we found it required an extraordinarily large enclosure, and the JBL seemed to model a bit better. We were a little worried about the quoted 89dB sensitivity of the JBL, not knowing whether it was with or without cabin gain.
Now we need an amp, and the options considered are that of a cheap, entry-level Sony car amp running off an ATX supply. I pointed him towards Peter's audiosector kit to save him.
My personal experience is that there is bass a plenty even with low capacitance, as long as the supply on the whole is up to the task. I however use 4700uF caps extra just in case, along with overrating the transformers. I suggested a bridge-parallel to be able to handle the low impedance of the sub, and also provide a healthy swing, producing an amp capable of at least 150 watts RMS, and one that I thought would be of superior quality to an entry-level (or just about any) Sony car amp.
The biggest issue, as rightly pointed out, is that plate amps are simply not available for love or money hereabouts... another alternative would probably be a 'professional' amplifier but those get expensive quickly. Home amps are out of his budget (quoted at about $60 equivalent, slightly flexible).
He's left out some bits of information, whch I'd like to fill in.
This is a sub he will be using at home, based off a JBL car sub driver. The other driver he was using was this one:
http://www.peerlessaudio.com/products/drivers/subwoofers/main3.asp?pname=14
After modelling this one we found it required an extraordinarily large enclosure, and the JBL seemed to model a bit better. We were a little worried about the quoted 89dB sensitivity of the JBL, not knowing whether it was with or without cabin gain.
Now we need an amp, and the options considered are that of a cheap, entry-level Sony car amp running off an ATX supply. I pointed him towards Peter's audiosector kit to save him.
My personal experience is that there is bass a plenty even with low capacitance, as long as the supply on the whole is up to the task. I however use 4700uF caps extra just in case, along with overrating the transformers. I suggested a bridge-parallel to be able to handle the low impedance of the sub, and also provide a healthy swing, producing an amp capable of at least 150 watts RMS, and one that I thought would be of superior quality to an entry-level (or just about any) Sony car amp.
The biggest issue, as rightly pointed out, is that plate amps are simply not available for love or money hereabouts... another alternative would probably be a 'professional' amplifier but those get expensive quickly. Home amps are out of his budget (quoted at about $60 equivalent, slightly flexible).
I'm definitely not the most reputable guy in DIY audio but with a 60 volt power supply, shouldn't the LM3886 be producing 144 watts RMS into 4 ohms?
That's what the math says anyway and the chip is rated up to 90 volts. I would think that with that much juice, selective choices on internal components and some passive components on the amps speaker output, it would be up to par with of amps claimed to be very superior. It's amazing what the select internal and external components will do for your overall sound quality.
It should be noted that the best amp around may sound like turds with a speaker that sounds amazing with something as affordable with a gaincard set up. I once heard a pricey Onkyo that made every style of music you played through it sound like digital samples.
I think no matter what though, you're pushing into the price range of a commercial sub amp built for plugging straight into the wall, I know of several sources for some great models around the $50-$70 USD price range.
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That's what the math says anyway and the chip is rated up to 90 volts. I would think that with that much juice, selective choices on internal components and some passive components on the amps speaker output, it would be up to par with of amps claimed to be very superior. It's amazing what the select internal and external components will do for your overall sound quality.
It should be noted that the best amp around may sound like turds with a speaker that sounds amazing with something as affordable with a gaincard set up. I once heard a pricey Onkyo that made every style of music you played through it sound like digital samples.
I think no matter what though, you're pushing into the price range of a commercial sub amp built for plugging straight into the wall, I know of several sources for some great models around the $50-$70 USD price range.
.
No, a 3886 has a maximum of +/- 42v on the rails. In actual practice, they are current limited to about 3 amps (which at 8 ohms would be about 23 volts). Of course, this isn't instantaneous, which can be higher. If the OP wants to use a GC instead of a traditional amp, he might be better served by using two GCs and two woofers - you would get a +6 dB gain over a single one.
Yes I'm aware of this now.
He can still push about 90 watts RMS into a 4 ohm load if powering his gaincard with about 40 volts. Slap on a coil and cap crossover to get 12 or 18 dB of separation emphasizing the bass and I still say it will make for one heck of a thundering sub system.
He can always go with a car sub-woofer which will deliver some heart stopping bass with that much wattage and a 12 or 18 dB crossover in use.
No matter what though, he's peaking into the price range of simply buying a sub amp that installs directly into his enclosure that will have all the bells and whistles on it. You can snag one for about 50-60 bucks new that will deliver around 60-90 watts RMS and have bass gain, crossover frequency selection, Q and of course, master volume.
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He can still push about 90 watts RMS into a 4 ohm load if powering his gaincard with about 40 volts. Slap on a coil and cap crossover to get 12 or 18 dB of separation emphasizing the bass and I still say it will make for one heck of a thundering sub system.
He can always go with a car sub-woofer which will deliver some heart stopping bass with that much wattage and a 12 or 18 dB crossover in use.
No matter what though, he's peaking into the price range of simply buying a sub amp that installs directly into his enclosure that will have all the bells and whistles on it. You can snag one for about 50-60 bucks new that will deliver around 60-90 watts RMS and have bass gain, crossover frequency selection, Q and of course, master volume.
.
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