[crisscross]

Hey guys,

I am planning on building these speakers soon and need recommendations on a good DIY Amp project for it.
My budget is around $100-$150 for the amp.

I plan on hooking the speakers to my PC so will just an Amp do or do I also need a DAC?

I also have a subwoofer and Swan M200 (I will get rid of these once I build the new speakers)which is currently hooked to my speaker's Line-Out with a splitter.

Thanks in advance and apologies if some of my questions make no sense I am a complete noob.

 

[Juaquin]

Tube or SS? If SS, you can't go wrong with a nice Gainclone (based around LM3886) for that price. There are a lot of DIY options if you're interested in tubes. You might want to invest some of that into a DAC if you're using a PC as the source, say $40-50 for a BantamDAC/GrubDAC and $80-100 to build a Gainclone.

 

[Paul J.]

Those are not efficient speakers, so they are going to take some power. Power on a small budget is tough. Tubes aren't really an option unless you are listening near field. Even then, $100-150 won't buy you much of anything for a tube amp. I think a chip amp (gain clone) is the way to go. You may as well go with the 4780. Peter Daniel (Audio Sector) sells some nice kits, but you'll have to work darn hard to get it done for under $150. The kit is $80, and you'd need to source a power transformer and an enclosure. Use a cheap volume pot, and think about avoiding a selector all together.

You might also consider the Sure Electronics TK2050 board. You can also find them on ebay. Their 12V 3A laptop style SMPS should power it for $12. The nicer MeanWell supply is $40. Again, you'd need a cheap enclosure and cheap pot. Probably no selector switch. Pay attention to shipping costs!

I haven't heard either of these amps. I have built lower powered amps similar to both, an LM3875 chip amp and a Sure 2020 amp. I can't really compare the two, as the chip amp used much nicer parts.

Note that there are cheaper and alternative PCB assemblies out their for either chip. Peter Daniel and Sure are both known quantities with known parts quality. Peter is especially picky, so you are getting good stuff. There may be some bargains out there (I noticed the gigawork LM3886 on ebay), but they may also be gambles. In some cases those fancy looking parts are the real deal, in some they're not. And, with those Chinese PCB's (not Sure to my knowledge), they are generally ripping off somebody else's circuit, if not entire board layout. The gigawork power supply looks like it could be the snubber supply designed by CarlosFM. The signal board closely resembles Peter D/Brian GT's layout. But, who knows what the actually did.

In any case, a good working chip or tripath should get you great sound. And if you are careful, you can build it for under $150.

Paul

 

[fishski13]

i'm in the middle of a Tripath build from 41Hz Audio:Sounds Good to Me!. not much cheaper than a Gainclone but are a smaller package, requiring a smaller/cheaper chassis without the thermal/heatsinking issues.

i've not heard any of the Tripath amps. YMMV.

 

[Juaquin]

I have a Tripath off eBay, it sounds pretty good but I haven't been impressed with the power output on my BR-1's, although they are pretty inefficient speakers to begin with. Party volume would probably crank the amp for all it's worth, so I'm thinking of doing the Gainclone with a paralleled 4780 in each channel. Lots of fun stuff out there.

 

[ericj]

Quote:

Originally Posted by Juaquin /img/forum/go_quote.gif I have a Tripath off eBay, it sounds pretty good but I haven't been impressed with the power output on my BR-1's, although they are pretty inefficient speakers to begin with. Party volume would probably crank the amp for all it's worth, so I'm thinking of doing the Gainclone with a paralleled 4780 in each channel. Lots of fun stuff out there.

You have take class D power numbers with a handfull of salt.

Always find out what IC they're using and look up the power vs. distortion curves. You'll find that most of them are rated for between 3x and 5x the power that they can deliver cleanly. There is generally a very sharp elbow on that curve, too.

Also, generally speaking, class D designs have to be tuned for the impedance of the load, with lower impedance loads generally resulting in better performance (for both thd and how far out the elbow on the power/distortion curve is). Using a class-D amp built for 4-ohm loads with 8-ohm speakers also results in especially poor performance if the output network on the amp is not reworked for 8-ohm loads.

 

[Juaquin]

Yeah, I wasn't expecting rock-my-socks-off power, I just needed a quick amp to play with my new speakers. Now that I know how they perform (read: need a ton of power) I'm upping the ante.

 

[crisscross]

Thanks for all your replies guys.. I can up the budget if you think it's worth it, I would like something that lasts a while.. How about something in the $250 range?

Also, I do plan on adding a couple of rears and a center later on for a complete HT at that stage I will also be adding a receiver. Will i be able to still use the amp to drive the front speaker and drive the rest through the receiver?

Apologies if that question doesn't make any sense at all.

 

[Fishline]

I actually plan to put together a 5.1 setup with a computer and LCD projector in the basement. Currently I have the PC and the projector, a X-Fi 5.1 usb soundcard hooked up to a TA2020 board, hooked up to a pair of Zigmahornets I built myself and a powered sub (thus only 2.1 currently). My plan is complete the 5.1 with two more Tripath amps, one for the rear and another for the center.

Note there's no receiver, since the PC is the only source. If you have the amps, you'd only be using the receiver for switching between sources. If you have only one source, you can cut out the receiver.

 

[crisscross]

Thanks Fishline.. so DAC+ Amps is all I need if PC is the only source?

 

[oneplustwo]

I think the DAC would be integrated into the 5.1 soundcard you use. So you just need amps. Unless there are soundcards out there that do some sort of digital out that would require a DAC. I'm not well versed in PC audio, but my understanding is that they all just output some analog signal. Frankly, I'm not sure how "nice" these soundcards are. You might be better off just buying an off the shelf receiver vs. having a PC soundcard plus amps for 5 separate channels and another for the sub woofer. Might be fun, but just know the costs and space issues you'd be getting into.

 

[crisscross]

I have the Creative X-Fi Xtreme Gamer Newegg.com - Creative 70SB073A00000 7.1 Channels 24-bit 96KHz PCI Interface Sound Blaster X-Fi XtremeGamer - Sound Cards

I could also hook it up to my PC's on-board sound which is Optical Out.

 

[Juaquin]

Don't use on-board sound, even if it's optical. The X-fi has an optical output according to Creative's website, so you have a couple choices. Use the optical out from the X-fi to an external DAC that accepts optical like the Gamma1/2 (which is probably out of your budget if you still want room for amps), or use a standard USB DAC like the Bantam or Grub.

You could also just use the standard stereo headphone output from the X-fi and connect it to an amp, but keep in mind that the soundcard is in the middle of a hotbed of electronic noise. It's probably worth the $25-30 to build an external USB DAC.

 

[Fishline]

Onboard audio is usually not very good quality, and is subject to interference from other things on the motherboard, thus USB is usually the way to go.

Depending on how cheap you can make the amps, it may come out cheaper and sounding better than 5.1 HT receivers. I don't think the DACs in the low to mid range receivers would be any better than a good USB DAC. The Tripath based amps can sound really nice if you stay within their limits. As long as the speakers have >= 90db sensitivity, you should have no problem getting too loud... I have a pair of Infinity Primus P162 that I'm planning to use as the fronts. They get plenty loud driven by the TA2020. BTW, I believe Sureelectronic used to sell a 6-channel tripath amp (3 tripath chips) naked (i.e., no enclosure) on ebay. That is probably the most economical solution.

To clarify, a soundcard has a DAC. It may have other things (such as mic input, spdif out, etc.), but at the minimum it needs to be a DAC. I do not know of any "audiophile" quality DAC that can do 5.1, as those are usually just 2-channel stereo. I won't be using this set up for anything other than movies, so I believe the X-Fi is sufficient.

 

[crisscross]

Thanks guys now that I realize a receiver is not required I can probably stretch my budget even more so are the tripaths the way to go or should I go for something bigger?

So this is what I am planning on
BantamDAC + one of the Tripath based kits on 41hz

btw My cousin runs a transformer manufacturing company so I do have access to free transformers

thanks for all your help