Best beginner project

Hi!

I'm a newy when it comes to DIY. But I'm planning to make my own amplifier. Of course, I would like to get the best out of my money. So what I want is:
-easy to make
-as pure sound as possible (Class A?)
-a kit would be preferred (or at least directions of which components that needs to be good quality / order list)

Can anyone out there give me a good piece of advice on how to think or a tip of where to find such an amplifier?

Thanks a lot
andy
 
I think that the best beginner project is several beginner projects.

The sounds of LM (gainclone), Thompson, and Tripath are all remarkably different.

In addition to that, there's variety of scale, as in how much amplifier power do your speakers require before reaching a satisfying output?

Let's say that you had to choose one of the following:
1). A very forwards midrange, with clear treble and high resolution bass--quite good for television or critical analysis of audio signals.
2). A clear midband with a wide open presentation, level frequency response according to the human ear, and decent bass and treble--more musically realistic although slightly less revealing.
3). A remarkable, and award winning clarity, although slightly more upper treble (air) than usual--with this being the sole (and pleasant) exception to both a precise and musical presentation.

Everyone's ears, speakers, amplifiers and personal tastes are different. So, which would you choose?
 
Thanx danielwritesbac for writing back ;)

Yeah, you would like it to be just ONE that is good, and the rest is BAD, but I know that's not the case.

I was thinking of making a couple of Plutos to the amp. So no need for mazzive output! And I guess that also answers your qst about which sound would fit me: open, clear. In time, I've thought of making the subs as well, but since I live in an appartment... That will anyway be later on.

Since I'm a beginner, it would be great with an understandable construction guide as well.;)

andy
 
OK Daniel,

It's unanimous, we both would have to say #2. (I am interested in this too) There are some nice and some bad aspects of the other two choices but if I had to pick one, I'm with Andy.

I would also like to say that my speakers are not the most efficient. ProAc Studio 1 Mk IIs, 88 db at 1 watt at 1 meter.

Recommend away!

Thanks!

Regards//Keith
 
That was cool!

Okay,
#1 gainclone (LM chip amp)
#2 thompson (ST chip amp)
#3 tripath (durable class D amp)

Of the three, its #2 that has the most immediate gratification--the big sound of Bose in under half an hour.
However, #1 has more tonal possibilities, and they do vary by model as well--great for self-amplified speaker projects and for clearly audiable voice in home theatre as well.
And, #3 can give you the best of both, while easily paying back that extra hour of soldering because the overall timeframe for satisfaction can be shorter or similar at end result.

I do think that you should experience all three. Are there some friends in your area that would like to do projects with you? Its so much more fun that way. ;)

That's the point. Have fun!

EDIT: Support components and power are quite similar between #1 and #2, so you could easily try both.
 

lanchile07

Member
2007-10-06 6:29 am
LM3875!

Hello Andy!
Well,I have build three LM3875 integrated amps and the result is always the same,CLEAR,FAST and DETAIL amps.
build an amp using Peter Daniel "Audiosector.com" boards is easy and if you fallow all the steps you will end up with a wonderful amp.if I were you,I would go for the LM3875 no doubt!. :smash:
 
Hi again!

danielwritesbac: I made some research on the internet, but failed to find any thompson chip amps... :xeye: Do you have any useful links?

At another forum, I was given the tip of SKA audio http://www.ska-audio.com/diy/
What is your opinion of that amp? Seems really interesting!

lanchile07: Thanks for your tip! I will certainly look into that. It seems like an easy to make amp.

And thank you all for your interesting comments! I now feel better prepared to do some research and see what fits me best!:D
 
Thompson is ST Thompson (RCA and Bose). Although the transistor amp project is great too.
After all, its only a few extra minutes of soldering, towards many hours of pleasurable listening. So, as long as the documentation is good for your chosen project, don't let a bit of extra time with the soldering iron stand in your way.
I think that a Tripath, hole through (easier) project from 41hz.com could really be a "home run" experience, and its no more complex than a transistor amp.

All three of those projects have (or can have) human ear tapered audio, so they respond easily to the traditional and simple customization of input filter cap swaps, to adjust for personal taste (Translation: They're easier to tweak).

Tip: Do have an ohmmeter/multimeter standing by to double-check resistor values before installing them. ;)

Tip2: A nice jar of gel flux and some 90% (or better) alcohol (to wash it afterwards), can really speed up the soldering.
EDIT: A grade of steel wool, #0000 can quickly remove smoked flux from the iron with just one light touch--solder only with a bright clean iron.

Tip3: A desoldering iron is a nice clean way to make corrections, especially if the solder happens to suddenly run together in a tight space. Do have spare tips for the irons standing by, just in case something gets stubborn.

Tip4: Don't be nervous. If you burn up something on a kit, well, individual replacement parts are quite economical--so relax. ;)

Tip5: In addition to traditional audio path discussions, source, amp, and speakers, more is involved.
Within each component, there is possibility for it to have a different sonic signature, mainly from the efforts of pleasing either basic signal meter equipment or the more complex artisan/medical measuring equipment. But, also, some types of equipment do conflict.
The nicest way to resolve this is to interview several different types of audio equipment (source, amp, speakers) and decide for yourself which are the most pleasant. After all, pleasing you, is the only function of these materials. ;)
 
Here's a bunch of resources

Tripath
http://www.41hz.com (see "hole thru" beginner models, slightly more soldering, but guaranteed worthwhile audio)

ST Thompson
http://www.electronickits.com/kit/complete/ampl/CANUK194.htm (small)
http://www.electronics123.com/s.nl/it.A/id.328/.f?sc=8&category=33 (large--use with A20K dual potentiometer)

National Semiconductor (gainclone, miniclone)
http://www.audiosector.com (fantastic support)
http://www.chipamp.com (fantastic support)
http://www.electronics123.com/s.nl/it.A/id.425/.f?sc=8&category=33 (LM1875)
http://eshop.diyclub.biz/product_info.php?cPath=1_205_150_22_203&products_id=441 (LM3886 econo)
*It is generally recommended to use these products with a quality active preamplifier, or to create a simple buffer circuit.

Cool Accessories
www.alliedelec.com (center tap transformers and chip heatsinks)
www.partsexpress.com (green polyester caps for "bypass" caps and zobels, and they have project boxes too)
http://eshop.diyclub.biz/product_info.php?cPath=1_85&products_id=195 (remote control)
http://www.hndme.com/productcart/pc/viewPrd.asp?idcategory=67&idproduct=1968 (easy active preamp)
http://eshop.diyclub.biz/product_info.php?cPath=1_210_80&products_id=263 (decent ecaps)
http://www.hndme.com/productcart/pc/viewCategories.asp?idCategory=73 (decent ecaps)
http://www.digikey.com (stereo dual gang potentiometers and a heck of a lot more--good replacment parts too)

Things to look up:
See the chip manufacturer's PDF files for the chip in your chip amp.
See the local hobby store or computer store for Artic Ceramique thermal paste (keeps the amp cool).
Gel flux makes soldering fast and 90%+ alcohol washes off the mess.
See the subjects of decoupling, DC blocking, NFB capacitor, bypass cap practice, and most especially DC output/DC offset measuring.
Often heatsinks are available for free/salvage from thrift store electronics, and these old heatsinks are high quality.

I think that I've gotten both of us into enough fun trouble for now.

Please do explore several different types of amplifiers. They are all most certainly worth an audition. They are all different, and that is a fine resource indeed--because speakers, ears, and rooms also come in much variety.
 
andySweden said:
Thanx danielwritesbac for writing back ;)
And I guess that also answers your qst about which sound would fit me: open, clear. In time, I've thought of making the subs as well, but since I live in an appartment...
andy

Open and clear as a primary consideration, might match up well for LM3875. That is especially true if you also design speakers.

Speaking of speaker design. . .
Here's a few clues. ;)
For apartments, some ported speakers able for "flat to 45hz" response, could probably do very, very well, and you don't require a subwoofer.
Sure, ported is larger, but if you use "front ported" and make the speakers tall (mids at ear level while seated), then the footprint can be small. Its especially good if the inside of the cabinet is 48" to 51" tall, but its much easier to clone a design that's already done.
See also the subject of BSC because there's two nice "cheats" for cabinet width. You can aim the cabinet width frequency (named Baffle Step) straight at the crossover point for your midrange, or you can choose a woofer with a drop in FR corresponding to the baffle step frequency (relates to speaker cabinet width).
Generally -3 at baffle step indoors will make for level bass response, and no desire for a subwoofer. ;)

And, whatever you do, make it fun. ;)
 
Re: Here's a bunch of resources

danielwritesbac said:

Thanks for sharing all of those links!

I'm now using this search, and I'm finding some good stuff on the ST amps. Is the TDA7294 the best chip for ST amps? I'm seeing plenty of other TDxxxx chips out there.

Also, most of the stuff that I have found thus far on ST amps is dated around 2002. Is this still a valid design for a good-sounding amp? Or has it been superceded by something better? I realize that there are 30-year-old designs floating around out there that can hold their own against anything else, but I also know that some just don't quite last. What's the case with the ST?

Thanks!
Scott