41Hz Audio

[Tom Smit]

Has anyone built these amps? Here is the link... http://www.41hz.com/shop/
How difficult is it to build a complete 2-channel amp by going this route?
Is there more involved than the part shown?
How about for auto?
What would shipping cost? (to me)

I am curious since this follows the DIY route.

Thanks in advance!

[Bill Fitzmaurice]

They look interesting, but without North American distribution I won't do anything but look.

[trumpetbri]

I bought an amp kit from them. Haven't built it yet. For some of their amps you have to figure out the power supply on your own and I'm no electrical engineer and don't like getting electrocuted.

I'm seeking help from EE friends to build the Power supply safely

They have some smaller amps that use 12v power - much safer.

You'll have to brush up your soldering skills.

Also, Tripath, the company that made the chips on which all 41Hz amps are built, went out of business. Their assets are now owned by Cirrus Logic but no one knows what they plan to do with chip manufacturing.

41Hz claims they have ample supply of chips to last a long time.

For most of their boards, you have to provide connectors for speakers, input, a volume POT if you want one, and any other nice-to-have stuff that we take for granted with off-the-shelf amps. So at the end of this, you won't really save any money building your own amp.

but... you'll have a lot of fun (assuming you don't get electrocuted) and get to have more DIY parts in your sound system.

If you really want to go crazy,

http://www.paia.com/index.asp

has even more stuff you might want to build.

-Brian

[Gregory East]

They look interesting, but without North American distribution I won't do anything but look.

Distributor? He distributes a set of components and plans. A bit like Leland does for BFM. What's a thousand miles of postage between DIY buddies?

Anyway, neat concept. Looks like you need to be adept at soldering lots of tiddly bits and bobs, counts me out. Then it's a case of following the assembly instructions and knowing enough not to do something lethally stupid in the testing phase, doubly counts me out.

I suppose if you can solder and follow instructions you could always take it to a real McCoy amp tech. He could go over your masterpiece for mistakes and then, when he was fairly sure you hadn't built a mantrap, test it out.

One of the mono jobbies backed up to a sansamp would make a pretty nifty 1U package for a fraction of a Markbass or Genz-Benz.

[AntonZ]

I have built two kits from 41hz. Got me some models with through-hole parts, not the SMT versions. That worked fine. Mine are low power, no good for live sound/dj. I did do more soldering before I started on the first 41hz kit. The kits are pretty small, so postage shouldn't be prohibitive.

[Tom Smit]

Thanks for your posts, everyone.

[Rune Bivrin]

I've built one Amp5, and have an Amp10 waiting to be built.

One thing that you have to be aware of is the protection scheme these chips have. It will shut down if something out of the ordinary happens like a temporary short, a troublesome combination of speaker impedance and signal or just substantial voltage fluctuations. Then you have to reset it by toggling power or standby to get sound.

This is just not very practical in a gig situation. I'd much rather have it just current limit when the impedance drops slightly.

I also have stuff on order from connexelectronic.com. Two
TA3020 Audio Amplifier v3b and a switched power supply A1000SMPS
That stuff is supposed to be good down to 2 ohms, so should cause fewer impedance mis-match issues.

[bitSmasher]

I'd love to buy the 4 channel 12V kit for portable sound - but that'd mean trying to justify another project. Not yet

[horst]

I've actually built the amp9 12V 4 channel amp,



it sounds great, and gets good volume from the DR250's but the problem is that it only delivers a clean 8W into 8ohm, which is a little lean, the 24V version will do 40W into 4ohm, more into 2ohm, which it is actually very happy with.

I enjoyed building it so much that I have also build an amp4 amp32PS and an amp32 (which is just insanely small). I'd never soldered SMD before but after butchering one AMP32 I really got the hang of it, and pretty confident of my plan to build the amp2 but use two modules to make into a three or four channel amp (one amp can be bridged to deliver 1200W into 8ohm) with a switchmode power supply and possibly a passive line level crossover.

this is the amp32PS that I put in a 50x80x34mm box, next to a 1.6Ah battery, current draw with good volume is about 100mA, so good for at least 8 hours

[Tom Smit]

Horst, what does it cost for all of it? And what is all that is needed for a 40~50 watt X 2 amp?

[horst]

here is a table comparing all the 41Hz amps
http://spreadsheets.google.com/ccc?key= ... DZWc&hl=en
prices are on the website, they are between
$30-$40 for the small ones and $80 for the bigger ones with the most expensive but very powerful being ~$145, shipping is around $10, which I think is very reasonable, and by the time to buy the connecting hardware and cases you might have to spend as much again, the single rail amps you can run directly from battery or something like a laptop powersupply, some have powersupply onboard and you only need to add a transformer.

It's pretty straight forward and quick, more or less, you have to take your time, and you have to aquire new skills like taking a surface mount device out of it's little package, oh and don't work on carpet, preferably a white sheet, so you can see the little bastards when you inevitably flick them away

[joeybutts]

I built an AMP9Basic for a portable radio project and it does an excellent job off a 12V source of pushing two 5.25" subwoofers and 2 3" full ranges. When the voltage gets below about 11.5V it turns off to prevent any damage. First time it happened to me I thought I had killed it. Fortunately I charged the battery and voila! Back to life. The forum board over there is extremely helpful. I even sent mine to a guy in Sweden for him to trouble shoot and fix mine and received it back in about 8 days, working like a charm. Real nice people, real helpful, and real knowledgeable. I have a huge thread over there in the AMP9 section.

I will probably tackle a new 41Hz amp in the near future for different projects.

[horst]

too funny, I was thinking that your tag sounded very familiar, but i just couldn't place it,
that's quite an epic thread, I know New Line are making 'The Hobbit' now, but maybe they can make a film version of your thread after that.

[joeybutts]

yeah, it was quite the project and I learned a lot. Hopefully there will be no more epic threads of that nature Though I am planning to rebuild that project

[Tom Smit]

Thanks Horst. It looks like a project that I might endeavor to take on in the distant future.