Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

The crackle ended up being a faulty TRS cable, between the BT unit and the car head unit. How embarrassing!

I had no luck getting the VMA2016 to actually work. There conflicting wiring diagrams going around on the internet; some showing earth in different spots, and unclear information on the use of the EN (enable) pin. So it's in the parts bin for the moment. Might get a preassembled VMA2016 board to see if that will help (original issue was low sound volume).

Anyway, I rebuilt the whole unit to neaten it up, and put the power on a seperate circuit. The LM317T was getting hot (burnt me), so I fitted a makeshift heatsink, which brought it down to 69.5C maximum with the box open (measured on the body of the LM317T). Also drilled some vents into the top of the box to aid with cooling. If it becomes an issue, I might look into mounting a small fan in the side of the box.

Pictured attached for dr_frost_dk!

http://i234.photobucket.com/albums/e...111027_004.jpg

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Updated POST #1 with schematics and more pictures on my home amp on request :)

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Awesomeness, dr_frost! Since I bought a second N900 as my spare unit, a couple of weeks ago, and that means I'll be using my two N900's for quite a bit longer, I am considering taking your advice and building myself an amp like this.

Thanks for sharing!

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Your welcome :)

and 5spdvl how is the BT coming along?

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

It's alright. The VMA2016 I bought was a dud. Well, I couldn't get it to work. It only produced static, and got very hot. Seemed to be some discrepancies in the wiring diagrams I found. I'll buy another, but mounted to a board instead.

But lately I've noticed that if I don't drive my car for a few days, the battery struggles a little.Need to put a relay between the battery and BT unit, so the ignition turns it on. And the sound continually drops the left channel only - this is because the TRS socket it loose. Planning on fixing that soon.....been too busy enjoying holidays and fixing mate's cars! :p

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Just made a little "happy" speaker with the VMA2012, KBTEL Battery and 2x 3W speakers from DX

Has a good sound, better then expected from something that ways about 100g.

Application, for "long" journeys on the EV Moped (Limited Speed 30 KM/h by Danish law....), makes the time go by faster :P.

Only thing left to do is put in a charge plug so i don't need to open it up to charge.

The 1220mAh battery should last over 1 hour of play time so that would be plenty for the application

Additional info: Plays >3x as loud as N900, and here we are talking about clear sound, not that the N900 isn't impressive in that area.

Attachment 24296
Attachment 24297
Attachment 24298
Attachment 24299

EDIT: After using this amp for more then 4 hours and only seeing a battery drop to 80%, i think i can say this will blast on full volume for some hours, this i will confirm when the weather is NORMAL!!!, damm windy and raining right now, not the conditions for this amp sitting exposed on my Electro Ciao.
Right now there's a big storm over DK.....

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

^ That's really, super cute.

I doubt anyone would take you seriously though after seeing the happy face you drew on it. :)

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

I guess your right but i couldn't resist :)

But i will say that this little box really throws some sound out, if it was tuned to the speakers + bass reflex it would really be impressive sound wise.

Those speakers are pretty good.

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Nice, really, very nice! What about higher frequency sound (as opposed to bass) with those speakers? And overall balance between basses and high pitches?

/Estel

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

I would say so, don't expect 20Khz but all in all they are full tone, as i wrote on DX i would estimate them to 80-14000Hz, i don't have the time to measure them yet, but im use to making audio and i would call them at that freq.

Also VS. my asus laptop the audio is many many times better.

UPDATE: have been using it at home with N900 and laptop and have played for 1 hour+ but at low (normal levels) volume and so far it has only used 10% of the 1220mAh battery.
Have to make a new measurement on usage at full power (as much as the small speakers can take).

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Quite good - FM radio never output higher than 15kHz (no matter of speakers), and we don't complain (as long as signal is clear ;) ). Seems, I'm going to make something similar as gift for my parents - although, not in Boss Smiley shape - first of all, it resemble character from one of Neil Gaiman's Sandman episodes, second, it also reminds me Google Eyes - always watching where one click a link ;)

Seriously though, it turned out to be really interesting bastard for low price.

/Estel

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Pretty cheap, the raw parts, 2x speakers & AMP comes to 12$, but word to the wise, DX has no idea on how to package them, and so far i have 2x ruined out of 8x, they come loosely in the normal bobble plastic letter package


UPDATE: Have been using the "smiley" amp for +4 hours today with the laptop, note it has been on low volume, but just measured the battery and can report that there is 80%+ left!!!!

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Got some new small full range speakers, this time NOT from DX, and they are awesome, now for cabinets i decided to make my own, and a familiar choice of "building material" was used :p

Connected to the 2x3W AMP (N900 Add-on amp) they really throw out some VERY CLEAR audio, connected to the 2x10W (12V) they really really throw out some awesome sound.
The Bad.... well the supplier (EBAY) does not have any more of them...., but i ordered some other ones from the supplier that has a similar build.

Cabinets are 5x5x5 cm, and the holes are of course are glued shut.
It is a closed cabinet.

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

I've been working on this amp lately. Unfortunately, it doesn't produce any sound (apart from static), and I've been searching thoroughly for any errors without luck. It's a TDA1554Q 2x22W.

http://i234.photobucket.com/albums/e...120115_001.jpg

http://i234.photobucket.com/albums/e...120115_004.jpg

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

i think i made a few amps like that, the best i found back then was one that had 4x55W (4 ohm) but at 2 ohm it was rated at about 110Wx4 (at 16.5-17V), TDA7560, of course the 100W+ is PMAX, but back when i used it in a cheap but POWERFUL BI-AMPED system, used 24DB (4th order) active filters (Also DIY for EXTREME precision)

The 7560 is also MEGA easy to set up, almost no components, and it has a very good audio quality

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

I'm just building this little guy to boost the signal to my car's head unit (for the aforementioned bluetooth system I built). I'm about to replace a few capacitors and the resistors to see if that makes a difference.

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

@dr_frost_dk
Nice work on those 2 small speakers, but I'm pretty sure, that you would get much better sound quality using actual wood for cabinet. Much better resonance quality, than with any plastic.

/Estel

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Yes there's always a chance, but the fiberglass cabinets are pretty good i must say, they really hold together well even thou they are only glued together with hot glue

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Im building a new audio system at home, going back to foolproof bi-amped active filter system.

So im building a new AMP, this time with the TDA7293 since it can take 10+/- Volts more (= MORE WATTS), i have just finished benching a quick one i made with the extra POWER stage using the 2SC5200 & 2SA1943.
And of course this amp is a 4 Channel AMP, Filters will be external.

But i would like to know if any of my fellow maemo user knows a place where i can get circuit boards made (few and cheaply)
Something like the picture attached.

The DEMO amp :)
Attachment 24920


The circuit board used
Attachment 24921
This circuit board has A LOT of excess component space but it is built for both TDA7294 and TDA7293

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Finally got around to post my 3+ year old AMP on the official forums, you can find it at http://www.diyaudio.com/forums/chip-...come-also.html if you want to know more.

This is the Home POWER AMP not the 2x3W.

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Thinking about doing the 2x3W amp and putting it in an enclosure that will be a little outdoor friendly for those camping trips. Still deciding on a power source though.

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

well anything within 3v - 5v, like USB, but i would recommend LiPo/Li-ion battery's if you want to take it on the road.

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Heya Frost.

I was wondering if perhaps you could do something like this but with more of a budget on hand if possible.

http://www.youtube.com/watch?gl=US&h...&v=CqPntijMrbU

What's your thoughts on this?

Cheers. :)

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

HeHe done that before both with phones, PC/TV lcd's (panel only and high powered lights)

But if your thinking about N900/N9 the best way to this is to offer up a device and get more light behind the screen, this way it will allow you to project you device up to over 100" "screen"

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Do you still have them around, and if you do, mind sharing some pictures with us? :)

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Sorry no, that was along time ago, think about 7 years, i unfortunately don't save all my projects... if i did i would have a barn full of speaker sets that i have made in my time...

But the basics of what you can do if you have a device/laptop/netbook to offer is to youtube some DIY projector to get the idea of how to build it.

The video you link to is a quick fun project to do, but you won't get much light, you won't be able to make a big picture, cause this needs more light.

But a conversion with some high powered LEDs can yield a very good "little" projector that can actually be used.

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

What about an old GBA lite, GBA with Afterburner installed on it or a GBA micro?

Like what kind of LED power or light do you need behind the screen?

Having a modded GBA that could play on a 100" background would be awesome. :)

Sorry if I'm slightly derailing your topic here.

By the way, have you ever thought of something like this?

http://youtube.com/watch?gl=US&hl=en...&v=8eFvo6HqpK4

No electronics needed. :)

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Well everything with an LCD can be modded to a projector, and LED?, well any kind of power LED will do, or you can use 5mm (high power LED's) what matters here is getting a LED that is close to NEUTRAL White in it's emitting color, if you ever played around with LED's you will be familiar with the "normal" blueish color or the warm white, what you want is whats in between those, you can mix 50/50 but that's only good for general lightning, will look terrible used as a backlight for a projected LCD.

But get LED's that is in the 4000-5000K "color" range, and Power wise?, well the iPhone in the demo video has about 0.5W in LED backlight, so anything from 1-20W will make a very good projector when using LCD's that are less then 5" big, back when i made my DIY projector i used a 15" LCD Monitor, and that was when LED's where really expensive so i opted to use 2x 30W CFL in some headlamp reflectors i got from an old scraped Semi-Truck

And for the "tube" amp, yes it works but i would rather have some great AMP, and great SPEAKERS, to get some quality stereo sound.
Remember back when the first record players came, they used the same tube/horn amplification, back then not many power amplifiers have been made/invented + power was scares so it was better to have a wind up player.

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Addison, actually, doing DIY hi-res projector is one thing I always promise myself to do. Basically, for good-quality leds, there are 2 alternatives - either matrix of high-powered diodes behind light-difusing mat (thin one), or, for more power, a true reflector and optics, that collect passing light and transmit it in parallel to screen.

Normally, best thing You can scavenge for DIY projector screen, is small computer monitor of high resolution - thanks to it, You already have DVI (HDMI)/VGA input, and adding S-Video/composite is a matter of 20$ converter.

There is also 3th way - very interesting, although, giving only moderate results:

http://www.inventgeek.com/Projects/H.../Overview.aspx

/Estel

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

hottex can't reply to you PM since you don't have 5 or 10 posts or whatever is needed.
Don't know how you can PM me then?

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Interesting :P Well, I simply wrote the PM...noone stopped me :) You may answer over here or you may use my emailaddress. If I can PM it to you...wait and see :q

EDIT: Ok, now they stop me and I can't PM you my mailaddress. It seems I found a bug that makes it possible to send a PM without being allowed to do so...

<mumble> Nokia made this board right? That explains quite a lot....</mumble>

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

[off-topic]Actually, not Nokia - it's closed-source vBulletin. Nokia just pay bills here ;)[/off-topic]

/Estel

Re: N900 Micro amp, when compact power is needed (Yet another Frost MOD :D)
 

Hey, that's the same bluetooth receiver I used in my headphone mod.

http://www.azkay.com/images/hd201/v2/20120308_013.jpg
http://www.azkay.com/images/hd201/v2/20120308_022.jpg
http://www.azkay.com/images/hd201/v2/20120306_015.jpg
http://www.azkay.com/images/hd201/v2/20120306_017.jpg

The amp in the first post, would that be too powerful for headphone drivers? (hd201 are 24ohm), currently using a Fiio e5
Basically looking for getting the parts down as cheap as possible, see how cheap I can make my next pair.

Currently it's Sennheiser HD201, Fiio e5 amplifier and the same receiver as yours, two 3.5mm ports (one for charging, one for wired headphones), battery+charging circuit. Last over 24 hours straight everything on max volume.

Also, you seem to know a lot about these things.
What would your suggestion be to adding two extra speakers and using them as bass? ie; how

eg; adding two small dedicated bass speakers to the headphones.

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Well instead get better speakers to put in them, i can't recommend any right now since my last supply on good small speakers was from ebay, and as you know almost all ebay "offers" are temporary, but those 2" "bass" speakers i now use as fulltone (- bass) with my 8" speakers for home audio, they really sounded AWESOME as headphone speakers eg. using them as headphone speakers.

Else i recommend a bass boost filter, this can be done in many ways like the analog one i use, i did not work with the 2x3W amp thou.... but if you make a digital filter using a dual opamp you should get your bass that way if you headphone speakers can take it.

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Mmm

http://www.ebay.com.au/itm/Rail-Mast...item19d5896a62

I'm also looking for another bluetooth receiver, one that makes less "noise". Like if something low is playing or nothing playing the noise is a little annoying, random clicking too.

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Just noticed this thread and thought to share my "really small audio hack" which actually consists of just a cable adaptor from 3.5mm audio jack to twin XLR connectors...
...and on the end of the XLR's I have my pair of Genelec S30 Triamp active monitor speakers. :D :D

--- EDIT ---

For some reason Genelec's pages were offiline yesterday so I could not add links...
http://www.genelec.fi/s30/speksit/
http://www.genelec.fi/tuotteet/vanhat-mallit/s30/

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

I love the idea of a little DYI amped speakerbox for my N9.
Like this one, but in one box:
http://talk.maemo.org/attachment.php...1&d=1328035021
Would the stereo effect be noticeable if the box was trapezoid-shaped, somewhat like this?: ;)
I wouldn't mind if it was a bit bigger. Should be more robust with covered speakers too.
And I wouldn't be mean with the battery and provide a USB-port as power-source and the capacity to give the N9 a full recharge if its empty. How much mAh would be minimum?
Recharging should work via micro-USB jack.

Which LiPo/Li-ion batteries (with soldering tags or cables) have best capacity/price ratio, I guess from RC modeling?

I might solder something up, if cost can be kept low and an apropriate housing can be found somewhere.
Thoughts?

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

"Line of sight"of stereo speakers should cross eventually, while in your ASCII mockup, it is opposite, if I understand it correctly.

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

Also, my desktop setup:

http://i.imgur.com/HbkGK.jpg

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 

I bought something at the store recently that has the following features....

No batteries required
Frequency Response: 200Hz - 12KHz
50mm speaker, 8 ohms
Signal cable: 22cm STR, CORD

When I try to play anything through them, it's about half as loud as what it sounds like on my tablet. :(

What should I be looking for online?

Any links would be much appreciated. :)