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

Passive, so it's never going to be louder.
You need something active, batteries or mains fed.

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

Okay. Thanks.

I didn't know that.

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

Homespeakers have a sensitivity that are less than 0.1 percent, smaller speakers usually a couple of magnitudes lower.
So there is plenty to be gained from an efficient speakerconstruction.

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

Pretty awkard frequency response - enough for telephone (landline)-like quality of sound, but not much else. You should aim for >= 20 KHz upper frequency response, for quality music reproduction.

Sure, manufacturers tend to lie about upper limit, so true 20 KHz reproduction is rarity - but, it's at least something around, and frankly, frequencies around 20 KHz hardly matters, unless you're preparing sound system for your cat/dog. But, if producer actually *states* only 1w KHz response, you maybe sure, that it's else this or lower, no chances for better.

/Estel

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

Not so useful for a N900, but still... here are my homemade speakers ;)

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

Guess I was looking for something like this:
http://www.musicman.eu/images/storie...tter_klein.jpg
Claims to have 2x 3 Watt and 150 – 18000 Hz (±3 dB) and has good reviews.
Haven't heard it, but looks not too bad for less than 23 Euros?

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

It seem, that it have build-in decoders =pretty limited to decoding what was put there by manufacturer.

Why would you need it, having N900? it can decode whatever you want (and do it better), so just plug speakers (or connect them via bluetooth), for 1/4 of that price, or do like dr_frost_dk and build high quality ones, equally cheaply.

/Estel

Ps.

As for building, I would suggest wooden resonance boxes, even for very small speakers - sound quality difference from plastic (any kind) ones is exorbitant, no matter of speakers. Of course, better speakers gain even more thanks to wood (plastic won't let them unlease full potential).

/Estel

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

Have a look at my signature and you'll see I don't have a N900.
I would need it primarily as... stereo speaker! Connected via 3,5mm.
Nice to have possibility to connect other sources too. It's bonus, that's it.
Not as smart as a polished DIY but saves hours of time.
And I doubt you'd build something similar out of wood with given budget.

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

Wood is cheap, I'm sure you can find a broken desk or something for $1.

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

Made a new dock, well i remade a new dock, got this dock to fix and could not fix it, it had failed after some time and audio stopped working, but since i could not fix it i could keep it since owner could not use it.

So i threw in 2x VMA2012 to get the light working, well not a problem to make it work but why not go "all" out and make it go to the music, so one amp drives the speakers and the other drives the LED's

It is not done yet thou, need to put battery inside, im thinking about throwing in a 18650 since i have some left and i have the sockets so they can easily be changed if they go bad, charging can be done by the power socket that is used now with a battery attached to the wire, battery is 650mAh from a EGO-T cigarette, contacts to turn on light and AMP needs to be fitted properly.

Light could be brighter, this can be achieved with DIY led "controller" or using more powerfull amps but that will require more volts so more battery's etc..

https://dl.dropbox.com/u/29047266/ip...121127_007.jpg
https://dl.dropbox.com/u/29047266/ip...121127_010.jpg
https://dl.dropbox.com/u/29047266/ip...121127_011.jpg

-----

Video demo of the light's
https://www.youtube.com/watch?v=DKFx30eGZBc

-----

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

Just want to show off my newest project (besides the 1000' others hehe)


You don't have to have a facebook account, this is a public album :)

http://www.facebook.com/media/set/?s...1&l=0b484a5e9d

https://dl.dropbox.com/u/29047266/20130323_007.jpg

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

Nice, but what is it?

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

DIY smart TV/multimedia centre?

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

look at the link...

But it is a B&O avant 28" OLD (15+year) TV, a TV that cost's 10,000$ at the time, but now that flat screen's are so cheap NOBODY want's an old tube TV.

Now the project:
Compleately stripped it down, put in my AOC 27" LED-LCD, my computer witch is almost silent, not finished with the last things

Things to do:
put in better 4" then stock.
Build a dual 4th order subwoofer box with 4x 8" in isobarik config.
Build a 4 channel amp
Make LPT port control of the motor that controls the turning mechanism


TO conclude, yes a Smart TV/Multimedia Centre = Full HD, Awesome design (B&O not mine hehe), POWERFULL HiFi (Stereo) system we are talking 250/500W (rms/max)
An All in one, only 1x power cord

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

for those who are interested in the TDA7293/4 with power transistors then besides the forum we have a group on facebook
https://www.facebook.com/groups/760434413975466/

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

Good old thread...
Doing more nice audio stuff now like these im working on now
https://www.youtube.com/watch?v=2-qvH7Uq_K8




Some stuff here:
https://www.thingiverse.com/dr_frost_dk/about

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

Maybe not the listening equipment, finally I received my PCBs for hardware SID chip replacement. Over 10 years ago, on my first year of electronic technical school I started dreaming about built own synthesizer based on C64 SID chips and I almost finished it this summer.
https://i.postimg.cc/kRdvzc8T/20191225-025623.jpghttps://i.postimg.cc/ygRTL5JJ/20191225-025648.jpg

In the background of second picture you can see soldering station. This one is also built from scratch by myself. It uses Arduino as driver and temperature controller and only one encoder for all user interface. Tips of my choice was very good Hakko T12.
I know it is possible to buy ready drivers for T12 but guys who make it mistakenly founded / researched the thermocouple used in tips for measuring themperature is type K. But it really is something between type C and D so on cheap driver when you will set 350 Celsius degrees you will have over 550 on the tip. This motivated me to build my own station :D

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

Well, I received package with N900 boards so its time to be a bit more active on the forum :)

At the start some background:
Creative Audigy 2 ZS Platinum Pro from 2004. Last produced soundcard with the hardware MIDI synthesizer. In the sound quality this 24bit/192Khz soundcard is an absolute killer and for me it sounds better than most newer constructions, even USB and audiophile ones. In the November 2019 I changed PC and I had no more PCI slots, simple PCI->PCIe adapter make it work like a charm again. That card had its studio twin - E-MU interface with exactly same DSP and all of the ICs inside; to make Creative card for use for the civils they designed headphone opamp with very low gain.

Because I'm using Fostex T40rp as my daily headphones for many years, now MK3 (much sturdier MK2 has been stolen a month ago) I was living with a fact this great soundcard can't drive better headphones. Until now.
At the Friday, right before midnight, I was listening the music and I've got the idea - what if I can make this card compatible with more demanding headphones?

I was looking for the pictures of the board of SB0290 unit (frontpanel) but there was no pictures at all so I think mine are first ever sent. Opening is simple, just unscrew everything, remove potentiometers caps and remove screws also from there. There is also one screw under the casing in the middle.

On the top is a huge shield soldered to the bottom of the PCB
https://i.postimg.cc/fRKP7Rvv/IMG-20200905-024101.jpg

After removing it we can finally see the top side
https://i.postimg.cc/CxYtfqb1/IMG-20200905-010015.jpg

Okay, now zoom on the headphone amp
https://i.postimg.cc/5tKkGKTY/IMG-20200905-011255.jpg

Yes, that's Japanese NJM4556A opamp which amplifies signal from CS4392 24bit/192kHz DAC. It's DAMN good, but to secure users with 32Ohm and less headphones, and of course, separate this construction from proper E-MU solution, opamp gain has been set to less than 2. Just by adding 1kOhm resistors parallel to the R151 and R121 I set the gain to almost 8, because opamp is powered from the 9V regulator and maximum output voltage from DAC is 1.05V that's highest safe value for opamp, and I think my ears too.
https://i.postimg.cc/N0jzdvJv/IMG-20200905-022029.jpg

With those two guys there I made this soundcard compatible with almost any pair of headphones. The last thing to do is to replace encoder which change volume in the windows to the standard potentiometer right after opamp. Also encoder can be pressed and it will act as mute button, I found ALPS potentiometer with a proper switch so I will still have mute functionality.
https://i.postimg.cc/B6SbhByz/IMG-20200908-195932.jpg

If you can see, its already lying with the knob inserted but I'm still waiting for second potentiometer, microphone one because it becomes not enough reliable. That's everything :D

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

Finally got the time and resources to finish the RGB system :)

RGB System - Release Video