I am planning a webradio/audio media player for the kitchen.

 

Currently I have an original raspberry pi - 256MB without I2S.

A set of Infinity 6.5" component speakers "Reference 655CS". 92Db sensitivity, 54-20K response +/- 3Db

 

What I need is a reasonably small but good amp capable of driving the speakers (which will be ceiling mounted). The cunning plan is to false wall the amp and wiring gubbins such that there's a minimum of "crud" exposed other than maybe a couple of speaker wires and a mains lead.

 

Anyone done or attempted anything similar? Any experience of maybe SMSL or Topping amps? Or even "tripath" board amps from China?

 

Will probably upgrade to a better "pi" at some point as the RasPi 2 and HiFiberry DAC+ are calling to my wallet.

 

Budget is a consideration so I probably won't be getting a NAD3020 or similar.

 

J.

In the interests of proving some progress has been made....

 

TPA3116 board ordered from Inscrutablest China. In theory this will give 2x50W when fed with 24V DC. Reality with reasonable distortion numbers is probably more like 30W when fed with say 16-19V of the usual discarded laptop power supply.

 

Also found a blue-tooth only input board for £12. And something a bit meatier (TAS5630) doing 2x300W for £38 delivered.

 

May well order both of the above. Though 30+V DC is a bit out of scope for PSUs I have lying around.

 

Unfortunately I tripped over several "valve pre-amps" whilst looking through this lot. Now have to be on guard lest I spend another £50 on a 3xvalve preamp too.

 

Edit: Any interested should also pop over to the diyaudio forums or audio karma.

 

J.

Edited 2 June, 201511 yr by vindaloo

Well, the little bleeder is now up and running. Apparently it's not the most technically complete implementation of the TI evaluation board according to some comments on the DIYAudio forums. This one seems more highly regarded.

 

It is however VERY loud compared to my nice, warm sounding Arcam Alpha (from 1989!). IMO one wouldn't want anything louder in the average suburban house/flat. This is driving Tannoy E11 8ohm speakers.

 

I'm currently feeding it from a 16V Thinkpad brick. I managed to find a 24V 200W Meanwell PSU on eBay for £10 delivered. So its headroom could rise dramatically.

 

What I should have done, however, is considered buying the amp in a box for a few pennies more. Remember that it needs a PSU 16-24V to drive it. Though laptop power bricks are either just lying around or available for cheaps on the web.

 

J.

Well I'm still tinkering...

 

https://www.dropbox.com/sc/xpawzsak7i22kuj/AABJpy4O8GkgxBtfGoAldr61a

 

Temporary mount for the amp.... Though it's still powering my Hi-Fi speakers.

Speaker mounts for a component set of car HiFi speakers.

Speaker enclosures (big plant pots (from Amazon)).

 

I still have to finish off the proper box for the amp (and Pi) and add to the speaker pods to mount the enclosure and mount the tweeter whilst either hiding the crossover or making it a feature. Plan on using screws and roof/gutter sealant to attach the planter.

 

PSU for the amp went a bit OTT. I found a place selling used Meanwell PSUs so splurged a tenner on a 24V 200W PSU. a) it's about twice the maximum power needed, it's bloody huge in comparison to a teeny amp board and a Raspberry Pi.

 

J.

Getting towards the end of this fun project.

 

https://www.dropbox.com/s/13i3lfmpv3njhfd/DSCF0036.JPG?dl=0

https://www.dropbox.com/s/13i3lfmpv3njhfd/DSCF0037.JPG?dl=0

 

Raspberry Pi in a box on the left, TPA3116 amp in a box on the right.

 

The speaker pods haven't worked out so far. No sign of any bass. Seems to be related to i) using car speakers and ii) not having big enough enclosures. So maybe I'll try ripping the back out of the pods and see if that makes a difference. Compared to my Tannoy E11s, they're woeful.

Edited 20 August, 201510 yr by vindaloo

<sigh> didn't realise those URLs were that different from one another.

https://www.dropbox.com/s/ndq7ewjni84yey3/DSCF0036.JPG?dl=0

Incidentally....

 

The 16mm latching metal switches I used on those bezels are a little difficult in at least 2 ways.

 - They're "small", therefore the pins on the back are close together and difficult to crimp or solder without problems.

 - Other similar switches of say 19mm and 22mm seem to have "harness" or "connector" looms available which greatly simplify installation or later disassembly/replacement.

 - The worst: The 16mm switches are physically too small for grown up pudgy western devils' fingers. It's physically weird going on nasty to push the buttons in. It's like you are deforming your finger to push it.

 

 

So, all in all, stick to the bigger ones if possible.

Direct links to Dropbox piccies...

 

Pi Top

Pi Front

 

AmpTop

 

Amp Front