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Cheap Balanced Power Amplifier - Chip or Class D

Started building my icepower modules into my ultra-cheap perspex cases. Learned the lesson (again!) about drilling several perspex sheets at once. I really need a pillar drill, but each project is definitely my last one... then I get sucked into something else... anyway, I've got my tiny case design finalised, and my wiring looms cut, and hope to get the first of three 'smoke tested' this weekend... I've decided against even an indicator LED on these boxes, very much 2001 TMA style!
 
JemHayward said:
Started building my icepower modules into my ultra-cheap perspex cases. Learned the lesson (again!) about drilling several perspex sheets at once. I really need a pillar drill, but each project is definitely my last one... then I get sucked into something else... anyway, I've got my tiny case design finalised, and my wiring looms cut, and hope to get the first of three 'smoke tested' this weekend... I've decided against even an indicator LED on these boxes, very much 2001 TMA style!
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I have a small mill which makes mounting switches / pots / connectors easier. I listed all my audio projects on a sheet of A4 yesterday. Got to 16 before I stopped...must book a session with a psychiatrist
 
Cordless drill and a stepped cone drill is the cheapest solution.
For plastic try brad point drills for drilling wood they won't snatch on breakthrough.

Pete
 
mark121211 said:
I bought a number of these B&O Ice Power modules to build a pair of small active speakers with. Have to say they are excellent and far exceeded my expectations.
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Looking at your photo, it would seem that for 230v operation the jumper needs to be on the two pins closest to the blue caps. I fired mine up with 250v when the jumper was in the 115v position, and guess what? It doesn't work! With the jumper in the correct position, it still doesn't work, so there isn't a re-setting over-voltage protection system. There are some 'fuses' but these seem to be ok, but there is no voltage on the aux voltage output. Is there something obvious that will have blown? I'm not familiar with SMPSUs and at £17.50 a go, it's probably quicker and easier to replace it, unless there is something obvious I can fix?
 
Thats what i did
dont worry its an easy fix 3 fuses on the pcb the yellow star is the one you have blown ( T2.5A )
and the 2 with green stars are the aux supply from the pcb 25v-0-25v
if you have multimeter check the fuse for open circuit
(WITHOUT THE MAINS CONNECTED )

IF it is blown just unsolder it and replace with a T2.5A fuse you can get them on fleabay
a hot iron and desolder braid works well
if you haven't got the skills to do this pop in the post and i will sort it for you
pm if you need me to do this for you
regards Glenn

20170526_145252_zps4ze8rvmg.jpg
 
glenn jarrett said:
Thats what i did
dont worry its an easy fix 3 fuses on the pcb the yellow star is the one you have blown ( T2.5A )
and the 2 with green stars are the aux supply from the pcb 25v-0-25v
if you have multimeter check the fuse for open circuit
(WITHOUT THE MAINS CONNECTED )

IF it is blown just unsolder it and replace with a T2.5A fuse you can get them on fleabay
a hot iron and desolder braid works well
if you haven't got the skills to do this pop in the post and i will sort it for you
pm if you need me to do this for you
regards Glenn
Click to expand...

Ah, I tested the square fuses, but I don't think I tested the round one - it didn't look like a fuse to me!

I swapped in one of my other boards, and that one is working fine. I'm away this weekend, and off on holiday end of next week, so it may be three weeks before I can look at this, but I'll buzz out that fuse and at least get one on order ready for when I get back. I should be able to do the swap, as I used to build electronics as a holiday job, but that was about 38 year ago, when my eyes were better and the components were bigger!

Later: multimeter shows the fuse is o/c so I've ordered ebay replacement (got two, just in case...) - many thanks for your help.
 
My Ice power module in a Cisco DMP case, we chucked out lots of these so I grabbed a couple and found a Transcend 4gb 266X Compact flash card inside, that in the camera now!

B&O ice power by Pete Maddex, on Flickr

Pete
 
both modules bridged with B4 buffer preamp built into my stunt case
the stereo module gives about 13.8vac per channel before distortion into a 4R dummy load which is 47w @4R
and the stereo converted BTL module gives 26.1vac which is 170w @4R
this is a boldpark figure just wanted to find out if i had more power from the BTL conversion which i have :D
20170606_160033_zpsulkbf2uz.jpg
 
glenn jarrett said:
very nice you could just about fit 2 x BTL for 2 x 170w :)
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I did think about it, you could run the converter board from the aux power out socket, I used it for the power LED.

The top of the case is a aluminium heat-sink so good small power amps PSU's etc.

We through hundreds away!

Pete
 
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