*** The DIY Audio Thread ***

ok got some pics and some voltages sorted, voltages across each of the secondry rails are 28.50v and 27.34v Ac, at the hook up pounts between the psu and amp board im geting 37v dc.

Im using a old cambridge audio A1 case for now untill i can afford a custom one. im also hoping to utilize the input selector aswell.

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i know the heatsink is a little small for both chips but im using active cooling via a 80mm fan while testing until i can find 2 more suitable sinks.

you may just be able to see were the chip blew

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Havnt tried it for fear of blowing that to, ive got an analog multimeter and a digital one, the digital one is acting all screwy and the analog one is saying im getting around 60-70v from v+ and pg+
the digi one just keeps climbing and climbing so i think the dc bit is nackerd, the ac reader works fine though
ive checked everything for shorts and cant find anything im really lost at the minute.
im also a bit of a noob with a multi neter so how would i ohm everything out?
 
Well good news, even though the chips are insulated i found a short somewhere between the v- heatsink and chassis :( needles to say i sharply rigged up the other amp board moved the heatsink from the chassis and tested it with the meter, once it came back fine i rigged up the psu and presto there was music, all be it on a single channel.

im a little peeved at my self for rushing and loosing a chip but happy to know £10 will put it right and all i need to do is wait a couple of days gfor the parts to complete it.
 
if they are too hot to touch then you need bigger sinks. If you can keep you fingers on them - i reckon you are fine.

Run amps in? its only the caps that actually break in. I listen to it from the word go to be honest.
 
Well today i orderd my new lm3886 chip and replacemant caps for the ones i poped, really happy with the sound though only have one channel untill the other is repaird and refitted; Secondly what sort of improvemants can i start making, new componants i can add and what would these effect in the sound quality?
 
its a SOHA main board - 12au7 valve, with JISBOS buffers (http://www.diamondstar.de/jisbos/jisbos_overview.html).

I used an e12 (http://www.amb.org/audio/epsilon12/) to protect the phones, although i had to play with a resistor value to get it to mute for 30 seconds, the soha puts out 12v transients until the caps charge. I just socketed a resistor.

The switch is a bit overkill, but its on a circuit that latches a mosfet on or off (the switch itself is momentary).
 
Slight thread resurrection here.

I'm thinking about replacing my old second-hand Technics AV amp and 2 bookshelf speakers with something superior and preferably home-made. The D-Class amps at 41Hz.com have caught my eye.

http://www.41hz.com/

I'm a bit of a novice, but I have built a CMOY headphone amp and have breadboards/multimeters etc. Does anyone have any recommendations as to which kit would be best for my needs?

I'll also need some new bookshelf speakers. I'm a bit shallow, so they have to be black. I don't want to spend more than about £100 on a pair. Any recommendations while I'm here?
 
I've currently got access to all sorts of electrical gadgets at work, so I want to make use of it while I have the chance. Oscilloscopes, surface mount irons, huge 3-phase supplies... I'm pretty much in electronics heaven lol. :)
 
Glad to see this thread back to the top, allmost forgot about it ive been over at diyaudio so much.
little update for mine, got my new chips and the amp is up and running and sounding great, ill get some pictures up tomorrow. i havnt bought a case yet so its still housed in the cambridge audio a1 case for now, i have however ordered my self a lovely DAC kit that i will be modifying with Wima and OS-con caps, a steal at £30 deliverd from Hong Kong and also comes with the power supply board aswell. seems they are being sold cheap because of an error on the pcb prevents it doing 24bit 192khz sample rate but this is easily rectified with a bridge between the 2 on board chips so quids in £££.

Also getting prepared to start a shigaclone project for a custom DIY CD transport, damn i hate this hobby it eats time and money as though it was a fat kid at Mcdonalds on his birthday!

Ive also made a connection with a lad about 10 miles up the road from me who has some handy tools to make wood a lot easier so seems ill be making my own speakers eventually which i swore i wouldnt do, oh well cant be helped i suppose!

Hears a picture of the dac for any one interested.
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can be found on the bay for exactly £31.98p inc delivery, is advertised as doing 192khz but reliable sources who have purchased this found an issue and solved it so bad chinese for false advertising but good because we get cheap merchandise thats pretty decent!!
 
Hi there, the mods as far as i know are to A. enable full output function and B. the wima and os-con cap are to increase sound and component quality, ill also be adding blackgates on the power supply board and voltage circuits on the DAC board itself as per recommendation from the following thread, and lastly a new opamp instead of the one shipped in the unit as this was also recommended hear

HERE and HERE

my name is kanifee over at DIYAudio, a steal at £30 delivered i think you will agree :D Oh not my mods either buy a long shot just some stuff ive managed to source pre purchase to help my decision in buyng it
 
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