*** The DIY Audio Thread ***

Associate
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Can anyone advise me on an amp to build to power some book shelf speakers? It's been a while since I've made anything but I live with someone who builds sonar equipment for a living so can get help off him.
Not really interested in starting on a headphone amp as I don't own any headphones really.
 
Associate
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Munich, Germany
Hmm.. Don't know what DAC to go for now.

Was originally going to get a 'noodle DAC' from eBay. This would require an external soundcard from my Mac. Was going to use an M-Audio Transit connected to the noodle via optical then to the starving student.

However, I'm now looking into a USB DAC solution, and have seen the Fubar II. The OPAMPs are replaceable (OPA2604 stock) and it's supposed to have excellent results with the OPA627s.

Has anyone got any experience with this DAC? Or any other recommendations?

Was also looking at the CA Dacmagic.. BUT, it's pretty expensive.

Hi,

I bought a fubar II and replaced the op amp with twin opa627's on a brown dog adaptor. I got the op amps off ebay for circa 20 quid. They are not easy to solder and I ended up getting our engineering dept at work to do the mod.
The fubar II with opa627 sounds amazing. After the op amp mod, the channel separation is much improved as is the bass bottom end. I use the fubar II with a modified musical fidelity x-can; in which I also replaced the op amps, from philips Philips 5532 to 2 x Burr Brown 2134PA. I also changed the stock valves to old spec telsa military spec gold pins. And wow, the set up is amazing. I am so impressed with the system (I am using sennheisser hd600) that I also ordered the psu for the fubar (the supplier), but it hasnt arrived yet!


I like the fubar. Its "only" 16bit 48khz, I cant see the benefit of a 24bit upsampling DAC if your playing (like me) FLAC from 16 bit cd. You cant get any more info from the original 16 bit recording. Some say that upsampling is "better" as its easier to apply a brick wall filter at the higher frequency without impacting so much in the lower audible frequency. However I dont believe this. Some also say that you can apply interpolation algorithms at the higher frequency (192khz) and somehow round off sampling errors. But thats not true.

Also the Fubar II is extremely well constructed and IMO looks very cool.
 
Soldato
Joined
16 Oct 2005
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13,793
Nice one. Let me know what it's like with the power supply, have been eyeing that up too. And yeah, I'll be playing ALAC through it so didn't see the benefit of the 24 bit one.
 
Associate
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29 Jul 2006
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Finished the other PSU part and the soft start kit.

dscf3527yh8.jpg


Need to buy some transformers now. Where can i buy a 2x35v 500VA and a 2x15v 30VA from? PayPal would be easier.
 
Associate
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my valve amp is progressing..... very slowly as i am having to do way to much work at the moment

just plotting how i will do the layout. the Iron (transformers, chokes) will be mounted on top of the chassis.

img9427le0.jpg
 
Soldato
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On the wagon, sorta
Wow glad to see this thread still very active, i have a bit of a progress report, only a small one as i havnt had the time or money to progress the project untill now.

I was for a while running my new SOAP pre-amp i built on my Chinese DAC's trafo, i have now managed to buy an identical one to power my SOAP. this means for the first time yesterday i had the pleasure of listening to my DAC, pre-amp and lm3886 Gainclone together for the first time. I have which wasn't shown in the earlier parts of the thread dispensed of the output stage of my DAC and am soley relying on the pre for this.
Audio quality is good though it lacks a certain punch that the opamp i managed to blow provided, so i still need to get an OPA2134 from the bay and this should rectify the god awful stock one im using now! While im at it i need to replace 4 electrolytic on my pre's output stage for new poly caps, then some modu shop cases will be ordered by Christmas or January time depending on how brave i feel i am regarding the postal service over the holidays.

I also have my itouch sorted for vandalising ready to be the main music management of the system, just hope i can build it in to a high quality as i feel that will make or break the project.

So things are moving if not a little slower than id like, ill try and get some pics up as soon as i can find the blasted camera lead to upload the pictures.

By the way loving the tube work, really does give a unique character all its own to projects, looks pretty damn sessy aswell!!
 
Soldato
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well finaly got round to looking at muy dac again. seems the guy i got from sent the wrong diagram, as the power socket didnt have any markings on i followed the guide. stupid newbie mistake i made following it wired live to earth and earth to live i should have known better. no idea how it worked first time round like that. new socket from ******s had the markings for which wire goes where. all working fine now.

still tempted to sell my cmoy and try my hand at the starving student amp
 
Soldato
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i wish to start right now and place the order for the parts from mouser. just stuck for time atm


well in any case got the tubes, the holders for em and psu off ebay.
 
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Soldato
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a dark place
spent a day and a half pondering over it decided to go for it. guess its time to wave goodbye to cmoy. wish me luck.
also as luck would have it ended up with all the parts of a gainclone kit bar the psu and case for nowt
 
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Soldato
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a dark place
wow talk about good service. mouser an american company shipped items to me in 2 days with free shipping was expecting it to be here just before new years day.

compared to the cisco psu off ebay still not delivered yet.
 
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