*** The DIY Audio Thread ***

Soldato
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17 Jan 2006
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Seeing all the lovely things people have put together on here, I wondered if there was anyone on here who can repair hifi equipment (ideally in kent...) As my Marantz CD players analogue output has died on me and I'm fairly certain it's just broken solders but it's a bit beyond on my skills...lol
 
Soldato
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Thanks r2d2!

The Pluto speakers are supposed to be surprisingly good, will be interesting to hear what you make of them.


Did a quick demo with drums, only source material I really have to use with it!


Will sound best watched on youtube in HD or at least 480 :)
 
Associate
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21 Oct 2002
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cant remember if i ever posted this....


valve amp v2 by adamau5, on Flickr

sounds great, easily the best sound quality from a piece of kit i have made. A nice mixture of modern solid state and old german valves (d3a). parafeed circuit loaded with solidstate gyrators.
 
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Associate
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Manchester
Anyone here who thinks they might be able to repair an amp? I've got two Mordaunt short 309i Subwoofers here and both have the same problem with the amp. Some components seem to be fried/burnt. Looks like two capacitors and an inductor, same on both amps!

Can anyone help? Thanks!
 
Soldato
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London
Thanks r2d2!

The Pluto speakers are supposed to be surprisingly good, will be interesting to hear what you make of them.

Given me and two friends are waiting for the new boards to arrive and we've sourced all the necessary parts, I'll let you know when they're done! ;)

Given they retail fully made for $4K and we can make them for around $1K, I'm expecting good things.
 
Soldato
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I knew i could remember a DIY audio thread but didnt realise it was so old!

Have started my Wilmslow Audio speakers over the weekend. I had the cabinets made for me which is a bit cheating but with precision generally being needed i decided it would be better. Gone for 25mm birch ply compared to the 18mm MDF which Wilmslow Audio sell which has resulted in some damn heavy cabinets. With the drivers in i'm curious how i'll move them!

I5kMkrS.jpg
 
Associate
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Snipers hide
I knew i could remember a DIY audio thread but didnt realise it was so old!

Have started my Wilmslow Audio speakers over the weekend. I had the cabinets made for me which is a bit cheating but with precision generally being needed i decided it would be better. Gone for 25mm birch ply compared to the 18mm MDF which Wilmslow Audio sell which has resulted in some damn heavy cabinets. With the drivers in i'm curious how i'll move them!

Sexy! I still have some NwAvGuy O2 Headphone amps pcb's to build, i probably can't get the parts anymore as i must have had them for 3-4 yrs.

 
Joined
1 Oct 2006
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13,900
Morning all,

I fancy undertaking a wee project in the new year in the form of a desktop tube amp for my headphones.

Any recommendations for kit/schematics? I've found the Starving Student Hybrid which looks pretty good, but any better alternatives?

Cheers
 
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Lovely looking kit, but about 5x my budget. :D

Case isn't important at this stage as I'll probably make my own, as far as board design is concerned the only aesthetic I'd want is upright protruding valves.

Might as well capitalise on their appearance. :)
 
Soldato
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Hondon de las Nieves, Spain
Just thought i'd dump the finished product in here

rRcc8y8.jpg

Had some problems with the t-nuts (never used them before), where if there was some friction with the bolts, the bolt was pushing them out a little at the back, this combined with the powerful magnets was causing a fair amount of fustration.

Since i didnt want to keep messing up the wood on the inside. I spoke to a guy i know who has built various speakers and popped round to his for a bit of help. He suggested using vaseline on the tip of the bolts to add a bit of lubrication. Also pointed out not to use a cordless screwdriver as there's no feel for whats happening.

Got both speakers built fairly quickly at that point and had about 10 minutes to listen before i had to dash home for my mums birthday.

He's got a set of Ming Da 845 monoblocks and a much more open room than me. The openness and clarity was incredible and a lovely warmth to it which i'm always a fan of. The bass was also surprisingly capable for the 8" drivers being brand new out the box. (This was the opinion from the guy who has some collosal transmission lines for bass!)

Sadly had to pack them up and drive home at that point and that was it for the rest of the day since i had an exam the next day. The next day i managed to get my exams the wrong way round so turned up feeling quite confident, only to realise it was the exam i thought was 3 days later (not the best preparation).

The day inbetween the 2 exams i decided i could spend some time with the speakers. After all i'd done plenty revision for my final exam and had planned this time for the exam i'd already sat. Plus i was home all alone for 7 whole hours. Bliss.

Set the speakers up with my Peachtree Decco 2. This was a temporary amp for me and has a valve preamp stage with a solid state power stage. The valve stage can be switched out if needed and oddly enough this makes it considerably smoother and less muddied. It’s never been the best amp and certainly didn’t sound great. Certainly compared with what I’d heard from the speakers at the other guys house.

Went up to the loft and brought down the Astin Trew AT2000 plus amp I’d bought the week before (it was in the loft to avoid distracting me whilst I was meant to be revising!). Set this up and things still weren’t great. A little too clinical and since I mostly listen to acoustic type stuff I was a little concerned I’d spunked a pile of money to be disappointed. The amp was a decent enough deal though so I knew I wouldn’t lose much if anything if I had to sell it. After a couple hours I was feeling a bit disinterested, especially since bass now seemed to be lacking quite a bit. Went up to see if much air was coming from the bass port and that’s when I spotted the problem. The left bass driver wasn’t doing particularly much. Odd I thought since I was listening to relatively bassy music, although the midrange was moving quite a bit of air. Surely it's not so stiff out the box to barely move! Went over to the right speaker and that was moving much more freely and sounding much better.

Unplugged everything and took the driver out to check the connections were decent. Yep all seemed fine, so I put it back and connected everything up. Nope still the same. Wonder if the driver has got damaged. Unplugged it all again. Got both speakers on their backs and set about swapping the drivers round to check whether it worked in the right speaker. Got both drivers out and that’s when I spotted the problem. I’d wired up the midrange and the bass drivers to the wrong points on the crossover. This would explain why the little 5” driver was working so hard! Sorted that out and went back to screwing everything back in. Praying that no t-nuts would fall out!

Connected it all back up and things were sounding a lot better and less muddied. Still not quite up to the standards I’d heard with the valve amps though, although that could just be a case of them being much further apart than i'm able to give them (although they are currently placed where the standmounts are in the above pic with those speakers moved back upstairs). So I’m currently in the process of buying a World Audio Design KEL84 amp which should give me an idea of whether valves will give me back what I want. If they do then I’ll probably move on all 3 amps I’ve currently got and spend some more time finding out whats best for me, although I reckon something KT88 based will probably do it.
 
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