An Amplifier For The Computer

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simon
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#1 An Amplifier For The Computer

Post by simon »

I could do with a small amplifier to use with the computer - absolute fidelity isn't required, just decent(ish) sound, small(ish), and cheap(ish).

My first thoughts were valve, obviously, and I thought it was time I finally built a proper 6EM7 amp. And maybe I should. But once I'd factored in a pair of nice OPTs, a decent mains trafo and at least one choke I was looking at over £200 on iron alone. So maybe not right now.

So perhaps I should dip my toe in to the mysterious and dark world of the three legged things (I'm scared!). I know next to nothing about solid state stuff and absolutely nothing SS amps so all advise here is appreciated.

Are there any decent kits out there worth looking at? Nick's F6 sounded great at Owston as did Ali's amps, both are probably more money/complicated than I'm looking for. The Naim clones of Richard's are perhaps another option, though I don't know how much they are.

T amps are/were about £30 IIRC, any digital amps worth considering? What sort of money do I need to be spending to get me going? Under £50 would be good - is that realistic?

It's a frightening solid state world out there and I don't mind telling you a feel a bit dirty even considering this - I need help and reassurance!
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pre65
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#2

Post by pre65 »

I'd go on e-bay and search locally (there is a nearest option in search) to see what's in your area.

I use an old QED A240cd amp which I purchased new eons ago, it does the job for me.

If I was spending hours at a time listening then I'd probably resurrect my old valve pre and my original DIY amp, the 832a PP.

Did I ever mention my DIY computer monitor speakers ? :wink: :lol: :lol:
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Mike H
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#3 Re: An Amplifier For The Computer

Post by Mike H »

simon wrote:So perhaps I should dip my toe in to the mysterious and dark world of the three legged things (I'm scared!).
:lol:

Are there any decent kits out there worth looking at? Nick's F6 sounded great at Owston as did Ali's amps, both are probably more money/complicated than I'm looking for. The Naim clones of Richard's are perhaps another option, though I don't know how much they are.
Unless I misheard, I believe it's an F5. Reckon that's the simplest, there's hardly anything in it. Will need sizable lumps of metal as heatsinks, but that's the only complication AFAIK.

The Naim clone is a more traditional design and many more components involved. But an archetypal design that's been around for donkeys years, so is well proven.

Only thing to watch out for is bias adjustment, if there is any, can easily blow up o/p trannies by winding it up too enthusiastically. Guess how I know :lol:

Which is why while I was setting up the germanium amp I used a current limited supply.

Second thing to be careful of is soldering the semis, they don't like it too hot. Same precautions as for diodes basically.

HTH
 
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Dave the bass
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#4

Post by Dave the bass »

Howsabout...-> http://www.ebay.co.uk/itm/TDA2030A-Audi ... 33732f86a8

I've built 3 of 'em, 1 for the garage, 1 for the shed (aka. 'The Home of Tone') and 1 as a just-in-case-I-need-a-spare-amp. They run off discarded SMPS's. Tiny but Loud and proud. Nothing flash. Sound good TBH.

Threadage here -> http://www.audio-talk.co.uk/phpBB2/view ... highlight=

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al newall
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#5

Post by al newall »

Simon.

I've got a spare Tripath T2020 board if you want to have a play, before committing to anything. They all sound similar, so it will help you either cross it it off your list or maybe you'll like it.
Just needs hooking up to 12-13v dc, and a pair of input caps.
Much to learn there is.
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#6

Post by simon »

£5.69 including shipping?! Where's the catch Dave? I got some screening cans from Sowter a few Weeks ago and they charged me more for postage from Ipswich. Don't really know what an smps is?

Thanks Al, it would certainly be interesting to try the Tripath.
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pre65
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#7

Post by pre65 »

SMPS = switched mode power supply.
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al newall
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#8

Post by al newall »

simon wrote:
Thanks Al, it would certainly be interesting to try the Tripath.
PM your address Simon, and i'll put in the post.
Nothing lost if it doesn't fit the bill.
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Dave the bass
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#9

Post by Dave the bass »

simon wrote:£5.69 including shipping?! Where's the catch Dave? Don't really know what an smps is?
No catch, they arrive in kit form in a jiffy bag from Hong Kong. Easy to assemble, tracks on PCB are OK but lift easy. No glam components natch.

Yep, as our-Phil says, switched mode PS, I used a couple of spare old printer or laptop PSUs, 19V ish on the 3 I built.

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#10

Post by simon »

pre65 wrote:SMPS = switched mode power supply.
Mmm, yeah, but what does that actually mean? How do I get one? I don't have any spare laptop power supplies so I'm going to have to buy something or make something.

Dave, the schematic looks like it has a bridge and filtering on board, but if I understand correctly you ignored this and just hooked your laptop supply to VCC? Looks like it needs 24VDC (at how many amps?)?
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Dave the bass
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#11

Post by Dave the bass »

Yeah thats right Simon, I didn't use the Bridge rectifier or a TX, I had those spare laptop PSU's to hand so just used them to save 'em going in the WEEE bin (and it saved me having to buy 3 x 18V TX's).

From the eBay advert its says...

The input voltage: AC≤18V DC≤24V

Output power: Poï¼￾15W+15W(RL=4Ω)

Output impedance:4- 8 Ω

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Ali Tait
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#12

Post by Ali Tait »

Simon, just buy a cheap wall wart supply that has universal fittings. They are only a few quid from Maplin or the bay or similar.
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#13

Post by simon »

Yeah, that's what I was thinking Ali. I have one from Maplins but it's powering my NAS drive. This cheap amp project's going to be quite dear by the time I've bought a power supply, box, phonos etc. Possibly over £20, maybe £30 :lol:.
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Ali Tait
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#14

Post by Ali Tait »

Check out the Lepai t amp on the bay, can be had for about 23 quid from a UK seller with power supply. Should sneak in under budget!



:D
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pre65
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#15

Post by pre65 »

Ali Tait wrote:Check out the Lepai t amp on the bay, can be had for about 23 quid from a UK seller with power supply. Should sneak in under budget!
:D
http://www.ebay.co.uk/sch/i.html?_trksi ... &_from=R40
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