DIY Audio advice

[Chris Augier]

I'm a relatively new member of Hackspace looking to start my first project: a headphone pre-amp.

I do have some experience with electronics although it's been some years since. I'm really just looking for someone to discuss ideas with and potentially be shown around the Electronics area. I spent some time there this week but it was taking me forever to look for things.

I'd appreciate any help.

Chris.

[Toby Catlin]

I can't help practically but I always want to make one of these: http://www.instructables.com/id/Crystal-cMoy-Free-Form-Headphone-Amplifier/ mostly because they look beautiful.

toby

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[Saif Bunni]

Pop to Hackoustic meetups at the hackspace every last sunday of the month! It's the only audio/sound ish group at the hackspace. you might find someone there who would knows a thing or two about preamps. check hackoustic.org/ for info. 

[Stephen Lavelle]

consider hopping along to the hackoustic meetup - http://hackoustic.org next meetup they have is on the 31st - lots of audio people making hybrid electroacoustic stuff there :)

[Chris Augier]

Perfect! I did search on the wiki but I didn't come across this. Many thanks.

[Chris Augier]

Thanks for the advice.

On Friday, January 22, 2016 at 11:10:57 PM UTC, Stephen Lavelle wrote:

[Chris Augier]

That looks so badass. A little impractical perhaps 

[Peter "Sci" Turpin]

That is super pretty. :)

On 22/01/2016 22:36, Toby Catlin wrote:
> I can't help practically but I always want to make one of these:
> http://www.instructables.com/id/Crystal-cMoy-Free-Form-Headphone-Amplifier/
> mostly because they look beautiful.
>
> toby
>
> On 22 January 2016 at 22:27, Chris Augier <chris....@gmail.com

> <mailto:chris....@gmail.com>> wrote:
>
> I'm a relatively new member of Hackspace looking to start my first
> project: a headphone pre-amp.
>
> I do have some experience with electronics although it's been some
> years since. I'm really just looking for someone to discuss ideas
> with and potentially be shown around the Electronics area. I spent
> some time there this week but it was taking me forever to look for
> things.
>
> I'd appreciate any help.
>
> Chris.
>
> --
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>

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[Billy]

A friend that works in a music shop looked at the design for these.

His only comments were, "It looks great, but it'll be a bitch to repair."

If you're going to build one of this design, build a test one out of cheap components first, then when you're happy with how it runs, then use the most durable components you can buy.

In theory, you should be able to use some form of etching fluid to dissolve the resin to replace a ppoped capacitor, but in practice, it'll be incredibly slow. That's not to mention the fumes from the chemicals.

You might want to consider doping the resin with something that conducts heat effectively, as this would help with heat dissipation, as well as giving the resin an interesting tint.

Have a chat with Sci. He's given me a lot of advice about resin casting.

On Saturday, January 23, 2016 at 12:31:41 AM UTC, Sci wrote:

That is super pretty. :)

On 22/01/2016 22:36, Toby Catlin wrote:
> I can't help practically but I always want to make one of these:
> http://www.instructables.com/id/Crystal-cMoy-Free-Form-Headphone-Amplifier/
> mostly because they look beautiful.
>
> toby
>
> On 22 January 2016 at 22:27, Chris Augier <chris....@gmail.com
> <mailto:chris....@gmail.com>> wrote:
>
>     I'm a relatively new member of Hackspace looking to start my first
>     project: a headphone pre-amp.
>
>     I do have some experience with electronics although it's been some
>     years since. I'm really just looking for someone to discuss ideas
>     with and potentially be shown around the Electronics area. I spent
>     some time there this week but it was taking me forever to look for
>     things.
>
>     I'd appreciate any help.
>
>     Chris.
>
>     --
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>     Groups "London Hackspace" group.
>     To unsubscribe from this group and stop receiving emails from it,
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>
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[tek...@hotmail.com]

As a work of art it's a pretty unique solution, but over and above issues with serviceability pointed out by Billy and others, the main flaw in my opinion is the complete lack of EMI shielding.
You would not want to be running that amp anywhwre near a mobile phone, wifi device, computer, tv, etc.
Unless the circuit has been designed to reject interference wideband op-amps tend to amplify it with aplomb.
Often this interfererence is not measurable within the audio band, but it sure makes the op-amps get hot.

Before building a headphone amp, you'd better check that it's suitable for your headphones.
Music headphones range from of around 600Ohms to 8Ohms. Most consumer cans are around 32-64Ohms so a simple op-amp may be sufficient.
You may want to consider something different if your headphones are outside of this range.

If space and power are not an issue, the best universal heaphone amp i've ever used was a 1979 class-A design by John Linsely Hood.

I still use one with an Audio Precision SYS-2232A and a KEMAR for headphone testing.

Here's a link to someone who has published JLH's designs online.
http://sound-au.com/tcaas/jlhphones.htm

There are easy to build kits of this design on eBay for less than £30

Good Luck!
Hywel

On Friday, 22 January 2016 22:28:10 UTC, Chris Augier wrote:

[Dave Lambley]

I am curious to build one of these, http://nwavguy.blogspot.co.uk/2011/08/o2-details.html

Has anyone here built one?

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[chrisbob12]

@davel - I built one if those, and am very pleased with it. The sound is great, and it even brings new life to my old walkman.