Upgraded AirPort Express power supply LM1117

[Jayzee2912]

Hi everyone

I searched a long time for a good sound on my system

System:
Accuphase e205 amplifier with Van Damme Lcofc hifi Cables 2,5 And Dynaudio floorstand speakers Excite X32

I had a Bluesound Node n100 streamer And streamer Spotify lossy files And wanted to play lossless so decided to stream with Apple music (now to try for free for 4 months
Than i searched for a streamer for Apple Music And came out at the Airport Express A1392 (last generation) with AKM4430 Dac chip in it
After reading a lot about to change the standard Power supply Build in into a seperate supply external i Build after searching And trying a lot this unit (see pictures)
As they said that it will make a hugh difference and peoples talked over the internet about a audiophile high-end dac i was sceptical about it

So I wanted to use the Apple IPad charger as L.P.S. with very low ripple and noise, regulated on the entrance (220) as it work well as a low cost power supply 5V

In the AirPort express I took out the original power supply and build a print with the LM1117 voltage regulator to regulate 3,3v needed for the AE to work
2 ceramic condensators of 100nF at in and out for distortion filtering a cap (normal Panasonic) of 10uF at the in and I had in my collection from an old tv a cap from Philips 100uF (audio appl) with low ESR for the output

So I was very curious and do the test ..

Well, i must say that this is a releave for me … the sound is superb with everything i ever wanted in it!!

Depth, detail, warm and clear sounding together what I hadn’t got in the paste!

Everything can change and also can be better but for know I must say that I am a happy guy 😁😁😁

Anyone with remarks? Anyone who did also changements to an Airport Express?
Please share

Greetings Jayzee 2912

 

[linuxfan]

An interesting upgrade, though I wonder if it wouldn't be better to use an LT1963 or TPS7A4700 regulator.
It's good that you have squeezed extra SQ from the onboard AKM4430 DAC ... but with Accuphase amp & Dynaudio speakers, I think your system deserves a high-end DAC instead. Just use the optical s/pdif output from the AirPort Express.

 

[Jayzee2912]

Hey Linuxfan

Thanks for reply, i used this 1117 just because it is used a lot and from reviews

I know but i could buy this all in occasion
The amp is from 1986 en speakers a year of 9 i think but sounds very good

I was wondering if there is a very good dac to put on that is not expensive, do you have recommendations? Maybee fiio D3?

Thanks a lot

 

[brig001]

Interesting upgrade and might try that - I have a few around the house
Recently bought a Belkin Soundform Connect for the main system, and can recommend that as an upgrade on a unmodded Airport Express. Don't know how it would compare to your modded version though
Thanks for sharing

Brian

 

[Jayzee2912]

Hey Brik001

The Belkin is new for me .. wich dac chip it has?

The AE is a big difference now believe me ����

Grtz

 

[linuxfan]

I was wondering if there is a very good dac to put on that is not expensive, do you have recommendations?

$150 seems to be the entry-point for a decent DAC, but these will only bring an improvement over cheap/bad DAC's. I suspect that $150 DAC's will give you little or no improvement over your upgraded internal DAC.
For you I was thinking about Topping D90SE ($900) or SMSL SU-9 ($460) or maybe even Topping E50 ($270).

Maybee fiio D3?

I suspect your upgraded internal DAC will be better than a FiiO.

 

[brig001]

The Belkin is new for me .. wich dac chip it has?

I can't find anything about the DAC chip online. Looks firmly stuck together too, so I don't think I'll be opening it to find out

Brian

 

[jean-paul]

The LM1117 is one of the more noisier regulators available. It is way better than a switcher but please note there are many LDO regulators with less noise and better specifications.

You have experienced the joy of linear regulation, now find out the finesse 🙂

 

[Jayzee2912]

An interesting upgrade, though I wonder if it wouldn't be better to use an LT1963 or TPS7A4700 regulator.
It's good that you have squeezed extra SQ from the onboard AKM4430 DAC ... but with Accuphase amp & Dynaudio speakers, I think your system deserves a high-end DAC instead. Just use the optical s/pdif output from the AirPort Express.

Hey Linuxfan

I just looked at the specs of the 2 regulators you mentioned
Here is the result of the output generated noise for the 3 regulators:

LT1963 : 40 uV RMS
TPS7A4700 : 4,17 uV RMS
LM1117 : 30 uV RMS

So the TPS7A4700 looks nice i am between the 2
The TPS is adjustable so doesn’t it generate more heat?
Keeping in mind my amp which has a SN ratio of 86 would it be hearable with the TPS reg.?

Thanks for info

 

[jean-paul]

That noise number of LM1117 is not right I think. It was around 90 to 100 µV when set for 3.3V output voltage.

Either TPS7A4700 or LT3045 will let you squeeze out the maximum. "A device is as good as its PSU"

 

[linuxfan]

I didn't mention LT3045 because I assumed the AirPort Express had a too-high current draw at 3.3V ... but now I see that possibly the AirPort Express has both a 5V rail and a 3.3V rail, so maybe the current draw on the 3.3V rail is quite modest? Sorry, I don't know the full details of your device.
Provided current draw on the 3.3V supply is no greater than 500mA then you can use any of the 3 present "champions" of low-noise regulators - LT3045, TPS7A4700, or ADM7150.
I can't guarantee that those regulators will be drop-in replacements for your present circuit - they may require different circuit design with different capacitor values - jean-paul is the expert in this area.
If you are happy not to go full DIY, you could use one of these boards -
LT3045-M Ultra Low Noise LDO Voltage</br>Regulator
TPS7A4700-78XX Ultra Low Noise LDO Voltage Regulator

The TPS is adjustable so doesn’t it generate more heat?

The TPS7A4700 can be configured for adjustable voltage by using two external resistors, but that's not correct for you - you want a fixed output of 3.3V, configured by shorting the relevant programming pins from pin 4 to pin 12. See the datasheet. Heat is a product of Vin - Vout, x current. That's the same for all regulators.

Keeping in mind my amp which has a SN ratio of 86 would it be hearable with the TPS reg.?

Numbers don't always translate to what we hear, despite what they may tell you on the audiosciencereview forum. I consider it likely that a regulator upgrade will improve the sound of your AKM4430 DAC ... but there's no guarantee.

 

[Jayzee2912]

Finally decided to built an lineair power supply to deliver the 5v 😁 much better than the apple little supply