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What PSU for Air guitar-iste Preamp

new naim boy

pfm Member
I have just put together an Air-guitar pre, as described on the Acoustica web-site. I just wondered what PSU to use. After all the recent posts about different types of reg lately there seems to be various options:

1: 2 x ALWSR as specified on Acoustica site.
2: Traco 30V supply and no regs with 0V close to 0V of Traco a la Mr Tibbs.
3: 30V Traco followed by two Teddy regs dropping down to 24V.
4: Linear supply feeding two Teddy regs with 30V out.

I'm sure some have built one of these preamps and wondered what PSUs have been used and prove to work well.

Aidan
 
Yes, thanks Jim. I should have put ALWSRs as an option (now rectified).

Unfortunately, I don't have the bits to build the ALWRSs to hand so it wold be a costly solution.
 
Over a year ago I made a PCB and collected the parts for this preamp. I didn't use it as Jim announced the Starfish. The Starfish now complete left me wondering what to do with the Air Guitar-iste PCB. So I decided to finish the job. I finally pluged in and connected a laptop 24V supply last weekend.

The results are absolutely astonishing. :D:D:D:D

A big thank you to anyone involved in the development of this preamp.

The design is minimalist. It took me about an afternoon to solder all the parts onto the PCB.

If there was ever a giant killer of a preamp this is it.

I'm now going to experiment with different PSUs.
 
Aidan,

did you populate the relay section? If so what value zener did you use on D3? I cannot find reference to it anywhere.

I'm going to power mine with a pair of ALWSRs that I just happen to have lying around unused for a while. But the TeddyReg options sounds good to me too.

Neil
 
I run my Air pre with 4 x HP (not switch mode, unregulated) printer PSUs into 4 x VBE + 4 x ALWSR. i.e 2 supplies per channel, split as per the starfish schematics if that makes sense......

The HP PSU gives about 35v but sits down as you load it. The fet based VBE drops around 4.5v, super reg set to output 25.2V. These HP printer PSUs can be used but only if you don't load them with a full preamp, hence the problems other people have reported and partly why I use 4 of them.

How this compares to the likes of hicaps, hicap clones, teddyregs etc I'm not sure. I'm happy though, and have no desire to seek another solution. Although I may try a split rail supply version in the future.
 
...I run my Air pre with 4 x HP (not switch mode, unregulated) printer PSUs into 4 x VBE + 4 x ALWSR. i.e 2 supplies per channel...

midcm,,,why 4 - what two other sections are you powering? Mine has only the 2 gain sections. Is there another version of the Air-G too?
 
Hi Neil,
sorry but I have not used the relay section. I get a big thump when I turn on my power amp so always turn on the pre first.

The Air-G is sitting on a shelf at the mo taking a back seat to the Starfish. I plan to put it in a decent box and build a second system around it though.

I have been so amazed at what the Sigma PSU's can do I'm going to turn my unregutated supply into a 30V Sigma11. It will be interesting it to compare Teddyregs.
 
midcm,,,why 4 - what two other sections are you powering? Mine has only the 2 gain sections. Is there another version of the Air-G too?

Hunt down the starfish gain board schematics and you'll see the supplies are split albeit by a +/- supply. Teddy Pardo has also suggested something similar using VBEs for each transistor.
 
I think I managed to find it. The original Naim part is a ZX070 - at least in my NAC72. And it's a DO-41 6.8V 1W ZENER.
 
I run my Air pre with 4 x HP (not switch mode, unregulated) printer PSUs into 4 x VBE + 4 x ALWSR. i.e 2 supplies per channel, split as per the starfish schematics if that makes sense......

How this compares to the likes of hicaps, hicap clones, teddyregs etc I'm not sure. I'm happy though, and have no desire to seek another solution. Although I may try a split rail supply version in the future.

At present I'm using two Teddyregs. It will be easy to add another two, but where exactly to add them I'm not sure. Is there a schematic of the AirG anywhere? I can't seem to find it on the Acoustica website.

While I'm at it I may aswell look at making it split rail aswell.
 


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