Audio Note SUT (again)

So you’ve posted a thread about the appearance of this, claiming not to be worried about its appearance?

:thinking:

Stop being a derponaut - strip and polish the copper bit, lacquer it and maybe, just maybe ask Edd politely if he’ll CNC a new front plate for it. The wiring looks fine in your pics.

Haha, there was even a specific thread for all AN products in the other place called ‘Built by Badgers’ :grinning:

“Built by badgers - sold by weasels” :zipper_mouth_face::face_with_symbols_over_mouth::face_with_symbols_over_mouth::face_with_symbols_over_mouth:

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:heart_eyes:

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:thinking:

Acceptable

:smirk:

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Some of the AN silver cable can be a bugger to solder, be careful.

According to James at Audio Note it is a very old (1990’s) Audio Innovations S3.

He’s wrong. I was there. I know what was made & what wasn’t. The last AI transformer (T2) actually moved away from that format and the company never made a copper chassis variant.

image

When AI moved to Weymouth in about 1992, PQ stayed in Brighton & started manufacturing under the AN UK name. This will have been one of the items made at that time obviously still using metalwork from Brighton Sheet Metal or whoever it was who’d been doing those boxes for AI.

I’ve had a similar issue recently trying to establish the provenance of an Io Ltd power supply which comes from the same era. ANUK say they didn’t make it & don’t recognise it but the internal parts shout UK not Japan manufacture as does the look with gold printing & knobs. Japan definitely didn’t make this so who else would have?

It’s actually quite a cool thing with a charging circuit & 3 selectable batteries (one of which is fecked but a replacement just arrived)

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It is quite a colourful period in the AN UK history and I would imagine that PQ is the only constant through the various stages

Re the STU i wiuld agree with Guy, it is almost certainly an early AN UK unit

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Spoke to Peter Q today and he said the same as you but thinks it may have been an employee build from spares or bits they pinched as the case has no writing on it.

He said he recognises the label on the transformers which place it as one of the very first silver S3’s made as the company that supplied them are long gone now.

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Should be the last question, I don’t see any loading resistor on the output of the SUT and although it works it does sound a bit shit.

If I’ve got a 1ohm cart and the SUT is 33dB which equals a step up of 45x I calculate I’ll need a 2100 ohm resistor in parallel to provide the 1ohm load to the cart.

Closest I can find is a 2.2k one and nice and foo’y from audio note

https://www.hificollective.co.uk/catalog/res351w2k2nm-audio-note-tantalum-nonmagnetic.html

Can someone check my maths and confirm I’m not talking bollocks (as is generally the norm)

My spreadsheet agrees with your numbers

But is 1ohm the output impedance of the cartridge ? Or is 1ohm the load impedance that the cartridge needs to ‘look into’ ? If you put a 2200 ohm resistor on the secondary of the SUT then 1ohm will become the input impedance of the SUT primary i.e. the impedance that the cartridge looks into. Usually cartridges like to look into an impedance which is a few times (sometimes people say 10 times, or more) larger than the impedance of the cartridge itself.

VB

The coil impedance is 1ohm so I assumed I’d need to match that for max power transfer.

Looking at the spec for the AN-S3 on the audio note site it says the L version for the Io is 1 ohm.

The spec on @Ciderpig website says the loading should be 3-4 ohms for the Io though

Me is confoosed :thinking:

^^ this

^^ also this

IIRC

Matched loading should indeed give max power transfer. But it’s not clear that that’s what will get the best out of the cartridge (or any source for that matter). It will only deliver half the source voltage, for instance. And it might draw enough current to induce magnetic misbehaviour in the cartridge itself. In the end you can either go with what the manufacturer recommends or you can try a few different resistors and see what works best for you.

VB

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Bollocks to faffing about with different values, I’ll go with what it says on Jacks website.

Fuck me, first time a dealer has ever given good advice.

Cheers.

I’d actually aim to have it showing 7-10 Ohms.
Put a 30K resistor across the 2ndary.

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Doesn’t that strange Japanese thing mean that the 1, 3 and 40 ohm settings on an SFz really represent 10, 30 and 400?

Therefore corroborating your 10 Ohm recommendation

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Cheers, 2x 33k tant resistors ordered :slight_smile:

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