Field Coil cartridges

I think so.

Yes Natasha

Hi, would you mind telling me the following:

  1. Is yours an AN or JPN / Kondo Io Ltd? I’m assuming from your comments that its a JPN
  2. What PSU you using, a Battery based one or a 'mains based one?

Thanks,

nige

Hi, How did you work out the resistor values and what battery cells are you using?

Thanks,

nige

Hi Nige,

Mine is a Kondo version. I have the original kondo (Early version) mains power supply and a battery type power supply.

hi, thanks for the reply.

With the two PSU, do you have a preference as to which is best and for what reasons?

Also, is the Battery PSU a ‘self made’ item or a Kondo version, or did someone make it for you?

Thanks again and much appreciatd.

Nige

Does anyone know how this sounds / performs compared to a ‘normal’! Io Ltd?

nige

The battery supply sounds better marginally… but is more faff.
The battery circuit is basic, perhaps @murrayjohnson would comment further?

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Hi,

thanks, when you say more ‘faff’ is that because of the charging? or something else?

Thanks.

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x2 exchangeable batteries / battery charger / leads / time charging / the odd replacement battery when they get bloated etc … No big shakes but more shakes than nothing.

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AN UK psu appears to be passive linear supply

looks something like: 8-0-8Vac, dual diode full wave rectifier, possibly LCLC psu, with various series resistors to switch between to tweak output voltage, and instructions require measurement at the cartridge pins to set the final value, with dire warnings about exceeding 1.3V

so hardly zero faff, but less so than batteries

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Hi, @sjs.

This is current version they are in the process of finalising a new Signature PSU for the Io Ltd. Supposed to be much, much quieter.

Check out the picture in the last one on this IG post: gigharboraudio on Instagram: "Powered coil low output #audionote_uk IO LMTD Signature insanely good, smooth and musical."

They take a very ‘serious’ approach to their PSU for the Ltd, which is make the ‘simple’ Battery PSU approach so interesting…

nige

obvs we can’t see all of the new psu from the photo, but what is visible is not dissimilar

bigger double C core mains tx, 2 diode full wave rectifier, AN Kasei psu cap instead of Black Gates, bunch of resistors and two chokes. Maybe the secret sauce is well hidden behind the front panel :man_shrugging:

I was wondering if a Tentlabs filament supply board could be an interesting alternative, they are normally used to power filaments on directly heated triodes, however the regular 2.5A version may not be quiet enough for this application, and the low noise version is for up to 1A, rather than the 1.4A required, so maybe it wouldnt do the trick after all.

in the end it is another “how to make a nice sounding dc psu” question, and in this case very low noise is likely to be key

I do have some Thomas Mayer style LCL filament supplies, maybe they would do the trick with some switchable resistors for voltage adjustment?

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Yes, AN spend a lot on PSU development, I understand this is a ‘trickle’ down from the M10 Pre Amp PSU (these are two Meishu sized boxes of PSU) and of course the new AN E Ltd FC speakers.

I understand from someone who has recently heard this new Ltd Sig. PSU, which is not finalized yet, it goes a very long way to solving the noise issues of the current ‘Standard’ PSU.

But its a big old box to fit into a system…

Still dubious it’d actually be better than a yuasa cell.

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Don’t know about noise issues with the AN PSU, I’ve never owned one, but my heath-robinson effort is silent.

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difficult to apply sufficient markup on a Yuasa cell mind

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Mobility scooter power for the win.

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Kevin uses a big Optima Yellow top for the GP Audio Monaco turntable, seems to do the trick

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Hopefully we’ll get to find out one day.