Inductors

[Wakefield Turntables]

I need to make a couple of inductors out of solid silver, yes it has to be silver and not copper. I understand virtually zip about inductors so I will explain my problem. I need 1mm solid core silver but it has to be enamelled, trying to find 1mm solid core enamelled silver is proving pretty difficult. I can find 0.5mm solid core silver, so here is my extremely dumb ass question. Will I get the same effect of the extra 0.5mm diameter by using either a magnet twice as strong, or long, or by using twice the number of coils with 0.5mm solid core around the magnet. Oh dear, this just sounds so stupid. :doh: Sorry for my sorry ass explanation, I'll understand if you want to laugh me out of the forum. :door:

[karma67]

could you not make the inductor in the right gauge wire and then dip it in varnish?

[Barry]

Why do the windings have to made from silver?

[Firebottle]

Hi Andy, if you don't ask questions you don't learn.
The core material (not a magnet as such) will affect the value of inductance. You don't just double the number of turns to double the inductance as the relationship is non linear.

What value are you needing? ^^ that was my next question.

[Barry]

Hi Andy, if you don't ask questions you don't learn.
The core material (not a magnet as such) will affect the value of inductance. You don't just double the number of turns to double the inductance as the relationship is non linear.

What value are you needing? ^^ that was my next question.

Agreed. Inductance tends to vary as the square of the number of turns, since inductance is the total number of flux linkages per unit current. But it is in general more complicted than that, and depends on the winding density (and number of layers), diameter of the wire, and core diameter, amongst other things.

There is information available on coil winding and formulae to predict the inductance of coils. The most comprehensive is one written by the National Bureau of Standards in the US. I'll see if I can find its exact title and ISBN.

[Pharos]

The diameter of the wire is related to the current which flows; too thin and it might overheat.

If you double up, by having two wires running in parallel, the overall bulk required to get your specified value of inductance may be too great, and achieving a consistent packing on the wind will be difficult..

Doubling the length will (very approximately) double the inductance value, which I think is not what your application will require. Why do you want silver? Are resistive losses that significant?

[Barry]

A 1 mm diameter wire will have a current carrying capacity of several amps. Why does the wire have to be so thick, and why does it have to be silver?

[Wakefield Turntables]

Its a couple of inductor coils in the paradise phonostage, currently I have pure copper, so decided to go down the route of Silver, we are just experimenting to see if it has a positive impact on what we hear.

[Wakefield Turntables]

Guys, I'm not sure about values or anything else, hence my ignorance. I'm trying to just solve a sourcing problem as we cant get the 1mm silver, so, I'm looking at ways of maybe using 0.71mm diameter, oh dear, I'm a little out of my depth.

[YNWaN]

There is no magnet in the inductors you are referring to Andy, they are air cored. By all means source the wire, but I would leave the winding to Si who has done the necessary maths and has wound a whole bunch - he does a really outstanding job too.

[Barry]

Well that should be straightforward; make a 'Chinese copy' of the inductor: count the number of turns, measure the core diameter and measure the diameter of the wire.

Is the wire daimeter really 1mm - that seems very thick to use in a small signal current circuit?

[Light Dependant Resistor]

The diameter of the wire is related to the current which flows; too thin and it might overheat.

If you double up, by having two wires running in parallel, the overall bulk required to get your specified value of inductance may be too great, and achieving a consistent packing on the wind will be difficult..

Doubling the length will (very approximately) double the inductance value, which I think is not what your application will require. Why do you want silver? Are resistive losses that significant?

Inductors in series is L1+L2 , Inductors in parallel is L1xL2 / L1+ L2

In some circuits what appears plainly physically as an inductor is actually deployed as a resistor, this is usually used in filter circuits and referred to as a FDNR
which is a Frequency Dependent Negative Resistor Circuit. It also occurs in some power supplies where loads are grounded using inductors, that
then transform to be resistors.

[Wakefield Turntables]

There is no magnet in the inductors you are referring to Andy, they are air cored. By all means source the wire, but I would leave the winding to Si who has done the necessary maths and has wound a whole bunch - he does a really outstanding job too.

He dosen't have any left, and I want a pair! That's why I'm asking dumb ass questions to try and get a pair organised!!!! :sofa:

[Barry]

It might help if we could see a photo of the inductor you wish to replicate, and if possible know the value of the inductance.

[karma67]

He dosen't have any left, and I want a pair! That's why I'm asking dumb ass questions to try and get a pair organised!!!! :sofa:

why dont you leave it to simon as already been said,surely if he makes them he can buy some more wire??

[Wakefield Turntables]

He can't source any more silver in small enough quantities hence all the questions, otherwise he'd be my first port of call.

[Pharos]

If the coils in the phono stage are in the signal path, the currents will be tiny, but maybe more if in a power supply circuit, but still unlikely to be of the order of amperes.

[Wakefield Turntables]

ok, here's the inductor coil on the Calvin board of the Paradise.

26036

[Columbo]

These do a 18AWG which is 1.02 mm. It's not enamel but their own special dielectric which they seem to say is better than P.T.F.E. At $28a foot, hardly inexpensive.

http://vhaudio.com/unicrystal-occ-silver-wire.html

If it were me, I'd get the 1mm plain silver wire and give it a couple of coats of nail varnish; whatever colour took your fancy. Less than 18" would probably be the length for one.

[Primalsea]

You could try just winding the inductors with uninsulated wire and then sliding small squares of a thin insulating material like mylar heatsink insulators in between each wind to separate them. If you cut through to the holes in the insulators there will be no electrical contact between sections as the cutouts will interlock with the wire.

[Bksabath]

Use just normal Wire the coil is just there to stop oscillation and I never seen 2 of Simon coil that are the same they seem to get longer and whit more turns as time got by
Not criticising that is the way it is and if it works it works and I am sure Simon Know when it does and by the way yes I must confess and came out of the closet I had a look a lot of them that is just HiFi porn :D

but if you insist gogle up Advent materials the got it all. (well almost all one can imaging apart from copper plated silver but if one ask for it... I have used the insulated silver wire to make interconnects in the past There is no much current going trough that coil and the resistance is negligible the only thing is thick wire keep it's shape

[Light Dependant Resistor]

Use just normal Wire the coil is just there to stop oscillation and I never seen 2 of Simon coil that are the same they seem to get longer and whit more turns as time got by
Not criticising that is the way it is and if it works it works and I am sure Simon Know when it does and by the way yes I must confess and came out of the closet I had a look a lot of them that is just HiFi porn :D

but if you insist gogle up Advent materials the got it all. (well almost all one can imaging apart from copper plated silver but if one ask for it... I have used the insulated silver wire to make interconnects in the past There is no much current going trough that coil and the resistance is negligible the only thing is thick wire keep it's shape

Inductors are usually used to control current in a circuit. Oscillation is a manifestation of applying positive feedback. Whilst inductors are found in oscillator circuits
their purpose is multifold, but includes as oscillators in RF circuitry, combining with relatively small values of capacitance to form what is called a tank circuit.
A tank circuit though is not stable enough to maintain frequency without added components - it works, but it also drifts up and down with temperature.

Up to 15 Mhz inductors can be wound on toroids - which begs the question ( there's always a question ) why air Cored inductors are preferred in
speaker crossovers. It may suggest a return to toroid inductors for crossovers rather than barrel types, and care with adjacent components given
that inductors create a magnetic field.

Audio frequency circuits using inductance are more likely to be combining inductance with capacitance for power supply filtering. The power supplies seen in the
Quad 2 valve amp, as example relied heavily on inductance. This was tied to the fact that capacitors were not available then with large amounts of storage.

The inductor remains a valuable component in audio purpose circuits to control current.

[Bksabath]

Maybe it would help if same one could post a SCH of the Calvin Buffer I have been looking for it but I have to much staff in the puter to be able to find it.
Below is a link to the Silver PTFE insulated wire Price is quite interesting if one get the 50 meters
https://www.advent-rm.com/catalogue/silver/insulated-wire/AG5500/

[Bksabath]

There was a few days ago a listing on Ebay for same surplus silver wire 0.40mm and it was sold by the meter whit a cotton braid over it as is not insulated By the same dude that make those

https://gekkocables.com/products/silver%20lining.html

That listing is not there anymore, probably because I got the last 10 meters of it :lol: but it may came up again
Is the one in Advent as posted what you are looking for ?

would 0.4 uninsulated do you maybe whit a silicon tube or heat shrink sleeve over it ?
maybe in this case you can get one of the Gekko cables and chop a bit of it :D

look for audiosopuk (seller name) or Gekko interconnect on Ebay

[Wakefield Turntables]

Thanks for the heads up Sandro. ;)

[337alant]

The inductor is L1 in the calvin buffer and its value is stated as 10uH (10 turns)
The current draw of the Calvin is only 30ma
The inductor is in parallel with the output resistor R14 27 ohm (Zobel)
Manual is here https://www.diyaudio.com/forums/group-buys/239776-calvin-buffer-paradise.html

Alan

[YNWaN]

@AnDreW, I suspect that, on the whole, you regret ever asking this question now.... .. .

[Wakefield Turntables]

The inductor is L1 in the calvin buffer and its value is stated as 10uH (10 turns)
The current draw of the Calvin is only 30ma
The inductor is in parallel with the output resistor R14 27 ohm (Zobel)
Manual is here https://www.diyaudio.com/forums/group-buys/239776-calvin-buffer-paradise.html

Alan

Alan, thanks for the post. Might as well be in Mandarin (no insult intended). Is it possible to have a version those of us that are a bit thick in this subject?????? :scratch:

[Wakefield Turntables]

@AnDreW, I suspect that, on the whole, you regret ever asking this question now.... .. .

Yep! My Paradise is out, waiting for Si to update with a raft of upgrades. Is he away! Also, what about the 3D printed covers that your offering, are they still available. Could you send me a PM?

[337alant]

Andy
The ones that Si has made look like 19 turns arround a 7 or 8mm drill bit, why not just copy that, looks like 0.5mm wire as well ?
Just stick the drill bit in a vice and start winding like this

https://live.staticflickr.com/4831/31844833008_3d1889e62c_c.jpg (https://flic.kr/p/Qw26oY)1.Winding on Drill Bit (https://flic.kr/p/Qw26oY) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

Alan

[Wakefield Turntables]

Alan, firstly many thanks. Si claims you need 1.00mm wire and you can't source it for love nor money unless your prepared to pay for many meters of the stuff. I can find 0.71mm but he's pretty sure that 1.00mm is the only way to go. It would be easy to make slight larger inductors with the 0.71mm stuff but he's not keen.

[337alant]

Andy
looking at the calvin build notes the one shown in the picture looks nothing like 10uh

Good info on inductance
https://rimstar.org/science_electronics_projects/coil_design_inductance.htm
Alan

[smangus]

1mm silver wire £5.99 for 1 foot (30 cm)

:)


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[Wakefield Turntables]

From technical point of view this coil is not necessary in that position , I assume Calvin's intention was to reduce an overshoot with low impedance loads like headphones for example as buffer is universal and can have different applications .
Certainly it don't hurt to use RL filter in Paradise , I assume values from 1uF up should be fine , exact value don't really matter .
I will send an e-mail to Calvin to confirm if I'm correct on this .

Thanks Slav.