1H and 100mH single inductors

[Tubetec]

I was able to get 100mH on a Mullard FX2240 pot core with 0.3mm magnet wire ,
the insulation was damaged as i wound it though ,so I suspect a few shorted turns ,
measures around 3 ohms dc ,
I have some 0.1 mm wire that might get me in the right ball park .

Mostly you see a brass screw securing the pot cores , I was wondering how the core properties might vary using different materials like iron or nylon screws to secure the assembly .

An iron core might have a more forgiving overload at low audio frequencies , ferrite seems generally only reccomended down to 1khz ,

 

[Tubetec]

The exciting thing about making inductors is you can exercise control over the alchemy to create something more than just the sum of it parts ,

I was hunting around for a filter calculator for audio , where all the rellevent factors have an input field , that only gets you so far though , it tells you nothing about how your filter sounds under real world conditions .

 

[thomasdf]

I can confirm the 1H Mesa inductors work well in the few circuits I've tried them. The last ones measured about 600 ohms. For $5 they are a steal.

Thanks !!! I’ll give them a try then

Edit : arg, shipping is a real downer… 57USD to France

 

[scott2000]

Came across this..

https://www.talkbass.com/threads/acoustic-320-graphic-eq-repair-3h-inductors.810974/

 

[ruffrecords]

Came across this..

https://www.talkbass.com/threads/acoustic-320-graphic-eq-repair-3h-inductors.810974/

Interesting. I believe the very earliest bass inductors used on the Helios 69 EQ were small transformers purchased from one of the many electronics shops in Tottenham road so there is no obvious reason why they would not work in a pro circuit.

Cheers

Ian

 

[thomasdf]

I've always assumed that these Xicon worked okay at instrument level for very small DIs, wah inductors and such, but would saturate on line levels due to their poor / small build ?

 

[ruffrecords]

I've always assumed that these Xicon worked okay at instrument level for very small DIs, wah inductors and such, but would saturate on line levels due to their poor / small build ?

That is always a concern but first we need to know if the inductors actually see anything like line level in the EQ circuit. I am not familiar circuit being discussed but if the inductor is in a negative feedback loop the levels it is exposed to could be very small.

Many of these small transformers are a lot better than their spec would lead you to believe. The specified transformer is a 10K:10K type according to the Mouser data sheet. I have used a Triad 10K:10K transformer of very similar dimensions o provide a balanced floating input to a VU meter buffer. Distortion is not much of an issue in this application but bandwidth and saturation levels are. From my own measurements of the Triad transformer I found its response is flat up to 20KHz and it would not saturate at levels in excess of +8dBu (which is the meter pegged to the stop) at mid range frequencies. Transformer distortion/saturation in all cases is never really a problem above 100Hz. The Zicon transformers are specified for a power of 200mW which tells us very little for a 10K transformer but for a 600 ohm one it represents +32dBu.

Cheers

Ian