[Giog]

Hi everyone
Presentation:
I've always been a DIY audiophile. I would be very interested to know how to build an inductive audio attenuator, with autotransformer or transformer, to control the analog volume level (type of magnetic iron, calculations etc). Or experiences on commercial inductive volume level controls (Silk, Intact Audio etc).
My experience is based on DACs, preamps and tube amps, triodes, pentodes etc. which I preferred to stereo, solid-state playback systems.
I found little information to build such transformers. Any experience or information in this field is valuable to me.
Thanks in advance to anyone who can help me with this.
John

[FullRangeMan]

Welcome to AC 
This project is interesting, a rare bird, without a reliable schematic you will need many try and error tests.

[Phil A]

Welcome!

[mgalusha]

Dave Slagle of Intact Audio makes really nice autoformers. I have assembled a number of them for myself and friends. I've had zero issues buying from Dave, highly recommended. As for building them, depending on what you buy, it's pretty easy, Intact offers autoformer modules that have the switch wired mounted on a pcb along with the autofomers, just connect them to some jacks and an input selector if desired.

Hi everyone
Presentation:
I've always been a DIY audiophile. I would be very interested to know how to build an inductive audio attenuator, with autotransformer or transformer, to control the analog volume level (type of magnetic iron, calculations etc). Or experiences on commercial inductive volume level controls (Silk, Intact Audio etc).
My experience is based on DACs, preamps and tube amps, triodes, pentodes etc. which I preferred to stereo, solid-state playback systems.
I found little information to build such transformers. Any experience or information in this field is valuable to me.
Thanks in advance to anyone who can help me with this.
John

[navi]

Hooking up the switch is the most complicated. If you can figure that out it's pretty easy. I think the new models have a switch built in.

I built mine back in 2004 and it's the only piece of gear i've still kept all these years. everything else has been replaced. Keep you interconnects short and low capacitance. it's simple but effective.

[Giog]

Thanks for the replies.
I was not clear in asking the question, I would like to build an auto-transformer type inductive attenuator, starting from the type of magnetic iron to be used EI (HyMu 80) size, winding layout, section and type of wire, calculation of the various inductances and resistances for each winding, Gap type. Somehow I designed it with LT Spice but with a lot of misgivings, attenuation: 23 step.
I've stolen information here and there, but I still don't have the knowledge to try and design optimally.
I really like what Intact Audio does, little autotransformers that take up little space and are of great quality, but I could never ask Dave Slagle how he builds them.
           
I think there is someone out there who has the right knowledge for this.
John

[FullRangeMan]

I think there is someone out there who has the right knowledge for this.
Yes the transformers builders know how to made a volume att trafo, but I suspect hardly they will share the strategic details of the knowledge even with payment, IMO.

[ArthurDent]

Greetings & Welcome to AC John 

[Giog]

Thanks for the welcome to this juicy site.
If I had found other interested curious people like me, I could have published my project for these autotransformers. Now it seems like too big a feat, I'll have to settle for buying two on the market, and then compare them with the ones I'm going to make and which certainly won't go well right away, but since I want to live for many more years....
Greetings to all DIYers who love music.
John