Tír Na HiFi

on the right trail?

nige2000 wrote:

on the right trail?

Yea, as I said, If you email me I'll give you the details I have later today

A quick run of some numbers, the spec I've outlined is just possible with (ultra-thin) 0.05mm wire for the primary and 0.08mm for the secondary.

Primary is 4300T (made up of two windings of 2150T) and secondary is 2150T.

I shall have a go myself to see if this design works in practice, if so then let's put it out to get some made in China...

abraxalito wrote:A quick run of some numbers, the spec I've outlined is just possible with (ultra-thin) 0.05mm wire for the primary and 0.08mm for the secondary.

Primary is 4300T (made up of two windings of 2150T) and secondary is 2150T.

I shall have a go myself to see if this design works in practice, if so then let's put it out to get some made in China...

That's a challenge! Rather you than me.

I managed to wind all the wire on, just one break in the primary which used an extra pin for the connection.

Then I made some inductance measurements and checked the DCR. About 700ohms for each primary.
But then I tried to fit the core over the bobbin and snagged one of the 0.05mm wires in doing so. So I only
have a single primary on this, but its enough to try it out and measure a few parameters. I tried to upload
a picture but hit a snag in that the limit for attachments was a lot smaller than my .jpg file.

<later> Resized it to fit.

Easiest is to host the image file elsewhere (photobucket or the like) and then enclose a link to the file between the tags

Just a note, Richard - in Nige's setup, your trafo sounded excellent on the output of my Ciunas DAC - can you tell us what are its specs?
Do you reckon this new trafo might sound even better?
When getting a quote for trafo construction it might be a good idea to include your existing trafo as an option - it seems a simpler construction & likely cheaper?

its really sad that i think the trafo looks cool

winder arrived today im gonna order and try with the 0.14 wire and PQ32-25 if i get the go ahead :)

jkeny wrote:Just a note, Richard - in Nige's setup, your trafo sounded excellent on the output of my Ciunas DAC - can you tell us what are its specs?

I will have to search through my notebook to see if I have made mention of the wire gauge and turns that I used. The core was a 10K material which is higher permeability than the PC40 I'm using for this transformer. Seeing as I designed the transformer you heard for just 1VRMS input (a smartphone) its not a design I'd want to recommend for using on 2VRMS. I also didn't design it to go all the way down to 20Hz, it cuts off around 40Hz.

Do you reckon this new trafo might sound even better?

I would hope so yes due to the above mentioned factors. But there is another interesting difference which may well impact how it sounds. That transformer you heard has a split bobbin, meaning the primary and secondary are wound adjacent, not one over the other. This probably provides better isolation between the input and output, which as we found from our experiment is what really makes the difference to the soundstage (with the grounds common, no major improvement). So perhaps a version of the transformer you heard but wound with thinner wire could beat the design I'm working on purely because of those mechanical aspects having a bearing on the inter-winding capacitance. We'd have to build both and have a listen methinks.

When getting a quote for trafo construction it might be a good idea to include your existing trafo as an option - it seems a simpler construction & likely cheaper?

Its simpler because it only has one winding for primary and one for secondary. Otherwise no difference that I can see. The cores are cheaper yes but its the difference between 0.5rmb and 1.5rmb so about 13p in UK money. I have a feeling that's not too significant in the whole scheme of things - probably the winding cost is going to swamp that difference.

abraxalito wrote:

jkeny wrote:Just a note, Richard - in Nige's setup, your trafo sounded excellent on the output of my Ciunas DAC - can you tell us what are its specs?

I will have to search through my notebook to see if I have made mention of the wire gauge and turns that I used. The core was a 10K material which is higher permeability than the PC40 I'm using for this transformer. Seeing as I designed the transformer you heard for just 1VRMS input (a smartphone) its not a design I'd want to recommend for using on 2VRMS. I also didn't design it to go all the way down to 20Hz, it cuts off around 40Hz.

You had two trafos with you - were both designed for smartphone use?

Do you reckon this new trafo might sound even better?

I would hope so yes due to the above mentioned factors. But there is another interesting difference which may well impact how it sounds. That transformer you heard has a split bobbin, meaning the primary and secondary are wound adjacent, not one over the other. This probably provides better isolation between the input and output, which as we found from our experiment is what really makes the difference to the soundstage (with the grounds common, no major improvement). So perhaps a version of the transformer you heard but wound with thinner wire could beat the design I'm working on purely because of those mechanical aspects having a bearing on the inter-winding capacitance. We'd have to build both and have a listen methinks.

Yes, that's interesting - the isolation was certainly a big factor in Nige's system & we really don't know how much the impedance change affected the sound?

When getting a quote for trafo construction it might be a good idea to include your existing trafo as an option - it seems a simpler construction & likely cheaper?

Its simpler because it only has one winding for primary and one for secondary. Otherwise no difference that I can see. The cores are cheaper yes but its the difference between 0.5rmb and 1.5rmb so about 13p in UK money. I have a feeling that's not too significant in the whole scheme of things - probably the winding cost is going to swamp that difference.

Yea, well I was thinking that the winding costs of such very thin wire my be significantly different (both in number of turns & breakages) compared to thicker wire?