Winding an audio transformer

[mark_titano]

I want to read something about how to wind an audio transformer, has someone an idea of where can I find some articles on line?

Thankyou, Mark

[Larry Lomax]

Hi Mark!
To wind an OT is not an easy task. But, with a lot of patience, some calculations and a lot of oil to burn at midnight (as someone has told!).......
Results are good.
But if you try to achieve a fast result in a day or so... forget winding your own OT.
If you are a professional with a winding machine this is another story.
I'll be happy to tell you what are my experiences in the field and all the "secrets" (rather few, if any) I know.
Best regards
Larry.

[audiousername]

This document prepared by Craig Ryder is an excellent resource for links to almost anything to do with valves!

There are many good transformer references in there - I've copied them below:

• RG Keen, OPT Design and Winding: Located in the “Tube Guitar Amp Tech Pages” section here: http://www.geofex.com/
• Jan Rowland, Roll Your Own Power Transformers: http://members.tripod.com/~schematic...m/xformer1.htm
• Patrick Turner, Output Transformer Design Calculations: http://www.turneraudio.com.au/htmlwe...esigncalcs.htm
• Transformer Basics, from Lessons in Electric Circuits: http://www.ibiblio.org/obp/electricC...s/AC/AC_9.html
• Determining OP Transformer Impedance: http://www.geocities.com/vintage_radio/outimp.htm
• Basics of Inductors: http://www.hills2.u-net.com/electron/induct.htm
• VoltSecond and Mike Lefevre, What does the Transformer Inductance do to the Loadline of the Tube? http://www.siteswithstyle.com/voltse...LOAD_LINE.html
• Gabe Velez, Transformers: http://members.tripod.com/~gabevee/transform.html
• Michael LaFevre, Transformers and Phase Shift: http://www.magnequest.com/tech2.htm
• Color codes (MarVac Electronics): http://www.marvac.com/funpages/chokes.htm
• University of Surrey, Producing Wound Components http://www.ee.surrey.ac.uk/Workshop/advice/coils/#turn
• David Berning, An Audio Amplifier Design Philosophy: http://www.meta-gizmo.com/Tri/otlology/BERNINGS.htm
• Randall Aiken, OPT’s Explained http://www.aikenamps.com/OutputTransformers.html
• Richard Sears, Trany Math: http://richard984.tripod.com/transformer_math.htm
• Lundahl, Technical Papers from Lundahl: very short pieces from Lundahl lab: http://www.lundahl.se/papers.html
• Pete Millett, Power Transformers for Audio Equipment: http://www.pmillett.addr.com/images/ax_power.pdf
• VoltSecond, Damping Ringing in LC Circuits: http://www.siteswithstyle.com/VoltSe..._in_xfmrs.html
• Plitron Site:http://www.plitron.com/Pages/sitemap.htm. Link takes you to site index. Under “Publications”. A collection of articles including:
  -Secrets of Output Transformers, Menno Van de Veen
  -Measuring OPT Performance, Menno Van der Veen
  -Theory and Practice Of Widebandwidth Toroidal OPT, Menno Van der Veen
  -Modeling Power Tubes and their Interaction with OPT, Menno Van der Veen
• John Atwood (One Electron), Transformer Measurements: http://www.one-electron.com/Trans_Tests.html
• Max Robinson, Understanding the Transformer: http://www.angelfire.com/electronic/...nsformers.html
• Dean P Currier, A Biographical History of Induction Coils: http://radiantslab.com/quackmed/Deanbio.html
  Edcor, Transformer Tek Notes: http://www.edcorusa.com/gadgeteer/tek-notes_xformer.htm
• Toroid Corp. of Maryland Tech.Bull. #1 ( Application Notes on Rectifier Transformers) and #2 (International Line Voltages and Frequencies): http://www.toroid.com/technica.htm

[mark_titano]

Hi guys

Originally posted by Larry Lomax
Hi Mark!
To wind an OT is not an easy task. But, with a lot of patience, some calculations and a lot of oil to burn at midnight (as someone has told!).......
Results are good.
But if you try to achieve a fast result in a day or so... forget winding your own OT.
If you are a professional with a winding machine this is another story.
I'll be happy to tell you what are my experiences in the field and all the "secrets" (rather few, if any) I know.
Best regards
Larry.

Larry, I think that I will never try to wind an output transformer but some friends of mine want to try...I just want to find something that can help them. Anyhow...I'm interested too, this is an important aspect for tubes amplifier and studying which are the problems connected in winding a transformers seems to me a good idea...
isn't it?

audiousername...thankyou

Mark