output transformer turns per volt

[ataul]

Hi friends

my friend he want build a SE tube amp with 300B tube but output transformer is not available we deside to make an output transformer we have formula or idea for turns ratio for impedense but no idea that how many turns we shall wind in primery and which dia or which number of coper enamel wire we use our transformer size is 80VA chinice power transformer with good lamination black colour iron core. and if any friends have idea about it please share your experience with us.it is very kind if anyfriends reply.
sorry for bad english

Best regard

Ataul

 

[Arnulf]

1000 turns on the secondary side seems like a good starting point. You usually end up with 1000/1400 secondary and 3000+ primary.

 

[Yvesm]

Hi Ataul,

I did that :
http://www.dissident-audio.com/SE_300B/KISS/DA143.pdf
Beware ! Metric numbers !

and obtained that:

Yves.

 

[ataul]

thangs friends cannot understant about "mod"

ataul

 

[ataul]

Hi Ataul,

I did that :
http://www.dissident-audio.com/SE_300B/KISS/DA143.pdf
Beware ! Metric numbers !

and obtained that:

Yves.

hi Yvesm

great infformation Yvesm ,thanks

ataul

 

[kavermei]

thangs friends cannot understant about "mod"

That's just a joke. Some people cannot stop changing parts in their amplifier even when it already sounds very good. 😉

 

[Efren Noble]

hi,
when it comes to output trannies, we have a local manufacturer here in our country, I have used this product and I can attest to the sonic as well as ruggedness. They dont use ordinary irons, otherwise your project will sound mediocre and a fire hazard as well. Here it is, performing on my tube amp, a
6F6G single ended driven by 12AV6:

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fresh from the shipment|:

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[Efren Noble]

by the way that was 6AR5 before I finally replaced it with 6F6G, sorry 'bout that, here it is now.

[/IMG]
they specialize in output as well as power trannies, I think their main office is at Switzerland, the plant is only located here in Phillipines.

 

[ataul]

Efren Noble

Nice output transformers photo, singapore is my nearest country so may i colect them from singapore.ok first i will try it to make because this is the
cheap solution, but when i will fail then i go to comertial tr

thanks

Ataul

 

[Efren Noble]

Ataul,

no problem, glad to be of help in my own little way to a fellow DIY'er,..
here's my amp driving a vintage Philips AD50600 in Onkyo D-032AX bokshelf enclosure.

[/IMG]

Best Regards,
🙂🙂🙂

 

[ataul]

That's just a joke. Some people cannot stop changing parts in their amplifier even when it already sounds very good. 😉

oh yes "mod" u are right , ha ha ha .

 

[dave slagle]

1000 turns on the secondary side seems like a good starting point. You usually end up with 1000/1400 secondary and 3000+ primary.

Did you mean 100 turns on the secondary?

1000 turns on the secondary and 3000 on the primary is a 3:1 turns ratio which assuming a 8 ohm load nets you a 72 ohm load on the 300b.

Yves design with 82 secondary and 1620 primary looks to be much closer to reality.

dave

 

[Matt BH]

Hi,
The turns per volt is calculated around the area of the centre leg in an EI core. Too few turns and it will saturate, too many and the copper losses, interwinding capacitance and leakage inductance will suffer.

Its a bit more complicated than that in reality but I think its great that your willing to give it a go🙂

Check out this page on Patrick Turners site for single ended transformer design:

se-output-trans-calc

Cheers Matt.

 

[Yvesm]

I just can tell that the OPT built with the above data does the job correctly !
More than 50 guys (some regulary posting here) can testify.

Of course, there are many other ways to go.

Yves.

 

[Arnulf]

1000 turns on the secondary and 3000 on the primary is a 3:1 turns ratio which assuming a 8 ohm load nets you a 72 ohm load on the 300b.

Sorry, you are correct, late hour and an extra zero 😱 The actual number is 100/141, I'm not sure how I managed to mess that up. Well spotted !