300B SE Output Transformer Calculation and Winding

[@matthewroszkowski4674]

it is great to see the cnc winder in action. Thanks for the video

[@Delatsch]

Thank you!

[@ElPasoTubeAmps]

That is beautiful, Marko. This sets my mind on fire thinking about what to build next. The transformers and chokes I have purchased from you already are top-notch quality that I am very pleased with. Keep up the good work and congratulations on your new equipment.

[@Delatsch]

Thank you very much, David! Really looking forward to your new build!

[@01masuda]

Oh, nice easygoing gap contorl！

[@Delatsch]

Yeah, very nice!

[@makavrah_doom1491]

Awesome!! I’m so glad to see you’re back on. I found your channel several months ago and LOVE it. If there’s any way you would be open to helping me out with a consultation, I would be more than happy to compensate you for your time. I would love some advice on several project ideas I have been planning. Either way I absolutely love your videos, thank you so much for sharing your knowledge!

[@Delatsch]

Thank you! You can contact me via my website or my facebook page.

[@makavrah_doom1491]

@@Delatsch thank you for your response! I will reach out via your website to make further contact early next week!

[@gregj.gotham4402]

Beautiful workmanship !

[@Delatsch]

Thank you!

[@ЮрийНиколаев-к7ъ]

Моталка отличная, ничего не скажешь. А у меня простая ручная моталка, чисто для радиолюбителей. Но я её, тоже модернизировал. Я убрал ручку, поставил сервопривод с редуктором от военной радиостанции , и мотаю на ней каркасы от 1 кв/см , до 50 кв/см . Только перекидываю, шестерни разных диаметров на редукторе. Спокойно перемотал на ней, трансформаторы на 3 кВт...) 😎

[@rasoulkhandan9334]

Hi dear friend Please make a video on how to make and parts of the 300BSA winding machine

[@stefanomocci9228]

Graziee Marko, davvero bello e divertente... non vedo l'ora di provarci, a presto!

[@ronbell3781]

Nice catch!!

[@Delatsch]

Thanks!

[@Pollys13a]

Hi, why do you have those little squares of plywood at each end of the bobbin at 2:17 of video ? Thanks.

[@Delatsch]

Those are brackets hokding the bobbin in place. Ideally it should go all the way thru to prevent bobbin from deforming.

[@Pollys13a]

@@Delatsch " Ideally it should go all the way thru " I don't follow what you mean here, please clarify? Thanks.

[@alexanderstuartpetty485]

Love this Marko!! I also have this winder, its a great unit!

[@Delatsch]

Thank you very much, Alexander!

[@mattportnoyTLV]

Ooh, nice! Did you use M6 steel or another core material?

[@Delatsch]

Thanks! I used the basic M530-50A because most people have access to it. But, I am planning to swap the core and retest.

[@mattportnoyTLV]

@@Delatsch I’ve got a couple of these low watt beam triode style amps. I use M6 and it’s great. I like Metglas cores too but they get pricey.

[@Delatsch]

@@mattportnoyTLV Yeah, I guess M6 is more than enough, even the one I've used performs perfectly from 20Hz-20khz+ with this winding configuration.

[@mattportnoyTLV]

@@Delatsch I did an M6 10:1 transformer earlier this year. I chambered the windings and used layers like the old Neumann U47 output transformers do. I got a flat 20-50k response out of it. Some day I’ll wind a tube amp output transformer using a similar strategy.

[@Delatsch]

@@mattportnoyTLV Nice, yeah those were wound by hand in 4 compartments. With good quality core you don't need too many turns in primary which automatically reduces leakage inductance.

[@CraigHollabaugh]

I'm excited to see where you take transformer design, fabrication and test. Thanks for the video. Nice winder, congratulations.

[@Delatsch]

Thank you, Craig!

[@Ειρηνη.ΣοφιαΕλευθερίου]

Very nice video. Do you put insulation on the screws and nuts? thank you very much

[@Delatsch]

No, I just use regular screws.

[@ColocasiaCorm]

Can you tell us where to find more infos on the 300b amp circuit?

[@Delatsch]

I found the schematic online: diyaudioprojects.com/Schematics/300B-SE-Tube-Amp-Schematic.htm

[@BubblesCarlton]

Where do you get the forms and eleaminated plates? I can't find them anywhere in the US

[@Delatsch]

I get them locally here in Europe, but I've heard that Edcor is selling them on order, but usually for slightly larger orders.

[@rafaelvillegas7425]

En el canal de Fran se explica como utilizar transformadores de Alogenos para sustituir los transformadores de impedancias.

[@juanjobravo4476]

Excelent!!! I will try your SE calculator to winding a old style champ 5f1 SE OP trafo. So is possible to you make a video tuto. about the interleaves and layers to clarify that. Best Regards

[@Delatsch]

Thank you for your support, Juanjo! I will make a series of videos going into details on audio transformers.

[@juanjobravo4476]

@@Delatsch hi Marko, I'll be waitingthe videos! Today I started my calculations of the 5F1 champ output trafo with your SE Spreadsheet Calculator. It is very versatile and concise. The only thing that I am not sure about is if I should make interleaves between primary and secondary and how many layers and interleaves do I need in this type of vintage amplifier transformer.

[@Delatsch]

@@juanjobravo4476 For 5F1 champ, no interleaves as far as I remember. Just wind the whole primary and then the secondary on the top of the primary.

[@juanjobravo4476]

@@Delatsch Thanks Marko!

[@mayinjageorge8907]

Am knew to this channel but products are amazing

[@Delatsch]

Thanks!

[@toapraedinius4254]

Any technical informatiom about this transformer? Frequency response, copper losses and so on? This looks like a very simple transformer which migth work but not the performance an expensive tube as a 300B needs.

[@Delatsch]

You can check my other video where I do detailed measurement on this transformer. The 300B tube is expensive, but that doesn't mean it performs technically well. It is expensive for marketing and demand reasons only. The performance of directly heated triodes is very poor by technical standards and the transformer has far superior performance to the tube. If you check the western electric data sheet it shows it clearly. Now the way it sounds is another topic. It sound absolutely wonderful.

[@microlatinamicrocontrol1240]

Hi ! I tried to buy the advanced spreadsheet for calculating the trafo but Norton AV didn't allow me to proceed. I left a msg. in Facebook. Any workaround ? Thanks !

[@Delatsch]

Hi, I wrote you on facebook. There seems to be someone issue on some browsers with accessing or selecting different products. I am working on resolving it. If anyone is facing similar issues, please contact me directly if you would like to order anything from the website. Thanks!

[@Delatsch]

The site should work properly now, please try ordering again.

[@cityslacker6221]

Are you going to be starting a transformer winding company? Two of the most well known winders in the audio industry have now closed shop, Magnequest and ClassicTone, so there is a need for someone to step up. Mike LaFevre of Magnequest owns the original diagrams and drawings for Peerless and Acrosound, maybe he would license or sell his library. Anyways, I enjoy your videos.

[@Delatsch]

Thank you, glad you like the videos! Maybe some day I will, for now I am experimenting and testing, and also winding upon small orders here and there. I really enjoy it, we'll see what the future brings!

[@vicjames2743]

Where do you get your bobbins from

[@Delatsch]

I get them locally, you can check out my website I have some for sale: delatsch.com

[@ianmorgan6104]

Interesting video, are those EI 114 laminations you are using on the O/P transformer? I like the CNC winding machine you have there. What gauge of wire can it handle min to max if you don’t mind me asking? Thanks

[@Delatsch]

Thanks, no I'm using EI-96 32x40mm bobbin. The winder can handle 0.03mm-1.2mm.

[@ianmorgan6104]

@@Delatsch ok thank you for info, I better start saving up!

[@notnikola]

👏 great work!

[@Delatsch]

Thank you!

[@ibrahimkroglu5484]

super production.

[@Delatsch]

Thanks!

[@Pollys13a]

How do you adjust the wire tensioner pads correctly? Thanks.

[@Delatsch]

I adjust it by feel. The wire should be very tight but still go smoothly when you pull it by hand. You should feel resistance but no binding or squeeling. It takes some practice and a lot of broken wire until you get used to it. Very thin and very thick wire are problematic, but from 0.2mm-0.7mm it should be relatively easy to adjust.

[@Pollys13a]

@@Delatsch OK thanks, much appreciated.

[@mauricedemel6142]

How much does it cost. Please send me details of this machine.

[@robervalfaustino9855]

A minha Cnc está com erro Err-P alguém sabe tirar?

[@Delatsch]

Maybe this: kzbin.info/www/bejne/q3nCpIVoppJ_rpI

[@Виталий-щ9з5в]

Hello. Did you find a solution to your errr-p error problem? I faced the same issue.

[@PatrickInCayman]

Very very cool! Do you wind PP transformers as well? Anything in the higher wattage like 50W to 100W?

[@Delatsch]

Yes I do. What tubes do you use?

[@PatrickInCayman]

@@Delatsch hi, I bought all your spreadsheets I was really looking for this type of information, thanks! I have several sets of tubes I am experimenting with. EL34s, KT88s, and 6L6GCs. I ordered a couple of OT from edcorusa and a couple of hammonds from amplified parts. I think it's awesome you can make those. I would love to do it, but its difficult in the middle of the ocean on a small island to get all the parts. Let me knowing you are interested in making/selling a couple custom OT. Right now I am playing with a fender design (blackvibe) that i am modifying into a hifi version. I have a compactron 6af11 version working on my videos on my profile. I am hoping to get the el34 version up soon. Thanks again for your vids awesome stuff!

[@Delatsch]

@@PatrickInCayman Thank you so much for your support! Send me a message regarding the custom OT and I will see what i can do.

[@PatrickInCayman]

@@Delatsch Will do. I have a transformer in mind

[@uniteddrones7626]

I have 2 or 3 power converter transformers I need rebuild, can you help me? Definitely will pay for it as it’s for a panel that costs A LOT of money LOl

[@SkunkieDesignsElectronics]

Interesting video. Hope one day you can try my cascode mods to that JC Morrison design, I think you will be shocked at how much better it performs :)

[@Delatsch]

Thanks! I have a spare chassis with most components already in. I just need to take some time to modify it to your cascode mod. Hopefully soon I will do it and make some measurement again.

[@ElPasoTubeAmps]

Hi Marko, I hope all is well with you and your loved ones. I think about you often being in Ukraine. I am about to start on a couple of projects - one a Theremin for a musician friend and another stereo amplifier using 1619 tubes. The filaments are 2.5V, 2A and I need two separate filament windings as the cathodes are directly heated so I took a 12V, about 100VA outdoor lighting transformer and removed the secondary and wound two secondaries for 2.5V each. I used silver plated, Teflon coated wire - I assume the Teflon will be OK and not melt. Your thoughts on that would be greatly appreciated. It buzzed a bit when I reassembled the core so I did the best I could to tap and tighten it up and then dipped it in shellac and it worked - I hope it doesn't catch on fire... 🙂 it provides proper voltage under load of 4A each winding. Stay safe -

[@Delatsch]

Hi David, nice to hear about the upcoming projects. Sounds good, if you used around 20 awg wire or thicker there shouldn't be any problem.

[@tomekukowicz3359]

Pozdrowienia! Szczelina to do klasy A?

[@Delatsch]

Witam, tak, to przez prad staly w klasy A.

[@Михаил-х6н8й]

Провод наматывается рывками, может повреждаться от динамических ударов, система натяжения провода неудачная или отсутствует

[@steputube]

Is the large size necessary for a single 300b?

[@Delatsch]

I would strongly recommend it. You could do it with a bit smaller core of higher permeability of course, but I still haven't got around trying it with better laminations. With push pull it is easier to get away with smaller core since there is not gap to compensate for. I must say that it is well worth the cost and trouble. Was listening to this amp couple of days ago. Despite the fact that it "only" 6-7W per channel, even with the volume on half it is too loud an average room. And that's on average speakers (don't know the exact spl) Because of the large core the bass is amazing, but due to interleaving method used the high end extends to 29 Khz. At 4.5W -3db point is around 15 Hz if I remember correctly and at 29Khz. I will post a video today or tomorrow with the tests, just need to finish the voice over today.

[@steputube]

@@Delatsch thank you for the very detailed answer. What wire diameter are you using? Primary looks fairly thin?

[@steputube]

I think , let me just get your software and see

[@Delatsch]

I'm using 0.25mm wire for the primary, but 0.2mm would work just as well for the current in question.

[@gregj.gotham4402]

I’d would love to hear them play through real speakers 300’s in stereo note seam to float in the air. Heaven sent. 😊

[@Delatsch]

Yeah, i tried it on several different speakers and I am really impressed.

[@cromag141]

Kick ass!

[@Delatsch]

Yeah! :)

[@pachacache5186]

thx! 👍

[@BruceAdi布鲁斯阿地]

测个1000HZ方波看下

[@Delatsch]

You can check my other video where I do the tests.

[@chuckmaddison2924]

I would like to try this with a 6BM8. It's cheaper : )

[@mosfet500]

You can't hear the difference between rectifier tubes, in fact, you can't hear the difference between a tube and a silicon rectifier - it's DC, you can't hear DC!

[@Delatsch]

I am probably not the best one to explain it, but the tube rectifier has a significantly greater internal resistance compared to a silicon rectifier, and the voltage drop is therefore greater. When power tubes draw higher plate current (when the input signal is higher) the tube rectifier cannot supply all the voltage and this creates a sort of compression or sag in the audio output. I've tested it in practice many times and it is extremely easy to hear the difference and it is a significant difference. You can check some better technical explanations online if you search for "tube rectifier sag".

[@mosfet500]

@@Delatsch Thanks. I'm asking why people are using tube rectifiers at all, you're better off with solid state, less energy wasted too. Some people think you get a gradual rise in voltage as the rectifier filament heats up but you can do that with SS too. Cheaper and better.

[@Delatsch]

You are welcome and thanks for your comment. Yes, in theory it is easier, more efficient and measures better, but in practice it just sounds a lot better with a tube rectifier. SS amplifiers in general work better, have lower distortion and superior performance and are more cost efficient, but myself and most people still prefer the sound of the tube amplifiers more. If you would have the opportunity to hear the tube vs ss rectified amplifier I am sure you would be positively surprised by the difference in sound. Of course there are people who prefer SS rectifiers, but they still hear the difference@@mosfet500

[@mosfet500]

After the rectifier there's a choke and capacitors smoothing the 120hZ ripple. Unless there's poor rectification there's nothing to hear, it's DC at this point, any unfiltered B+ noise will be in both circuits. A tube and a diode do exactly the same thing. I've heard both and designed both, it doesn't matter if it's a tube, diode or 300 volts of batteries strung together.@@Delatsch

[@ЕвгенийИвлев-ц2р]

😂😂😂😂😂

[@egimabe4869]

more than an audio transformer, to me it seems to be a power supply and also badly done.