Build Basics FAQ #3 : OUTPUT TRANSFORMERS!! ...and primary impedance

Рет қаралды 4,775

Күн бұрын

Third in a series of FAQ build basics. Here I discuss and outline how to go about choosing an output transformer for your build, and also go on to discuss the fundamentals of an OT's primary impedance.
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0:00 Intro
1:30 Cheat sheet table
3:30 Primary impedance Rule of thumb
7:33 Primary impedance basic theory
13:33 Outro

Пікірлер: 35

@komorowski381 Ай бұрын

Finally a video that made it understandable for me .Many thanks 🙏🏼

@PhuketMyMac 2 ай бұрын

Thank you again Jason! So much to learn and you’re really helping. I might have said that already but you’re the Louis Rossmann of guitar tube amps!

@russiangoose7053 Жыл бұрын

Please continue the build basics series! These videos are the most helpful ones I've seen!

@HeadfirstAmps Жыл бұрын

Glad you like them! What else would you like me to cover?

@russiangoose7053 Жыл бұрын

@@HeadfirstAmps now that I look through your videos you've done most of what I could think of off the top of my head. Maybe you could cover lead dress and ground schemes? Or perhaps biasing in practice? Whatever you cover I just appreciate the knowledge you share!

@PhuketMyMac 2 ай бұрын

@@russiangoose7053ground schemes would be a great one!

@wakjob961 2 жыл бұрын

I was just like you about ten years ago. Totally obsessed with this stuff. Morning noon & night it was all I thought about....modding, experimenting, theorizing, studying caps and resistors ect... I just watched my playing skills take a huge nosedive as my soldering skills went through the roof !!!

@HeadfirstAmps 2 жыл бұрын

Find time for both!

@felinekaiju4517 Жыл бұрын

found useful?. I learnt something alright!. I'm glad that at 40 I'm understandinig concepts that would have fried my brain. I consider this Output tranformers for dummies!!. love it!.

@lechstryzewski9350 2 жыл бұрын

Yet another fantastic video Jason!! - The way you deliver the information makes it very easy to understand. Thanks man !!!

@HeadfirstAmps 2 жыл бұрын

Thanks Lech, that’s the goal for sure. Make it easy!

@BCEpedals 8 ай бұрын

This was so helpful!

@NewReligion1954 2 жыл бұрын

This was explained very well. Great video Jason. Thank you for all of the great support in our community. David Hopkins.

@HeadfirstAmps 2 жыл бұрын

Tnx David.

@andrewwilliams5042 2 жыл бұрын

Great information / explanations, amp audio, production. Working my way back through the older videos.

@marvelharris9540 2 жыл бұрын

Fantastic job Jason!

@cheyneluke9330 2 жыл бұрын

Fantastic thanks Jason!

@TheFrozenDesert 2 жыл бұрын

I am so glad I heard you on Tone Talk. Brilliant.

@HeadfirstAmps 2 жыл бұрын

Thanks!

@danielsaturnino5715 2 жыл бұрын

Thanks for sharing your knowledge :)

@LucasMastropasqua 11 күн бұрын

I still love revisiting your videos all the time, especially great as reference when I am working on something and need to refresh my memory. I was wondering, with a speaker load attached is there any way to measure the primary impedance, if for example you have an OT in an amp but don't know what specs are? The other question is if measuring the resistance of the primary should the resistance be equal on either side of the center tap?

@cobar5342 Ай бұрын

Great video. I find this subject very difficult to grasp

@shredding51 10 ай бұрын

Great video! Think i have a OT going out on my jcm 800 2204

@schmolly75 2 жыл бұрын

Marshall 100w uses four tubes and needs 1.700 ohms at primary. If your remove two tubes to get only 50W, the two tubes need 3.800 ohms at the primary. So if the 100w have a 16 ohms cab connected to the 16 ohms terminal output, to get 3.800 ohms with two tubes you only need to move the jack of the cab from the 16 ohms terminal to the 8 ohms terminal.

@HeadfirstAmps 2 жыл бұрын

Correct! It’s a useful additional point this.

@freaksarise Жыл бұрын

Hi Jason, when power scaling such as with the JCM 800 Studio Classic whereby the plate voltages are lowered to achieve the scaling, how does this affect the OT with respect to the equation (b+ voltage)2 / (plateDissipation X numOfTubes)? Thanks!

@HeadfirstAmps Жыл бұрын

It changes the performance for sure, they are so coldly biassed it's not an ideal operating point.

@HandWiredAmps 7 ай бұрын

The Origin 20 output transformer on my bench measures 5.4k Perhaps they decided to go with an impedance that's less efficient, as they only needed 20 watts, or, to fit better with the power scaling? Would have been a good question for Santiago's Q&A. Thanks for the video Jason!

@HeadfirstAmps 7 ай бұрын

Yeah, as you drop the b+ voltage you’d increase the primary to keep the operating point optimal.

@ramilrodriguez8340 2 жыл бұрын

Very nice. Do those formulas work with single ended amps?

@HeadfirstAmps Жыл бұрын

No, only push pull

@Phantasm70 9 ай бұрын

What's your preference for output tap Jason, the least or greatest resistance?

@HeadfirstAmps 9 ай бұрын

Makes no difference, as long as your negative feedback line is not connected to the speaker jack.

@jpb962 2 жыл бұрын

I know this is a tech video, and I thank you Jason for sharing your knowledge, I've learned a lot from your channel in the past year or so. But WTF JASON! I feel ripped off. I watched the whole video hoping that you would close it out with some a$$ kicking and face shredding on one of your amps!

@HeadfirstAmps 2 жыл бұрын

Hahaha, will keep this in mind!