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 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!
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!.
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?
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.
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!
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!
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!
Finally a video that made it understandable for me .Many thanks 🙏🏼
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!
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 !!!
Find time for both!
Please continue the build basics series! These videos are the most helpful ones I've seen!
Glad you like them! What else would you like me to cover?
@@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!
@@russiangoose7053ground schemes would be a great one!
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!.
This was explained very well. Great video Jason. Thank you for all of the great support in our community. David Hopkins.
Tnx David.
Yet another fantastic video Jason!! - The way you deliver the information makes it very easy to understand. Thanks man !!!
Thanks Lech, that’s the goal for sure. Make it easy!
Great information / explanations, amp audio, production. Working my way back through the older videos.
I am so glad I heard you on Tone Talk. Brilliant.
Thanks!
This was so helpful!
Fantastic job Jason!
Fantastic thanks Jason!
Great video! Think i have a OT going out on my jcm 800 2204
Thanks for sharing your knowledge :)
Great video. I find this subject very difficult to grasp
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?
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.
Correct! It’s a useful additional point this.
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!
Yeah, as you drop the b+ voltage you’d increase the primary to keep the operating point optimal.
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!
It changes the performance for sure, they are so coldly biassed it's not an ideal operating point.
Very nice. Do those formulas work with single ended amps?
No, only push pull
What's your preference for output tap Jason, the least or greatest resistance?
Makes no difference, as long as your negative feedback line is not connected to the speaker jack.
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!
Hahaha, will keep this in mind!