Thanks for the complement X. I really appreciate that. I will admit I have been a tinkerer, model builder, woodworker for most of my life. My current goal is to have a deeper understanding of electrical circuits and how they function so that I might be able to design my own amplifier some day. Or at the very least be able to tweak other's designs.
We have had very similar paths! I joined diyA for the very same reason. Being a music listening buff since I was a kid, I wanted more from my bluetooth speaker. I never realized it would lead me to building full size amplifiers, pre-amps, speakers, etc. I completely agree with you. You can't necessarily make a small BT speaker at the same level as big manufacturers but other hi-fi gear can blow most stuff out of the water at a very small fraction of the price compared to some of the best stuff out there.
We have had very similar paths! I joined diyA for the very same reason. Being a music listening buff since I was a kid, I wanted more from my bluetooth speaker. I never realized it would lead me to building full size amplifiers, pre-amps, speakers, etc. I completely agree with you. You can't necessarily make a small BT speaker at the same level as big manufacturers but other hi-fi gear can blow most stuff out of the water at a very small fraction of the price compared to some of the best stuff out there.
Hi Jwjarch,
That’s great that you have been so active - your amp building will get you to designing your own amps in no time. It’s helpful to collaborate with an experienced amp designer. Everything I know about amps was taught to me by Aksa (Hugh Dean).
For the LuFo Lite, I ran the simulations with the -ve bias and it seems about -900mV to -960mV at the JFET gate is what you need to get about 1.4A bias current and 1ohm total DCR from the chokes, no resistors needed.
Removing the resistor seems to have decreased the distortion and increased the headroom.
That’s great that you have been so active - your amp building will get you to designing your own amps in no time. It’s helpful to collaborate with an experienced amp designer. Everything I know about amps was taught to me by Aksa (Hugh Dean).
For the LuFo Lite, I ran the simulations with the -ve bias and it seems about -900mV to -960mV at the JFET gate is what you need to get about 1.4A bias current and 1ohm total DCR from the chokes, no resistors needed.
Removing the resistor seems to have decreased the distortion and increased the headroom.
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Yes. Even a 1.5v AA battery would work. Certainly quieter.
There is negligible current draw. 1.5v and 33k is 45 micro amps. That battery would last for weeks.
I think current on JFET gate is almost negligible as well.
The divider if 15k and 10k pot set near 5k is about 75 micro amps.
There is negligible current draw. 1.5v and 33k is 45 micro amps. That battery would last for weeks.
I think current on JFET gate is almost negligible as well.
The divider if 15k and 10k pot set near 5k is about 75 micro amps.
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Anybody experiment with felt? David Ralph discovered that midrange driver improved from a felt application.
Diffraction Doesn't Have to be a Problem
Diffraction Doesn't Have to be a Problem
Scotchbrite scouring pads around the tweeter help too. Adding felt etc to reduce diffraction has been done by many people. BBC LS3/5A, Dunlavey SC/IV, …
I also played with it here.
FR58EX and AC130F1 micro-FAST / WAW
I also played with it here.
FR58EX and AC130F1 micro-FAST / WAW
For audio although not necessary in a perfect world the ideal candidate is a diyer experienced in audio, a genius graduate high at 12 years old with a degree in English,music, physics, mechanical and electrical engineering, math, and background in woodworking. For the rest of us an interest and passion in diy will suffice. So what is your story?
Haha, funny. I was young but I don’t think it matters when one graduates from high school, because as an adult, no one has ever asked me “when did you graduate from high school?” 
I’m a mechanical engineer with a chemistry minor by training, but almost went into art history. What a funny path that would have been. For many years, I worked in the lab as an experimentalist setting up combustion experiments with lasers spectroscopy and optics and used a lot of instrumentation - so I dabbled in electronics. Nowadays, I manage spacecraft programs by day and play with audio by night. I did not touch any audio until 9 years ago. Before that I just bought the usual stuff from a store like everyone else. My most serious purchase was a Yamaha RX-360 integrated 45w amp. I had some Boston HD-5 bookshelf speakers. That was it until I went DIY.
I’m a terrible woodworker so that’s why I made speakers out of foamcore and hot melt glue. That coupled with Akabak allowed me to study and model hundreds of speakers over the course of a few years. If I had to make them out of wood, maybe I could have built 10? So I leave woodwork to the professionals.
Everything I know about audio I learned from DIYA and the amazing people here who have helped me and collaborated with me. People who have influenced me greatly include: AKSA (Hugh Dean who taught me everything I know about amp design), Don Hills (for showing me how to program in Akabak), Byrtt (for helping me get into measuring speakers and providing me a lot tools and drivers and encouragement to follow the data and not the hyperbole), BWaslo (for inspiration with his Cosyne speaker and his super tools like the famous Synergy spreadsheet and Xsim software to make synergies and passive crossovers), Apex Audio (for inspiration to make lots of amps!), JPS64 (the 35 year veteran of commercial PCB layout design and for his incredibly beautiful layouts snd superhuman productivity), Jhofland (the greybeard of wisdom amongst us for his ingenious circuit designs which give us as DIYers so many tools), Zman01 (for his continual honest guidance and encouragement with superb insights into the audio world), Vunce (for his superb ability to build prototype versions of amps like no one else), and Freddi (for giving me the impetus to learn Akabak to model the Karlson K15 , and for his continual advocacy of the much under-rated Karlson speaker). There are many others and I apologize if I did not mention you. These are some of the wonderful folks on DIYA who shaped my travels through the world of audio.
I owe you all a huge humble thank you!
I’m a mechanical engineer with a chemistry minor by training, but almost went into art history. What a funny path that would have been. For many years, I worked in the lab as an experimentalist setting up combustion experiments with lasers spectroscopy and optics and used a lot of instrumentation - so I dabbled in electronics. Nowadays, I manage spacecraft programs by day and play with audio by night. I did not touch any audio until 9 years ago. Before that I just bought the usual stuff from a store like everyone else. My most serious purchase was a Yamaha RX-360 integrated 45w amp. I had some Boston HD-5 bookshelf speakers. That was it until I went DIY.
I’m a terrible woodworker so that’s why I made speakers out of foamcore and hot melt glue. That coupled with Akabak allowed me to study and model hundreds of speakers over the course of a few years. If I had to make them out of wood, maybe I could have built 10? So I leave woodwork to the professionals.
Everything I know about audio I learned from DIYA and the amazing people here who have helped me and collaborated with me. People who have influenced me greatly include: AKSA (Hugh Dean who taught me everything I know about amp design), Don Hills (for showing me how to program in Akabak), Byrtt (for helping me get into measuring speakers and providing me a lot tools and drivers and encouragement to follow the data and not the hyperbole), BWaslo (for inspiration with his Cosyne speaker and his super tools like the famous Synergy spreadsheet and Xsim software to make synergies and passive crossovers), Apex Audio (for inspiration to make lots of amps!), JPS64 (the 35 year veteran of commercial PCB layout design and for his incredibly beautiful layouts snd superhuman productivity), Jhofland (the greybeard of wisdom amongst us for his ingenious circuit designs which give us as DIYers so many tools), Zman01 (for his continual honest guidance and encouragement with superb insights into the audio world), Vunce (for his superb ability to build prototype versions of amps like no one else), and Freddi (for giving me the impetus to learn Akabak to model the Karlson K15 , and for his continual advocacy of the much under-rated Karlson speaker). There are many others and I apologize if I did not mention you. These are some of the wonderful folks on DIYA who shaped my travels through the world of audio.
I owe you all a huge humble thank you!
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You are welcome, Myles. I also have to thank all the people like yourself who build the projects that I come up with. Without your support, this would not have been possible.
Today is a holiday on the US - Labor Day. I finally get some time to build something in the lab for fun. After all, why would we do this if it wasn’t fun?
Today is a holiday on the US - Labor Day. I finally get some time to build something in the lab for fun. After all, why would we do this if it wasn’t fun?
Sept. 7, 2021, On the Bench Tonight: The new sample chassis for the HyperDrive-2 hybrid tube/SS headphone amplifier. It is one beautiful powder coated all CNC chassis. This is going to be a real special headphone amp.
Btw, have you guys seen the latest review of my Warp-1 amp on TONE Magazine?
Btw, have you guys seen the latest review of my Warp-1 amp on TONE Magazine?
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