I consider an amplifier to be "perfect" when its imperfections are well below the limits of audibility. My amplifier is already the strongest link in the audio chain.
Cool, but I think that Class D measurements are misleading - they ignore the elephant in the room (ultrasonic noise).
I agree that audio is a great way to learn electronics, and a good retirement hobby too.
Well, my new design will remain on the computer for now. I may build it some day if I feel that I can learn something. I am somewhat curious to find out what modern transistors can do.
Ed
Surely the elephant in the room is that most forum members can't hear 20kHz, worrying about ultrasonics in the room is like worrying about radio waves.
Because it’s fun to take a bunch of parts and make something great out of them! I always am thinking about my next amp and what will be different than the last one. It becomes a health obsession! Right now I’ve only got six tube amps I’ve built on hand and have sold many more to friends who appreciate them. It keeps me of the streets at night too!
- Yes
- Pleasure of continuously building stuff and curiosity to hear how different type and amps topology will differ.
- I’ve kept all my amps except for one that I gave my ex brother in law for Christmas.
Why build more? To entertain yourself.
I have built examples of Class D with immeasurable distortion but no, they don’t sound as good as Class A amps, at least to my ears.
I have built examples of Class D with immeasurable distortion but no, they don’t sound as good as Class A amps, at least to my ears.
Saving money isn't really a motivator for this hobby. In fact I would say it's more expensive than buying gear. Buying parts at retail, NOS tubes, sockets, costly mistakes, re-do's, then there is chassis fabrication where one might be motivated to buy a table saw, drill press, more tools, maybe even a CNC machine. Then there is wood, aluminum, nuts and bolts. Then there is the need to stock parts capacitors, resistors, misfits, regulators, wire lots of wire, solder, and biggies like output transformers, power transformers, chokes, etc. Then there is the need to set up your bench maybe with a few oscilloscopes from eBay, Fluke meters, signal generator, distortion measuring, maybe software to do detailed analysis, bench power supplies, then an array of hand tools for electronics.
For me I could have bought a few top end 300B amps by now! For the investment in the hobby is that big financially. But some people buy a boat or an RV or an airplane for their hobby, or elaborate wood shops. Cost saving is always touted as a reason for DIY, but I have not found that to be true! 😉
For me I could have bought a few top end 300B amps by now! For the investment in the hobby is that big financially. But some people buy a boat or an RV or an airplane for their hobby, or elaborate wood shops. Cost saving is always touted as a reason for DIY, but I have not found that to be true! 😉
An interesting question. My first amplifier was a Mullard 3-3 over 60 years ago, followed by two Mullard 5-10's, two Mullard 5-20's.
The 5-20's quickly became Williamson's because the class A triodes were more musical with much better mid range and sweeter treble.
After many years the EL34's were replaced with KT88's (power transformers just had a sufficient current rating) and remain so to this day.
My venture into transistor amps began began with the Tilbrook AEM 6000 design and followed by the J. L. hood class A amps (still exist and used).
Have also built Hiraga class A amps (my favorites) and the D Self trimodal amps.
Wow, it adds up when one looks back.
Then there are preamps......
The 5-20's quickly became Williamson's because the class A triodes were more musical with much better mid range and sweeter treble.
After many years the EL34's were replaced with KT88's (power transformers just had a sufficient current rating) and remain so to this day.
My venture into transistor amps began began with the Tilbrook AEM 6000 design and followed by the J. L. hood class A amps (still exist and used).
Have also built Hiraga class A amps (my favorites) and the D Self trimodal amps.
Wow, it adds up when one looks back.
Then there are preamps......
If there is a maker space somewhere in the neighbourhood, that can be an alternative to buying all kinds of tools for yourself. The members of the maker space then buy or build and use them together.
What motivates me? The search for audio ecstasy, as Gizmo (Harvey Rosenberg) calls it.
I agree. DIY is more expensive, but one can build a different class of equipment.
Ed
Try the Hypex. They are a different league as the other stuff I know and for sure everything you can build with available chips.
@EdGr - what's your problem with ultrasonic noise?
There are more and more ultrasonic devices around us and to be honest I don't mind them. Not sure about cats and dogs ... But it's a part of my business to build speakers to ba able to measure up to 60kHz and for my new project even higher. So I can say the following cause I tested up to 80kHz - most tweeters don't do a lot over 30kHz. You need to search for some which could actually reproduce the high frequency garbage you get with switched amplifieres (and there is alwas some, but the amount is vastly different) and it will not be particularly loud. Maybe I do some measurements with my next test setup if you are interested about it.
I love reading Dr. Gizmo! I spent many hours reading him before I decided on a SET Tube Amp build as my very first Tube Amp.
He's worth re-reading as well.
What motivates me: optimising Audio amplifiers and instrumentation amplifiers, be it for Euphonic/Neutral listening, including making transistor amps sound as good as or better than my SET Tube amp, or lowest-distortion measurements.
I do not want this thread to turn into the amplifier wars, but since you asked...
I have made some speaker measurements above 20KHz. The reviews of Class D amplifiers measure ultrasonic noise of hundreds of millivolts. That is comparable to the signal for low volume listening. I do not want my ears to be the low-pass filter.
Switching techniques can give good performance in D/A converters, but Class D amplifiers are not close (in my limited knowledge).
Let's get back on topic.
A simple analysis based on Ebers-Moll says the distortion of my amplifier is less than 0.1% before applying global feedback. I may upgrade the analysis to a Spice model, but I am not feeling a need to shell out the bucks for a distortion analyzer.
I listened to Judy Collins' Colors of the Day on vinyl. This is a shockingly good recording made with vacuum tubes. My system reproduces it with you-are-there presence.
The points being raised in this thread are good: hobbyists like to build, learn, and experiment. Sometimes perfection is not the goal. My kudos to everyone.
For me, perfection is the goal. I think I am close.
Ed
Coincidence motivates...I found 2 driver amps for 100V line system wit nice toroids 1:2,5:2,5.
Maybe for a transistor-circlotron? A balanced Zen or something?
Maybe for a transistor-circlotron? A balanced Zen or something?
When the system creates a credible illusion of not listening to a recording.
I hear no amplifier imperfections. The Maggies sometimes sound like listening to musicians through a sheet of mylar. Most often, I hear recording engineers mucking things up. 😉
Ed
😂 😂😂From the image, the audio device seems like it has a great personality. It's whats on the inside that matters
I am doing 2 more. They are a mosfet to bjt output. An OTL to bjt amp using 6922.
The recently finished one has bjt drivers and irfp9150 irfp240 outputs it is awesome.
The first is in an sx780 chassis, the other one will go into an Sx3700 chassis.
The recently finished one has bjt drivers and irfp9150 irfp240 outputs it is awesome.
The first is in an sx780 chassis, the other one will go into an Sx3700 chassis.
