I just got a serious lesson in room acoustics. Please let me explain.
Continue readingThat Was Surprising
3
Distortion Misunderstood
I just had a little tussle with with the local blatherskites over at one of the less hospitable internet audio forums. The actual subject of the exchange is unimportant. However it got me to thinking about distortion and how today the concept of distortion has become seriously misunderstood.
Continue readingLoudness?
Anyone who has taken a look around this site should soon realize that I really like my low power amplifiers. What this means is that most of my listening is at lower volume levels. Now the only problem with this is that the sensitivity of the human ear to different frequencies is dependent on volume level. So at low volume levels, the ear has relatively poor sensitivity to both low and high frequencies. And the quieter the music gets, the worse the mismatch becomes. Traditionally the answer to this conundrum was the humble “loudness” control.
Interesting Discovery
So I was sitting down today to prototype a new 6SN7 preamp with a buffered output. As I was getting equipment arranged and pulling components I looked over at my dedicated prototyping station and something didn’t look right. As I looked more closely something jumped out at me that was unexpected and frankly, more than a little surprising.
A Little Change
If you look over to at the top of my blog page you’ll notice a little change. At the top of the sidebar is a little yellow PayPal button readers can use to donate to CascadeTubes. There is also one at the base of the home page. And I thought that after all these years, a little explanation was in order.
Tube Sound – Power Stage Topology
In one of the page comment sections, Dave K asked this particular question:
You have both SET and UL pentode amps, from the listener’s standpoint, what are the audible differences in sound between the two types?
From a tech standpoint, I know that triode = even harmonic distortion, pentode = odd harmonic distortion
UL pentode = ??
And this was the simple answer I provided:
Amp Layout Tools and Ideas
A big part of building custom vacuum tube amplifiers is layout. Even when the schematics are finalized and parts are ordered (and even delivered) the preparatory work is not over. With this phase comes the arranging and rearranging of transformers, tube sockets, potentiometers, switches, jacks, terminal strips, and all the other miscellaneous parts that make up the final amplifier. And this is where some simple quality tools can make all the difference.
What is Wrong With Tech Companies Today?
A little background. I am a thirty year Electrical Engineer. I have spent those thirty years woking on some of the most amazing pieces of technology ever built. I have worked with cutting edge technologies before most people knew they even existed. I have had a phenomenal career. And I’ve spent that entire career with one company. That company has treated me very well, and I am grateful. But times are changing.
Something New
So, CascadeTubes now has a Twitter feed. The link is “CaliSuncalc”. The link is also on the left side of the Blog page.
If you ask me what that means for the site, I can’t really say. There are a few tweets there already. This is going to be a journey of discovery. So I guess we’ll see how it goes.
Feel free to take a look or even follow my tweets.
Projects Coming Together
There is something very satisfying about seeing a project really start coming together. I finally got some time today to start working on my 6V6 Marblewood amplifier project.
It now looks like an amplifier instead of just a pile of boxes and parts.
Early Morning Lightning Storm
So, this morning, I got a little reminder about the nature of the technology we all use. I currently have the 6EM7 Vertical Amp in my office at home connected to my computer sound card. When I reached over and turned it on this morning I got an interesting surprise.
One Busy Summer
I imagine that some folks have been wondering where I’ve been since the end of May. The truth is it’s been a very busy summer. Shortly after my last blog post, I learned that I was being transferred for the second time in less than two years. So far this summer I’ve bought a new house, moved ≈1500 miles (≈2400 km), totally packed and unpacked an entire house, a complete workshop, and an electronics lab, started a new job, and basically just tried to keep my head above water. However, in the process of unpacking things at my new house, I found something interesting.
Something Different
A while back, I was at my local hardwood supplier and found a plank of wood of a species with which I was unfamiliar; marblewood (zygia racemosum). This is a South American hardwood with a golden yellow to orange color and large dark streaks of deep brown throughout. This, I thought, would make a very interesting chassis.
One Little Transposition
Well, my blog seems to be quickly becoming a list of things to avoid doing. I’ll get back to the more technical stuff soon but in the mean time I have one more blooper to share. I hope there aren’t too many objections.
So I have a new amplifier I just finished which will soon be added to the ever growing list of amplifiers on the web page. But when I was putting it together I managed to destroy a couple of expensive tubes due to a very simple error early on in the design process. Let me explain.
It’s Supposed to be Fun!
Sometimes I feel like an idiot!