Category Archives: Commentary

Reviewing the Gemtune APPJ PA1501A 6AD10 Stereo Tube Amplifier

Posted on August 17, 2016 by jwk

I recently picked up an interesting little tube amp via a group buy on Massdrop, the Gemtune APPJ PA1501A stereo tube amplifier. Try saying that three times fast! It’s a cute little single-ended stereo tube amp using a pair of 6AD10 … Continue reading →

Posted in Audio, Commentary, Electronics, Hi-Fi, Stereo, Toys | Tagged , , , , , , | 15 Comments

“Won’t that ruin the vintage sound?”

Posted on March 16, 2016 by jwk

Audio as a hobby sits in an interesting place in the world. There are hard numbers and objective measurements made with lab equipment on one end, and on the other end you have the subjective and variable linguistic descriptions assigned … Continue reading →

Posted in Audio, Commentary, Electronics, Hi-Fi, Vintage | Tagged , , , , , , , | 3 Comments

Friday Link Roundup: March 11th, 2016

Posted on March 11, 2016 by jwk

What’s good this week? Let’s see: Mohammed Samji takes us through a hifi power conditioner supplying electricity to some very expensive B&W speakers. Interesting! [Part Time Audiophile] Break something plastic? There’s a plastic welding kit for that. Looks like it … Continue reading →

Posted in Collections, Commentary | Tagged , , , , , , , , | 2 Comments

New Bench Storage

Posted on February 26, 2016 by jwk

Some pegboards, and wall mounting some parts bins, really cleaned up the benchtop!

Posted in Commentary, Photos | Tagged , , | 2 Comments

555 timer teardown (and a Retrovoltage drum trigger project)

Posted on February 23, 2016 by jwk

Ken Shirriff’s blog has a fantastic and detailed teardown of a 555 timer, the ubiquitous decades-old timer circuit that turns up in so many places: If you’ve played around with electronic circuits, you probably know the 555 timer integrated circuit, … Continue reading →

Posted in Collections, Commentary, DIY, Gadgets | Tagged , , , , , , | 1 Comment

Like Classic Receivers? Check Out This Blog

Posted on February 3, 2016 by jwk

If you’re reading this, you’re probably at least somewhat interested in vintage stereo gear, since that’s a huge amount of what I work on. There’s a lot of it out there! I just discovered a great new blog that showcases … Continue reading →

Posted in Commentary, Internet | Tagged , | 2 Comments

How to Read Capacitor Codes

Posted on January 24, 2016 by jwk

I ended up with a massive stash of mil-spec CDE Mica caps recently, and was searching for a refresher on decoding their military part numbers like “CM05FD221GP3”, since the caps came marked for their values but not their voltage ratings. … Continue reading →

Posted in Commentary, DIY, Electronics | Tagged , | 1 Comment

Merry Christmas from Retrovoltage!

Posted on December 25, 2015 by jwk

Radio & Television News, December 1954

Posted in Collections, Commentary, Vintage | Tagged , , , , , , , | 4 Comments

What’s On Your Workbench?

Posted on December 20, 2015 by jwk

People ask me what kind of gear I use at Retrovoltage and at Rain City Audio for projects. So, here we go: While it’s by no means the best-equipped workbench out there, it has a good mix of lab- and service-grade … Continue reading →

Posted in Collections, Commentary, Test Equipment | Tagged , , , , , , , , , , | 6 Comments

It’s Beginning To Look A Lot Like Christmas

Posted on December 16, 2015 by jwk

Bring the Sound of Christmas Into Your Home with RCA Victor Radio

Posted in Collections, Commentary, Vintage | Tagged , , , | 4 Comments