Category Archives: Commentary

Reviewing the Gemtune APPJ PA1501A 6AD10 Stereo Tube Amplifier

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

AUX in Volvo Stock Head Unit Radios

Dangerous Prototypes shares an article detailing how Karl Hagström hacked an aux input to his 2007 Volvo V70 stock stereo. Why, why, why isn’t there an AUX input on my car stereo from 2007? Yes 2007 was before the big … Continue reading

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

“Won’t that ruin the vintage sound?”

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

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

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)

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

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

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!

Radio & Television News, December 1954

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

What’s On Your Workbench?

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