Category Archives: Stereo

Repair, Not Replace

I’m a big proponent of fixing stuff rather than replacing it.  The “new” home I moved to has a built in audio system in a lot of rooms and on the front and back porches and even a speaker way out in the woods on a deck.

The speakers on the back porch are all fouled up and only produce sound from the tweeter.  The outdoor speakers are all Polk Audio Atrium55’s which are discontinued.

Polk Audio Atrium 55

So, as luck would have it, so are the replacement speakers ( Part Number RD0756-1).  Can’t find them anywhere.

The successor to these speakers seems to be the Atrium 5’s which cost $250 at Amazon, Best Buy, eBay……….everywhere.

So let’s see how I deal with this………

Continue reading

Listen to Top Secret Radio

Well not really.  But a whole lot of radio stations out there call themselves High Definition Radio (HDR) and is really called In Band On Channel (IBOC).  If you look at the top of my pages you’ll see this image.  Where the red line is, is the center of the signal or the station frequency.  On the side of the signal are two rectangles which can can carry digital information.  This doubles the bandwidth required to 400kHz.   This works in the US because of our FM channel spacing but won’t work in other countries.

John’s Tech Blog

At any rate, there is data transmitted on the rectangles and lots of times entirely different radio stations.    This is why your car radio shows album art or tells you the name of the song and what is playing next.  Some larger metropolitan areas will also transmit weather or traffic maps.

Continue reading

3D Printed Back Load Horn Speaker Project

Back Load Horn 3D Printed Speakers

I have a 3D printer.  Well, actually 3, but who is counting?  The other night I saw a new project upload on Thingiverse for a Back Load Horn Speaker.  It was so cool and I knew I had to try it.  And besides, I had an actual need as I had just purchased a Uniden SDS200 Police Scanner and it had a little internal speaker that was mounted on the bottom of the case.   It screamed for a powered, external speaker.   Win, win.

The first thing I’d like to say about the project is I didn’t quite need all the bells and whistles the designer did.  He set his up as bluetooth speakers and that is darn cool, no doubt.  I just didn’t need to do that.  I just needed a powered external speaker.


The back panel is designed for a stereo amp board which the developer lists a source in China that costs a few bucks.   The exact same board can be had on Amazon for about $14.  Getting 2 day delivery is worth it to me.  The parts from China probably wouldn’t show for weeks.

Anyway before you build and wire these you kind of need to know how you are going to deploy them.  Let me elaborate.

Continue reading

Refoaming Old Speakers

A couple of years ago I bought an old set of Bose 501 speakers.  Audiophiles poo-poo Bose speakers but the truth is way back in the 70’s they made some decent speakers and the 501’s were one of them.

However 40 years of sitting around tends to dry rot the foam surrounds on the speakers.

Dry rotted Foam Surrounds on Bose 501

Yep, that’s what both of the speakers looked like.  And they sounded worse than they looked as well.  Actually they would sound okay at super low volume but as soon as you turned them up …….they sounded awful.

Continue reading

Saving Old Stereo Gear From Craigslist – Pioneer SX-650

Without a doubt the old Silver faced Pioneer Receivers from the 70’s and 80’s was some of the most epic stereo gear ever designed.   Sadly with the advent of cell phones and tablets everybody listens to their music on cheap earbuds while streaming low res music from some far away server.

Well not everybody does that.  But most.  And that means all those old boat anchor sized amps are in the back of the closet, the garage, in the attic and turn up at the estate sale from time to time.

Stupid old guys like me who are trying to relive their childhood will pay top dollar for an old amp that realistically time forgot.   So these days it becomes the challenge of the old audiophile (audiophool) to find one cheap and bring it back to it’s once epic status.

Continue reading

DeOxIt – What is it? What ISN’T it?

Started messing around with “vintage” audio again.  Drug a couple stereos out of the attic and picked up a new stereo or two (or three).   I’ve been heavily involved in vintage audio since around 2001 or so on and off and one thing that any old stereo guy will tell you is that DeOxIt spray is a miracle solution for audio.  Spray it on and rust falls off, light bulbs glow brighter and the gravitational force of the moon gets stronger if you accidentally spray some on the moon.


Continue reading

Adding LED Lights to Vintage Receiver – Pioneer SX-780

So I have this SWEET Pioneer SX-780 that I bought off of eBay a while back and I like everything about it but the lights are kind of yellowish and I keep seeing pics of Pioneers with Bright White or even Blue tints.   What gives?

So first of all this is an easy modification.  The old Pioneer incandescent lamps are 8V lamps and over time they get a little smokey looking and tinted.   All you really have to do is replace them with an LED lamp.  The lamp fixture in the amp is the same one in a lot of modern automobiles today.  So what you need is a T10 5 watt lamp such as this one.

So this is where it gets dicey.  People will tell you on the internet that this is a 12 volt lamp and the Pioneer wants 8 volts therefore it will be dim.  NOT TRUE.  Almost any modern T10 LED has a voltage regulator inside of it which means it will work GREAT at any voltage between say 5 and 15 volts.

Continue reading