DSP Done Dirt Cheap!

Posted on by hoppesbrain

How would you like a DSP speaker management processor ~and~ digital mixer for less than the price of a low-end speaker processor like a DBX DriveRack? A LOT less… Like $25? 😲

These Biamp Nexia SP DSP Speaker processors from circa 2008 are cheap and plentiful on the used market. Very high quality and built to last. I got two for $50 on Craigslist! Normally, they’re used in big distributed audio systems, like in conference centers, concert venues, sports arenas, and churches. The Nexia SP Speaker processor is just one part of a whole ecosystem of networked teleconferencing, video conferencing, and distributed audio products.

But they’re great for pro audio applications as well! They just don’t happen to have any XLR connectors. It’s all terminal blocks, as is common in large installed commercial systems. But you can add XLR connections on a patch panel. (Or RCA jacks for a home system. See here for Biamp’s wiring diagrams for unbalanced connections. )

Continue reading DSP Done Dirt Cheap!

Bluetooth KOSS Resto-modded headphones!

Posted on by hoppesbrain

OK these are just beyond sick! Wireless Bluetooth version of my Resto-modded Koss DJ Headphones!

And they’re switchable from Bluetooth to wired connection! A removable cord is realized with a mini-DIN plug. The cord features a holder for the 1/4″ adapter, and a section of bungee-cord strain relief.

Continue reading Bluetooth KOSS Resto-modded headphones!

Resto-modded Koss DJ Headphones now in BLACK!

Posted on by hoppesbrain

OK, these are just too gorgeous!

These beauties are Koss Pro/5LC, and are basically the same headphone as the Koss Pro/4AA that I resto-modded in a previous blog post.

The Pro5/LC has a squared-off earcup instead of domed, and features level-control dials along the bottom edge. (Thus Pro5/LC) I removed the dials and filled the gap with epoxy putty and painted it to match. It’s hardly visible.

Yes, they are for sale, and yes they are expensive! It’s a entire day’s work for me to build a set of these headphones. I sell the beige Pro4/AA for $550, and these are $600, because of their rarity, and the extra work involved filling the gap left by the removal of the level controls. They come with lifetime earpad replacement for $20, and a $50 flat-rate repair warranty.)

The Koss DJ Headphones, now with a locking headband! (Article has been extensively updated.)

Posted on by hoppesbrain

Updated article:
Koss Pro4/AA Headphones resto-modded into great DJ Headphones!

Why don’t all DJ headphones do this? I’ve installed a locking mechanism to the headband on my Koss resto-modded DJ headphones! No more fumbling to adjust while I’m playing. If you buy a set from me, they will now come with this feature.

Koss Pro4/AA Headphones resto-modded into great DJ Headphones!

Posted on by hoppesbrain

Did you know that stereo headphones for personal music listening, were invented right here in Wisconsin? In 1958, John C. Koss, and engineer Martin Lange, Jr. invented the Koss SP/3, as an accessory to a new stereo portable record player. The headphones were a smash hit, and proved more popular than the record player!

Continue reading Koss Pro4/AA Headphones resto-modded into great DJ Headphones!

A GFA-555 customer success story. Audio-Precision verified performance!

Posted on by hoppesbrain

Hi Chris! I bought some refurb stuff from you a couple years ago to rebuild an old 555. I got the input board and the soft start power supply. I just wanted to circle back and tell you how it’s working out. I recently was able to get an Audio Precision System 2 analyzer in trade for some work. I have been learning how to use it and thought I’d run the 555 on it!

This is just a small sample – looking amazing:

image.png

The frequency response is very flat. And the THD+N is really low even at very low volume. THD is even across the frequency range. 

Nice stuff, Chris! You gave me a lot of help and it’s sort of kicked off a hobby for me. I’ve been fixing up old gear in my spare time and have had a lot of fun with it. 

Chris