Category Archives: General

New Standalone Tone Control coming

The old Standalone Tone Control

A long time ago we did a scrapyard project with leftover and foraged parts, it was an active Tone Control (you can read about it here) that was just intended as a working proof-of-concept for the tone control that we use in our Octantis and Kingsway models.

This unit was never in production; it was just a rough working test.

And yet… it has been the page that constantly gets the most hits on this site, and the most requests by email.

So, in this post we are announcing our intent to design a new version of the standalone tone control, functionally similar to the prototype but in a more cosmetic package.

Features list:

  • Bass and treble controls offering ±12dB of adjustment at 100Hz and 10KHz (non-parametric)
  • Switchable ON or BYPASS
  • Powered by 12volt external power supply
  • 2-tube design
  • Stereo RCA input and output sockets
  • Mode indicator LEDs
  • Can be left in circuit continuously; if powered off will automatically enter BYPASS mode

Our schedule is to have it available by Christmas 2023; pricing yet to be finalised, we’re aiming for a price point at or under $400 if possible.

Watch this space!

A name change for the Matariki amplifier

Back in 2018 when our integrated amplifier was first designed, the name Matariki suggested itself because it was designed during the winter months and completed during Matariki season. Co-incidentally, Wellington Harbour was visited by a Southern Right whale at that time which was named Matariki owing to the timing of its visit.

Our amplifier was actually named after the whale.

Times have moved on, that whale’s visit is history now, and Matariki has taken more of a dominant view in the public discourse in Aotearoa New Zealand.

ATRAD-Audio has no desire for any of our products to be seen as commercially exploiting something of deep cultural significance, so in future our integrated amplifier will no longer be sold as the Matariki.

So, starting from June 2023, and continuing the astronomical theme, the Matariki will now be known as the Octantis.

Everything else about it will remain the same, just the name will change.

See the Octantis amplifier here

Patrick Turner Tribute

Those in the vacuum tube/valve amplifier game, particularly in Australia, will probably have heard of Patrick Turner. His site turneraudio.com.au was full of information and an often-cited reference for many, written in a style and with a humour that was uniquely Patrick’s.

Many projects were presented, with background information, theory and construction information all tightly jammed in together. The man was a goldmine of information and his knowledge was guru-level.

I had some conversations with Patrick in 2018/19. During that time, he implored me to take a copy of his site, as he was not sure how long he had left, being elderly and in poor health. This was a subject he wrote about on his site as lucidly as though it was a broken radio that needed diagnosing and fixing!

Patrick died in May 2021; his site is offline now.

In tribute to Patrick and his rich legacy of work, I’ve put up the scrape I did of his site with no changes whatsoever

turneraudio.com.au tribute mirror site

Note, As time passes, links on Patrick’s site may go stale.

When suppliers go the extra mile

Since I started building amplifiers, I’ve been reliant on one supplier in particular, for my chassis and casework.

Most suppliers of parts can be replaced – however when you’re sourcing outwork services you enter into a relationship with your supplier that goes beyond a straight customer / supplier dynamic.

Introducing Embrace Design who have provided all the CNC and laser cutting and engraving services for the cases for my amplifiers.
The service doesn’t stop there however. Henri has been a rich source of suggestions and ideas and has been completely cooperative in working with me to get exactly the look and aesthetics I have been looking for, as well as a good emergency weekend source of fasteners and other necessities.
Much of the exterior appearance of my amplifiers is down to Henri’s skill with translating the designs into reality.
Worth acknowledging here.

A tale of two products

… in which I make myself unwelcome at a high-end hi-fi store.
This is a personal experience which happened over a decade ago, but I decided to put it here because it’s still relevant.
These are the two products in question

Audio Alchemy Digital Transmission Interface, US$ 1600

Generic 10/100 8-port auto-sensing ethernet hub, around US$ 40 – 60 (at the time) depending on brand.

On the day in question, I walked into a hi-fi shop and the proprietor greeted me with a wide smile. This was a real high-end place where the demo systems are set up with speaker cables as thick as fire hoses, and just the rack that the system is sitting on has a five-figure price ticket.
We got talking (this was years before I started designing and building gear myself, I was just looking at buying a new pair of speakers which is what drew me into the shop). Pretty soon he had figured out my system and had decided that it would be improved by the addition of the top product, above.
While extolling its many and varied virtues, he inadvertently tripped himself up by completely inaccurately describing the phenomenon of jitter … seems he hadn’t read up enough on the technical manual that accompanied the product.
After a little while, I attempted to summarise my understanding of this product back to him, to show him I’d been listening. He was all ready to sell me one until I started asking some questions which led me to explain the function of the second pictured device…

Conversation went something like this:
“So, this machine will take a PCM data stream at 1.4 megabits per second (Red Book CD standard), store and buffer it, then output an identical data stream according to its own internal clock, which is carefully designed to be high-accuracy and not susceptible to disruption, correct?”


“Yes, and [long spiel about how that makes it sound better, yada yada]”


“And it’s $2200.” [That was the $NZ price at the time]


“Yes, possibly the best value enhancement you can make to a digital system…..”


“OK, so what then would you say about a device that does this at around 70 times the data rate, and not for one but eight separate inputs?”


“Well the DTI represents the cutting edge of digital transmission design, so perhaps in the future something might be designed that could do what you say, but it would be a very high-end piece of equipment, so only the most serious audiophiles would require it, and that’s assuming there’d ever be a digital recording standard that would utilise such a bit rate”


“So you’re saying it’d be expensive then?”


“Something with over 500 times the processing capacity of this machine? Very!”


At which point I explained the functionality of the 10/100 ethernet hub, and then its price.
He wasn’t smiling any more.

In fact, I got the distinct sense I’d outstayed my welcome in that establishment.

– This is why I don’t go into high-end hi-fi stores any more. –

Update Dec 2021: Since the above mentioned product is long-discontinued, it stands to reason that its absence has left a hole in the audiophool world. And, an enterprising company has identified this (perhaps they came here first?) and we now have a $2,500 ethernet switch. Audiophiles, never fear. You won’t have to endure that burning sensation from all that cash in your pocket any longer.