Like film, performances in audio don’t just occur, they must be captured; we take for granted the artistry and vision of those who guide the recording process. Conveying these musical truths to the listener is the true Spirit of the Turtle.

 -Neil Patel


Neil Patel (Avalon Acoustics) and Bert van der Wolf's friendship goes back over 25 years and the basis of the HQ|NORTHSTAR/TSoT monitoring is mainly equipped with Avalon loudspeaker technology. (see studio picture)

Groundbreaking in the day, but still at the pinnacle of what is possible in sound reproduction. A long friendship and shared passion for the subject has lead to several products sprung from their collaboration, like the highly successful Studio Mixing Monitor, whereby Bert has been working with Neil on the final tuning. All monitors in the Northstar Studio are personally tailored by Neil and many, also current Avalon products, receive their litmus test with HQ|NORTSTAR/Turtle Records® recordings.

Fine Tuned Eidolons Special-X, Indras, Mixing Monitors and Symbol Sub-woofer.

Neil Patel and Italo Adami (DAAD) in 2004 assessing the Northstar studio characteristics for adapting their products.



Founded in Cambridge, UK in 1988 by a group of expert electronic engineers, dCS, originally designed and manufactured high performance analogue-to-digital (ADCs) and digital-to-analogue (DACs) converters for major telecommunication companies and military agencies, whose major requirement was technology that delivered state-of-the-art precision, linearity and reliability.

Recognizing that this technology had a key role in music recording and playback, in the early 1990‘s we decided to concentrate on developing products for the digital music recording industry. It was in 1996 that we intensified our collaboration with Bert van der Wolf from Turtle Records®, who had been involved with dCS as a sales agent from the very beginning in 1989, and it quickly became clear that we shared the same beliefs about the recording and playback chain and how recorded music should sound to the listener.

At dCS we believe that the role of recording technology and the hifi system is to preserve all of the subtle information on a recording through the reproduction chain and present it to the listener with every last nuance of the emotional content intact. Our scientific approach to the conversion of the live performance into digital bits (A-D) and those same digital bits back into living and breathing music (D-A) is a perfect fit with the talents and vision of Bert. Over the years we have shared ideas, debated how to implement and use various technologies and driven each other on to continually improve our products.

From the dCS perspective its been a wonderful and fun partnership. Yes, our products are high end - a combination of world class craftsmanship and leading edge technology; but for the people who buy dCS and listen to wonderful music such as that recorded by Turtle Records®, our systems offer the chance to experience that unique, spine-tingling moment where the world stops and there is… Only the music.

- David Steven, Managing Director 

In the Picture: For dCS' 25th anniversary a special gift-box with SACD and BLURAY was produced for dCS with for the first time "The Spirit of Turtle" as branding, a name proposed by David Steven.

30-11-2013. David Steven at the road show of dCS' 25th Anniversary celebration and presentation of The Spirit of Turtle at Rhapsody's Hilversum, The Netherlands. 



We have been working with Bert for a long time.

Supplying special Siltech and Crystal cables with an ultra silent background noise and error free conductivity has helped bringing Bert ‘s deep musical understanding to great sounding recordings, both musically and entertaining from a sound perspective.

Not often do we find recording engineers who combine both skills in a uniquely involving way.

Yes, he may be at times demanding, but for a good reason, the results speak for itself.

We are very happy to contribute to the wonderful unique Dutch label, one of the few independent labels left!

 - Edwin van der Kley Rynveld, CEO to International Audio Holding, The Netherlands


Edwin van der Kley Rynveld and Gabi Rynveld from Siltech and Crystal cable have been supporting Northstar Recording Services and The Spirit of Turtle for almost 25 years now. Still we use almost exclusively Siltech and Crystal Cable technology for our microphone-, break-out, interlink- and loudspeaker cables.

Several professional product lines have been set up over the years through our collaboration, like the Siltech PRO-S4 and PRO-S5 cables. The most advanced technologies in metallurgy and isolation give us the opportunity to reach far beyond the normal specifications of professional audio tools. The microphone cables of our main microphones in all the recordings, are a Silver-Gold mono-crystalline design, which delivers unprecedented transparency, neutrality and transient response. 

The support of Edwin and Gabi has shaped the results of The Spirit of Turtle recordings to a high extend!


Siltech mono-crystal Silver/Gold Microphone cables, power cables and Crystal Cable break-out cables.


Sonodore microphones have been conceived by Rens Heijnis from the Netherlands, directly dedicated to us in the early 90's. From the early days at Channel Classics, they have been the basis of the ultra transparent recordings we have produced. No other microphone brand has been able, for almost 30 years, to change our mind. From that first moment on, these microphones have been the sole basis of all recording projects by Bert van der Wolf from the Spirit of Turtle/HQ|NORTHSTAR.

A true collaboration and friendship between Rens and Bert have lead to many new products, from mixing desks and microphone pre-amps to Boundary Layer microphones that are responsible for the HQMM recording principle and for about 10 years Northstar has been handling the world wide distribution of the microphone products of Sonodore.

Until today, every recording by The Spirit of Turtle is almost purely Sonodore based, with only a few additional other spot-microphones from more well known manufacturers, which is a tremendous prove of excellence for these unrivaled custom made products!

The legendary RCM-402 Omnidirectional microphone, first conceived for us in the early 90's. 

The Sonodore Boundary Layer Microphone, custom produced for Northstar Recording Services / The Spirit of Turtle and basis of the HQMM Immersive microphone matrix.


 Merging Technologies has been filling the gap of dCS when the latter withdrew from the professional audio community. All recordings are done with the extensive use of Merging's ADC/DAC/DDC and workstation "Audio over -IP" technology.

From day 1, there again has been a thriving collaboration and friendship between Bert van der Wolf of TSoT and the Merging Technologies team, regarding new developments and feedback on new product lines. From 2015 onwards Edison Production Company, the home of TSoT has been distributing NADAC products in BENELUX, Germany and Austria.

Without the truly inspiring passion of the Merging team and the unrivaled products like the Merging +CLOCK-ULN, many results in our recordings would have been impossible and together with the other great supporters above, The Spirit of Turtle can always be at the State of the Art of technology.

This to only serve the talented musicians that meet us during the recordings and fulfill a live long passion for the recorded arts.

In the Picture: The Merging Technologies +CLOCK-ULN-X, the one and only (!) working prototype of Merging's flagship Master Clock unit existing.

+CLOCK-ULNx during recordings in Bratislava.

The Merging Technologies team, Claude Cellier, Dominique Brulhart and Chris Hollebone, together with Takahito Miura during an evaluation listening session on the performance of +CLOCK-ULN at the 5.1 Surround Sound demo Room of the High End Audio show in Munich, May 2019.

Claude Cellier and Bert during their presentations at the HE show Munich May 2019.



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