Reviewed by Rushton Paul

“Bert van der Wolf is one of the best recording engineers in the business today. His recordings have only gotten better and better over the years as he's been able to incorporate into his recording chain the latest developments in high end technology. I've written many times in these pages about various of his recordings that I treasure. His releases are always of the highest musical value (with excellent artists and interesting repertoire) along with the highest sonic standards. My feeling is "If Bert recorded it, I want to hear it." I've yet to be disappointed. Rushton Paul Posi+ive Feedback”

“High-quality music at The Spirit of Turtle- I like listening to music. My taste is quite broad, both modern, classical and jazz and blues and also a bit of pop. I like to take my time to listen to music: chair in the right place, check whether the speakers have not been moved a bit by my dear spouse, find the booklet with the CD and enjoy. Sometimes I listen with headphones so as not to bother my housemates. Although, CD? I threw my SACD player out the door after it broke and switched to fully digital. I had already digitized my CD collection, but for super audio that was not so easy and in my opinion too expensive. I tried three, not to be named, streaming services for a while, but I was missing something. Because what if I stop paying monthly? Then I will lose all my music. I want it. While searching I came across the website of The Spirit of Turtle. My first purchases were Bach Solo by Raaf Hekkema and the 9-CD box (download) with the passions of Bach by La Petite Bande, Sigiswald Kuijken. What fantastic recordings. I was immediately sold. Now, a few years later, I have added too much music to mention here to my collection. Why? I already mentioned one reason, the recording quality. It strikes me that recording after recording is very clean and clear with good placement of the instruments. This is the case with a duo or small ensemble as well as with a large orchestra. With a small ensemble (I mention Van Baerle Trio, Narratio Quartet, Marc van Roon Trio) the entire ensemble is in my living room. It strikes me that recordings with violin and harpsichord are very beautiful. Raaf Hekkema's saxophone also sounds fantastic, as if he were live in my living room. I already mentioned the passions of Bach. I can really enjoy how beautifully both choir and orchestra are recorded. I have used parts of the St. Matthew Passion in my search for new speakers (I am now thinking of “Erbarme Dich”). Another reason is that I enjoy the choice of music by Bert van der Wolf-Oude Avenhuis. For example, the album Drumwise by Wim Kegel (together with Marc van Roon, among others) is of a completely different style and with fantastically recorded drums (I am thinking of the number “The land where cymbals ring” and ‘Night and Day” by Cole Porter). Furthermore, I find a whole series of albums with music for double bass (Double bass in Concertos by Jan Krigovsky), with accordion (Dance! and Love! by Cécile Huijnen and Marieke Hopman), and various albums by the Calefax reed quintet. Each and every one is a gem in terms of music and recording. Recently I also came across organ music. The album ‘Six Sonatas for Organ BWV 525-530’ by Aart Bergwerff. I find organ music rather difficult to play at home. The impressive impression of an organ cannot be reproduced in my living room. This album has succeeded well, although these pieces by Bach do not pull out all the stops. This makes me want more. I forgot to mention that the albums come with a digital booklet. The software I use (minimserver on a Synology server and BubbleUpnp on a tablet) can handle this well. So I can select the music, send it to the streamer with DAC and read the booklet in the meantime. Bert, thank you.”

Reviewed by Willem Loonstra

“Binaural - a listener's testimonial I'm a Classical Music lover and listen with headphones often. Therefore Spirit of Turtles' newest Binaural format immediately got my attention. I bought the Mendelssohn Violin Concerto by Ferschtman, for which I have the album as Stereo DSD in my collection too. What a wonderful surprise to listen to this music with the special headphone rendering. It takes me a minute or two to get used to the audiable circumstances. Is it because my brain got tricked actually? It's like some extra space has been added between your ears and the headphones. This allows for so much room that the soloist and orchestra alltogether fit very well. Furthermore, there is like a third dimension added, as if you could look straight through the orchestra, identifying individual instruments with ease. The music really is in front of you, instead of centered in your head. Pay attention to the playback volume. It should not be too loud of course, but loud enough to support that feeling of being in the concert hall. The solo violinist is presented clearly and nicely balanced with the orchestra. You can hear the passion of her playing as if she stays right in front of you. Only in a few cases there is the risk she merges a bit into the background resulting in a thinner violin sound. I can imagine this happens if physically the soloist moves a bit back and forth during playing. The string section of the orchestra sounds warm and you can almost touch them. Sometimes I was inclined to look left or right to see the violins resp. celli. In the third movement the fast rythmic countermelody played by the flute (along with the soloist) is very clear and forms a nice combination. What caught my ears as well was the detail in a timpani roll, where the individual hits were remarkably well defined. All in all a really great experience that longs for more! Willem Loonstra Classical Music and Hifi Enthusiast Sennheiser HD600 with Chord Mojo”

Reviewed by Michael Schønwandt | Director

“Bert has an acute and open musicality which enables him to inspire the musical ideas... Michael Schønwandt | Director”

Reviewed by Bob Zimmerman

“"What an exquisitely transparent yet deep sound, and impeccably balanced!"”

Reviewed by Marion von Tilzer

“"I've never experienced such an open athmosphere in a studio situation before!"”

Reviewed by Gunar Letzbor

“"... it was the moment I knew: with this man I will work together with pleasure!"”