@SIY has measurements posted for this amp here:
Fresh From the Bench: A Tale of Two Class-D Amplifiers Orchard Audio BOSC and Purifi Audio Eigentakt EVAL1Stuart Yaniger examines new amplifier solutions from two disrupting audio companies. Purifi Audio from Denmark, founded by Bruno Putzeys, Lars Risbo, and Peter Lyngdorf, together with a remarkable engineering team; and Orchard Audio, with a product developed from the creativity and...audioxpress.com
They correlate with all the measurements that I have posted in this forum. Basically what I posted has been verified by a third party.
It was a blind test, not a DBT. As someone who does design experiments for a living, I don't see how a single blind test was done incorrectly in this particular case.I haven't had the patience to read through all of it... But has this thread grown over 100 posts, because the OP refuses to do a DBT (or simply a BT) correctly?
Dude - feel free to remain in the warm embrace of your presumption, but if you want to be sure of the truth there is no replacement for a proper blind test, that a many here have advised you on how to do it.
Anyways - best of luck to you, I'm unwatching.
Welcome to the club, with this sentence, "One thing I did notice was that my ability to hear a difference was dependent on the speakers used", you have just become a subjectionist.We recently got a few folks together to do as close to a 'blind test' as we could of the Purifi Eval1, McIntosh MA252 and the Benchmark AHB2. We had 3 reviewers and a 4th person who switched the gear.
Test Setup: Topping D90SE (balanced outputs) directly connected to each amplifier.
Streamer: Tidal Bluesound Node connected via optical SPDIF to Topping D90SE
Speaker: Magico S5 MKII
Randomization: For each song selection: Each amplifier was randomly assigned a number 1,2,3, A random amplifier order was used for playback.
Level Equalization: For each song/amplifier, a 1K sine wave was used to normalize the level to about 0.1 Db using a calibrated microphone, Focusrite 2i2 and REW before playback of each selection. The level was managed using the Topping D90SE in pre-amp mode and managed to about 90-95 db.
Process: 6 songs. Each song was played and the reviewers wrote comments and then rank ordered amplifiers. Between switches loud music was played to drown out any switching related noises that could indicate which amplifier was being connected.
Some of the selections used:
1. Africa -Toto
2. The Street only knew your name (extended version) - Van Morrison
3. What a wonderful world - Eva Cassidy
4. Beethoven: Triple Concerto in C Major, Allegro - Mutter/Ma/Barenboim
and a few others.
Results: 2 out of 3 reviewers had very similar results with the Purifi in 1st place and the Benchmark in last place in all or a majority of the time, while one reviewer had mixed results from which we couldn't determine a specific pattern.
I was one of the reviewers and I picked the exact same order 100% of the time of the Purifi in the top spot followed by the McIntosh and the Benchmark as a distant 3rd place. What I noticed that distinguished the best (Purifi) from the worst (Benchmark) in my case was the following: The Purifi had better clarity, detail and high end compared to the other two, especially the Benchmark and it was noticeable. It was especially easy to hear differences for me with complex stringed instruments like a strummed acoustic guitar or cello and cymbals and triangles.
This wasn't the result that we were anticipating going into the comparisons. Based on the ASR reviews all of us went into thinking that Benchmark would be far ahead of the other 2 amplifiers based on its measurements. One of the reasons for the bakeoff was that one of the reviewers was seriously considering buying the Benchmark but wanted to do a comparison before. He decided to pan the Benchmark and buy the Purifi instead.
I hate add fuel to this debate about whether amplifiers with great specs can sound different, as I went into this believing that it wasn't possible, but some of the differences we heard weren't subtle. I am really curious as to whether there is some psycho-acoustic reason for this or limitations in what and how we measure these systems to begin with. I actually bought the Purifi Eval 1 and an NAD 2200 which I upgraded based on the measurements from ASR with the assumption that I wouldn't be able to hear a difference and I was quite surprised by the fact that there were differences. One thing I did notice was that my ability to hear a difference was dependent on the speakers used. On a few run of the mill speakers, I really couldn't tell much of a difference as they themselves just don't have the detail resolution of the S5 or the Magnepan LRS.
I must add it was loads of fun and I would highly recommend comparing the Benchmark and Purifi since in theory there should be no real difference that you should be able to detect to see if you can.
But exactly with a 'switch' you build in a systematic error, which would have the greatest effect especially with the purifi with the very high DF.Yeah it would be nice to have had a 'switch' as that would have made the process faster allowing for more samples also. We will think about that for next time.
Based on my post #64, the amps will become more equal when using a speaker 'switch' with an assumed contact resistance of 0.05mOhm (2x0.025) and that is less desired in a comparison! Idealized calculation approach:
AHB2 (8ohms, 6.5kHz): DF > 65 (without 'switch'), > 47 (with 'switch')
Purifi (8ohms, 6.5kHz): DF > 1500 (without 'switch'), > 145 (with 'switch')
Ich kann Deutsch sprechen und lesen.