see here what ON Semi said about THD with/without NJL https://www.patreon.com/posts/kto-sprashival-v-61728357
Let's discuss the nx2-Amp on this thread. If you want to explore the NJL devices and the claimed distortion reduction from ON, please do that in another thread - I'd be happy to participate, but I don't want to pollute this thread with unrelated stuff.
This design looks really interesting, I was always on the edge of ordering the ax board so perhaps I ought to just do it now with the nx2 ! Is there a way to get the boards with the SMD devices already installed ? Or are they reasonably easy to assemble ? Eyesight not what it used to be.
Do you mind if I ask if you're a "piece of wire with gain" person or you believe we're trying to re-create music as the artist might have heard it (or intended it to be heard) when it was created ? I only ask as this will have a bearing on how your amplifier sounds. How do you think it sounds ?
Do you mind if I ask if you're a "piece of wire with gain" person or you believe we're trying to re-create music as the artist might have heard it (or intended it to be heard) when it was created ? I only ask as this will have a bearing on how your amplifier sounds. How do you think it sounds ?
Hello Steve, thanks for your interest.
I am not paranoid about ultra-low distortion, although the ax-Amp is one of those types of amps - I could only measure down to 3.5ppm distortion with my setup, but I think it is much lower than that - hopefully I can one day get it onto an AP somewhere.
The axe-Amp is a big project, and if you do it properly, it will be expensive.
The nx2-Amp is an altogether more accessible as a project.
It's difficult for me to give a sound impression because I'm the designer! But I'd characterise the sound as big, open, with a lush mid-range and delicate top-end. The PSU on my build is substantial (2 x 22mF per rail); I'm using a high-quality 500VA transformer, so there is plenty of low-end grunt, and it drives my B&W 703s easily to very high volume levels. Importantly, it is very quiet with no audible hum or buzz with the ear in the speaker cone and the preamp connected - this is in large part due to the PCB layout and wiring, where the cables are tightly bundled and routed away from noise sources.
Anyway, if you decide to try one of the amps, I'm here to help with any technical issues you may run into.
I am not paranoid about ultra-low distortion, although the ax-Amp is one of those types of amps - I could only measure down to 3.5ppm distortion with my setup, but I think it is much lower than that - hopefully I can one day get it onto an AP somewhere.
The axe-Amp is a big project, and if you do it properly, it will be expensive.
The nx2-Amp is an altogether more accessible as a project.
It's difficult for me to give a sound impression because I'm the designer! But I'd characterise the sound as big, open, with a lush mid-range and delicate top-end. The PSU on my build is substantial (2 x 22mF per rail); I'm using a high-quality 500VA transformer, so there is plenty of low-end grunt, and it drives my B&W 703s easily to very high volume levels. Importantly, it is very quiet with no audible hum or buzz with the ear in the speaker cone and the preamp connected - this is in large part due to the PCB layout and wiring, where the cables are tightly bundled and routed away from noise sources.
Anyway, if you decide to try one of the amps, I'm here to help with any technical issues you may run into.
I believe he is.
He is the one who would put TMC on the specs. I don’t see other explanation.
Hi Andrew,
I really like this project, if the boards are available I will probably place an order in early July. But I have a few questions, ...
What copper thickness does the nx2 amplifier use?
Where does the antivandal button attach to the softstart board , I looked it up but didn't find these points.
Thanks, Roman
I really like this project, if the boards are available I will probably place an order in early July. But I have a few questions, ...
What copper thickness does the nx2 amplifier use?
Where does the antivandal button attach to the softstart board , I looked it up but didn't find these points.
Thanks, Roman
TMC is easy to implement and exploits all of the available loop gain compared to MC. Over the last 15 years or so, TMC has entered the mainstream wrt to linear power amp compensation. Douglas Self found Baxandall had figured this out just before his death, but it wasn't made public until much later. If I understand it correctly, Edmond Stuart (RIP) discovered it independently before 2010, and Cordell discussed it in 'Audio Power Amplifier Design'. On all of my previous amps, I provided a jumper so TMC could be disabled and the amplifier could then use conventional pole splitting, aka MC. This one has TMC wired in permanently. There is a bit of a write-up on the amp compensation in the nx2 presentation (also in the ax-Amp)
TMC really shows up as an improvement in HF linearity - you can use a 19+20kHz IMD test to see the difference. TMC gave >15 dB HF linearity improvement on the ax-Amp compared to MC.
TMC really shows up as an improvement in HF linearity - you can use a 19+20kHz IMD test to see the difference. TMC gave >15 dB HF linearity improvement on the ax-Amp compared to MC.
The copper thickenss is standard 1 ounce, but the current carying tracks are all wide
Hello Roman, there is a single 6.3mm tab on the PSU+Inrush PCB LIVE [HOT] that goes out to the anti-Vandal switch. The other side of the anti-vandal switch must be wired directly to the incoming neutral on the IEC power inlet. J1 on the PSU+Inrush board is the + and - to the anti-vandal switch LED (limited via 2 x 4.7k resistors to ~6.8mA). Please see the wiring diagram on slide 32 of the presentation.
Thanks, what I was asking about the boards, is there a version available, or could there be, with the SMD devices already soldered in place ?