Hello.
I saw a YouTube review of the STA-9X and wanted to try this amplifier. But I couldn't find any measurements or what chip it's based on. Is it a TPA3255, Infinion, or something else? I also wanted to know if anyone has compared the STA-9X with the Topping B200 and Purifi. I'd be interested in your opinion. Which one should I choose for studio monitors?
Thank you.
Hi, Bishop.
I own a couple different Nuprime amps. I have no connection to Nuprime other than that I own Nuprime gear that I'm pretty darned happy with. It's reliable, and does what it's designed to do in my opinion. I already own an STA-EVO amp (not the new SE model) for a different pair of 96.5dB speakers, and I really like it. It has a very tube-like sound. It's rated at 230W/ch into 8 Ohms and 310w/ch into 4 Ohms.
Anyway, I very nearly ordered a pair of STA-9x amps to use as mono amps because I have a pair of hard to drive two-way monitors (4 Ohm/82.5dB) whose sound I really like. My speakers eat amps for lunch and spit them out, so I need a strong amp to power them. I'd heard a different pair of more efficient speakers being driven by a single STA-9x at an audio show, and I was mighty impressed by its performance. After researching the various different Nuprime amps and discussing their different power characteristics with my Nuprime dealer (John Casler), I came to the conclusion that I would be better served by buying the new EVO STA-SE amp. It'll be more powerful than the original EVO STA yet retain the sound characteristics that I already know I love.
When one chooses an amp, it's important to consider how many amps of current it produces. The Nuprime website says this about the EVO STA: "The 550W high-power ultra-thin toroidal transformer power supply has been enhanced to deliver cleaner and more stable power with lower noise floor. The entire power path fully adopts
40A ultra-high current and low resistance terminals. Improved current dynamic capability. Total of 52,000uF power supply filter capacitors."
If I remember correctly, the STA-9x delivers 10A current power. While two STA-9x amps would deliver plenty of Watts/ch, they'll lack the 'grunt' that a high current amp like the Evo STA-SE will deliver. My low efficincy two-ways sound best when powered by a high current amplifer.
What are your studio monitors rated? If I were going to power higher efficiency speakers, I'd probably opt for the STA-9x.
Just my two cents. I hope this helps you in your decision process.
Michael