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Class D amplifier with TPA 3250 board

Hello,

I'm new to this forum. I recently purchased my endgame setup comprised of Closer Acoustics Ogy speakers (91 SPL), REL T5X subwoofer and a custom hand built tube amplifier with EL34 tubes. The tube amplifier is giving me trouble with hissing noises, so it's constantly at the artisan's workshop. Since my speakers are extremely efficient, I was wondering about smaller amplifiers as an escape route (if the artisan can't fix the amp, he surely can). The Octavio Amp looks nice on paper. So does the Atoll IN80. Is one obviously better than the other for my revealing speakers?

Folks on another forum I shall not name seem to heavily imply that all amplifiers should sound the same (or very similar). They rave about these cheap tiny Topping/Aiyima amplifiers with class D TPA 3250 amplifier boards. These same boards are used in Genelec active monitors, so they must be good? I'm flustered because there no direct comparisons between these TPA 32xx amplifiers and more conventional/expensive branded amplifiers. The same folks on the forum I shall not name imply that I'm a dunce for spending so much money on a tube amplifier (quote: it's a distortion factory and it can't play grindcore metal music so it sucks). If it weren't for the hiss I wouldn't post here. 

Can I cheap class D amp replace a custom hand-wired EL34 tube amplifier for extremely revealing Closer Acoustics Ogy speakers?

kokakolia
russ69's avatar
russ69
3,572 posts
 

They rave about these cheap tiny Topping/Aiyima amplifiers with class D TPA 3250 amplifier boards.

Like most things in life, cheap products are not always very satisfying. What you want are products that deliver good value for the performance. In class D amps, the Rogue Hybrid Sphinx is in that category. But don't read the ASR review because they hate audiophile products and don't have the slightest clue on what sounds good. 

dekay's avatar
dekay
5,710 posts
 

FYI:

Here’s a review of the Atoll.

https://www.tnt-audio.com/ampli/atoll-in80_e.html

 

DeKay

 

mlsstl
1,457 posts
 

Do you hear hiss when the amp is hooked to the speakers, turned on, with NO source (including preamp) connected?

While sometimes hiss is connected to an amp that simply doesn't have a very good S/N ratio, it is just as often connected with a mismatch between input sensitivity and gain levels between sources, preamps and the amp.

If you have no hiss while just using the amp only, add components back one at a time and see when hiss returns. You might be able to fix the problem by decreasing the input sensitivity of the amp, reducing the output of the source, or using resistors in between the two to reduce gain.

ghdprentice
7,598 posts
 

I have an all tube system. With very efficient speakers you have a lot of great options. I highly recommend finding a a great amp made by a company, not an “Artisan”… a company that knows how to design and manufacture great tube amps… Audio Research, Conrad Johnson, Cary, VAC, or budget… Rogue. There are more… but they will be completely noiseless and sound fantastic.

kokakolia's avatar
kokakolia OP
198 posts
 

The OGY are 8 Ohm 15W. 

I heard the Unison Research Simply Italy in a shop and it was perfect. I was blown away.  I wanted to save money by having the artisan build a clone. Now I feel like an idiot. Another shop recommends Fez Audio but I didn't have a chance to go there and audition. I'm trying to prioritize Euro brands over Chinese.  

The amp was clearly defective at the analog inputs. They were all noisy. So when I plugged the speakers in, the noise gradually built up over 10 seconds and reached about 40db. It didn't matter which input was selected or if music was playing.

Today the amp is (supposedly) fixed. I have to drive over to the artisan and retrieve it. 

Thanks for the kind replies. It's funny how you guessed ASR instantly. Yeah I'm not too stubborn on getting a class D amplifier or tubes. I just drank the cool aid wanting to believe that a 60€ amplifier with a TPA 3255 would satisfy my needs. I like Atoll because they're easy to find on the used market around 500€. I am more familiar with class A/B and know it's just fine. Class D is more expensive for some reason, unless you go for the really cheap TPA boards. 

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