Wouldn't it be easier to simulate tube distortions with non-linear components in the op-amp feedback loop? Or, better yet, with a DSP whereby different "tube profiles" could be selected for various degrees of sound "warmness" and noise spectra? Heck, even stick some fake glass "tubes" at the top of the enclosure, with LEDs producing soft glow of programmable intensity and hue for a steampunk-like effect.
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AIYIMA T20 Tube Pre-amplifier Review
- Thread starter amirm
- Start date
Overall, I'd say it all makes sense considering the target market: a customer base without much technical knowledge, or simply not caring about technicalities as long as it's "good enough" - which this one certainly is from an audio point of view. Nice looking tubes, even proper ones (ECC83), not starved plate design but 180V supply. Plus modern convenience like digital volume control, remote, perfect channel balance, and display.
The whole certainly is gimmicky and technically clownish somewhat. But still good enough quality to be perfectly fine in use, while looking nice if you happen to like tubes. Still cheap too, so what the hell.
The whole certainly is gimmicky and technically clownish somewhat. But still good enough quality to be perfectly fine in use, while looking nice if you happen to like tubes. Still cheap too, so what the hell.
My understanding is that it should be low because of the op amps handling this ...
Delighted to read the opinion of a tube aficionado! I'm not sure about (but I am going to listen to) this YouTube. I don't actually want 'warmth' from tubes. I bought one of these T20's and I am delighted to read this review (T20 struck me as unusual/filling a genuine niche - balanced - genuine tube gain with decent op amps to handle the outputs). Delighted to see my impressions of the volume control vindicated also!
It enhances the sound to my ears by adding body to vocals and speech. I have "improved" perceptions of stage width and depth. Really interesting imo. I changed the valves to Tung-sols. Not romantic at all. It's a pity a switchable op amp driven bypass could not have been included to challenge the nay-sayers.
thewas
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I also wonder who the target market for such is, as its distortion is too low to be audible (and unfortunately rather odd instead of even order) and people who want it for the looks usually like classic sized equipment (even better from a desired brand) and not such a typical low cost "desktop" size/style one. Maybe for confused rookies without real understanding of such who don't know what they really want and hope it will bring warm sound to their desktop system where they would have much better, cheaper and actually audible software emulations of all kind of famous tubes?
My two cents… I believe there are two aspects here: the tube technology, and the “tube sound”.
The Aiyima T20 shows that a well-designed tube preamp can perform (measure) well. Does it deliver the expected “tube sound”? I’m pretty sure it doesn’t… Tube sounding is entirely euphonic, subjective, biased… Simulating tube sounding through DSP should work pretty well, but none of the tube aficionados would go that route: it’s missing the tubes—the entire point !!! Heck, I even wonder if the brand, Aiyima, is a liability: it’s missing the subjective, biased, “cachet” of a proper tube-design boutique.
I think Amir puts the absolute transparency threshold at -115dB. I personally don’t agree with his methodology, but to be fair to him he’s saying that’s the threshold beyond which there is no conceivable argument or circumstance that a person would be able to detect a difference. In other words, he’s baking in considerable error bars and taking the most conservative figure.
The vast majority of people, audiophiles included, will have a heck of a hard time differentiating sound at even 1% THD+N (40dB SINAD). SINAD in the 80s isn’t getting in the way of anyone’s musical enjoyment.
In technical and engineering terms, definitelyoversimplification always leads to false conclusions
.Do not forget the profile, please. With crossover distortion it may be well audible.
Don't mix THD and SINAD. SINAD has noise. And I can hear noise very well. I don't want -80 dB or even -90 dB noise. Although I enjoy listening to old digital recordings with -52 dB noise, I don't want the amplifier section adding his noise. As for the THD, since all voices and musical instruments contain overtones, distortion is really not audible up to very high values, because it is masked by the useful signal.
I have been a tube guy in a previous life and I don't remember how many hours is the lifetime of an ECC83... Maybe will last long enough until you get bored and buy another new toy you fall in love at first review... Better then because if you wait too long and need to replace your aging tubes by new ones, you will discover that your gear, WTF, no longer sounds the same again... This is why I got bored with tubes and said never again...
ECC83/12AX7 really aren't that bad in that regard and last long. Not very expensive either, the good ones are like 20-30 each, so replacing a pair every 5-10 years doesn't hurt at all.
What's hurting is that you will never find a replacement tube that sounds/measures the same as the replaced unit... Unless maybe if you buy them by hundreds and hand select the winning units and discard (resell) the rest... Living aside simply defective units...
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Haha, good one.
I've replaced 20 year old cheap China ones in my old amp with new proper JJ (Slovakia) ones, matched by the shop too and still only 30€ each, and the difference was so minimal, I probably just imagined it. Naturally impossible to do an AB if it's the same amp.
Really doesn't matter. Just don't get the worst crap imaginable, as always, and you're golden.
1% THD+N should be audible to anyone. It sounds like a weak FM radio with broadband noise. At 0.5% and below, it becomes more and more difficult to identify that it is different from a more pristine output.
THD - Total Harmonic Distortion - Test Tones
Audio Test Tones : understanding Total Harmonic Distortion
www.audiocheck.net
1% and 0.5% are very clearly audible here. 0.1%(-60 dB) is barely audible and I mayn't be able to discriminate in program material, but the higher distortions should feel like a higher noise floor.
Of course, I tested it with IEMs that have very low distortion. If you use headphones/speakers whose distortion is higher than the amp, then the distortion of the former would mask the distortion of the amp.
phoenixdogfan
Major Contributor
Here's the thing: Anyone who buys a tube device wants tube sound. That warm, fuzzy glow that comes from generous, heaping helpings of second harmonic distortion. It's to be expected that it's SINAD will be in the 40's or 50"s in the same way it's expected that a Python will swallow a live rat whole. It's just its nature.
Now here Aiyima comes along and offers a tube preamp with SINAD in the low 80's--something we'd expect from a poorly engineered solid state design. Most of the distortion will be inaudible to most people most of the time. That has to mean no burnished golden glow overlaid on its sonic output. In short it falls short of the very sound effect people paying to obtain. So it has to be a thumb's down. It's neither good tube sound. nor good solid state. It's neither fish nor fowl. It's a headless panther.
Thank you for the fine review, Amir.
Now here Aiyima comes along and offers a tube preamp with SINAD in the low 80's--something we'd expect from a poorly engineered solid state design. Most of the distortion will be inaudible to most people most of the time. That has to mean no burnished golden glow overlaid on its sonic output. In short it falls short of the very sound effect people paying to obtain. So it has to be a thumb's down. It's neither good tube sound. nor good solid state. It's neither fish nor fowl. It's a headless panther.
Thank you for the fine review, Amir.
OP
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It is the same strategy as Schiit. They used to produce products with poor objective performance while mostly catering to subjective crowd. Got tired of us making them look bad
, so bought an AP and cleaned up their designs. Now they continue to cater to subjectivists without us complaining (too much).Similar threads
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