Aiyima’s new balanced amplifier- A20

[Elvom]

When rotating the HPF to minimum position... is there a physical resistance and does it actually switch off (relay can be heard clicking)? As it is the case e/g with the Douk Audio A5 & A5 Pro?

The knob stops at 60 hz, but you can enable or disable hpf with the front lever, it has 3 positions: off, on(disables hpf), and hpf(enables hpf)

 

[pickyAudiophile]

The knob stops at 60 hz, but you can enable or disable hpf with the front lever, it has 3 positions: off, on(disables hpf), and hpf(enables hpf)

Sorry, my bad! There's that front switch I completely forgot about. - Somewhat ankward decision anyway combining it with the power switch.

 

[Jon L]

Question for Aiyima. What is the official DC input jack size for Aiyima A20? Internet search seems to indicate it is 5.5/2.5, but many 5.5/2.5 male connectors I have around don't fit. For example, Oyaide DC-2.5G (5.5/2.5) male connector generic Chinese 5.5/2.5 connector will not insert, blocked right at the DC jack. I even tried some 5.5/2.1 connectors (Oyaide), which doesn't insert, either.

The DC connector on the stock Gan 48V/5A power supply does fit, which I suspect is 5.5/2.5 but with "wiggle room" due to plastic barrel with spring-loaded inner metal contacts. The Aiyima DC input jack is also one of those made of metal strips bent back, so perhaps my A20 has sample variation in size?

Oyaide 5.5/2.5 (red), Stock plug(middle), then Oyaide 5.5/2.1 (right)

 

[Jon L]

There also seems to be a significant sound difference when "Bypass" is engaged, but what exactly is bypassed? Is it just the volume pot or is there more circuitry/opamp being bypassed?

 

[AIYIMA]

There also seems to be a significant sound difference when "Bypass" is engaged, but what exactly is bypassed? Is it just the volume pot or is there more circuitry/opamp being bypassed?

Hi! Thanks for your question
When "Bypass" is engaged, only the volume knob is bypassed.

 

[AIYIMA]

Question for Aiyima. What is the official DC input jack size for Aiyima A20? Internet search seems to indicate it is 5.5/2.5, but many 5.5/2.5 male connectors I have around don't fit. For example, Oyaide DC-2.5G (5.5/2.5) male connector generic Chinese 5.5/2.5 connector will not insert, blocked right at the DC jack. I even tried some 5.5/2.1 connectors (Oyaide), which doesn't insert, either.

The DC connector on the stock Gan 48V/5A power supply does fit, which I suspect is 5.5/2.5 but with "wiggle room" due to plastic barrel with spring-loaded inner metal contacts. The Aiyima DC input jack is also one of those made of metal strips bent back, so perhaps my A20 has sample variation in size?

Oyaide 5.5/2.5 (red), Stock plug(middle), then Oyaide 5.5/2.1 (right)
View attachment 483163

Our plug is the standard 5.5 × 2.5 mm. May I ask if you were able to connect it properly?
Also, are there any other issues you’re experiencing during use?

 

[Jon L]

Our plug is the standard 5.5 × 2.5 mm. May I ask if you were able to connect it properly?
Also, are there any other issues you’re experiencing during use?

Input jack on A20 has metal "petals" on the walls, which must have some variations, so certain male connectors like Oyaide initially cannot fit until wiggled and pushed in with quite a bit force. After expanding the metal petals, the plug does insert, rather tightly.

 

[Audionaut]

t's just like the 4K and 8K TV market: the static specs look fantastic, every parameter seems perfect, every pixel is precisely where it should be, yet motion performance is often blurry—but there's no metric telling you that

It's relatively simple: the display is very good, but the video processor is not up to date.

However, the best models from Hisense and TCL no longer have any problems with this, even in the mid-range models.

 

[delta76]

Is there a specific reason we still dont have measurments on ASR?

Aiyima has supplied all of the Youtube "reviewers" (snake oil sellers) with their units, bunch of them with the A20 + T20 combo, even the ones with like 500 subs and yet we still have no tests on ASR?

because measurements take time and Amir is in no business to jump on a hype train to get more viewers/subscribers. He does not want/need to be the first - clear and simple - something youtubers, especially smaller ones, desperately do. I can only imagine his backlog is long and only if some product sparks his personal interest, he will go with FIFO approach

 

[Audionaut]

Apart from the design, how does the A20 differ from the A70 Stereo?

 

[IceLord]

Apart from the design, how does the A20 differ from the A70 Stereo?

Apart from some internal components or dissipation improvements (due to the new box shape and design) ... I would say main improved feature is HPF (and that's all).

 

[Pep2020]

Apart from some internal components or dissipation improvements (due to the new box shape and design) ... I would say main improved feature is HPF (and that's all).

And bypass switch

 

[ampguy]

One thing that would be interesting to me in speaker reviews is if @amirm had a way to measure distortion if a full range source is distorting a speaker. I suspect that many speakers measure well in their specified range, and suggestions of needing a sub may be recommended, but do some speakers distort more than others, and thus benefit from a HPF?

 

[IceLord]

And bypass switch

You're right, that's something A70 does not have... but volume control bypass is not a main improvement, IMHO.

 

[ampguy]

You're right, that's something A70 does not have... but volume control bypass is not a main improvement, IMHO.

Unless you measure it against an A70 with volume at same output as T20 with bypass engaged, it's questionable whether it's an improvement. I have multiple bypasses (tone, digital, etc.) on my Japan made PM7005 integrated amp, and I don't think I've a) seen measurements of their benefit, or b) heard differences with them bypassed.

 

[toilagamer852]

Do I really really need the T20 together with A20 for the best sound quality?
Are the original tubes fine or should I replace with something else?
How about the op amp?

I mostly listen to music and watch anime. I'm a big fan of neutral balanced sound btw.

 

[Schlippwhip68]

Do I really really need the T20 together with A20 for the best sound quality?
Are the original tubes fine or should I replace with something else?
How about the op amp?

I mostly listen to music and watch anime. I'm a big fan of neutral balanced sound btw.

No, the T20 is not a necessity for the A20.The appreciation of the sound including the T20 is subjective and many will prefer a direct link from an high resolution dac.
The trick with the preamp is to find the most neutral components for the ‘Tube/Valve sound’ to shine through. I am not sure which op amps Aiyima have used in the T20 but some have used the opa1656 to replace whatever they did use as well as the Sparkos model.

I can see why the opa1656 was used as it’s a very clean, detailed balanced op amp and will not colour the tubes sound. The Sparkos ss3602 (?) on the other hand may colour the low frequency a little by comparison.

I plan on sticking the Muses 02 into the A20 and even maybe the T20 as a like the sound of that op amp quite a lot. It’s a warmer sounding chip with a clean, dark background and punchy bass and I personally don’t mind if it adds just a touch of colour to the tubes. I also have the opa1656 here which I will try in the T20 with the Muses 02 in the A20.

In your situation and what you are looking for if you were to go for the T20 then I would go for the opa1656 in the T20, it’s the safest, most neutral and inexpensive option without any compromises and Psvane Horizon tubes. These tubes are an upgrade apparently but not cheap, around twice the price of the stock Psvane tubes. That said I don’t plan on upgrading the tubes as the stock tubes already sound decent.

Depending on your budget, if it’s not large then I would go with the opa1656 first. I cannot guarantee the result will be exactly what you maybe looking for as I have yet to test these when my amps arrive but speculating on what is already known regarding the characteristics of the opa1656 I would say these may work best. The tube type are new to me and actually wished Aiyima used the more common 5654 but it is what it is and the type used have various manufacturers and quite a vast range of differences in prices. Psvane Horizon seem to be a popular choice for upgrading from stock tubes.

Another upgrade to the T20 would be the power supply. Replace the provided supply with a Linear Power Supply or an iFi Power X if the ampere requirement is within regulations. I would expect to hear a difference with either of these options for the better.

You could say that would be the T20 maxxed out on consumer upgrades.

Cheers!

 

[toilagamer852]

No, the T20 is not a necessity for the A20.The appreciation of the sound including the T20 is subjective and many will prefer a direct link from an high resolution dac.
The trick with the preamp is to find the most neutral components for the ‘Tube/Valve sound’ to shine through. I am not sure which op amps Aiyima have used in the T20 but some have used the opa1656 to replace whatever they did use as well as the Sparkos model.

I can see why the opa1656 was used as it’s a very clean, detailed balanced op amp and will not colour the tubes sound. The Sparkos ss3602 (?) on the other hand may colour the low frequency a little by comparison.

I plan on sticking the Muses 02 into the A20 and even maybe the T20 as a like the sound of that op amp quite a lot. It’s a warmer sounding chip with a clean, dark background and punchy bass and I personally don’t mind if it adds just a touch of colour to the tubes. I also have the opa1656 here which I will try in the T20 with the Muses 02 in the A20.

In your situation and what you are looking for if you were to go for the T20 then I would go for the opa1656 in the T20, it’s the safest, most neutral and inexpensive option without any compromises and Psvane Horizon tubes. These tubes are an upgrade apparently but not cheap, around twice the price of the stock Psvane tubes. That said I don’t plan on upgrading the tubes as the stock tubes already sound decent.

Depending on your budget, if it’s not large then I would go with the opa1656 first. I cannot guarantee the result will be exactly what you maybe looking for as I have yet to test these when my amps arrive but speculating on what is already known regarding the characteristics of the opa1656 I would say these may work best. The tube type are new to me and actually wished Aiyima used the more common 5654 but it is what it is and the type used have various manufacturers and quite a vast range of differences in prices. Psvane Horizon seem to be a popular choice for upgrading from stock tubes.

Another upgrade to the T20 would be the power supply. Replace the provided supply with a Linear Power Supply or an iFi Power X if the ampere requirement is within regulations. I would expect to hear a difference with either of these options for the better.

You could say that would be the T20 maxxed out on consumer upgrades.

Cheers!

I read somewhere in this forum that for a tube preamp, there will always be a cheaper solid state preamp that perform equally well if not better, is it true?
Objectively, if I don't want to spend more than $300 on preamp, what will be my best option to go with the A20? Personally I don't care much about tube aesthetics and only care about budget options that maximize sound quality. I'm looking at the Fosi P4 now.

Last but not least, when I read the previous pages, someone said that preamp is absolutely necessary with class D amp, otherwise the sound will be too analytical and lifeless. Is it true?

 

[Losmi]

In the next few days, the D20 DAC will be released - maybe it's better to try pairing the A20 with that first. Later, you can try the T20 with tubes.

 

[Schlippwhip68]

I read somewhere in this forum that for a tube preamp, there will always be a cheaper solid state preamp that perform equally well if not better, is it true?
Objectively, if I don't want to spend more than $300 on preamp, what will be my best option to go with the A20? Personally I don't care much about tube aesthetics and only care about budget options that maximize sound quality. I'm looking at the Fosi P4 now.

Last but not least, when I read the previous pages, someone said that preamp is absolutely necessary with class D amp, otherwise the sound will be too analytical and lifeless. Is it true?

Well that could be true to the ear of the person that wrote that statement concerning a solid state pre amp. We have to remember that in Audio while measurements are helpful, mostly it’s one’s own ear that will decide the outcome of the wallets weight loss. Some people prefer a more analytical approach to music and solid state will certainly provide that accuracy. That being said, the T20 is not a sloppy sounding pre amp either by all accounts. I personally like using tubed pre amps when using clean cheaper class d amps. The Fosi Audio P4 is a solid state pre amp and not expensive which has favourable reviews alongside the bigger Fosi Audio ZP3 another solid state pre amp but balanced which the P4 is not.

A tube preamp will add a touch of colour or character to the sound, this being more body or weight to the over all sound signature, in some cases more width and depth to the soundstage. At least I have found that to be case in my own experience, more warmth too. This might be controversial to say but it’s like adding an R2R dac into the chain rather than a Delta Sigma chip dac. The R2R resembles a more tubey sound which again will be down to personal preference.

I would say the best tubed pre amp option under $300 could very well currently be the T20. It has been well engineered, is quite a big advance over previous pre amps from Aiyima and the other currently popular small Chinese manufacturers in this bracket like Fosi Audio etc.

Amirm’s review of the T20 has proved the measurements for you to read. He was very happy with the results of his testings.

My own T20 should arrive this week along with the A20 amplifier.