AIYIMA T20 Tube Pre-amplifier Review

[pdodo2003]

Hello .
I got my T20 a few days ago . Still stock ,but want to upgrade to Horizon tubes and opa 828 in future .
I am in need of a little help from anyone who knows and wants to share .
So I have the Topping D50 III dac and wanted to trigger the T20 from the dac , but I can't make it work . I can confirm the cable is good , I tried it with my amplifier from denon source (dac) , so cable is good .
One more thing is that Aiyima T20 is able to trigger start my amp with the cable , but not working when I try to start T20 from dac or denon . Is the ,,dac" section from up top aiyima input ? Because the ,,amp" section is clear and it works . But the dac section I can't make it work ...I am out of ideas . Ohh and I have stereo 3.5 mm cable , I put a picture of the cable . Any help is much appreciated

 

[franz777]

Hello .
I got my T20 a few days ago . Still stock ,but want to upgrade to Horizon tubes and opa 828 in future .
I am in need of a little help from anyone who knows and wants to share .
So I have the Topping D50 III dac and wanted to trigger the T20 from the dac , but I can't make it work . I can confirm the cable is good , I tried it with my amplifier from denon source (dac) , so cable is good .
One more thing is that Aiyima T20 is able to trigger start my amp with the cable , but not working when I try to start T20 from dac or denon . Is the ,,dac" section from up top aiyima input ? Because the ,,amp" section is clear and it works . But the dac section I can't make it work ...I am out of ideas . Ohh and I have stereo 3.5 mm cable , I put a picture of the cable . Any help is much appreciated

The Topping D50 III trigger output is mono, while the T20 is stereo, with the tip and ring being 12V positive and the sleeve being negative. You could try making a stereo-to-mono cable like this. In my experience, the T20 trigger doesn't work with many devices.

 

[Ykar]

My suspicion (as discussed p17) is T20 can not be triggered on, it can only trigger out on both sockets. Very happy if anyone proves that wrong with effective testing.

 

[pdodo2003]

Hello.
Unfortunately it seems that both socks are output only , no input , so you can not start it from a source , dac , etc.
This is what aiyima said in my email sent to them , they said the T20 is capable of only output , no Input. So ...that's bad , but the preamp is really really nice and good sounding

 

[ICIETDIYEUR]

People Hi

It's a shame because I'm convinced that by removing the 2 tubes and their dedicated circuits (which 'destroy' the SINAD without actually bringing the desired harmonics 2 because of the SEPP assembly, and not SRPP, probably badly powered and optimized... in which case it would be assessed by the measurements), this device would have been very efficient in addition to having been well thought out with a 'unique', nice and modern look

NB: to obtain harmonics 2, it was enough to use OPA2828 'in the right place' in the circuit by observing figure 6-43 on page 15 of its datasheet.

This Op-Amp is excellent, J-FET type with very good characteristics and even allows, depending on the circuit topology, to do without a link capacitor unlike those of bipolar types (such as LME49720).

Although more expensive to purchase than LMEs, the savings made by not using additional 'multiple' capacitors (+ circuits + soldering + degradation of measurements + replacement to be planned over time, ect...).

But much more: obtaining a reliable device, with excellent measurements and ABOVE all a very high satisfaction of customers (who will undoubtedly praise this product)

AIYIMA, you only have to make a version 2 (II) or 'Pro' as some do

 

[ICIETDIYEUR]

Precision: I am not concerned by this type of device since my DAC knows how to do all this in the expected way with much better measurements ->

Here is some 'H2' that we would have liked to obtain with tubes ->

It should be noted that the H3 on this measurement (TOPPING DX5, not DX5 II, in valve sound mode) is less 'noisy' than the best measurement obtained with the device (AIYIMA T20) in this review

Moreover, the XLR measurement is not as good as the one obtained in RCA, which allows me to deduce, without having seen the circuit of this device (AIYIMA T20), that the signal is not balanced from its input to its output (otherwise for this it would have been necessary 4 rigorously paired tubes and, of course, another 'design' of its circuits)

But pretend I didn't say anything...

As Master Yoda would say: "You do it or you don't, there is no try"

 

[morejazzplease]

But pretend I didn't say anything...

I wish I could.

 

[antcollinet]

"You do it or you don't, there is no try"

"Do ... or do not ... there is no try"

As in audio reproduction, accuracy / lack of distortion is key.

 

[SMen]

Is it not the case with this T20, that because it is a hybrid two of these valves suffice for balanced operation? ... Just thought I'd ask generally, but I'm pretty sure Aiyima answered this also.

This seems to measure well enough - always nice to go back to read the original review on page 1.

 

[ICIETDIYEUR]

Hi.

Here is the simplified SRPP diagram in 'SINGLE END' (RCA jacks) which uses the 2 triodes of each tube for one channel ->

In 'BALANCED' mode, the signal also has an audio ground (not to be confused with the ground which is the ground of the power supply) but it uses two signals (+ or 'hot' and - or 'cold') instead of only one in the case of the 'SINGLE END' mode which needs one valve (tube) to operate per channel.

Also to work in 'full mode' Balanced, it will need twice this circuit for each channel, i.e. a total of 4 valves (tubes) for the device since it already uses 2 for the simple 'SINGLE END' mode...

... i'm just a little technician, not a science fiction novel writer and even less a magician, which means that I don't upset the reality of science, which is the leitmotif of this site:

I'm just observing, nothing more

 

[Ykar]

What about that one ?

Is it possible to have fully balanced from input to output amplification with only 1 tube?

Was looking at a design for a class D amp with a tube input stage. I only see one tube for the mono block. My question is, can you have a fully balanced design with one tube in it... wouldn't you need one for each inverted signal? Please forgive if its a dumb question.

www.audiosciencereview.com

 

[SMen]

Each 12AX7 tube contains two independent triodes, so my understanding is that a pair provides four active gain stages.

 

[KL....]

Hi.

Here is the simplified SRPP diagram in 'SINGLE END' (RCA jacks) which uses the 2 triodes of each tube for one channel ->

View attachment 494947

In 'BALANCED' mode, the signal also has an audio ground (not to be confused with the ground which is the ground of the power supply) but it uses two signals (+ or 'hot' and - or 'cold') instead of only one in the case of the 'SINGLE END' mode which needs one valve (tube) to operate per channel.

Also to work in 'full mode' Balanced, it will need twice this circuit for each channel, i.e. a total of 4 valves (tubes) for the device since it already uses 2 for the simple 'SINGLE END' mode...

... i'm just a little technician, not a science fiction novel writer and even less a magician, which means that I don't upset the reality of science, which is the leitmotif of this site:

I'm just observing, nothing more

Thank you, @ICIETDIYEUR, the SRPP can be done with both sides of 1x 12AX7 Triode Tube, can't it, as you have shown? The TL20/SEPP delivers SE to the LM4562 which inverts the SE input to Balanced/XLR output, doesn't it, so the SRPP could also do this, couldn't it? The RCA/LM4562 is feed L/R SE outputs, as shown, isn't it?

@ICIETDIYEUR, to ask, are you suggesting that the TL20 SEPP could easyly be changed to SRPP?

 

[ICIETDIYEUR]

Hi KL....

I mentioned a 'FULL BALANCED' circuit, hence my intervention, not a 'technical tinkering' (e.g. balancer) that allows to 'recreate' a balanced signal from an 'SE' signal, which is applied with this device.

It just seemed interesting to me to specify it, that's all: I didn't mention the possibility of carrying out a 'MOD' on this device, even if it is undoubtedly possible and would improve the measurements obtained...

 

[Noske]

"Do ... or do not ... there is no try"

As in audio reproduction, accuracy / lack of distortion is key.

Perhaps you mean noticeable distortion, and as a consequence accuracy is compromised?

 

[antcollinet]

Perhaps you mean noticeable distortion, and as a consequence accuracy is compromised?

well I certainly noticed "Do ... or do not ... there is no try" being distorted into "You do it or you don't, there is no try"

[/star wars pedant mode]

 

[Noske]

well I certainly noticed "Do ... or do not ... there is no try" being distorted into "You do it or you don't, there is no try"

[/star wars pedant mode]

Pedant status duly recognised. Thankyou for sharing that; it provides me with a related thought (and recognising that we are still on the T20 thread) and which I shall try to convey. I may fail.

What if the distorted version of the original - in this instance, perhaps by virtue of barely noticeable (to non-pedants) alteration of grammar and punctuation - makes it more pleasant or easier to read and comprehend?

Alternatively, are there any objective rules which stipulate that this inaccuracy must necessarily render the distorted version, one not intended to be conveyed by Master Yoda, to be any less pleasurable to those with English as their first language (except to those who by virtue of their pedant status may prefer the original) ?

I think I may be all thought out for a bit.

 

[Mikig]

Without overdoing the modifications, I replaced the tubes with some I already had at home, but above all I ordered and added a serious linear power supply; nothing expensive or exotic, in fact, a 12 V 25 W BRZHIFI.
I'm very satisfied with the device, it's comfortable, the remote control works well from any position, the volume level is clearly visible, it has a weight and consistency, it doesn't move due to the cables, as sometimes happens with desktop devices.

Subjectively, it works very well.

Objectively, the Amirm measurements say it's a good device.
Probably for lovers of vintage, like me, it competes with the top of the class from the golden years,... so by me it's fine!!

 

[ICIETDIYEUR]

Good morning.

Here is an example of a DAC/preamp with tube buffer output which is fully symmetrical thanks to the use of 4 tubes (whether the assembly is SRPP or SEPP does not matter) ->

This is the FIIO WARMER R2R DAC R2R

Available at Audiophonics (FR) -> Fiio Warmer DAC

 

[SMen]

This is my understanding:

T20:
[DAC / Source]
│ (balanced L+/L–, R+/R–)
▼
[Tube 1: ECC83/12AX7 dual triode]
- Triode A → Left hot (L+)
- Triode B → Left cold (L–)
│
▼
[Tube 2: ECC83/12AX7 dual triode]
- Triode A → Right hot (R+)
- Triode B → Right cold (R–)
│
▼
[Op‑amp buffers per leg]
- Lower output impedance
- Stabilize drive
│
├──► [Balanced XLR out: L+/L–, R+/R–]
└──► [Unbalanced RCA out: L, R] (derived)

FiiO Warmer

[R2R DAC ladder + FPGA]
│ (balanced L+/L–, R+/R–)
▼
[Tube 1: E88CC dual triode] → Left channel
- One triode → L+
- One triode → L–
│
▼
[Tube 2: E88CC dual triode] → Right channel
- One triode → R+
- One triode → R–
│
▼
[Tube 3 & Tube 4: E88CC] (per‑channel duplication for symmetry/headroom)
│
├──► [Balanced XLR out: L+/L–, R+/R–]
└──► [Unbalanced RCA out: L, R] (derived)


Is this correct? The T20 uses op amps in place of two of the tubes used by the FiiO Warmer.