AIYIMA T1 Pro Tube Preamp Review

[Rainier939]

@amirm

Does the THD stay consistand with output level or is it dependent on the output level. Do you have a THD vs output voltage graph?
And what is it maiximum output voltage?

 

[SIY]

@amirm

Does the THD stay consistand with output level or is it dependent on the output level. Do you have a THD vs output voltage graph?
And what is it maiximum output voltage?

It's about the third graph in.

 

[Rainier939]

It's about the third graph in.

Thanks. My bad

 

[DualTriode]

Large amount of harmonic distortion is what you expect to see and it delivers on that. Dialing down the input however, sharply reduces that:

So if you are after that tube sound, you would want to listen at elevated volumes.

amirm,

Thanks for the inside Hi-Fi review of this brave little tube amp. Pure as Reverse Osmosis water it is not. Vacuum tube performance is what it delivers, proudly and intentionally.

Some times I like to squeeze a little lemon in my water. I do not want the whole lemon.

"dialing down the input however, sharply reduces that:"

Please tell us how the tube harmonics can be turned down or reduced.

I want to turn up the volume without going full tilt tube harmonics? You know just a little lemon not the whole thing.

Thanks DT

 

[DualTriode]

In addition, a number of members pointed out that the distortion spectrum deviates from a “proper” tube amp.: too much odd order components.

Hello,

This little amplifier's stair stepping harmonic series is classic Class A vacuum tube distortion.

Thanks DT

My Guess is that this vacuum tube is a inexpensive pentode wired as a triode.

see attached sample: oops a triode sample

 

[mycose]

My unit just arrived today and I believe this might be useful for someone here:

In my experience, this little preamp adds 0.000% perceptible harmonic distortion to the sound. There are plenty of reviews already there and yeah, it looks cool and feels solid.

I asked my younger siblings (~20yo) to help me test it out and see if they'd notice any changes in sound in an A/B test. I used music and pure 1, 1.5 and 2kHz tones at regular volume levels and they couldn't notice any differences (Topping E70 + Topping PA7 Plus + Klipsch Speakers). All my quick and dirty testing was done with the preamp set to unity gain and "direct mode" (no EQ applied).

Conclusion: this little guy is great if you want to EQ the sound, and that's about it. There's no noticeable "tube sound" though. It's a great purchase anyway, and I prefer it over software EQ.

 

[Joe Smith]

FYI, there is a new non-tube preamp (P4) coming out from Fosi that is a nice match with the V3 amp - it does not have Bluetooth, but has three RCA inputs, a remote, tone controls with tone/direct switch, preamp out. I am an early tester and will writing longer impressions of the device next week.

This Aiyima is such a nice match with the A07 MAX, it would be great if they also would come out with an improved preamp that would mate nicely with the A07 MAX...

 

[livinon2wheels]

I am quite curious about the circuit diagram...love to see how this thing works. 12VDC supply doesnt seem like enough to make the tubes do anything, except maybe light the filaments.

 

[solderdude]

DC-DC converters ?

 

[power4utoo]

Interesting post, for which to reply, on my first ever post on this forum. I am on a journey to rediscover the pre-digital sound of my youth. I never had any equipent that would be concidered audiophile, but I remember analog sounded better. The listening fatigue would be the most saliant reality that becomes apparent streaming the average digital file without remediation. That being said, my journey, it has taken me to certain place. Of course money is always the limiting factor. Not always that one doesn't have the money, but what one is willing to spend on the hobby. I have chosen to take my chances assembling gear from Marketplace and Ebay and the like.

I have a tech question for @amirm : Since the voltage is implicated, being associated with the distortion, would this device most assuredly benefit from a cleaner source of power? I initially had my SU-1 dac powered by a dc phone charger, when I proved to myself that clean power matters. I have since purchased an appropriately priced linear power supply for the same. So naturally, I am wondering if this T1 Pro Tube Preamp would perform even better with clean power.

My Current System is quite eclectic:
Dave Hafler DH-220 Refurbished, Upgraded and certified by a retired Dynaco Engineer.
S.M.S.L. SU-1 dac
EverSolo DMP-A6 Gen 2 (currently prefer the external dac, however....)
KEF 104.2 speakers (these are the best speakers I ever owned)
Also, currently on trial, The AIYIMA T1 Pro Preamp

Music:
Currently a proud lessee of Millions of albums and tracks of all genres through TIDAL and Amazon Music
Also currently deciding whether I want to redpill myself, by getting into the turntable world, whilst I am happy as a turkey the day before Thanksgiving.

 

[SIY]

Since the voltage is implicated, being associated with the distortion, would this device most assuredly benefit from a cleaner source of power?

I'm not Amir, but I have a reasonable grasp of tube design. Basically... no. Power supply deficiencies manifest as noise, especially at even multiples of 60Hz. The problem here is non-linearity, which is a function of the audio circuit design. A "better" power supply might reduce the 120Hz spike from an inaudible -120dB to a really, really inaudible -130dB. Maybe.

Typically, if there's a power supply issue, a better fix is improving the circuit's power supply rejection. Things like CCS plate loads and differential operation can make a much greater difference with less added expense.