March 20, 2024
#477
Gentle reader,
This video takes over from the previous one here: The Robb Collections: UPDATE Inexpensive Chinese-Made TUBE BUFFER amplifiers. A Review of One using 6J1 Tubes Upgraded to GE JAN 5654W Tubes
The Chinese people have invented many things and were far ahead of much of the Earth's peoples in many ways for many centuries. Today, they are known as the world's factory and have an infrastructure that is the world's envy.
Sure, there are a lot of cheap items that come out of China and land in dollar stores all around the US. But, they are an industrious people and have created items that are designed to attract the West's collective eyes.
I have found a tube radio or two over the years in thrift stores. None of them, including this find from a year or two ago, did anything more than hum or hiss.
That all changed when one of my readers, who became a real friend, came up with the idea of us three (including another reader / friend) should all build a DIY tube buffer kit. He provided the kits and PCB soldering kit. I found the needed 12 volt AC transformers and knobs.
Well, none of us got around to actually building one. I bought a couple completed ones via eBay. The link below is to an article I wrote about finding a major flaw in the ten-dollars-or-so kits. At least when using the massive AC transformers I found: 60 Hertz hum. The Robb Collections: UPDATE Inexpensive Chinese-Made TUBE BUFFER amplifiers. A Review of One using 6J1 Tubes Upgraded to GE JAN 5654W Tubes
Which leads me to this article in which I gave up on cheap Chinese tube buffer kits and bought a pair of REAL tube preamplifiers with solid engineering behind them and real electronics and DC (not AC!) transformers.
This is an image of the inside of the T2 Pro. The standard T2 can also be had in silver. I was looking for a photograph of the inside of the unit. This the closest I could find. A whole lot more "guts" than the ten dollar plastic cased tube buffer. But, these do offer tone controls and Bluetooth input and it's associated electronics.
While there is an "op-amp" inside, I don't think any digital effects are happening inside. But, I could be wrong. No transmitting either, only receiving. Bluetooth, that is.
Volume control is nicely detented and all knobs are solid metal. All the controls seem to be of good quality.
I have two stereo systems, plus a nice home theater system, in the house. The listening room uses 1990's Panor-era Dynaco equipment and the stack of vintage Yamaha 500U equipment with an OPPO universal player taking the place of a finicky Yamaha 500U CD player.
Right now, I am listening to a SACD of Herbert von Karajan conducting the Berlin Philharmonic performing Beethoven's 9th symphony way back in 1963 on the DG label through the AIYIMA T2 6K4 and my outstanding Audio-Technica AIR ATH-AD700 headphones. And, let me tell you, it sound's FANTASTIC!
Here are some more images of this amazing little gem in the listening room system. In order of my trying one of them out first, then moving it down to it's final destination, sitting atop the Dynaco PAT-6 preamp/tuner where it is safe from being bumped.
"AIYIMA T2 6K4 Tube Preamplifier Bluetooth 5.0 with Treble, Midrange & Bass Controls, Hi-fi Audio Preamp for Home Audio Amplifier System with DC12V Power Adapter.
Item Dimensions LxWxH 4.69 x 3.74 x 1.22 inches
Voltage 12 Volts
Manufacturer YIMA TECH
Mounting Type Surface Mount
Brand AIYIMA
This Bluetooth 5.0 equipped Vacuum Tube Preamplifier has Bass/Medium/Treble controls, has really sound good quality. (sic)
It lets you enjoy sweet and warm sound quality associated with Tube equipment.
1 pair Stereo RCA inputs and Bluetooth Audio input (includes antenna) with manual switch mode.
2 pairs Stereo RCA outputs can connect to two amplifier devices.
Equipped with DC12V/1A power supply.
Can be upgraded using the 6K4 tubes design for easy replacement. Designed so the tubes can be replaced to 6J1, 6J2, GE5654, 6J3, 6J4, 6J5, 6*1N, 6AK5, etc.
Build quality is very solid, the unit is surprisingly heavy.
The power circuit is completely separate from the audio circuit, minimizing interference for a clear sound.
This AIYIMA T2 is a preamplifier use for Audio Component Power Amplifiers.
And/or it can be connected to a pair of powered speakers and a rear amplifier.
Equipped with warm sounding 6K4 Vacuum tubes. These tubes can be replaced with: 6J1, 6J2, GE5654, 6J3, 6J4, 6J5, 6*1N, 6AK5, etc.
Because the design has current passing through the tubes, the tube must be fully inserted during use!
Both Bluetooth and RCA audio input modes are selectable.
Use Bluetooth 5.0 Version, it can offer high bit-rate transfer and supports AAC, SBC, APTX, APTX-LL, APTX-HD.
And the RCA input (red/white) is compatible with most audio devices, such as computers, tablets, laptops, phones, TV, CD player, etc.
Dual Channel RCA output.
This upgraded T2 tube preamplifier can use for most home audio amplifier (such as A07), or connect your active speakers directly. It provides you with clean and warm sound!
Dual Channel simultaneous output. This T2 tube Preamp is special, as it can directly output connected to 2 Amplifier devices.
Nice buttons design and knobs layout with: Treble, Medium, and Bass Control, it can achieve different sound style. This upgrade T2 is a perfect Tube preamp for your home Audio system. Use it to achieve purer music experience.
Use the NE5532 Dual Op Amp Chip. The op amp chip can be replaced to double op amp chip, such as OPA2604, OPA2314, LM4562, JRC5532, etc.
Note: If there is no soldering technology, it is not recommended to replace the op amp chip. Poor soldering will cause noise, which will damage the sound quality!
With DC 12V Power Adapter. This T2 Tube Preamplifier can not be used in cars, turntables, also it cannot be used directly for headphones or passive speakers. Please know it.
Note: To ensure sound quality, please use a good audio cable.
Thanks!
Specifications:
Tube Model 6K4(Can upgrade Replaceable)
Chipset 6K4+QCC3034+NE5532
Bluetooth Version 5.0supports AAC, SBC, APTX, APTX-LL, APTX-HD
Operational amplifier chip NE5532*2
Distortion =0.15%
Frequency response range 20hz-20khz (±1db)
Signal-to-noise ratio =100db
Volume adjustment range ±6db
Audio Input mode Bluetooth or RCA
Audio Output mode RCA
Input voltage DC12V
Product information:
Item Dimensions LxWxH 4.69 x 3.74 x 1.22 inches
Voltage 12 Volts
Manufacturer YIMA TECH
Mounting Type Surface Mount
Brand AIYIMA
Number of Channels 2
Product Dimensions 4.69 x 3.74 x 1.22 inches
Item Weight 1.15 pounds
ASIN B0BCKCDQR7
Item model number AIYIMA T2
Date First Available August 30, 2022
Country of Origin China"
It does come with a warranty, which is good. I downloaded the manual, such as it is. At this point, both are working perfectly. Whether they in fact adds "sweet and warm sound quality associated with Tube equipment", I don't know. It does NOT add anything negative, that is for sure!
Thank you for taking the time to read this rather long article. I tried to get all of the specifications columns aligned vertically with the Tab key, but, every time I rechecked in Preview mode, they were still misaligned. OCD sucks sometimes. I mainly use mine for good, not evil.
Feel free to comment below or on Facebook.
Scott Robb
March 20, 2024
#477
No comments:
Post a Comment