Low Cost Dip-of-the-Toe Into Tube Waters


Frequency Response: 5Hz – 50 KHz (-1dB)
Distortion: < 0.15% @ 1kHz
S/N Ratio: >75dBa
Input Sensitivity: 500mV
Vacuum Tubes: 6J1×2
Crosstalk Separation : >75 dB


  • Enhanced sound staging and details. Warms up sterile digital music and solid state amplification. Does not remove any musical information.
  • Connects to your existing system in many ways, including; Between your CD or DVD Player and your Receiver/Amplifier, Between your Pre-Amp and your Amplifier, in your Receiver/Amplifier pre in/out loop,
  • Gold Plated RCA inputs/outputs.
  • No ‘thump’ power switch.
  • Small and attractive styling with brush aluminum plating. Easy to use and maintain.
  • Custom, hand-made, oversized transformer, all point-to-point hand wiring.
  • 5 x 7 x 5 ¼”, 6 lbs

Information above courtesy of Grant Fidelity

This product does exactly what its sellers say it will do. It adds some tube sound to a solid state stream and it makes digital sources in particular much more rich in terms of sound quality, soundstage and depth. It even added some soundstage depth to analog sources like a turntable on my system.

First off, this is a Chinese built tube processor that uses small 6J1 tubes (You can also tube roll with 6AK5 or 5654 tubes.) to simply process the sound between your source and your amplifier. In my case, I'm using it with a Pioneer SX-650 vintage receiver and I'm basically using the tape loop to take sound out of the receiver, run it through the B-283 and back in using the tape monitor switch. It's a pretty simple set up and the results are nothing less than astonishing. The unit is similar to ones made by Yaqin but it has a few nicer touches than the ones marketed under the Yaqin brand name and, best of all, it comes with the support and assistance of Ian and Rachel at Grant Fidelity in Calgary, Alberta, Canada. 

My unit arrived here in Roswell, Georgia, USA, in less than a week from Canada. I did pay for express shipping-—a $10 charge for U.S. destinations—not bad as the unit sells at $150 US as one of the "Hot Deals" on Grant Fidelity's website. MSRP is $219 US. Ian at Grant answered questions via e-mail and phone and made the buying decision a no brainer. He was more than helpful and that service was the final selling point for me on the unit. Not to mention that they will allow you to upgrade from here to a full-on tube amp!

My unit is still in the burn-in phase, but I noticed, using an iPod as a source through the AUX inputs on the receiver, an immediate improvement in soundstage depth. The sound moved from the middle front of my system to the back of the system–coming almost from behind the wall. The depth and breadth of the soundstage was markedly improved on this digital source and the same held for using FM radio as a source on my system. 

I did a quick test with my Technics SL-D303 turntable and Grado Green cartridge and noticed a similar shift and improvement in soundstage. That is beyond what Ian promises, by the way. He insists that the biggest improvements come on digital sources and they make no promises on analog sources such as vinyl. I understand that position and I'm sure results will vary but I have noticed an improvement with an analog source. It's not as dramatic or pronounced as it is with digital, but it's there nonetheless. Of course, your experience may vary as they say.

For $150US, I've made a nice upgrade to my system. One I am pleased with and one that will likely lead me farther down the slippery slope of tubes!

Grant Fidelity B-238 Tube Processor