TubeCube 7 tube amplifier

I picked up this little desktop tube amp for my son's Christmas present this year, replacing the Realistic System 11.

This fully assembled unit was well packaged and the fit and finish is really nice. It feels like a solid little amp in your hands.

I am just listening to my Electrohome Marseilles tube amp for the past few months as my only source of amplification. I was pretty excited to see what this 3.5 watt would sound like in a comparison. I burnt the amp in for 12 hours before giving it a serious listen.The Tube Cube 7 can be found on the Tube Depot site and runs for $179.95 with free delivery in the USA.

I first had a listen with the stock Chinese Sino EL84's with the Sino 12AX7B connect to a pair of Tannoy Oxford Gold's. The Tannoy's are very efficient so it was best suited to the 3.5 watts per channel.

The sound was very clear and transparent in the mid range and high's. The midrange and highs were not warm even having a bit of shrill at times. Although imaging side to side was excellent, back and for depth of the sound stage was not as deep as the Electrohome.

I also tested the TubeCube 7 with the Sound Dynamics Concert 500's, these are another efficient horn loaded speaker that pairs really well with tube amps. The sound was a bit better in the bass along with the same traits in sound as with the Tannoy's. Last up were the NAD Model 30's of which this little unit was striving to drive with clarity, the bottom end was very muddy.

I opted to replace the Sino tubes over to J/J EL84's and a J/J 12AX7B

The change over in tubes had an instant impact on the sound this little amplifier could achieve, it was like a veil was removed from the sound. Back where the sweet luscious mid's and high's with the bottom end filling out. The Tannoy's had their shine back, the warmth was there along with the depth of sound, next was the Sound Dynamics, where the bass was clearer and much more refined. Any shrill associated with the original Sino tubes was gone.

Overall this is a pretty cool entry into tube amps for a small space, we still have them hooked up to the Minimus 11 speakers. When trying to fill a larger room with bigger speakers this little amp tries and does a surprising good job, I found this amp best suited for a smaller office or bedroom. The output transformers are obviously not as robust as you would find in higher power units, I found it shy on the bottom end.

My wish list that I had for this amp is a headphone jack being a priority, it would be great to listen to through headphones. Two inputs would be nice too, but I would take the headphone jack first.

I would recommend one of these units as a starter into the tube world. I had mine shipped to a US address which help keep the cost down with the exchange rate.

The TubeDepot will also supply better tubes for this amp which I would step up to the J/J tubes all around.

The TubeCube 7 can be found here and the tube upgrades here.

Tube: Shuguang EL84 2pcs, 12AX7B 1pc

Power Output: 3.5W+3.5W @ 8 ohms

Frequency Response: 30-40Khz (+-1db)

Input Sensitivity: 500mV

Signal-to-Noise Ratio: -80dB / 3.5W

Residual Noise < 1mVac

Input AC Voltage: 100-250Vac

Power Consumption: 38W

Input Impedance: 50K ohms

Output Impedance: 8/6/4 ohms (Japan Z11-EI48*24 Output Transformers)

Dimensions: 130mm (w) x 130mm (d) x 130mm (h)

Weight: 2.6KG

Input: RCA Jacks

Output: Banana Jacks

AC: Standard IEC Jack with Fuse protection (2A Fuse)

Color: Black