Krank - Revolution Junior PRO

Many guitar players know about the Krank famous mini stack amps.
Since Krank introduced the Revolution Junior Standard (Rev.Jr) back to year 2007,
the new version of Rev.Jr was introduced during the next year which is called Rev.Jr "PRO".
The Rev.Jr "PRO" is upgraded to TWO channels - Kleen and Krank with independent EQ controls.
And also "Pro" version has 20watt or 50watt output options which is same as Standard version.


There is no "Standby" switch on front panel for both "PRO" and Standard versions.
The place was replaced by "Sweep" control (Mid Parametric-EQ)


Back panel -
"PRO" version doesn't come with "Line Out" but "Presence" control which is much more important.
Famous Pirate Skull flag from Krank Amplification.


Internal circuit


Five 12AX7 preamptubes and two 5881/6L6WGC powertubes.
Front row of the left is 12AX7 for "Kleen" channel and
the next two 12AX7 tubes are for "Krank" channel.
Back row of the left is the effect loop buffer tube
and the next one is Phase-Inverter which is beside the powertubes as usual.


Ruby "Hi-Gain" selected 12AX7AC (Chinese made)


Sovtek 5881 powertubes (Russian made)


Black or Chrome front grille options.
The logo was stuck by twin-adhesive tape.


Assembled and QC check. Burned-in time was total 30 hours.


Worldwide voltage selector


Giant chassis screws


" ... The Rev Jr. Pro’s circuit is very similar to the 120W Revolution"+" in design
and offers the same raging high gain sounds it’s big brother delivers!"
- from Krank official website.

Because of those sentences mentioned above, I bought the Rev.Jr "PRO" from eBay, USA.
Don't be a fool by this mini amp, it can sound really loud even with 20watt version.
20watt of Rev. Jr is lounder than my 60watt Peavey 5150 combo at the same volume level.

You can easily control overall volume better by connecting a patch cable into FX loop.
Therefore, the FX volume pot will be served as "Master" volume.


The FX boost from "PRO" version is not functioning as "Gain Boost" from Standard version.
It is just a switch. All the gain range is controlled by "gain pot" on front panel of the "PRO" version.
You have to be careful about the "Presence" control.
Sound will become too buzzy if you turned it more than 9:00.
Compared with Peavey 5150 combo or Randall Ultra/Ultra XL modules,
the gain level of Rev.Jr is lesser than them.

The video clip of my Krank Rev. Jr "PRO"


Although Rev.Jr is cathode-biased amp, but it only accepts 6V6, 5881 or 6L6 powertubes.
You aren't able to run other octal tubes such as EL34, 6550, KT88, KT77 on it.

From Krank Amp Official website -
How does Rev.Jr PRO compare to the Krankenstein Jr ?

Basically it’s kind of the same difference as the comparison of the full size Rev+ and Krankenstein+.
With the Krankenstein Jr. having a little more gain and the eq being voiced just a bit differently.
The Rev Jr. Pro is probably more versatile as it can easily mesh into a lot of different styles of music
while the Krankenstein Jr. has more of that metal, “grab you by the throat” thing going on…
So it depends on what you’re really looking for… but both are great little amps!

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From Patrick, Krank amp tech -
Rev.Jr PRO having different circuit board with Krankenstein Jr.
The easiest way to let Rev.Jr PRO to get a similar tone with Krankenstein Jr.
is to use a line driver in the effects loop.
Something like a MXR micro amp pedal, or a Electro-Harmonix LPB, or equivalent device.