Henriksen JazzAmp 12-R Review
Introduction
In Fall 2008, I evaluated and photographed the Henriksen 12-R guitar/bass
amplifier. I also compared this amplifier to a Polytone Mega-Brute plus a
Stealth 12 speaker speaker cabinet. The test guitar was a borrowed Gibson ES-175
electric strung with flat wound strings and played with a heavy, 1.5 mm D'Andrea
Pro Plec pick. Some players view the 12-R as an upscale Polytone and in some
ways its tone is reminiscent of Polytone amplifiers. Both have the vintage era Jim
Hall, Wes Montgomery, Pat Metheny, or Joe Pass style tone with warm, round notes
and softer attack. The basic "Brute" Polytone sound is quite dark and heavily colors
your guitar's natural sound. There is also a non-removable boost
of the frequencies somewhere between 1 to 3 KHz. Additionally, a subtle “pillow over the speaker”
muffled sound may be heard in the lower mid-range of some 12 and 15 inch combo amps which
disappears when using a separate extension cabinet.
In comparison, the 12-R colors the guitar
sound much less, has incredible warmth and brightness, is stellar clean even at
very loud volumes and can be best described as warm, bright and muscular.
Many non-performing jazz guitarists suggest that their favorite 15 watt or so combo amp
has
an excellent jazz tone and in fact they are probably correct when playing alone at
bedroom volume levels. They may even question the need for high wattage, jazz voiced guitar amps. Some people lack
awareness that jazz guitarists may have to compete with loud horn sections and
often even louder drummers and still have to have a squeaky clean/unclipped/undistorted sound at
the volume required to be heard in their ensemble. Lower power final amplifiers
tend to distort more than higher power final amplifiers when the preamp gain is
turned up. You can now find jazz amplifiers rated at 200 watts or more for this
reason. The 12-R is rated at 120 watts alone and 160 watts when an 8 ohm
extension speaker is connected to it and thus the power amp load is 4 ohms. The 12-R
seems to lie
somewhere in the middle ground between a clean guitar amplifier and a hi-fi
(some say sterile) PA style amplifier.
Amplifier tone is subjective and I have discussed this fact at length elsewhere on this web site. All I can provide is my impressions and hope that you will try out any
amplifier for yourself to see if it meets your needs before purchasing it.
Most of the photographs of the 12-R on the World Wide Web are poorly lit and/or
contrasted
which obscures details, so I photographed it in the sun for sake of appropriately
lighting a dark, black object.
To the right is a photo of the graphic equalizer section of the 12-R. This EQ really sets this amplifier apart from other jazz guitar amps. There are no passive or op amp feedback loop tone controls in the signal chain. Instead, there are 5 band pass filters centered at at the frequencies shown. The controls allow a 10dB boost or cut of the center frequency. You do not hear much difference when turning the 10 KHz control as this is outside the fundamental frequency a guitar can produce and only applies to harmonic multiples of the higher frequencies from your guitar. To my ears there is a slight emphasis of the higher frequencies with this amp and to get my desired jazz guitar sound I needed to turn the neck pickup tone control down to between 5 and 7. I have never played through an amplifier that worked so responsively with passive guitar tone controls! This was true for the bridge or neck pickup. The guitar tone controls serve as high frequency roll off filters and allow you do dial in the baseline brightness of your sound. Then you can tweak the amp EQ to tailor the tone for the room characteristics, to overcome problems with your instrument such as boominess or even to tweak if you are playing in a lower key which has more low frequency notes. I pretty much maximally cut the 300 Hz band and boost the 3 KHZ band as shown in the photo above. For our computer room, the above setting gives a wonderful, warm, yet punchy guitar tone. For some songs, I increased the 1 KHz band control a little.
To the right is the 12-R control panel. The amplifier chassis is relatively small compared to the cabinet and so the layout is quite compact. With my big, clumsy hands. I had a little trouble turning the volume knob when my thick bodied, right angle, instrument cord was was plugged into the input jack. Happily setting the volume control is not required that frequently and also can be performed from the guitar. The controls are simple and relatively few which I like. There was a bit of a learning curve to master using the EQ, but now, I really like having this feature on a guitar amp.
To the left is a photo of the digital reverb wet/dry mix control and on/off switch. I have read both positive and negative comments about this reverb and to be truthful, I do not normally use reverb, so I am probably not the best person to offer an opinion. The reverb does not add noise to the signal unlike many guitar amps. When switched off, the reverb circuit is fully bypassed. I like this design consideration. You cannot adjust the reverb characteristics and in general the reverb is subtle with a relatively fast decay and non-surprisingly is oriented towards jazz and not surf guitar. The switch is a little hard to see and get at, however, really this is a non-issue as if you do not want the reverb when the circuit is switched on, you can just set the reverb knob to its lowest setting. With the reverb switch on and the knob at the 9 o'clock position, I was able to get a pleasing reverb effect that I would definitely use for variety from time to time.
Mouse over the images below left to view a full size photograph
Reverse view of the JazzAmp 12-R. To keep the finals cool, a large heat sink is mounted onto the chassis.
This amp cabinet is very solid and has a cube shape. The tolex work is quite good. The speaker is an Eminence Beta A-12; 250 watt RMS rated, with a frequency response from 43 - 3800 Hz. It is very smooth and strong in the midrange frequencies and sounds more like a hi-fi speaker that a typical guitar speaker. The 12-R weighs 14.5 Kg/32 pounds.
The next choice if you need something more light and portable, might be the 10-Plus. The 10-Plus is reported to have less bass response, more mid and high range definition and a bit sharper of an attack than the 12-R. The 10-Plus has the same power amp as the 12-R and apparently projects lower frequencies a little better than the straight 10-R. It also has reverb and weighs about 11 Kg/ 24 pounds. I think the tonal differences will also depend on your guitar and strings. Try them all!
Top angle view. This amplifier is a welcome addition to the jazz guitarist armatorium. The 12-R is fantastic! When playing solos, the notes fly off the speaker with a breath-taking fullness and clarity which inspires you to play better. I will still keep my beloved Polytone Mega-Brute and by no means think that Polytone amps are not a worthy consideration for jazz guitarists; but at least for me, this amp is a keeper. Well done Henriksen!
A close up photo of the external speaker jack. You must use an 8 ohm or greater impedance cabinet as the speaker cabinet will be in parallel with the stock 8 ohm speaker and loads less than 4 ohms will cause severe heat and damage to the final amplifier.
The 12-R has a removable AC cord and also can be switched for 230 volt use in Europe. When you turn this amp off, it emits a 60 cycle power supply hum that lasts for 40 seconds or so until some capacitor(s) discharge. At least we know that they have well filtered the B+ power supply.
The Henriksen JazzAmp 12-R is given final Jazz Cat approval. He won't perch on an amplifier he dislikes.
Related Links
Henriksen Amplifier web site
Review(s) at Harmony-Central
Main Guitar Home Page
If you arrived on this web page via a search engine- here is the link to our main guitar-related home page
