Allen Amplification Encore Amplifier Review



Here's some pictures, sound files and comments on my new Allen Encore tube amp. I ordered it with the Eminence Double-T 12 Travis Toy Signature Speaker.

  • The fit and finish of all parts is excellent!
  • There are various options on the grill and knobs etc. I went with the amp as pictured on the Allen web site Encore page.
  • I opted for the beefier TO40MT power transformer. It runs really cool even at full load.
  • The amp can be ordered with 6L6 or 6V6 output tubes and the corresponding rectifier. For pedal steel use I am using the 6L6's (user swappable).
  • Assembly instuctions are quite detailed and clear. Excellent photos of the wiring layout are provided.
  • Some of the amp's low hum levels are probably due to the fact that the first tube stage is physically located right next to the input jack. This novel layout reduces the length of the tube's input leads.
  • I was very careful to run signal wires close to the grounded chassis and at right angles to other wires to reduce hum and unwanted coupling.
  • The amp chassis is stainless-steel with welded corners and very sharp in appearance!
  • Pots are high quality with damped action and have a very luxurious and smooth feel to them. The control knobs have metal inserts that allow you to tighten them securely without worrying about cracking the plastic.
  • A back panel impedance switch alows you to match the 4 and 8 ohm loads to the amp. It also allows you two selections for different tone with an existing load with a slight power drop in one position!
  • Everything came well packed and not a single part was missing.
  • I used magnifying illuminating headware to inspect every single solder joint for good flow and adherence after the job was complete. I did find a few where the eyelet was soldered competely but the solder did not flow onto the component lead as much as I would like. I think this sort of inspection ensures the long term integrity of the amp.

    • Some useful links:




    Two full song recordings with real bass, rhythm guitar, EZKeys piano, EZDrummer drums. All pedal steel and guitar parts are played through the Allen Encore amp.
    Click here to listen to Encore Blues
    Click here to listen to Four On The Floor

    Another bonus song! This one was recorded with my 4 string electric mandolin with a low C string like Johnny Gimble's.
    Click here to listen to Texas Swing
    Click here to see the story of the electric mandolin


    Review Summary

    This amp is the most quiet tube amp I have ever owned. By that I mean there is almost undetectable hiss or white noise. In fact standing a few feet away, you can't even tell it's on except for the glow of the pilot light! I've owned a ton of black and silver face Fender Twins, Deluxe and Princeton Reverbs. This amp is far quieter than any of those and has a far more flexible tone stack. Even at extremely low bedroom levels of playing it's a cinch to dial in any desired level of cleanness or distortion by cranking back on the Master Volume control, increasing the Raw control and adjusting the input Volume control. Different settings of the raw control make this sound like a totally different amplifier. Other useful features you will use everyday are the front mounted power switches and the reverb tone control which I vary when switching instruments. While I really can't totally separate the sound contributions between the Eminence Double-T 12 Travis Toy Signature Speaker and the amp itself, I can say the combination of the two is quite awesome for pedal steel and guitar. The speaker sounds very clear and not harsh with no piercing treble on the pedal steel high frets. Having the bias jacks and adjustments handy means that you never have to wonder if the bias is correct or if it has drifted. Just take a few minutes to measure and set it! The super long 11' 4" power cord comes in real handy and is just another nice and thoughtful touch. The overall weight is quite manageable.

    In keeping with the vintage tube sound I used my Goodrich pot pedal and no stomp boxes on all the recordings. The amp's reverb is a lot like the classic Fender tube reverbs when they sounded good years ago but with maybe a hint more of a hall reverb sound to it. Not at all tinny or metallic sounding. The Reverb Tone control is very useful in tailoring the reverb sound. In fact I swapped in my super smooth Hall of Fame Reverb box quite a few times to compare it with the amp's reverb. For both steel and guitar I'd say they are about equal to my ears and I really don't have a preference between them. I'm not a big amp reverb fan but this amp's reverb equals and even improves the reverb of the best vintage Princeton's I've owned. All of the recordings on this page use the amp reverb. The amp at about 40 watts RMS output will not compete for volume with a 300 watt pedal steel amp in a large venue. It does however have a TON of gain which makes volume pedal dynamics and expressions easy. With a typical guitar pickup you can easily drive the amp to full power with no additional preamps or active electronics. The vibrato circuit directly modulates the output tube grids in the same manner that the tube bias does. The effect is quite stunning and has a broad range of depth and speed adjustments.

    The speaker weighs 7.1 pounds, the chassis weighs 20.0 pounds and the cabinet with reverb tank weighs 16.6 pounds. For comparison here are the relative weights of some popular amps:

    Fender 68 Custom Deluxe Reverb 40.2 pounds
    Fender Steel King with casters 64.4 pounds
    Peavey Nashville 400 57.0 pounds
    Allen Encore 43.7 pounds





    Sound Samples



    Here's some sound samples. All pedal steel samples use the Goodrich volume pedal with a Dunlop Hotpotz, 12' of George L's cable between the amp and volume pedal to roll the highs off a bit, Allen Encore amp with a Shure SM-57 mic, onto a Zoom R24 recorder then ported to Reaper to convert them to mp3 files at 320 kbps. Guitar samples omit the Goodrich foot volume. No reverb or EQ is added by Reaper. The samples are very raw and close to what I hear sitting next to the amp. My initial amp settings (subject to change):
    • Volume = 7.0
    • Treble = 5.5
    • Middle = 1.5
    • Bass = 3.0
    • Raw = 0 (except for distortion sounds)
    • Reverb = 7.0
    • Tone = 6.0
    • Master = 9.0 (except for distortion sounds)
    • Bright Switch = Off for Steel, On for tele


    Selection
    Recording Method
         		Comments
    Shure SM57
    		 Pedal Steel - E9th - Sample 1
    Shure SM57
    		 Pedal Steel - E9th - Sample 2
    Shure SM57
    		 Pedal Steel - E9th - Sample 3
    Shure SM57
    		 Pedal Steel - C6th - Sample 1
    Shure SM57
    		 Pedal Steel - C6th - Sample 2
    Shure SM57
    		 Guitar - Sample 1
    Shure SM57
    		 Guitar - Sample 2
    Shure SM57
    		 Guitar - Sample 3
    Shure SM57
    		 Guitar - Sample 4
    Shure SM57
    		 Guitar - Distortion
    Shure SM57
    		 Reverb Sounds
    Shure SM57
    		 Vibrato Sounds



    Bench Testing and Accessories

    I used the Weber amp cradle after assembling the chassis and while initially powering up and bench testing the amp. It's a decent unit but I did modify the feet to widen them and make it more stable. I also had to counter sink its mounting holes as they were shoddily left sticking out of the sides. Check out the pics below to see all of this. The cradle's rails are also a few inches too short to hold an amp chassis firmly in place so I added a clamp to securely hold the chassis. It's a bit expensive but very sharp looking if your in a situation where you want to impress customers in your shop. Of course you can easily build such a thing yourself for a lot less cost.

  • Weber amp cradle

    A 20 amp variac was used to adjust the input voltage to 120 VAC just for uniformity and because my house line voltage can run pretty low. The 20 amp variac is overkill but it's built more ruggedly than the lower amperage rated units. For a dummy load I used the Weber TRU-LOAD DUMMY LOAD with a mod to switch out the unit's internal speaker motor allowing for a more resistive load. This keeps the load voltage and current in phase eliminating power factor considerations which simplifies power calculations.

  • Weber TRU-LOAD DUMMY LOAD

    Here's a schematic I traced out showing the added switch (click on picture for full size pdf file):

    Note that you can save some money by just buying discrete resistor loads. Also its possible to use only three 200 watt resistor to creat 2,4,8 and 16 ohm loads at 400 watts each! This is pretty cool and you can click on the picture below to see my implementation of it using simple ohm's law calculations.

    For bench testing I used an audio signal generator, 200 MHZ digital scope, variac set at 120 VAC with the amp impedance switch set at 8 ohms and the dummy load set at 8 ohms. A tube amp will deliver maximum power to it's load when the load matches the amp's internal impedance. A lower or higher load will result in a lower power output to the load but can result in useful damping transient and tone changes in actual use. Note that a 3 db increase in audio level only yields a slight increase in audible volume but requires twice the power! Similarly a 6 db increase requires 4 times the power and a 10 db increase requires 10 times the power but will sound twice as loud. Nevertheless, amps are heavily marketed based on wattage and it's hard to convince buyers that whether an amp is 40 or 50 watts or even 80 watts really doesn't much matter in terms of sound levels. Going from 40 to 300 watts for example is a useful power change if you need higher sound levels. For my setup I used a sub $100 audio generator and it's pretty amazing. You can see the waveform purity immediately below and pictures of the setup far below. The scope has a somewhat useful FFT (Fast Fourier Transform) function that shows a decent frequency domain representation of the signal. What is REALLY cool about the scope is that it calculates the RMS value of the waveform allowing for accurate output power calculations of various waveforms. A square wave will have a lot higher power output than a sine wave at the same frequency. Thus, as the amp starts to get pushed out of it's linear region , you can get more than 40 watts of RMS power out of it.

    The first picture below shows the amp delivering a fairly clean 40.4 watts with a 300 mV peak to peak input signal at 1 khz. The 6L6 plate voltages are at 455 volts and the tubes are biased at 34.55 and 35.00 volts. Most passive pickups that I've seen put out between 90 and 400 mV.

    The next picture shows the amp delivering 51.3 watts with the RAW control cranked up a bit.

    Finally what follows is a picture of the amp delivering a distorted 63.3 watt RMS obtained by cranking up the RAW and volume controls.

    Note that the amp is capable of producing two different sources and sounds of distortion. You can overdrive the output section or you can overdrive the preamp section depending on how you set the master Volume and Volume/Raw controls.




    There are quite a few pictures below. Click on them to see them full size or at least sized to a browser window. Click on the picture again if needed to zoom in even more!







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