Why the Fender Blues Deluxe does not sound like Vintage Fender

The Blues Deluxe is one of Fender's popular lower end tube models and plenty of folks  use and enjoy them.  However they do sound different than the vintage Fenders they are supposed to emulate. So why is that?  

First a Common Misconception about the Blues Deluxe:

A common misconception about the Blues Deluxe is spread by Fender's marketing department: the clean channel is a Tweed Bassman sound.  They have different circuitry and sound dissimilar. A brief look at the schematic or playing them side by side will disabuse you from that notion immediately. That’s not to say that the Blues Deluxe is bad amp or that you can’t enjoy it. It’s just not a Tweed Bassman. The marketing does sell amps--but it is deceptive. This type of marketing not new either.  When it was introduced, Fender billed the Super Reverb as a Tweed Bassman with reverb and tremolo (Fender called it Vibrato (incorrectly)). Both amps are classics but sound nothing alike. 

Basic Construction Differences from Vintage Fenders:

The Blues Deluxe is constructed differently  from vintage Fender amps. By lowering the labor and material costs Fender keeps the price low and the profits high.  Here are some major differences:

⦁    Particle Board or MDF Cabinet rather than solid Pine: Sonically dead and is much heavier. Hi-Fi speakers often use these materials so the cab will not resonate.  Pine cabs resonate and color the sound. The sound can be described as warm and woody. This neither good nor bad but does sound different.  Pine and hardwood plywood cabs hold up better over time in comparison to MDF and particle board. 

⦁    A thick Baffle is mounted like a tweed Fender but does not allow for vibration like those found in the Tweed "floating baffle" designs.  Vintage Tweed Fenders used 3/8" plywood for the baffle that resonated along with the speaker. At Carl's Custom Amps I often use this design in my amps for an organic 50's sound. 

⦁    PCB Board rather than hand wired: keeps the labor cost low, makes the amp hard to repair and PCB board causes tonal loss due to stray capacitance since all components are on one physical plain and placed close together. Some components are smaller and of lower quality too. The ribbon cables are a servicing nightmare. It should be mentioned that not all PCB board amps suffer as severely from these problems, but most big-name amp's PCBs are poorly thought out, cheap and not very serviceable.  However, PCB make the amp more affordable.

⦁    Tube sockets are PCB mounted a cause damage if a tube's screen resistor blows. They can be  damaged by normal tube heat  too .  Vintage Fenders are hand-wired with chassis mounted tube sockets and do not have these problems.

Circuit Design:

Similarities to Vintage Fenders:

⦁    The Blues Deluxe uses 6L6GC power tubes like many vintage Fender Amps for round top end and slightly scooped mids.  
⦁    It uses a similar Phase Inverter circuit to what Fender used on most of their amps.
⦁    Many of component values are what you would expect in Fender designed amp so you have some sonic similarity.
⦁    The Normal Channel is non-master volume. 

Differences from vintage Fenders:

⦁    Solid State Rectifier: with the exception of the Twin Reverb, Blackface Bassman and a few Brownface designs  vintage Fender amps used tube rectifiers which gave them a softer bottom end and singing quality to the sustain. The Blues Deluxe has a solid state rectifier which is generally brighter with a tighter bottom end. It is cheaper to produce a power transformer for solid-state rectification and solid state diodes only cost pennies. This is neither good or bad but does change the sound.  Note: tube like sag can be modded into these amps (or any amp with solid state rectifier) with the addition of sag resistors or side chain compression circuits. 

⦁    Solid State Reverb: vintage Fenders with reverb used tube driven reverb. Solid-state reverb is far more economic.  The Blues Deluxe's reverb is solid state and does not sound as lush, deep, or warm like a tube reverb. It can be very useful for players where the reverb sound is not critical but it's nothing close to the real thing.

 In generally solid-state reverbs in guitar amps are designed to be as inexpensive as possible. With some additional components a solid-state spring reverb can sound very deep and lush but few companies design that into an amp that is meant to be econmical.

⦁    Solid-State Effects Loop:  Blues Deluxe has solid-state effects loop.  Even without effects plugged in part of the loop is in circuit path and changes the sound of the amp a little since it a is serial loop. Vintage Fender amps did not have effects loops or Solid-State circuits within them giving them a purer tube sound.  

⦁    Cold Power Tube Biasing:  The Blues Deluxe biased cold from the factory to increase tube life and prevent problems with low quality tubes and user error. It also hinders good breakup tone. Power tubes really need to be biased correctly to sound their best.   Some of these amps do not have bias pot so you cannot adjust the bias. Many of amps with the bias pot need the bias circuit modified for proper biasing while other just need better adjustment.

⦁    Tone Dumping Caps:  In couple of spots caps are used to bleed treble signal to ground.  This is done because the amp is unstable without them  due to poor PCB layout and to shape the tone of the drive channel.  

⦁     Two Channels: Having two channels can be very useful for players who do not use pedals for dirt or multiple amps.  However, the Blues Deluxe is a bit of an odd ball in how the two channels get their sounds.  In most two channel amps separate circuity is used for all or part of the signal path for each channel.  In the Blues Deluxe the two channels have the same signal path in an arrangement known as a “tapped pre-amp”.   The channel switching basically switches in and out the Drive, Volume and Master pots and dumps signal to ground to achieve a clean sound.  This results in less harmonic content and touch sensitivity.  A vintage Fender amp does not use this strategy but also does not have a drive channel.  

⦁    Output Transformer:  The output transformer is pretty light so it has less low end than some vintage Fenders of the same power rating. This is not good or bad; just different. 

⦁    Speaker:  Speakers can vary in the Blues Deluxe. Some do have nicely built Eminence speakers (often branded Fender) . 

⦁    Low quality filter caps:  Fender continues to Illinois filter caps which are of poor quality. Pretty much all boutique builders steer clear of Illinois caps. Many other foreign brands work much better so it hard to figure out why Fender continues to use them in their amps.    Replacing them with better caps can help with the cranked tone of the amp.

 The Blues Deluxe is pretty different than a vintage Fender.  I'm not saying vintage Fender amps are perfect but many models are proven tone machines.  Whether you like the Blues Deluxe or not is up to your ears.   If you are looking to purchase one do not expect to perform like an old Fender---the Blues Deluxe is its own amp.