The 5E3 is undoubtedly one of Fender's best-known amplifiers and enjoys great popularity, both amongst musicians and the DIY scene, despite the fact it is over 60 years old.
This is due to countless commercial replicas and clones, although the 5E3 is not exactly known for easy handling. Nevertheless it wrote music history by its unmistakable sound and unconventional overdrive behaviour - or could have Neil Young without a 5E3 been possible? We do not know, but we know what our DIY community wants and the 5E3 is at the top of the list.
After the great success of its little sister, Emma from our LoW series, we decided at the end of 2016 to also include the big brother as a kit.
But do you really need another 5E3 kit? Certainly not! We deliberately refrained from a 1:1 copy and put together a 5E3 with many well-known and sought-after modifications, as well as some requests from our customers got integrated into the amplifier.
The result is a highly flexible 5E3 which can sound really "oldschool" but also modern and fresh to get the maximum out of this circuit and the concept of this amplifier.
The following is a brief listing of changes to the original circuit and their effects.
a) Separate cathode resistors at the first double triode for normal and bright channels, the channels can get voiced differently and independently.
b) The normal channel has been expanded with a switchable tonestack which gets activated by a push-pull potentiometer. This allows versatile settings and greatly enhances the sound spectrum, it allows to realize some “cleaner” amp sounds.
c) Negative feedback, switchable via a push-pull potentiometer. Often desired, especially when effects are used in front of the amp. When engaged the output stage offers a "more controlled" sound.
d) A pentode/triode switch has been added. In addition to the lower output power in triode mode, there are also sound differences between the pentode (normal case) and triode operation. Slightly different voicings of the overdrive behaviour can also be heard.
e) Cathode bias / fixed bias switchable, with an additional bias setting trimmer on the PCB. A request from some forum members. The basic effect is partly similar to the NFB or the pentode/triode mode. The amp sounds a bit “tighter” when overdriven.
f) Master Volume. Should be self-explanatory.
g) Partially Coupling capacitors with lower capacities for a more controlled bass range. This measure serves primarily to tighten the bass reproduction and also reduces blocking distortion.
h) Gridstopper/voltage divider before the cathodyn phase inverter to avoid unpleasant distortion when the amp gets cranked. Also a known problem of the 5E3 at higher volume levels which gets thereby (almost) eliminated.
All further details can be taken from the schematic and layout plan.
Schematic PDF (2 Pages, DIN A 4)
Layout PDF (1 Page, DIN A 3)
You can get the 5Ä3 kit in our Online-shop together with other nice parts for this amp
Care is necessary during construction! The voltages used in this amp are potentially fatal. This amp is NOT a beginner's project!
A successful build requires that you can read (and understand!) a schematic diagram, you know how to use various measuring devices, and you have some experience working with voltages over 60V.