TUBE AMP SAG CHAPTER FOUR: Solid State versus Tube Rectifiers.
In this instalment of “Tube Amp Sag”, we will look at the Datasheet of silicon diodes as well as the main tube rectifiers found in tube guitar amplifiers. We will look at the heater filament current draw, the voltage drop that some call sag, and the maximum value of the first filter capacitor.
We will answer the question: “Can you make a silicon rectifier sag like a tube rectifier?” and work through the calculations.
You will also gain a better understanding of the effect of different capacitor values on your solid-state or tube rectifiers.
Can you experiment with changing tube rectifiers in your amp? Yes, but it WILL impact your amp’s bias.
By the end of this Chapter, you will have filled out your knowledge of Tube Amp Sag and be able to find your way closer to your ideal amplifier tone.
00:00 Introduction
00:49 The high efficiency of Solid State Diode rectification.
01:25 Tube Rectifier Introduction and the key values in the DataSheets
04:05 Key values of 5Y3 rectifier
05:25 Key values of 5U4GB rectifier
07:00 Key values of 5AR4 & GZ34 rectifier
08:50 Summary chart of the differences between tube rectifiers
10:45 When is Tube sag not a good thing
11:18 How to make a diode rectifier sag like a tube rectifier
18:20 What happens if you use an underrated capacitor with solid-state diode
20:44 Does a solid-state rectifier and big capacitors make your amp sound sterile and stiff?
22:38 Why does a small capacitor and tube rectifier sound good?
24:40 Is it safe to swap rectifier tubes in an amp?
25:00 My thoughts on whether Mesa Boogie amps require biasing.