Written by Bob Pletka In memory of our dear friend Jan Jurco. On November the fourth 2013 Mr. Jan Jurco passed on. It was very sudden and unexpected. He was […]
Marshall Amps
Before we even get started here we need to address the MOST asked question about all Marshall DSL and TSL 50, 60 and 100 watt amps. Even though we always […]
Orange Amps
We have tubed a lot of the old Orange amps thru the years and with the AD series released in 1999 Orange began its rise once again and it’s good […]
Mesa Boogie Amps
Mesa amps are fixed bias and generally they are very cold. The exceptions to this are the EL84 amps like the DC2 and DC3’s and also the F30 and Loan […]
#1. Tube Changing, Care, and Handling
Vacuum tubes are shockingly durable. They get hastily pulled off stage, loaded into tour buses, trailers, back seats, and then rattled about for thousands of miles on end without fail. […]
#2. Common tube base configurations: Noval/9-Pin, Octal, Four Pin
Noval/9-pin tubes such as your typical 12AX7 or EL84 have pins that are mounted directly through the glass envelope. Since there’s no base assembly these tubes are indexed by aligning […]
#8. USA, European and Military preamp tube designations
Many tube types have a large number of common and not so common names that denote the same tube type/specs or similar specs with subtle changes or optimizations. The classic […]
#4. What Is Biasing?
In regard to basic tube amplifiers we can define “Biasing” as setting the idle plate current flowing through the tube. Less current means lower dissipation in the plate (less heat […]
#5. Does My Amp Need To Be Biased?
Generally speaking when we talk about biasing an amp we’re specifically referring to the output/power tubes. However there are some applications where specific pre amp stages may have adjustment or […]
#6. Is My Amplifier Class A? (Classes of Operation)
Very few guitar amplifiers are strict Class A. If you have a guitar amp with one power tube, which is known as single-ended, it’s Class A by default. This would […]