HOT TUBES 70

looking for anyone to explain the difference between these 2 terms when it comes to the running of these modes on your marshall amp ?

1. PENTODE MODE
2. TRIODE MODE

__________________
MARSHALL 6100LM
MARSHALL 1960A W/-G12H 30's
CUSTOM BUILT 2X12 W/-V30's


"MARSHALL" - only the best will do !

siav

Here is a good link

Pentode: Pentode - Wikipedia, the free encyclopedia

Triode: Triode - Wikipedia, the free encyclopedia

__________________
Kramer 600ST
Gibson Les Paul STD 2005
Martin D16 Custom

Marshall 6101 30th Anniversary
Marshall 2555SL JCM Slash

Rocktron VooduVale

HOT TUBES 70

thanks for those links , i took a few minutes to read them but , i was looking for a more basic explanation for these terms .

__________________
MARSHALL 6100LM
MARSHALL 1960A W/-G12H 30's
CUSTOM BUILT 2X12 W/-V30's


"MARSHALL" - only the best will do !

siav

As you have a 30th anniversary, my guess is that it affects the power, but not quite shure which of them is splitting from 100 to 50w and which is reducing from 50 to 25w

__________________
Kramer 600ST
Gibson Les Paul STD 2005
Martin D16 Custom

Marshall 6101 30th Anniversary
Marshall 2555SL JCM Slash

Rocktron VooduVale

ProfChaos

The triode sound for the Marshall is punchy and crunchy, as in JCM 800; the pentode setting on the 6100 is more suited to sonic sculpture and trippy sounds with many cool overtones, as in Mesa Boogie. (This is because of the two extra "grids" in the pentode tube and the effect that they have on harmonic tones. There are fewer stray electrons bouncing around the plate [output element] of the pentode tube, and this influences nicely how the tube deals with harmonic tones.)

Everyone's aesthetic tastes vary in relation to those of other individuals, but my preference for Marshall 6100 settings is the 100-watt, pentode setting (with the "Contour" control engaged and tweaked to one's tastes). I use the red--hyper-overdrive--channel into a PowerBrake, and I just roll-off the guitar volume slightly if I want a glassy JTM 45 sound. The two extra tube grids in the pentode setting add a special sonic headiness that you will not find in many other amps this side of Mesa Boogie land. That said, there is still a place for the Marshall 6100's triode setting, so thank God for the option of using either one or the other...It is just important to remember to avoid switching tube-type or power-level settings with the amp powered-on: That doesn't end well.

cheers,
--Professor Chaos

Wilder Amplification

EL34 power valves are known as a "pentode valve", meaning there are 5 active elements in the valve with the exception of the heater. They are -

Cathode - a metal "sleeve" in the valve that is wrapped around the heater that is grounded and emits electrons when heated by the heater.

Control Grid - This is where the negative bias voltage gets applied. The input signal is also applied here and the input signal modulates the bias voltage above and below its preset value to make current flow through the valve fluctuate at input signal frequency.

Screen Grid - Reduces interelectrode capacitance that exists between the elements in the valve by applying a positive voltage to it that is just a few volts lower than the plate.

Suppressor Grid - This grid is grounded, which makes it negative relative to the plate, and serves to push stray electrons that are emitted from plate heat (known as secondary emission) back onto the plate to keep them from getting sucked up by the positive charge on the screen grid and causing a power loss. Electrons being negatively charged - like charges repel - which is how it pushes the electrons back onto the plate, much like two magnets pushing each other when you face like poles of two magnets toward each other.

Plate - This is the outermost element that you typically see in the valve. The plate is connected to the positive side of the supply through the output transformer primary and is where the electrons from the cathode flow to.

In TRIODE mode (which isn't true triode btw), a switch connects the screen grid directly to the plate, thereby making the screen an extension of the plate itself, and not allowing the screen grid to function as it normally would in a pentode. This effectively makes the valve into a triode, although you still have the suppressor grid performing its primary function.

__________________
Jon Wilder
Wilder Amplification

sales@wilderamplification.com

tech@wilderamplification.com

HOT TUBES 70

gentlmen , thanks for taking the time to answer this question , you
have done that in great detail as well i might add , it gives me a basic
understanding of what is going on when i use the two different modes .

for what its worth , i use the triode mode for some classic rock but most
of the time its all pentode tone for me . the third channel is just killer on
these amps !!!

thanks again guys

__________________
MARSHALL 6100LM
MARSHALL 1960A W/-G12H 30's
CUSTOM BUILT 2X12 W/-V30's


"MARSHALL" - only the best will do !

American Viking

JCM800's and most other Marshall amplifiers all work in pentode.

__________________
-I'd rather be a good liver than have one...