Put the plate voltage at V. Locate the remaining preamp filter caps near their respective stages, and connect their ground to the local node grounds of the stage they bypass. Good questions, all of them. It takes a fairly firm grasp of electrical engineering to understand the intricacies of the theory behind the cathode follower. Mar 30, 6.

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How can I get rid of the hum if it is caused by the filaments?

Which is the cathode follower? | The Gear Page

Does cathode biasing mean class A? If you loaded it at full load, you would get 7.

Is it true that the only true class A amplifier is a single-ended amplifier? Exactly how does this work? It won’t usually hurt anything to substitute them, but it is not a fair tonal comparison if you don’t also change the cathode and plate resistors to optimally bias the tube. Just click on this beautiful picture below to read our little TubeMeister 18 to TubeMeister Deluxe 20 case study:. I use only axial-leaded capacitors, because rever are designed for point-to-point style mounting, and the epoxy end seals do not crack when they are mounted on the board.

Aug 8, Make sure you don’t route the choke wires near any sensitive preamp nodes – there are also lots of current spikes traveling in these wires, and they will radiate or couple into adjacent wires.

I’m going to try the Matchless Chieftain Reverb’s topology where the wet channel is mixed in the unused grid of the long-tailed pair phase inverter, and a lot of the blank areas in my rough eeverb are filled with Chieftain parts. This is why you have to be careful when spec’ing out a transformer – you might think, “I want to allow for a lot of extra current to add reliability or to have extra margin in case I want to add more tubes later This class of operation is characterized by high-linearity and low distortion, which makes it ideal for audiophile-type gear, and very low efficiency DC carhode in vs.


I don’t know anything about amp building but I do know about engineering, and when I do a test on something I will try to duplicate cathodee exact environment in which it will be run in the real world.

Cathode-follower clipping plus Valvewizard’s cheap current source reverb driver amp

A properly-compensated type 2 L-attenuator is probably the best sounding, but it takes a bit more circuitry to tailor the output impedance for best tone at all volumes. Is there a mod to make both outputs work at the same time?

Essentially, the part of the DC input power that is not passed on to the load must be dissipated as heat in the plate of the tube. Your name or email address: Would you potentially need a Master volume for that?

The cathode follower: the tech secret behind classic tube amp guitar tone? – Hughes & Kettner BLOG

Can the 20 be that much better? Because the tubes are in cutoff for half of each cycle, the average plate dissipation is much lower than it is for class A, so more output power can be obtained from the class B configuration. Don’t be misled by the higher plate voltage on the phase inverter either, because the cathode is usually sitting somewhere around 30V – V above ground, which lowers the plate-to-cathode voltage by that amount.

Are you bothered about whether your amp has a cathode follower? A reactive load will skew the results because of the frequency-dependent impedance magnitude changes. Note that this will only work if you bias the amp into class A, because you will only be running one side, cathoxe it will clip if biased at class AB or class B.


Take a bow, designers! Most designs use a switching jack to bypass the loop when no cable is plugged in, but these are notorious for getting dirty contacts and becoming intermittent. revefb

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carhode Damping factor is basically the ratio of the amplifier’s load impedance to its own internal output impedance. This usually leads to cracking of the epoxy seal around the lead entry points, which can allow moisture into the capacitor, leading to drift and potential failure. In a true class A amplifier at idle, no power is developed in the load, so all the power is dissipated in the tube.

The fully bypassed gain stage really drives the cathode follower stage into some strong compression and growl, and the added gain gives a broader range to mix pre- and power amp distortion to taste. They are not all internally identical and the overvoltage issue is very real with certain 12ax7s with spiral-wound filament and lower cathode-to-filament voltage spec.

The way the tube is biased and the circuit is set up determines when the tube or tubes is on. If revetb can find foollower other Rk value in between, then by all means go for it.

Attempting to simultaneously operate a 4-ohm and a 8-ohm speaker from the 4-ohm and 8-ohm secondary taps of an output transformer

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