7

There is no constant current component over the speaker. When the speaker works, current flows through it altering direction roughly as many times per second as the main frequency the speaker is emitting. When the speaker is silent, there is no current at all, and any load on the speaker will stay cold. However the filaments of the vacuum tubes must stay ...


6

To oversimplify slightly, assume that matched tubes all have the same "bias point". Meaning, if you have unmatched tubes, the bias adjustment that works for one of them might not work very well at all for the rest. If you have matched tubes, they are close enough that one bias point will work for all four. You only have one bias adjustment dial on that amp, ...


6

Vacuum tubes or valves (UK) have a number of factors that contribute to their life span: 1) integrity of design 2) choice of materials 3) integrity of manufacturing 4) cooling 5) physical shock 6) electrical stress 7) number of hot to cold, or cold to hot cycles Integrity of design factors should be considered, tubes are optimized for performance or ...


4

Sigh, in the old days you would pull ot the tubes, put them in a suitable protective container (Standard was a woolen sock) and take them down to the local radio shop. They had a machine that would measure both cathode emmission and voltage gain. These days you probably need to try replacing the tubes. Common failures are Filament failure (no red glow from ...


4

If you really need a power attenuator depends on what you want to achieve. A 22W amp can usually be turned down sufficiently to be played in an apartment. However, if you want it to sound as if it were cranked up, i.e. you want the power amp to saturate, then you'll need a power attenuator. And in this case any attenuator that matches the output impedance of ...


3

The short answer is that it is for stomp boxes. Stomp boxes are normally designed to be put between the instrument and the amplifier so they have different levels than the (usually rack mount) effects that normally go into an effects loop. In order to allow the lower output from a stomp box to be used in an effects loop it needs special treatment. I would ...


3

Better is very subjective, but the simple thing to acknowledge is that you are operating an electronic device outwith the parameters for which it was designed. Therefore you cannot assume it will sound 'better' as much as 'different'. Eddie Van Halen is possibly the source of this (mis)adventure, as he commented, erroneously, in early interviews that some ...


3

If your amp works and if it sounds OK you haven't damaged it. We all know that tube amps shouldn't be operated without a load, but depending on the exact circuit and on the power tubes, most tube amps can survive such a condition for a while, and it looks like yours has survived. I haven't actually experienced a single case where the tube amp would be ...


3

One thing that might be worth noting that people talk about the characteristics of pentodes and stuff. But in a typical tube amp, one important element with its own saturation and consequently distortion characteristics is the output transformer since tubes operate at voltages and currents unsuitable for most loudspeakers, requiring a transformer for ...


3

This is phenomenon of perception that is confined to guitar amplifiers, and those arguments against solid state amps are at least 45 years out of date. If you've been surfing the Internet, you're going to be inundated with information. In the arena of hi-fi amplification, solid-state wins--no contest. Total harmonic distortion is the almighty parameter, ...


2

Most of the other responders have touched on what I think is the main point, that tube amplifiers distort the sound in a way that can sound more 'natural' and more 'pleasing'. One thing I think they have not mentioned is that solid state amplifiers actually replicate the sound much more exactly, amplifying the sound of the instrument or whatever input ...


2

Not all tube amps need/should be re-biased when changing tubes. E.g. Mesa/Boogie amps have pre-set bias and need some sort of modding in order to change it. The tubes should be bought as a matched set though.


2

Before you go out and buy an attenuator, ensure you really need one. @Matt's answer makes very important observations. Typically attenuators have variable attenuation level; you should be able to get the volume you really want without problems. (Yes, this is the big knob). Weber MiniMASS The only real caveat is maximum power dissipation; they are ...


2

If the hissing gets louder as the volume control is increased, the source of the hiss will be before the volume control. I would start looking at the input lead(s) and sound source (guitar). Swap the guitar and connecting lead with a known good one or even two. It is cheaper than buying a replacement set of valves you might not need. If the hiss is not ...


2

I did this 3 days ago and it works a treat, BUT, the combo speaker is 8ohm and so is the external. It's ok to attach more ohms to the amp but not less. I think what you want to do will work, however the volume of the 16 ohm cab may not be as Loud as the combo. I used a Switchcraft 1/4in mono jack plug with shunt. These are also called 'switched' jack plugs. ...


2

Assuming the amp originally contained a matched quartet, you can get away with a matched pair, and install both of them with the following setup in mind: The four output tubes in your Windsor are used in pairs to achieve the combined amplification (schematics here). Your tubes are placed in row A,B,C,D (thats V4-V7) and A,B is amplifying the positive ...


2

There's no special treatment, just avoid mechanical shock (tubes have parts that can move under shock, and they're obviously in a glass envelope), and moisture (including beer ...), the latter of course being true for any electronic equipment. And, as a rule of thumb, never leave your tube amp anywhere where you wouldn't want to sleep, e.g., in a trunk of a ...


2

My variac arrived today and I have to say I'm very happy with it. My wall voltage seems to run a little high usually between 120-123V so the knob on the variac was a little off from the actual voltage reading. (The actual voltage coming out of the variac seemed to be about 5V higher than what it showed, but from what I've read this was to be expected). ...


1

Yes, with an impedance matching transformer like this one: https://www.sweetwater.com/store/detail/LittleIMP--whirlwind-little-imp-lo-z-xlr-to-hi-z-1-4-inch-inline-impedance-matcher


1

If anyones interested I managed to find a reasonable solution to this (which didn't cost the earth) Also just want to say thanks for all your suggestions. They all helped in some form or another to reduce the problem. Basically a guy in Forsyths music shop in Manchester suggested getting one of these; https://www.amazon.co.uk/Tacima-6-Way-Mains-...


1

The main purpose of the power soak is not to reduce the signal level, but to offer a reliable low impedance like a cabinet, even if none is connected. A tube power amp requires such an impedance, else it'll destroy itself. With the power soak in place and set to -32 dB, it doesn't really matter anymore what you connect. You can as well step it down yet a ...


1

Five or ten minutes is not tube warmup (which is more like 15sec) but rather the warmup of other circuitry. That may include bad solder joints. It's often possible to hunt such thermal problems down using a bottle of cold spray (which is specifically used for such diagnosis). Of course, you don't want to reach the hot tubes with that in order not to cause ...


1

You are better off with 10% too much voltage than 10% too little. Higher voltage stresses condensers and some other parts, but their tolerances are pretty high. Lower voltage, however, leaves the tube cathodes too cold which means that they are bleeding metal vapor in addition to just electrons. The metal resublimates in places where you don't really want ...


1

The simplest answer is no...and yes! It will sound different, and you may find a voltage that changes the valve bias to a level that you like the sound of. But you may not. There are plenty of amps that have variable voltage control for valve bias and other sections, or variacs. Play with them (or with simulators because at the end of the day you just need ...


1

Old and new is not the only difference. If these four tubes really must be balanced, you need a tube testing tool for selecting the matching group from much more than just four tubes. However selecting the matching pairs was much more critical for transistor electronics, as individual transistors vary in parameters much more dramatically than tubes. Maybe ...


1

How to measure loudness Sound pressure level (SPL) is used to measure loudness in this case. The unit of measurement is dB(SPL). Sound pressure meter is an instrument used to measure dB(SPL). Cheap sound pressure meters can be bought starting at 20 USD. The decibel (dB) is a logarithmic unit used to express the ratio between two values of a physical ...


1

I just got a blackstar ht-5r combo tube amp and it sounds great with my distortion pedal, it's a Biyang Metal End King pedal. If you like playing heavy metal then this pedal will give you any type metal sound you want, very heavy, fat tones and not muddy like a lot of pedals! Cheap too, only $79. I play anything from black metal, thrash, or death metal and ...


1

Just for info: a few years back an electronics specialist friend took my 'classic' valve guitar amp into the lab and ran a few tests. Now this person had been educated to believe that solid state was king. He came back a bit surprised and reported that it had frequency response (flat) matching solid state hi-fi amps and he could not detect distortion until ...


1

You will know. It will start to sound truly terrible, or even go silent. When it does you need to isolate which one it is, which can be tricky unless you have two channels, in which case the one that moves the problem from one channel to the other when you swap it between channels is the one. This rarely happens unless there has been physical damage, or a ...


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