just wondering, but what is the difference between tubes like 6L6's and EL34's? do the make a big difference in the sound? does one have more kick than the other? ??? please help me!
There is a cryptic ingredient in many of our modern improvements--we are awed and pleased without knowing quite what we are enjoying.
well there are many old topics on this to search through...but since I dunno what kind of amp or anything you might be referring to....basically the difference between the two is
the EL34 generally has more bite, midrange, etc....(think Vox/Marshall/all original british amps)
the 6L6 is not as bright but is more fully rounded....(think Mesa/Boogie)
I'm talking about guitar tones here....not the physical differences between the two...and keep in mind those are power tubes....to hear what I'm talking about...you have to crank them
someone else here can give you more info I'm sure...that's just my experience
6L6 power tubes can be a little too clean for the tastes of many. One option is to use 5881 tubes. These are direct replacements for the 6L6 which require nothing more than a re-bias after installation. They give a little less headroom, break up a little sooner, and add a little more grind to the amp.
Another option is to swap your 6L6's with EL34's. EL34's have a darker tone, the break up allot earlier than the 6L6, and their overdriven sound is radically different than a 6L6. If you're looking for a big change in tone, then this may be just what you're looking for. But EL34's ARE NOT direct replacements for the 6L6. You'll need to make a slight modification to your amp so it can use them.
1. Replace the 470 ohm resistor that's between pins 4 and 6 of each output tube socket with a 1000 ohm, 2 watt resistor.
2. Disconnect pin 1 only of the 1500ohm resistor that's between pins 1 and 5 of each output tube socket.
3. Disconnect the wires on pin 1 of the output tube socket.
4. Reconnect the wires that were on pin 1, to the end of the 1500-ohm resistors that are now standing free on each output tube socket.
5. Connect pin 1 to pin 8 of each output tube socket with a solid wire.
6. Increase the value of the resistor that's in series with the bias diode to reduce the bias voltage until you obtain proper bias. This will vary from amp to amp.
The good news is that after this mod is in place, you can use either EL34's or 6L6's just by adjusting the bias. You need to be really carefull when working on a tube amp they have voltages that will put a real hurt on you. take it to an expert.
Hope this helps
Joe
Joe- I'll have to consult you when I get replacement tubes for my Hot Rod Deluxe. Mine has the stock Groove Tubes. I would like to get a little tighter bass. I don't know anything about the difference in tubes. I was never a "techie", just spent my time tryin' to learn how to play.
If you know something better than Rock and Roll, I'd like to hear it - Jerry Lee Lewis
Wes_Inman- I haven't seen the schematics or the inside of one of amps, but If they stayed close to their older Fenders I'll bet the mods I did for my 1959 bassmen with bring it to life. I'll have to look for it. Maybe a tech in your area can see and whether or not they can do them.
It's really not that hard, you just need to at least know safety precautions because of the voltages involved. It can put a hurt on you. Like in six feet under fit your not careful. I'm not trying to scare you just make you awhere of the safety first.
Joe
ok, that's what i needed to know. :) but one more question, what exactly do rectifiers do?
There is a cryptic ingredient in many of our modern improvements--we are awed and pleased without knowing quite what we are enjoying.
An amp's rectifier performs the function of converting ac power to dc. There are two types of rectifiers, tube and solid state. A tube rectified amp uses a tube to do the job, and an amp with a solid state rectifier uses one or more diodes.
Vacuum tubes (valves) require quite high direct current (DC) voltages to operate optimally. The power that comes out of the typical wall outlet is 110/120 or 220/240 alternating current (AC). Tube amp power supplies must convert this AC to DC and step the voltage up to somewhere between 400 and 600 volts and occasionally even higher.
Transformers are used to step the voltage up or down. Transformers consist of a core with two different strands of wire wrapped around it. One strand is the input and the other is the output. The number of windings of each strand determines the ratio of input to output voltage. I won't go into transformer windings at this time.
Once the voltage has been stepped up, it needs to be converted from AC to DC. The simplest way to convert is to put a rectifier in the circuit. Rectifiers (and/or diodes limit the flow of current to one direction only.
The rectifier tube in your amp plays an important part in its sonic character. With experimentation with several rectifiers some amps will not exhibit much of a difference in sound between rectifiers, others can be quite dramatic. Voltage sag under peak conditions can produce that vintage sound a lot of players like.
However, when replacing your tube rectifier there are some things you should take into consideration. With a tube rectifier, there is a "warm-up" period before B+ is applied to the plates of the tubes. This gives the filaments in the tubes a chance to warm up and emission to begin before applying the full B+ voltage. Applying B+ too early causes what is known as plate-stripping, increasing tube wear.
For this reason, I always recommend using your standby switch and allow 20-30 seconds or more before applying B+ voltage. Today many makers offer dual rectifiers which is really just a switch that can alternate between tube and solid state rectifiers. While this does add some versatility to the amp, it in no way indicates that you will get superior performance to an amp with only one rectifier.
Joe
???...and this is why I dont mess with electronics
You now your stuff Joe,
always handy to know a few things like that. The more you know about the workings of your equipment, the more you will know how to get the right sounds and tones out of it.
On the subject of "Rectifiers", what Joe said was spot on, but there is another type, which some serious audio buffs like to use - mainly (I think) for the way they look. The "Mercury Vapour Rectifier" which do look spectacular when working. They are almost obsolete, but a few can still be found in older industral factories. They where used in projection equipment in the 20's & 30's and became popular during the industrial boom of the 50's, used for heavy DC power plant and rail systems. They still make "small" versions of them for said audio buffs but I have no idea what they sound like.
While we are on the subject off tubes, I Was thinking about getting low gain tubes for my Marshall to get the amp to stay clean on louder power but the dist on it would not be so great then Right? But are their tubes that just change the Clean channel
(Hope somebody understands)
Enter the madness http://www.maggib.tk
