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Difference between a straight 4 pill and a 2x4 amp?
- Thread starter Bundy
- Start date
A straight 4 transistor amp will require NN watts to reach the designed output. A 1 (or 2) x4 would use the extra transistor(s) to provide NN watts when the radio cannot.
2x4 amps (insert lumber joke) are generally competition amps for short keydowns.
1x4 amps are useful if you have a low output (stock) CB radio.
My personal preference is a straight 4.
2x4 amps (insert lumber joke) are generally competition amps for short keydowns.
1x4 amps are useful if you have a low output (stock) CB radio.
My personal preference is a straight 4.
The correct drive power for a "daily driver" amplifier that you can use without worrying about how long you key it usually boils down to a proportion of one-to-four.
That is, a four-transistor stage should not have more than one RF power transistor driving it.
An eight-transistor box should be happy with no more than two transistors driving it.
Sixteen transistors would be best to drive with no more than four.
As a daily driver, using the radio alone with a four-transistor amplifier would be even better. The size of your radio is the determining factor here.
But the "competition" setups you'll see are not so different from drag-racing mods done to a factory-stock motor.
Okay on a quarter-mile track, but not so efficient or reliable to get you to work and home.
The folks who sell amplifiers know that wattmeter numbers sell their product. Nobody asks what the "KBK" rating will be.
As in "Keys Between Kabooms"
A two-by-four is a competition setup. Might make a decent daily driver if you reduce the drive power to it.
A lot.
73
That is, a four-transistor stage should not have more than one RF power transistor driving it.
An eight-transistor box should be happy with no more than two transistors driving it.
Sixteen transistors would be best to drive with no more than four.
As a daily driver, using the radio alone with a four-transistor amplifier would be even better. The size of your radio is the determining factor here.
But the "competition" setups you'll see are not so different from drag-racing mods done to a factory-stock motor.
Okay on a quarter-mile track, but not so efficient or reliable to get you to work and home.
The folks who sell amplifiers know that wattmeter numbers sell their product. Nobody asks what the "KBK" rating will be.
As in "Keys Between Kabooms"
A two-by-four is a competition setup. Might make a decent daily driver if you reduce the drive power to it.
A lot.
73
I've seen 2x4 amps where the builder said he preferred the 2x4 to a 1x4 because he preferred a push pull design that required 2 transistors for his biasing scheme (B biased if I remember right but not sure), less drive on the input to the driver stage would then put the input to the 4 pill stage where you want it.
Any thoughts on this?
I don't know why he couldn't rework his bias circuit to supply proper current to 1 transistor. The first thought is that he copied it and doesn't know how to use it any other way. My mobile set up is a 2x16 but I'm just crazy like that. As the price of Toshiba transistors went up my driver got smaller. 
If you have a strong radio 40 watts or more go with a straight 4. If it's a low power cb that does 10 or 15 watts of go 1x4. I won't recommend a 2x4 to anyone. It's not hard to make one self destruct.
If you have a strong radio 40 watts or more go with a straight 4. If it's a low power cb that does 10 or 15 watts of go 1x4. I won't recommend a 2x4 to anyone. It's not hard to make one self destruct.
I don't care for amps with drivers in general because it's not hard to make one self destruct, although I do understand that with something that has 12 pills a driver is a part of the game.
I like a straight 4 myself just because most of my radios couldn't overdrive one if it tried, a 2 pill would be more than enough power but the extra headroom of a four lets me set up the radio to sound good barefoot and not need to turn anything down for the amp. But truth be told I rarely run an amp anyway.
I like a straight 4 myself just because most of my radios couldn't overdrive one if it tried, a 2 pill would be more than enough power but the extra headroom of a four lets me set up the radio to sound good barefoot and not need to turn anything down for the amp. But truth be told I rarely run an amp anyway.
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I don't know why he couldn't rework his bias circuit to supply proper current to 1 transistor. The first thought is that he copied it and doesn't know how to use it any other way. My mobile set up is a 2x16 but I'm just crazy like that. As the price of Toshiba transistors went up my driver got smaller.
If you have a strong radio 40 watts or more go with a straight 4. If it's a low power cb that does 10 or 15 watts of go 1x4. I won't recommend a 2x4 to anyone. It's not hard to make one self destruct.
Looking for an amp to pair with my "new to me" Galaxy Saturn base. I will look more into a straight 4. Thanks for everyones help!!
If it's the high powered turbo model then yes, a straight 4 pill would be best. You will still have to keep the variable power dialed back quite a bit. As an example this would work.
http://www.xforceamps.com/item/Straight-4Pill---Xtra-Duty---Base---400HD-B-101
If that radio is the normal 25-35 watt output then you could drop down to a 2 pill. Something like this.
http://www.xforceamps.com/item/Straight-2Pill---Xtra-Duty---Hi-Drive-Base---200HD-B-342
And if you wanted to run a mobile amp off a power supply then the Texas Star 500V could work on the top example. A Texas Star 250 or 350 would work with the bottom example.
If you have a high powered radio then you want to stay away from amplifiers that have a built in driver stage. (1x2,1x4,2x4,2x6) and so on.
Great info thank you. My Saturn is NOT the Turbo edition. The x-force amp looks like a good option for me as I really don't want to have to get involved with a large power supply and a mobile amp.
What about KLV400 base amp??? Thoughts?
It appears that the KLV400 base amp is a tube amplifier. Nothing wrong with running tubes you will have to learn how to tune and load the amplifier each time. The X-Force and Texas Star amplifier's are transistor amplifier's so you just hit the power switch.
As with most sweep tube amps the tubes are ran hard to make advertised output. An amplifier with a good tube like a 3-500z will cost you more but if you plan to use it for the next 10+ years it will pay off in the long run....as long as you treat it right.
The klv400 uses 2 el509 tubes. Each tube only has 35 watts of plate dissipation. Shop around to see what replacements will cost before you make a move. I'd go with a solid state amplifier before one with sweep tubes. They were cool back when they were a couple of bucks a piece but the price is ridiculous these days.
I'm using a Texas Star 350HD, it's a 1 x 2, AB biased for SB use. It's good with a 30 amp power supply. It gets me out there during skip!
