Our under-rated tube amps!

[musicbox]

I was wondering if any of the resident audiophiles can clarify something for me.

I remember reading back a year ago that in the 60's, and even today, marshall and fender rated their tube amps at the peak wattage before power tube breakup. Now, obviously these amp's were designed with power tube saturation in mind, and thus they achieved wattages way beyond their feeble ratings. 100 watt plexi's can typically put out another 20 watt's or so(i believe???), after the power section starts moving into it's groove. Given the reputation boogie's have of pushing out way more sound then amps with simliare wattage ratings, can anyone clarify that this is also true of our boogies? Maybe Mr. Smith uses some other method of rating his amps? Anyone have the technology to test this theory out?

 

[Dale B.]

I was wondering if any of the resident audiophiles can clarify something for me.

I remember reading back a year ago that in the 60's, and even today, marshall and fender rated their tube amps at the peak wattage before power tube breakup. Now, obviously these amp's were designed with power tube saturation in mind, and thus they achieved wattages way beyond their feeble ratings. 100 watt plexi's can typically put out another 20 watt's or so(i believe???), after the power section starts moving into it's groove. Given the reputation boogie's have of pushing out way more sound then amps with simliare wattage ratings, can anyone clarify that this is also true of our boogies? Maybe Mr. Smith uses some other method of rating his amps? Anyone have the technology to test this theory out?

Well, as far as some of the Marshalls are concerned, JerryP posted some figures on a 50 watt Marshall, hooked up to a scope, and it was making around 150 watts full out. Usually, they will produce anywhere between 110 to 150 depending on how healthy they are. I remember seeing an advertisement in a Marshall catalog that stated their 100 watt DSL peaked out around 189 watts or something another like that.

As far as Mesa being underated....Well, the Mark IV is rated at 85 watts, but Mesa says that it can dish out 190 watts cranked.

At Idle current, a Triple Rectifier is somewhere in the neighborhood of 70 watts. It can probably top 200 watts very easily cranked up to full blast.

A Dual Recto will be in the 45 to 50 watt range at Idle, yet it can probably do everything a 100 watt Marshall is able to do in terms of overall power.

Everything changes when you're playing though. I'm not an expert in this field, but if I had to guess, Mesa is underated as well when you look at what it's able to dish out at full blast.

Dale

 

[musicbox]

thats what i thought! also why tube amps seem to be sooo much louder than solid state amps of similare wattage ratings. solid state doesnt distort till the very peak of its output, so the wattage rating is a fairly accurate assesment of its capabilities.

 

[Dale B.]

Exactly.....Tube amps are analog devices, so when you are looking at them in terms of overall volume they're logrithmic (sp.?). Solid-State amplifiers aren't.

Tubes are also unpredictable. Take for instance when you're playing the and signal is being fed into the amplifier, the bias will shoot up to sky high levels creating enormous amounts of power that you normally would think would cause a tube to die. A series of diodes will not be able to accomplish the same thing. The way I understand it is that when you play, the diodes have a ceiling and are predictable. I could be totally off base on some of this stuff, but that's just how I process it all.

Dale

 

[no soul]

I guess this would be important if I was trying to impress somebody with how many watts my amp put out, but on the other hand if that impressed you Im guessing you probably dont know much about amps.

 

[vulture2600]

my f30 will kick the **** out of any 100w solid state for reasons mentioned above. and it sounds way better too!
also, another interesting point is that solid state amps have no power section breakup, just the preamp. not to mention speaker break up, which is very crucial to the over all sound. if you can get a solid state amp to break up speakers, it just flub, not musical at all.
i still think its amazing that primative technology still sounds the best.