Tubes and their sweet spots.

[ak_47_boy]

If you where to triamp what tubes would you use for high, mid and bass? ~15wpc hf, ~30wpc mid, ~50wpc bass. Triode or tetrode, pushpull or ultralinear? I was thinking 6v6 high. 6l6 mid, 807 bass. I don't mind buying expensive tubes as long as they are not 300b expensive.

thanks

[CarlyBoy]

Hey Ak_47,

Sounds fine to me. Like many other tubes, the 807 is from the 6L6 family. Many would not do dedicated bass with tubes.

[Geek]

6L6 and 807 are almost (not perfect) copies of each other, just different purposes and bottles. So you could use 6L6 or 807 there.

My ideal tri-amp lineup would be:

High - 6AH4GT (single ended)
Mid - 6V6GT (PP) or 3x EL36 (parallel SE trioded)
Low - 6L6 series (PP)

[ak_47_boy]

The 6AH4GT is a triode, the 6v6 and 6l6 are pentodes. Won't the gain difference between pentodes and triodes cause problems?

[Geek]

Hi,

Originally posted by ak_47_boy
The 6AH4GT is a triode, the 6v6 and 6l6 are pentodes. Won't the gain difference between pentodes and triodes cause problems?

Not if each are driven correctly and depending on crossover and speaker efficiency. If you have a SPL balanced 3-way, you're unlikely to notice. Actually, with the tweeter being SE, there's less chance of hard clipping and better chance saving a precious ribbon during overload

(power based on a rule of thumb for 100W bass, 10W midrange and 1W tweeter for average listening)

[ak_47_boy]

Originally posted by Geek
(power based on a rule of thumb for 100W bass, 10W midrange and 1W tweeter for average listening)

Wow, i did not know it was to that extreme.

[ashok]

I've looked at scope traces of filtered audio signals from various CD's.

Based on that if I were to make a triamped system this is probably how I would do it .

Bass 100 watt ( continuous rated )
Mid 50 watt ( continuous rated )
Tweeter 50 watt ( max rated - means smaller heat sink !)

Some transients are very large , you don't want them clipped.
However the average tweeter power level is very low and while the amp should have enough transient capability it can get away with a small heat sink because of the average low power .

If mids start from say 100 Hz upwards the heatsinking must be adequate . If mids start from say 500Hz then you can again get away with a smaller heat sink than one required for continuous power dissipation.

If you play electronically generated music or possibly "metal" then you may need larger sinks because of the much higher HF content in them .

Basically you choose power based on transient requirement in that band and the average power levels.
Even a 100 watt bass / 25 watt mid / 25 watt tweeter will sound great. Active systems always tend to sound louder ( and cleaner ) than their equivalent passive version .

Cheers.

[ak_47_boy]

Won't even a 10W drive a esl tweet panel to deafining levels?

[ashok]

Why deafening levels at the tweeter ? Want to blow your ears ?
They are priceless !

There is a catch in all this. One has to take into consideration the sensitivity level of the drivers. So if the tweeter is very sensitive , like say 100db/ watt/meter , then you can get away probably with a 5 watt tweeter amp ! You get the drift ........

In any case 100 +25 +25 watts will NOT get you into the deafening range . Is that what you are looking for ?

Cheers.

[ak_47_boy]

ya, my esl's are sensitive Does anyone have any other suggestions for tubes, is what geek said the best way to go? I can't find much on 6AH4GT's. 2a3's? EL37's? kt88? There must be tube that are legindary for there hf, mid, lf..