I posted this in solid state before, but I would like to hear what the tube people think.
What would be the best amp to use in a tri-amp setup, in your opinion? This would be for tweeters only. Approx. 10-20W power.
Thanks,
Steve
What would be the best amp to use in a tri-amp setup, in your opinion? This would be for tweeters only. Approx. 10-20W power.
Thanks,
Steve
I would like 10 watts minimum. I enjoy my music loud at times, and I like having sufficient headroom. Thanks for the suggestions, and keep them coming! If you have schematics to pass on, all the better.
The reason I asked about output power is that people frequently underrate tweeter amplifiers. Unless you know that the tweeter is more sensitive than the driver it crosses over from, you need exactly the same power. Thus, a typical "Britbox" (8" cone + 1" dome) sometimes has a tweeter that is 3dB more sensitive than the mid/bass, allowing a 40W tweeter amplifier to be used with an 80W mid/bass.
Unless you are using a horn tweeter or one of the new very sensitive ribbons, I suspect you need more power.
SY: Could have been worse - could have suggested 10Y!
Unless you are using a horn tweeter or one of the new very sensitive ribbons, I suspect you need more power.
SY: Could have been worse - could have suggested 10Y!
That would probably be sensitive enough for me. The advantage of a smaller amplifier is that it's a lot easier to build, especially if it's your first valve project.
Hi,
Hmmmm........10 to 20W for a dedicated tweeter amplifier?
Really?
I mean, do you really need that many watts to properly drive a 94dB/m tweeter (in a tri-amped system, no less)?
Could anyone be kind enough to shed some light on the theory behind this? And why is PP the recommended way to go, besides the obvious power output advantage, that is?
I mean, if there's any situation where I'd expect a recommend for a SET amp then this would be it......
Cheers,😉
Hmmmm........10 to 20W for a dedicated tweeter amplifier?
Really?
I mean, do you really need that many watts to properly drive a 94dB/m tweeter (in a tri-amped system, no less)?
Could anyone be kind enough to shed some light on the theory behind this? And why is PP the recommended way to go, besides the obvious power output advantage, that is?
I mean, if there's any situation where I'd expect a recommend for a SET amp then this would be it......
Cheers,😉
Hello Frank, although a tweeter amplifier doesn't dissipate much power in a tweeter, it needs to be able to swing as many volts at the crossover frequency as the midrange amplifier (assuming equal sensitivity drivers).
And yes, PP because of the power. Otherwise we're into parallel 300B to get the power. A more subtle thought was that the character of a SET would be so different from silicon that it would be difficult to integrate and conceal the crossover.
And yes, PP because of the power. Otherwise we're into parallel 300B to get the power. A more subtle thought was that the character of a SET would be so different from silicon that it would be difficult to integrate and conceal the crossover.
A more cynical thought was that in using it as a tweeter amp, the high HD and output Z would be less crippling than they are for other uses.
Why 2A3 instead of a triode-strapped beam-tube or pentode? Or, for that matter, a 6080?
Good point, you can get away with high output impedance driving a tweeter (especially if it's Ferrofluid-cooled) because it doesn't need much electrical damping and its impedance is nearly constant. Single-ended is capable of producing low distortion provided that you don't push it too hard. Ideally, that means that you'd rather not use more than 1/4 of the full power, so you'd want a 50W amplifier. 4212E would do the job comfortably, and I'm sure it would sound wonderful. Downside is that the heater requires 91W, and the anode would dissipate about 250W. Add in a few odds and ends, and your stereo tweeter ampifier would consume 800W. Not an amplifier for a warm day.
Why 2A3? Because the currently-made Sovtek seems OK. Traditionally, one would have triode-strapped a KT66, but as an NOS GEC KT66 is about twice the price of a new 2A3, we don't want to go there. Triode-strapped 807 might be a good possibility.
I'm assuming that the tweeter is 8 Ohm, but if it was 16 Ohm, OTLs become a possibility and 6080, 6336, and 6528 make sense.
Why 2A3? Because the currently-made Sovtek seems OK. Traditionally, one would have triode-strapped a KT66, but as an NOS GEC KT66 is about twice the price of a new 2A3, we don't want to go there. Triode-strapped 807 might be a good possibility.
I'm assuming that the tweeter is 8 Ohm, but if it was 16 Ohm, OTLs become a possibility and 6080, 6336, and 6528 make sense.
Not to mention about 800 quid.
One option beyond KT66 is the "super" 6BG6s being sold here for about $6. They appear to be electrically identical to the 7027 and work wonderfully with a 6.6K p-p load, triode strapped, 450-500V B+.
And six dollars... six dollars...
Well, I would like to try a SE amp someday. I've built a couple p-p tube amps and I liked them (nothing special- 6L6 and a dynaco). I would think the SE tube amp would be more appropriate for an efficient midrange driver. They do tend to have a limited bandwidth, which would seem to make them not such a good choice for a tweeter.
About the power... 20 watts might seem like a lot, but I think it's necessary for the voltage headroom on transients without compression. Maybe I'll typically use 1 watt max, but what about that FFF cymbal crash on orchestral recordings? I like to listen to them LOUD! Am I wrong about this?
Thanks for the ideas.
About the power... 20 watts might seem like a lot, but I think it's necessary for the voltage headroom on transients without compression. Maybe I'll typically use 1 watt max, but what about that FFF cymbal crash on orchestral recordings? I like to listen to them LOUD! Am I wrong about this?
Thanks for the ideas.
nobody special said:
Why ever not? In an active system, you simply position the bandwidth of the amplifiers appropriately. Thus, a SE output transformer intended for a tweeter amplifier would position its bandwidth to accomodate the tweeter, and have reduced primary inductance. Bandwidth is about octaves, but also about positioning.
You'd need to have one specially made. That's not as bad as it sounds because transformer manufacture is a cottage industry. In the UK, Sowter will do this, but I don't know about the US.
I have serious doubts that an active system using very different sounding amps will ever sound good. Keep in mind that amps with different tonalities will have to cover the same range around the crossover points.
It may give a similar effect as paralleling two different caps in coupling applications. Some will like it, some won't.
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