Ehart, there is no jealousy. Most posts asking about pre amp are from people that still have a receiver. He starts out with cary monoblocks, my poke was ment more at light humor. To much money, tubes with solid state. I guess I could have left the part about not knowing anything out. I need to work on my audiophile tact. |
Thats right, pre just amplifies voltage, not power. Gs556, what do you mean by a pre drives a load of thousands of ohms? The typical amp presents that much of a load, why? ONe more question: what is the problem using a SS pre with tubes? I thought SS pres were more dynamic, "faster", they add rhythmn and pace, and firm up the bass. Tube amps add bloom and tone. If you need what a SS pre can give you in the system, dont you use it? thanks.......mark |
Sogood: jealousy is a bad thing. If a guy wants to experiment with different combinations of equipment, what's the harm? |
Preamps depending on their circuit topology (and there are few ways to design an input driver) can produce an output power(especially ss-preamps).
There are also SS-preamps(base- or gate- coupled output stages) that do increase voltage in very-small sacrifice to current thus still able to increase power as well.
I did an experiment just like Sean mentioned by simply connecting an output transformer to Bryston B11 preamp and than to small monitor speakers(only to play with) and it worked but clipped not even reaching 12 o'clock...
An output power tube basically has a very large output impedance thus also mainly amplifies voltage. It certainly requires either transformer or reverse-polarity load(negative feedback) as it's done with OTL. |
above by Mythtrip>>>No one ever talks about preamplifier power, yet thats what it does, right?
The pre amp is misnamed as it is an amplifier but not a "power amp."
Pre and the first stage of an amp generally are voltage amplification. Power (current) usually the final (output) stage of the amp.
I agree with Pbb and Sean above.
I remain, |
I agree Pbb. The differences between a preamp with a phono stage ( a "real" preamp to me ) and the active line stages / passive line stages of today all seem to blend together due to a blurring of terminology. I'm sure that there are others that feel the same way and i bet that we all share a common age bracket : ) Sean
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Seems strange no one mentioned that in the days of vinyl only, the preamp had two basic and indispensable functions: to amplify the very small signal coming from a cartridge and to equalize it to the RIAA curve. Preamps seemed more of a "real" component to me in those days than the line stages today that are, more or less, required with higher output sources such as CD, DVD and SACD. I kind of liked the term Yamaha used years ago of a "control amplifier" since it is where the other components are plugged into and where you have the controls. |
You could always simply be choosing unequal volume settings between the two preamps, maybe unconsciously, based on their sounds. But it could be that the SS preamp is just doing a better job of driving your interconnects and amp inputs, which would presumably be due to its lower output impedance, not higher or lower gain (which is ultimately limited by where you set the volume control anyway, usually well below the available maximum).
In other words, even if you were to volume-equalize the two preamps at 1,000 Hz (the ear's most sensitive range), the tube preamp might suffer from an impedance mismatch - relatively speaking - driving its load as compared to the SS preamp, which would tend to slightly roll-off its response in the 'power range' of frequencies below the midrange which give music its "balls", as you say, causing it to sound a bit more lightly-balanced.
Another possibility (not mutually exclusive) is that the tube pre is suffering from a bit of dynamic compression, again relative to the SS pre, which is limiting its amplitude response on musical peaks and making it sound 'quieter' overall (in the sense of being less loud, not less noisy). Time for new preamp tubes, maybe? But even if neither of these scenarios is the case, SS preamps will commonly have somewhat firmer low bass than tubed models, and also better S/N ratios, and I suppose the results could sound like "more balls" to some listeners, even if volumes were broadly equal. |
Funny, I never thought of it until reading this post, but I guess that is why it is called a (pre)amplifier! I like days when I a lightbulb goes on in my head (Lord knows there are not enough of them!) Good Listening!! :-) |
Preamps do not increase power, only voltage. A preamp drives a load of thousands of ohms, which is far larger than its own output impedance, and that, along with a smaller power supply, decreases the power produced and transferred. Instead, it increases the voltage, so it is a small signal (voltage) amplifier not a "power" amplifier. A power amp drives loads of less than 10 ohms, which require a lot of current at a given voltage - so there is substantial power transferred. That's the basic difference - one amplifies voltage and the other power (voltage and current). |
Tube preamps typically have a far higher maximum output level than the mass majority of SS designs. As such, the only thing that i can think of is that the tonal balance has shifted due to different power transfer / loading conditions and you seem to like those changes.
Other than that, a preamplifier is nothing more than an amplifier designed to work with a lower input signal and a lower output signal. Think of a preamp as an "intermediary gain stage". It can take a weak signal and boost it enough to drive the next gain stage or it can regulate a signal that may otherwise overdrive the next gain stage through attenuation. Pre-amplifiers got their name as they are nothing more than an amplifier stage prior to the main amplification stages, hence "pre" ( before or prior to ) amplifier. As such, most do not consider "passive units" to be pre-amps as they have no amplification stages. However, one "could" say that they go "before the amp", so in effect, it is still a "pre" amp.
Other than that, there are preamps with enough voltage swing and a low enough output impedance that they can drive speakers. They will typically sound like tin cans vibrating when doing so, but you might be surprised what comes out of the speakers if you were to try doing this. This is NOT a suggestion to try driving the speakers via a preamp even though i have. For the record, i did this as a "yout" ( pronounced "youth" ) when i didn't know better. Sean
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You have to much money, Cary 2A3 monoblocks with solid state, no way. Just for the info: How did you learn about a company like Cary and not know anything about audio.? |
When I was studying electronics I was never introduced to such component as preamp. The whole section in electronics were dedicated to amplifiers and they are only realy different with output power.
If preamplifier is basically an amplifier than it certainly have an output power only you can't use it to drive speakers since the output impedance might require matching
I'm not familiar with 2a3 monos but pretty familiar with the bulbs' output characteristics. It realy seems to me that by cranking volume on your SS-pre you're getting these tubes onto clipping. Since they're working far away from their specified region, they might end life pretty quick. |
