$18k Tube preamp for large scale symphonies please

Philipwu, I have to agree with Lenny here. If a preamp is competent, it will not matter what type of music you play. I suspect you are looking for something with good bandwidth and detail but if a preamp is competent it will provide those things.

So the Nagra is a contender if it can drive your amplifier comfortably without loss of bass. It is that latter issue that is a concern if you are using a transistor amp. Some transistor amps have lower input impedance values (!0K being typical); this coupled with some tube preamps (ARC for example) will result in less bass. To that end I would compare the output impedances of your contenders; those that have more than 1K at 20Hz would be out if you have a transistor amp as in the example I gave.

Happy New Year!

Atma is spot on here. A good preamp will play all music good. A great preamp will play all music great. Now, the speaker is the piece that may play one form of music better. I have found the more resolving a great preamp and system is the better all music sounds.

Atmasphere, while on paper I agree with you that a preamp with an output impedance of 5k - 10k ohms does not seem like a good match with an amp with an input impedance of say 20k - 50k ohms, why do these combos sometimes work so darn well? No bass roll off at all and wonderful music.

I know from experience that what on paper should not work can work gloriously in reality. I am not sure why this is, but it is. Any ideas?

Bill (Grannyring), the two ways in which high output impedance of a line level component are most likely to have audibly significant consequences are:

1)Interaction of VARIATION of that impedance, as a function of frequency, with the load impedance, resulting in degradation of frequency response flatness and other effects.

If the output impedance is very low in relation to the load impedance, it assures that variations of that impedance will be insignificant in relation to the load impedance. But if the output impedance is relatively high, it does not NECESSARILY mean that those variations will be large enough to become problematical. A hypothetical output impedance that is purely resistive (as opposed to the impedance having significant capacitive or inductive components) will have no variation as a function of frequency, and assuming that the load impedance also does not vary significantly as a function of frequency the only consequence of that output impedance being high would be a slight gain reduction.

2)Interaction of that high output impedance with cable parameters, especially capacitance. If the interconnect cable is kept short, and a low capacitance cable is chosen, those effects will be minimized.

Happy New Year!

-- Al

Thanks Al. In the situations I have heard the IC's were 1 meter and low capacitance. Perhaps this has also played a role.

Hello Grannyring, you are correct. The higher the output impedance of any preamp, the shorter the IC should be.

However that does not explain bass response, but some of that depends on your speakers too, and whether you listen to recordings where the issues might show up. This is an area where audiophiles will say things like "this preamp has more impact than than that one" even when both preamps cut off at the same frequency. IOW, its in a realm of 'in comparison to what?"

What we are talking about here is issues with phase response, which behave to the ear more as a coloration than a frequency response issue, although when the phase is right you do get more impact.