SET Preamps

Hi Audiogabby. I have been using a Dehavilland Mecury II for the last three years. I agree with your assessment of it. However, I found that with the proper vibration control applied the bass can be deeper and taught. First, I put a 3mm Marigo Audio VTS dot under all of the tubes. Then I use a set of Marigo Mystery feet under it, which sits on an Adona rack. I also replaced the stock Russian output caps with Mundorf Silver/Oil ones (I consulted Kara before doing this). Finally, I replaced the 5 AW4 rectifier tube with a Tungsol 5U4GB. I'm no longer looking to change preamps.

Hi Audiogabby, did you read this?

I agree with everyone who said most or nearly all tube preamps are SET, but why?

In other words, why is a simple single-ended triode able to give 21st-century state-of-the-art performance in a preamp circuit, while similar performance in the power amp seems to require ultralinear push-pull circuits or something even fancier? Is it just the ability to drive the nasty load characteristics of the average loudspeaker? Just interested in case anyone knows the answer :)

Why is a simple single-ended triode able to give 21st-century state-of-the-art performance in a preamp circuit, while similar performance in the power amp seems to require ultralinear push-pull circuits or something even fancier?

Simply put, the power amp has to deliver vastly greater amounts of current and power to the speaker than the preamp has to deliver to the power amp. Which makes it a whole different ballgame.

Regards,
-- Al

If you want my opinion I really feel that if you do fully differential in the preamp, there is a huge benefit there also, IOW even though there are many very musical single-ended tube preamps, they *can* be improved upon.