Most powerful SE DIY design?

[jazbo8]

300B=AM Radio!

Distinguishes SE design from P-P design. Below are measurements of SET and P-P amps. White is SET tube amp, blue is P-P transistor amp and yellow is P-P tube amp. Yes, SET and P-P amps do sound different.

An externally hosted image should be here but it was not working when we last tested it.

Rod Elliot has some strong opinions against SET designs, but I think he is in the minority as many actually like "an amplifier that reminds me of a 1950s "Little Nipper" AM mantel radio..." More 2HD please.

Jaz

 

[TheGimp]

There is also a greater than 6dB difference in floor noise level. This may mask music detail resulting in a perceivable difference.

 

[Wavebourn]

Yes, I agree. Tubes can do great organic sound.
Even harmonics are what distinguishes valves from transistors and his sterille sound.

Look at the picture. That long tail of harmonics is one of reasons why sound is "sterile". Another reason is that this tail is long on low levels of loudness. Actually it is better to call it "dead" sound than "sterile". It smells like in morgue.

SE tube amps have short tails that go shorter and lower when sounds decay. It is natural, we expect that from natural sounds.

 

[tomchr]

I'm getting about 10 W from my 300B SET. Just beware that the driver circuit for the 300B needs to be able to swing about 180 Vpp with low THD and at least provide a few mA of grid drive. You'll need a low impedance output for this... I'm toying with an ECC99 + source follower and/or cathode follower and get good results.

Even with my 87 dB/W*m efficient speakers I still find 10 W to be plenty. It's plenty loud to make my ears ring (100+ dB SPL) and I'm not looking to rock the house off its foundation anyway.

~Tom

 

[tomchr]

There is also a greater than 6dB difference in floor noise level. This may mask music detail resulting in a perceivable difference.

I'd be more concerned with the 60/120 Hz IMD on the yellow trace, actually. That's a classic example of mains hum. And the main reason I decided to use DC for heaters...

~Tom