Manley Steelhead into Manley NeoClassic 250 monoblocks: dead quiet
This is an example of a phono section that employs a semiconductor at its input, IOW, it is not all-tube.
Ralph, is it possible to make a tubed phono section without a SUT that is noiseless?
No. All circuits make noise (tube or solid state), the question is how much? You can get a tube phono section to be pretty quiet assuming the tubes are good (our phono section is good to about 0.2mV); anyone saying that their all-tube phono section is 'dead quiet', that sort of thing is not telling the whole story!
If you are using a low output MC cartridge without a stepup transformer, there is going to be a limit as to how low output you can work with from the cartridge. For us that point is at about 0.2mV (0.2 millivolts), where if the preamp has good tubes in it, the phono noise will be below the surface noise of the LP.
What I have found over the years is that everyone has different tolerance levels for noise. Some people are upset when they have the volume up way high, and then lift the arm off the record, and hear all this noise. But you know what? All phono sections that are all-tube are going to do that.
If you run an SUT (its an option in our preamps) you can get the noise floor down to a point where it is near the same level as the line stage. That's pretty quiet! But if you turn the volume up real high, the noise is still there. What is happening is the transformer boosts the cartridge level so much that you just don't have to have the volume control up that high yet its playing at a very high level. So it makes the illusion that the phono section is silent. But no phono section is actually silent- they all make noise!
