Electrically speaking, is there any difference between the "sag" created by tube rectifier circuit and one built with a SS rectifier and a smaller ohmage, larger wattage resistor immediately after?
I am talking as far as the pre rectified PS, and the post rectified circuit see it.
Does it make a sonic difference, or is this one of those, "matter of opinion" subjects?
"sag"
Moderators: pompeiisneaks, Colossal
Re: "sag"
I'd say experience over opinion. Electrically, they achieve the same end of converting the AC signal to DC. I prefer tube rectos, simply for the "feel". But the Express has a lovely picking response using a resistor. And, the bloom I love is more apparent in Dumble designs that use solid state rectifiers with a choke.
My favorite build used an Express pre with the Dumble OD (switchable) and a rectifier tube/choke.
If you want to try "things" out, put in a tube socket then change out the tube for a solid state module to see which you prefer, or...
Another current posting (Look At This) shows a switchable tube/resistor option that will give you a taste of both.
a'doc1
My favorite build used an Express pre with the Dumble OD (switchable) and a rectifier tube/choke.
If you want to try "things" out, put in a tube socket then change out the tube for a solid state module to see which you prefer, or...
Another current posting (Look At This) shows a switchable tube/resistor option that will give you a taste of both.
a'doc1
Re: "sag"
One of the biggest factors in the amount of sag an amplifier has is the size of the first filter cap and the choke. When high current is demanded by the output stage, the increase in ripple is averaged out by the choke and the screen supply drops down reducing the gain of the output tubes and on down the line to the preamp. To make a fair comparison, the filter capacitance must be the same. Solid state rectification tends to have more capacitance.
Rectifier tubes are not as linear as a resistor. As current increases, the resistance goes down. You can come close with a resistor but only over a narrow range so there will be some audible difference or feel. It might not be noticed by all players depending on the style of playing.
Rectifier tubes are not as linear as a resistor. As current increases, the resistance goes down. You can come close with a resistor but only over a narrow range so there will be some audible difference or feel. It might not be noticed by all players depending on the style of playing.