Send your wife shopping or give her some ear plugs.
I hate to break it to you, but you just bought yourself a professional gigging amp, not a bedroom practice amp. The thing likes to be "cranked". Of course, "cranked" doesn't mean dimed, but it is still LOUD. Even at 1/10th the power, which is really how loud most people use them, it will rattle your windows and shatter your china. It also kills small animals!!
To deal with this frustration, I carry a case with me with a plethora of Tube options and I also have 3 different speaker enclosures, depending on what the particular situation calls for.
The sweet spot on this amp is with the master / volume between 9:30 to 11:00. My wife thinks my Dual is loud with a pair of yellow jackets (15 - 20 watts) in it running only one speaker with the volume almost off. If you want it to give that RECTO tone, it gets beyond loud into the region of "deafening", "thunderous", and "a force of nature" once you get the amp turned up. Find a drummer and a bassist and let the ponies run wild.
In regards to tone, you have to understand that a lot of the buzzy-ness comes from the speakers not moving sufficiently enough to work properly. Especially with a 4 x 12, you have to have a lot of power going through the amp before it starts to 'open up' and the speakers get moving. That usually happens at rehearsal / gig levels. Think of it this way, you just bought a Porche 911 twin turbo and you are complaining it is slow but your wife isn't letting you rev the engine above 2k because it will use too much gas. Of course once you get the revs high, the true power of that motor will manifest itself fully, but you have to give it the necessary gas to do so.
Hmm, in regards to your current problem you can get cranked tone at quieter levels by:
1) Pull out two power tubes, either the inside or the outside pair. So, your power tubes should look like
_ X X _ or X _ _ X
2) Pull out one rectifier tube. This will cut the available DC current down to match the available power tubes, provided you want rectifier sag.
3) Connect your head from the 4 ohm output to an 8 ohm cab or from the 8 ohm output to a 16 ohm cab. Removing power tubes not only cuts the wattage down, but also alters how the amp reacts to the impedence of your speakers.
4) Think about a 1 x 12 or a 2 x 12 cabinet for practicing. I PERSONALLY advocate running a pair of Yellow Jackets with the amp as well for practice / low volume application. A high quality speaker enclosure loaded with 1 or 2 Celestion Greenbacks or the Warehouse Guitar Speaker equivalent will give you good tones at a much more manageable level. Definitely look for a thiele, a 3/4 back, or some sort of ported or tuned guitar cab for this purpose. Save the 4 x 12 for gigging. Trust me, halfstacks are not good practice solutions for most people. They are simply far too powerful.
5) The fizz or presence is a quality of those G12T-75 speakers that are in the Marshall 1960a cab. I would describe them as being scooped, gritty, or scratchy, depending on how you want to think about it.
MY favourite tone with a recto is Celestion v30s mixed with Greenbacks with EL-34 tubes for rock or Celestion c90s mixed with v30s and 6L6 tubes for modern and metal tones.
One thing to consider. G12T-75s and Greenbacks are quieter (less efficient) speakers than c90s / v30s etc etc, so they will allow you to crank your amp a bit more before people whine. Just a HAIR more, though. The HAIR you gain with the quieter speakers as well as the HAIR you gain with yanking a couple of tubes makes some difference, but not a lot. Using YellowJackets gives 5 or 6 hairs, but the low power will not yield the necessary horsepower to drive most 4 x 12s hard. You need around a 100watt cab with this setup for maximum effect. At the end of the day, the amp sounds better when it is allowed to perform as it was designed!
6) Do whatever it takes to get on your wife's good side. Trust me, this works best. Maybe come up with an agreement where she leaves for an hour to go hang out with her girlfriends and you can crank the SNOT out of it. Midday is best, when your neighbors are at work. Believe me, they WILL hear it!! BAHAHAHA!
7) Buy an attenuator. This will allow you to get more of the cranked tone at a lower volume. As you rely on the attenuator to suck power more and more, it will suck tone more and more. Eventually it will alter your tone which really defeats the purpose of having one in the first place. By all accounts, the -3 to -6 db settings work best.
8. You can buy tubes that distort at lower volumes. This will also give you a cranked tone at a lower volume.
9) Some people run overdrive pedals at lower volumes to get more tube saturation.
Oh well, these are all solutions to try but they are really bandaids. Even worse, many of them cost MONEY! What you want to do is kick everyone out of the house, get your buddies over, and JAM!
When you unleash the beast, your jaw will hit the floor.
