Hey I'm expecting a Ceriatone JTM45 clone in the mail pretty soon and, being concerned about the level of noise i would be making if I cranked it up, I had a half power pentode/ triode switch installed. I have heard mixed things about the tonal characteristics of the the amp when the switch is thrown, so I'm thinking of trying to reduce the power of the amp using any other alternative ways. I also had a PPIMV installed, but am hoping I can keep that on 10 for the majority of the time.
My question is, what are some methods I can use to reduce the amp's power while avoiding any circuit modification? Specifically, I have heard that changing the type of power tubes from kt66's will have some effect. Can anyone shed some light on this situation? Any information will be greatly be appreciated by my ears, neighbors, and jam mates for sure

Did you try a Hotplate or similar? I find it does a pretty good job reducing power on my JTM45.

The VVR is more practical and may be the best solution over all.  It'll work just as well as most attenuators -- better than some -- and allow you a lot more control over output.  Yes, it may affect tone when used (all those solutions ill), but that the COMPROMISE you make when you have to lower output.

The Yellow jackets will drop you to 15 watts or so, but that's till too loud to crank in an apartment or even a house unless you aren't alone, even 5-watt Champ quick exceeds bedroom output.  Plus the Yellow Jackets don't allow the variability that the VVR does.

Correct.  The Yellow Jackets convert to cathode bias and a fixed bias power-scaling solution wouldn't be suitable.


The idea behind power scaling is that as you lower B+, you lower the efficiency and headroom of every tube, so they'll clip much easier, which compensates for the weaker gain factor of the preamp tubes.  I see no reason why a MV would be necessary in a vintage-style circuit.  Actually, PS seems most commonly like with non-MV circuits. 


While I think break-up characteristics do change drastically from tube type to tube type, I think the emphasis they have on tone is highly overrated.  There is nothing inherently chime-y about a EL84, that is all tone stack, they do have that tight, focused saturated break up though, but you can use them in a Fender or Marshall or Soldano and they aren't going to make any of them sound Voxy.

Not an ideal solution, really no different than turning the Vol knob down. 

DUDE! Enjoy that amp. Get to know your amp first before you start doing anything to it. One thing that helps me tremendously in the volume department (reducing volume and enjoying fantastic tone) is to plug in to the lower output of either channel, EQ to taste, favorite boost/OD, set the PPIMV at 50%, volume at 3:00, and wail away. Do not bridge the channels.  With the PPIMV anymore than that it seems to suck the tone and all you get is pre-amp tube crap. This set-up seems more earthling friendly and won't kill small animals. Also, I think one speaker for the house is better than two.

I've tried PS, Triode mode, VVR, PPMIV, Yellow jackets, THD hotplates and an ISO box for the speaker and mic

For recording quietly, The ISO box wins
For practice, PPMIV is effective to knock it down a little, and so is the THD at -4dB, at least as good as VVR+PPMIV
Any of these lose way too much tone if you drop the volume to conversation levels
Fitted after manufacture, VVR costs the same as a used THD hotplate, and is useless without PPMIV fitted. You cannot remove it, so cannot get the cash back if you decide it's no use for you

I have tried yellowjackets in my Twin, they made it sound like an "OK" EL84 amp, whereas my Cornell 18/20 sounds excellent (it has VVR too - still loses tone).

I think a JTM45 is a poor choice for quiet playing, and a THD hotplate + PPMIV is the best solution. You do need to first just play it though, like stratsrus says

Easiest solution is to buy a quieter amp that sounds OK quiet. There are some nice 5w amps out there. For cheap quieter practice, a Blackheart BH5 is convenient. I had one customised with an added 6L6 and tube rectifier, I can mix the El84 and 6L6 - there are other amps like this. the 18w model may be quiet enough for you, or try to find an inefficient speaker, or even those new variable-efficiency drivers

Cheers
Tone