The Adept Channel feat is for nonclerics and class features don't stack across classes unless they say they. As an example evasion does not stack, but uncanny, and being an adept does not grant virtual cleric levels, so even if they did stack you would just use your cleric levels, not your cleric levels for the purpose of channel.
PS:Multiclassing casters is generally not going to be in your favor.
Well a cleric could get it if he had a familiar sure, but the intent is not for clerics so it might require an FAQ for the channels.
As for command undead it doe not go by how many cleric levels you have for the purpose of channeling. It only references actual cleric levels.
So does that mean I can use channel energy from any source to power command undead, but it still functions as if it was used from the clerical channeling? It says only that I must use, "one of my channel negative energy" attempts
I would rule it that way, just to keep things simple but I am curious as to how your cleric is qualifying for this.
It really does not help you control undead so I would not go through all that trouble. What you could do is take extra channel if you want extra channels. :)
I see what you were trying to do now. Well you have to "legally" get the familiar first. If your GM allows that he will probably allow you to use the other channel as a 2nd pseudo-cleric to get more undead.
Have you looked at the Juju Oracle?
That eldritch Heritage would not work unless the GM felt like being nice.
They overlap, which is to say they do not stack.
What you can do is cast desecrate. It is only a 2nd level spell IIRC.
Furthermore, anyone who casts animate dead within this area may create as many as double the normal amount of undead (that is, 4 HD per caster level rather than 2 HD per caster level).
That is a good way to double your undead without feats and trying to dip classes.
I know what you are trying to do, but it seems to be overkill, and not worth the effort, even if it is possible by some means.
6HD per level would go up to 12 for a juju oracle.
So at level 7 you have 84 hit die of undead under your command. That might be more than the 3.5 Dread Necromancer.
You are correct about the command undead feat. It is used to control undead you happen to run into, or undead that you create, but are not able to control due to you having reached your limit.
Is there a reason why you won't want to use the desecrate + juju oracle combo?
ANIMATE DEAD
School necromancy [evil]; Level cleric 3, sorcerer/wizard 4
Casting Time 1 standard action
Components V, S, M (an onyx gem worth at least 25 gp per Hit Die of the undead)
Range touch
Targets one or more corpses touched
Duration instantaneous
Saving Throw none; Spell Resistance no
This spell turns corpses into undead skeletons or zombies that obey your spoken commands.The undead can be made to follow you, or they can be made to remain in an area and attack any creature (or just a specific kind of creature) entering the place. They remain animated until they are destroyed. A destroyed skeleton or zombie can't be animated again.
Regardless of the type of undead you create with this spell, you can't create more HD of undead than twice your caster level with a single casting of animate dead. The desecrate spell doubles this limit.
The undead you create remain under your control indefinitely. No matter how many times you use this spell, however, you can control only 4 HD worth of undead creatures per caster level. If you exceed this number, all the newly created creatures fall under your control, and any excess undead from previous castings become uncontrolled. You choose which creatures are released. Undead you control through the Command Undead feat do not count toward this limit.
Skeletons: A skeleton can be created only from a mostly intact corpse or skeleton. The corpse must have bones. If a skeleton is made from a corpse, the flesh falls off the bones.
Zombies: A zombie can be created only from a mostly intact corpse. The corpse must be that of a creature with a physical anatomy.
edit: Ignore. I misread what you wrote.
Desecrate allows double the amount of dead to be created with animate dead, not controlled. The DM doesn't throw high HD monsters at us yet, but desecrate is on my spell list. However regardless or the amount raised with animate dead, animate dead can control 6HD/level with the juju oracle ability. This is nice but I was looking for other ways to increase that limit, such as other methods of controlling undead.
So if the animate dead can hold 6HD/level (42 at level 7) then command undead feat with the ability to channel would add another 7HD with that channel, would getting channel from other sources also individually have a cap of 7HD with those channels? Or would the HD caps merge into 14? Or would they not affect each other and the channel limit would remain 7HD?
Command Undead goes by cleric levels so getting other channels would not help you. It would remain at 7.
Undead Master treats you as you are 4 level higher for the purpose of the animate dead spell.
-->It changes the total amount. You dont have to raise them all at once.