I'm working on a tube amp project. Does this make sense?

So I'm trying to make a tube amp gramophone. Very cheap though. So i bought an iPhone dock and a tube preamp and speakers. Is that it? Or do I need an actual amp? Because don't mp3 players have amp built in? Or are they like guitars? I'm very new to all of this

You need an audio transformer to match the impedance of the plate circuit to the speakers, unless you are using a cathode follower circuit, which will possibly be close enough with the speakers in series. You also need +100 volts dc for the tube plate circuit. Some tubes used as much as 500 volts, but they will operate at less voltage. Possibly your MP3 player has enough audio at the earphone jack for the tube grid circuit. I'm not sure the IPhone dock is useful.

Pre-amplifier made with tubes requires high DC voltage to operate, unless it came with its own built in power source. Its output could not able to drive any speaker. It requires one more power amplifier connects to its ouput, prefer also made with tube to obtain perfect matching.

Make that 2 amplifiers and 2 pre- amplifiers and 2 speakers, if you want stereo out.
I don't see the point of having an Iphone as a source. You said gramophone.
Preamplifiers for gramophones use different circuitry to that used for Iphone/ Ipod input.
There's NO point in using tubes, unless you use really sophisticated (read expensive) circuitry and speakers. Even then, "better" sound from tubes is controversial.
A PRE- amplifier is just that, a stage BEFORE a power amplifier.
I think you would be disappointed with results.

No. It doesn't make sense. You don't know what you're doing, nor what you are talking about.

I'm sorry to say that your question doesn't make sense.

A gramophone is an antique record player - no amplifiers, no MP3s and not even semiconductors or valves of any kind involved.

An iPhone dock is something yo plug an iPhone in - some of them come with amplifier and speakers, some don't.

And in the chain between music source and your ear, the following components are usually involved, some of which can be combined into one physical device:

- possibly a digital source
- possibly a DAC (digital to analogue converter), often combined into one
OR
- an analogue music source
- in case of a record player, a pre-preamp (amplifiying the very weak signal from the player's needle and restoring the frequency response from the record)
- a preamp (not so much amplification, but providing driver current for the following stage and the possibly long cables, plus mixing or selecting of the input from several sources)
- an amplifier (amplifying the output of the preamp to headphone or speaker levels)
- speakers (converting the electrical signals from the amplifier into air movement)
- some cables between the various stages

Nowadays, often preamp and amp are grouped into one box ('integrated amp') and are called amplifier. Or amplifer and speakers are packed into one box ('active speakers', 'amplified speakers') and are called speakers. And so on.

So, now you can build any of the active stages (pre-preamp, preamp, amp) with valves/tubes (ok, even the DAC, but that gets a bit cumbersome). The problem here is that valves are low current, high voltage devices while speakers are high current, low voltage devices. This means, while it is (comparatively) easy to build valve preamps, high power valve amps are a bit more tricky and in almost all cases require a hefty output transformer to adapt between the high voltage valves and the low voltage speakers. And those transformers nowadays don't come cheap. Or rather, you can't get the cheap ones any more.