Beginner looking for guidance into tube sound.

Tube sound is a myth save your money for better speakers.

https://audiosciencereview.com/forum/index.php?threads/if-tube-sound-is-a-myth-why-tubes.8656/

Tube sound is not a myth. However, it is about the distortion that is made, vs the distortion made by traditional solid state. In both cases you are up against a design issue- being able to apply enough feedback. If you could do this there would be no difference between solid state and tubes.

The advantage tubes have is that they make enough of the lower ordered harmonics to allow the ear's masking principle to prevent the higher ordered harmonics from being audible. This causes them to be noticeably smoother than traditional solid state and quite literally is why tubes are still around decades on after being declared 'obsolete' in the 1960s. Back then though, solid state amps were abominations for the most part- the declaration was premature.


If you can apply enough feedback you can get solid state to be as smooth as tubes, if you also pay attention to the distortion signature (keeping the lower orders as the predominant distortion product). The funny thing is that if you pay attention to the distortion signature, the difference between an amp with 1% THD at full power and one with 0.05% will be very hard to hear in a side by side comparison.

@rocray I spotted that Aric Unlimited last night and am interested. But am curious if having the variable output will it mate with the Peachtree. I assume that is the reason for the variable output, compatible with more equipment correct? My goal today is to try and verify what Peach tree recommends. Then look into the variable output option as I have no previous experience. If it will mate up I think that might be the best way to go at this point. 

I suspect your head is spinning now. There is never just the right amount of info available. Either too little or too much. And it can go from one to the other really quick.
Go ahead and build the ST-120 kit. I bought my ST70 assembled by Bob. I hear that the kits have good instructions. And Bob is always easily reached. Besides, you will save some $$$ and I believe it will meet your need and sound really good.  FWIW, I have Don Sachs custom build of this kit. It sounds very good

Regarding matching, here's an email I got from Almarg, an expert and a gentleman. RIP.

On matching Preamp and Amp

Almarg:

"To assure impedance compatibility the 10x rule of thumb guideline should be applied at the audible frequency for which the output impedance of the component providing the signal is highest. In most cases impedances are specified at a mid-range frequency such as 1 kHz. It is very common for tube preamps to have output impedances at deep bass frequencies that are much higher than that specified value, often 2K or 3K or even 4K ohms. That rise at low frequencies results from the output coupling capacitor that is used in the majority of tube preamps, and also in a few solid state preamps. The impedance of a capacitor increases as frequency decreases.

So ideally the 10x rule of thumb guideline should usually be applied based on the output impedance at 20 Hz, in the case of a tube-based preamp. If as is often the case the component’s output impedance at 20 Hz is not known, and is not indicated in published measurements (such as those Stereophile often provides), and if the use of an output coupling capacitor in that component cannot be ruled out based on available information, to be safe a considerably higher ratio than 10x should be used, something like 50x or 75x IMO.

This applies, btw, to tube-based source components as well as to tube-based preamps.

Also, to clarify a common misconception I should add that failing to meet that guideline does not necessarily mean that there will be an impedance compatibility problem. It depends on how much **variation** there is in the output impedance over the frequency range. But meeting that guideline (at all audible frequencies) assures that there won’t be an impedance compatibility problem.

I should note also that a significant number of tube-based preamps use coupling transformers at their outputs, and therefore avoid that low frequency impedance rise. Although depending on the specific implementation transformer-coupled outputs might have downsides of their own. Atma-Sphere MP-1 and MP-3 preamps, btw, cleverly avoid the use of both capacitors and transformers at their outputs. (I’m not sure about the UV-1). As far as I am aware they are unique in that respect, among tube-based preamps.

Best regards,

-- Al"