Thomas Mayer preamps - the 6AH4 vs the more expensive 10Y

I have not heard his products. But I DIY tube preamps and amps using very similar circuit and components.

In Thomas Mayer’s circuit, 10Y would be better than 6AH4, with a sound that’s more transparent and dynamic (btw this is the difference between DHT vs IDHT in general).

I expect the sonic difference to be quite noticeable in his offerings.

Thomas mayer also owns a tube manufacturing facility called Elrog.

You are paying for the external power supply-tube power supply

The usual responses apply for that.

By the looks of the product line-if you have to ask...

$80K for the top phonostage-perfect for a Techdas.

Phono preamplifiers by Thomas Mayer - VinylSavor - Thomas Mayer

I've never heard anything but praise for his audio components, and the build quality looks amazing.

Don't know.

But I can say this: Cost doesn't necessarily translate to fidelity, or even accurate audio reproduction.

Look inside the preamp. Short signal paths, good quality/reliable parts, heatsinks, a particular method of acheiving quality amplification (such as LIFES from Luxman etc.)

Not sure if someone else will have a suitable answer for you, but in cases like this, it's always best to contact the company directly via email/phone and have them break down the differences between the 2.