They are actually like 2 watts, even after the mods. And sorry I don't mod amps for people, but I am doing a total gut and rewire series on these little amps right now that should get them closer to 5W.

It's to balance the phases. Earlier designs were either slightly unbalanced or had a "balance pot" to adjust it. It corrects phase alignment distortion in the output transformer.

Thanks! :)

Add $230 shipping..

Nice build!

Yeah, that seems odd to me! And HOT!

I don't recall talking about doing mods to the X7? Oh installing smaller wattage cathode resistors? Any 10 ohm 1W resistor should work. These high precision Vishay should work fine: https://mou.sr/4c2Z4na

Thanks!!

That shouldn't be hard to hardwire past the phono board.

Yeah, no thanks.

I'm exhausted from "fixing" all these poorly designed China amps. As you said, not only is it easier in most cases to just build something correctly from scratch, it's much more fun!

Love it!

Like I said, you will have to tune that feedback resistor to taste. And the amp doesn't lose power, it just loses gain or input sensitivity if that makes sense. It still makes the same Wrms before clipping.

No need to bypass that small resistor, but if you wanted to TRY IT, do not bypass the LED. You will see, installing that feedback resistor will remove the shrillness. You can experiment with values from 300k to 680k to adjust the tone for your system

Without the schade feedback, it's gonna lack bass, sound shrill and so raising the coupling cap size might help cover that up. It's never going to sound right without it. Also cutting the cathode bypass in half hurts the bass response. Glad you had fun and looks good so far

my only suggestion, which might ruin the aesthetics for you is to rotate the power transformers 90 degrees to avoid the magnetic flux from them being transferred to the output transformers, Love the build though, very nice! If you want to really hear it sing, add my EAR834 clone phono stage! Also at 85ma they sound OK, but if you can find some of the early production tubes that are happy at 100-110ma, it really does improve the sound.

If it sounds good, it is good :)

You might be better off using a simple voltage divider on the output to drain off some of the gain. As I recall there is a 220k from the output to ground. Adding some resistance between the pre-out and this 220k to ground should work. Be careful as I've seen this sort of thing created a high pass filter when combined with the output coupling cap and ruin the bass response.

I'm really not understanding what you're trying to do cuz from you posts it appears like it sounds fine. You're just wanting to get some VU meters reading in the center or something?

Simple, don't use any device below 50k impedance connected to the output of this pre-amp. I have no experience on using that 2X3 pad on the board or what type of pot it was designed for, or even how well it works. I honestly don't understand why this phono-stage isn't just being connected directly to an integrated amp. Why would you want to insert a "mixer" in the signal path and complicate your system in this way. Also I have found "remote" styles of volume controls universally sound worse than one integrated into an amp, or in the case of s system using power amps, the pre-amp controlling them. Adding components in the signal path invariably degrades the sound.