I purchased this attenuator after giving up on a Fryette Power Station due to an inherent hum issue that it didn't seem possible to fix. I have seen several other reports online about the exact same type of hum with the Fryette Power Station, which points towards a serious, inherent design flaw with those units. Which is a shame, because apart from the hum it sounded really good.
When using an attenuator like this there will of course always be some coloration of the tone, but based on user reviews online this one from Tone King seems to be one of the better choices, so I figured I would give it a chance after the massive disappointment with the Fryette (which I guess isn't strictly speaking an attenuator, but more of a re-amp device).
For clean tones, especially with Fender-style amps, I actually preferred the Fryette Power Station by quite some distance. The tone was noticeably more open and detailed, but unfortunately useless due to the hum issue. The clean tones felt slightly more congested with the Tone King. Not bad, but not quite as nice as with the Power Station.
For more distorted tones I much preferred the Tone King. It seemed to preserve the character of the amp better. With the Tone King a Marshall still sounded like a Marshall. With the Fryette, it just didn't.
The dynamics, "feel" and playing experience was also considerably better with the Tone King. It felt like actually playing the amp. This was simply not the case with the Fryette. I guess part of the explanation is that the way the Fryette is designed, your guitar amp doesn't really "see" the speakers/cab, so you're not really getting the interaction between your amp and your cab.
I do miss those wonderful, detailed clean tones I got with the Fryette Power Station, but sadly it was useless due to the hum. In every other respect I found the Tone King to be far superior.
The build quality of the Tone King seems VERY sturdy, although it is impossible for me to say how robust it is electronically. Time will tell.
I don't like the use of a wall wart with a thin, flimsy cable though. This is very inconvenient, feels like something that can break, and it makes the whole product feel cheaper.
I'm also slightly concerned about the warnings in the manual about changing the attenuation setting while simultaneously playing your guitar. This is something that can easily go wrong if the guitar player is located in a different room when I'm in the control room and dialing in the tone/levels. I dread to see what can happen.... Because this is one of those thing that seem destined to happen at some point.
So far so good, I guess. Tonally I have no objections, apart from SLIGHTLY more congested clean tones than the ones I got with the Fryette.