[subwoofery]

I just got butler475 or I would be buying yours. GLWS

Sell your Butler, and buy one TU-4360. The TU-4360 is a much better amp. Own both and the Butler was just gutless and tinny sounding.
There's also a few threads that "apparently" demonstrate how the Butler can still play music if you pull the tubes out...

Kelvin

 

[subwoofery]

find me one, would you?
As of finny sound.. yours probably was defective as mine bottoming out 100w 8 Ohm speakers with ease, I wouldn`t call it gutless nor tinny

Took me 15mns but you're ready?

* tube taken out and amp still playing:
~thematt~ http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/44938-tube-ampilifiers-dont-ship-well.html
typericey http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/38441-anybody-familiar-us-amps-tube-amps.html
thehatedguy http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/16828-got-tubes-2.html
thehatedguy http://www.diymobileaudio.com/forum/system-design-help-me-choose-equipment-my-car/34125-can-someone-list-every-known-manufacturer-mobile-tube-amps-2.html

* tube not really doing much in the audio path:
DAT http://www.diymobileaudio.com/forum/hot-deals/68132-panasonic-double-din-tube-headunit.html
thehatedguy (again) http://www.diymobileaudio.com/forum/member-reviews-product-comparisons/12075-planet-audio-tube-hybrid-hvt754-w-cantons-etc.html

^ this is just on DIYMA - too lazy to search on other forums but when I first heard about the tube romoval thing, that was on caraudio forum I think... When I had the Butler, I wasn't on any forum yet. It's only after I sold it that I saw those kind of threads...
When I said gutless, I did not mean it does not put out rated power - but compared to the US Amps, it did not have as much headroom and the difference is not subtle even though both are rated for about the same power... Bottoming out a speaker doesn't say anything about power or guts

* US Amps not working if tubes removed:
killerb87 http://www.diymobileaudio.com/forum/system-design-help-me-choose-equipment-my-car/34125-can-someone-list-every-known-manufacturer-mobile-tube-amps-3.html

Kelvin

 

[subwoofery]

This is reply by the designer of the thing, IMO he has much more credibility that guy in first link you posted,he designed one of my favorite guitar pedals and he has tremendous respect in guitar players world. BTW I can find rave reviews of said amp on this very board.
A rumor spread by some ill-spirited and jealous PPI engineers perhaps. The amp has a fail safe circuit which will allow it to operate in solid state mode if the tubes fail. This adds to the confusion. Why would I risk 25 yrs reputation with pro musicians, etc and not have the tubes operational?? Makes no sense.

BK Butler

so if you read some more you`ll see that rubes works in diode mode, therefore can be disconnected without significant change in sound. that what I read, I havent pulled tubes out of mine- according to butlet it`s pointless because solid state circuit will be hot anyway. Is US amp better- maybe, maybe not, it`s a matter of opinion and I`ve heard yours. we hacked that topic to the end we should stop, really. OP I apologies.

Well, at least I tried to provide some evidence and what I heard when comparing both amps (bought new ).

GLWS to the OP.

Kelvin