Tubes in Audio Research Equipment: 6550


Are there any opinions on sound characteristic of these tubes? Do they sound too much like solid state or are they just more neutral? Do tube amps exist which are not overly euphonic?
haydn_josef
J_k. Thanks for your helpful feedback regarding the requirement for matched quads in the VT100 and VT100MKII, as it related to my post. In my post, I was relating cautionary information I was told so that anyone (not experienced with ARC gear) reading my post would not confuse this recent ARC design with earlier designs which had individual tube bias points. Thus, they may not know of the need for matched quartets. Also,I may be wrong on this, but I understood that the factory output bias setting for the VT100 6550C's is 65mA. However, for adjusting across the test points for each channel of the VT100, ARC recommends a reading of 130mVDC (0.13 Volt DC) for the 6550C's. Best Regards!
DEM -- You are also correct -- ARC does bias EACH 6550C at 65ma. The VT100MKI & II uses 6550C x2 in each side of the push - pull circuit, making the bias setting across the TP 130MV, equating to 130ma of current running through the resistor. I heard VT100MKIII has individual adjustments..