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Re: 5u4gb in Dyna ST70

IMO, the substitution of a 5U4 for the 5AR4 in a ST70 is bad. Not only is the 5 V. winding overworked, but signal tube life is shortened, due to cathode stripping, too. If that's the only mod, the power transformer is probably OK. A ST70 has extra VA capacity in the power transformer to feed PAM preamps.

IMO, other than another 5AR4, the only tube to replace a 5AR4 with is a GZ33, if it fits mechanically. A GZ33 will not fit in a ST70 if the tube cage is used.

Eli D.


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  • Re: 5u4gb in Dyna ST70 - Eli Duttman 02/14/0200:08:36 02/14/02 (0)


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