GZ34
On 23/04/2017 23:46, Peter Wieck wrote:
The answer is pretty basic as you found:
Modern off-shore 5AR4s are crap. They will not pass enough clean DC current for the amp(s) to operate properly.
There are after-market solid-state 5AR4s which are adequate, far better than the Chinese/Russian garbage. Search for "WEBER COPPER CAP", and you will find the one with the best reputation *and* a built-in delay.
And there are delay boards (15 seconds is suggested) that may be had as well. Neither of these devices likes short-cycling, so do understand that before investing in them.
The most common mod on the Weber is to remove the cover, ventilate it, and then put it back. They get HOT!
Peter Wieck
Melrose Park, PA
I've read lot of positive reviews about Matsu****a nos 5ar4/gz34 made
using Mullard machines. Maybe I'll try them one of these days.
I'd like to build some solid state rectifiers using some resistor to
simulate the voltage drop typical of a tube rectifier to leave the amp
circuit untouched in the bias voltage section but I'd also like to build
them with some kind of soft start to avoid the standby switch.
I really want to know what's inside those Webers ...
Frank
Florence, Italy
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