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Good question. no good answers IMNSHO

Posted by Ed Sawyer (A) on April 5, 2007 at 19:08:25

In Reply to: why use a gm70 when 845 is current production (chinese though) and... posted by jarthel on April 3, 2007 at 18:29:34:

845 is cheaper, as mentioned, and has MUCH more variety out there. The fil voltage is lower so less chance of hum, and finding a good quiet filament supply is a lot easier. And the GM70 is FUGLY! damn it's a bad looking tube, physically. I just think it looks like ass... with the ho-hum shape, weird base, inelegant proportions and ugly stepped tubular bulb... ugh. bring me a 845 any day, way better looking IMNSHO.

I think any hype/comparison vs. chinese build quality is moot at best and if anything favors the chinese. They have another 20-30 years of technology, materials and skillsets to draw upon vs. when the GM70 was made and engineered. not to mention the 845 was designed as a class-A audio freq. amplifier, which counts for something too. the so-called military might of the USSR, while large, was not generally known for quality control. they threw a lot of money into it, but they didn't have any motivation for good QC as it was a state job, guaranteed and subsidized by the govt. if you want build quality, look to US military tube developments, esp. stuff designed and built by the likes of Eimac, Bendix, WE, etc. The russian stuff looks like the poor quality 2nd-rate ripoffs of western tech that it is. They (russkis) had a few interesting tubes, but with a few exceptions (6C33 comes to mind) almost anything they made can be had in a better version in the world of western tubes. not that it was ALL junk of course, and the GM70 has its place, but the 845 is clearly superior in several ways.

-Ed

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