[Amps] 12 tube 3-500Z

Will Matney craxd1 at ezwv.com
Tue May 25 11:04:41 EDT 2004


That 12 holer on ebay using (12) 3-500Z's is a piece of work aint it? 
You would need at least 1 Kw to drive the thing where no standard radio 
could ever drive it. Although, it is possible to do this, I seen several 
flaws to this amp. First is the cooling as I only caught  5 muffin fans 
on the top, and what looked like 3 more blowing in at the bottom. I 
believe it were me, I would have used a couple of large blowers in the 
bottom, then chimneys around the tubes. We all know the heat these 
things create, especially around the tube pins at the bottom. Next, if 
this is what I was seeing, the filament transformer was in the bottom? 
If it was it, it kinda looked awful small to me! It about had to be it 
as the leads for the filaments choke was tied directly to it. Third, I 
never noticed hardly any bypass capacitors in the bottom of this beast. 
Forth, you can notice in the top that it was used in high frequency only 
with no band switch. Last, the plate choke looks awful small to me too! 
I think I'm just bad to knit-pick. Anyhow, it was an attempt wasn't 
it........

Will Matney
US Amp


More information about the Amps mailing list