Re: Tubes for Hammonds & Leslies (and more)

[Dan Kerl <dlkerl@ro.com>]

Ted Weber wrote:
> 
> > I missed a tube curve tracer a few months ago. Bummer!
> 
> Bummer is right!.. Those things are sacred and are as scarce as hens teeth.
> 
> >I guess it would have worked like the transistor curve tracer that
> Tektronic used to > build.
> 
> Yes. And Tek made some tube tracers.
> 
> >best way to check individual toooobs for distortion would be to have an
> >amp/test bed where the base band ops/parameters were known then compare each
> >tube over freq range with varying inputs and loads.
> 
> Yep. You can hold the plate, sweep the grid and vice versa. Also do two-tone
> test
> for IMD, singe tone test for THD.
>                                                                  Ted
> 

The tube audio craze has driven Tektonix 570 (tube characteristic curve
tracer)
prices well into the 4-digit range.  Most of these are finding their way
to
Japan.  I've wanted one of these for awhile, but not at those prices.

An Italian company has introduced a vacuum-tube curve tracer interface
for a
PC. Check out

http://www.mclink.it/com/audiomatica/audioeng.htm

for more information. I don't know the price of this unit. I suspect
it's
quite expensive (but not as high as Tek 570s have become).

                                                Dan Kerl
                                                dlkerl@ro.com