[Amps] T-T Titan 425 Q's

[Jim Brown]

On 12/2/2010 9:57 AM, Bob Arenella wrote:
> I would like to know if there are any "must do" mods or upgrades for this
> amp? T-T tells me that the padder cap problem was in the very early versions
> of this amp, and shouldn't be a concern. How 'bout the going on 17 year old
> filter caps?

I own three Titan 425s of various vintages, all bought used. The 
differences between them are minor. The tubes can last a VERY long time 
if not abused, which mainly means keeping the grid current low. The amp 
is fairly easy to work on, and most parts are easy to find and replace 
if needed. The semiconductors, for example, are all pretty generic 
parts.  The 425 was designed around 1978, so the fact that it was still 
in production in 1994 tells you that it was a pretty solid design!  The 
primary difference between it and the much more expensive Alphas is the 
lack of automation and more modern protection  circuitry.

The schematics in the book are a bit difficult to use for any 
troubleshooting, so I drew up a schematic that puts everything on one 
sheet. See http://audiosystemsgroup.com/publish.htm

73, Jim K9YC