Headphone Heights

Posted by mulveling (A) on May 21, 2014 at 08:54:55

In Reply to: RE: Nice system. Just be sure to keep a fire extinguisher handy... posted by genungo on May 20, 2014 at 14:43:09

I have some experience with this, having owned a couple and hearing (locally) a few more. Even met the owner a couple of times; "nice" guy until that awful, awful end. The ones more likely to be a danger are the later builds, when the owner seemed "cracked out", right before he disappeared (holding others' amps and money).

His workmanship was always sloppy. There were problems especially with the more "tricked out" amps, especially near the end. For example, I foolishly had my SDS (the 2nd made) "enhanced" to put more voltage on the output tube plates (6SN7/6BX7) -- never mind the lack of any tangible sonic advantage to this mod. The Black gate output caps he chose for this upgrade (2 in series, which does NOT guarantee an equal voltage distribution) did not have sufficient voltage rating, and it melted the voice coil on a nice pair of Sennheiser Jubilees (almost my friend's R10) with a epic POP when the caps inevitably arced in spectacular fashion.

The other common problem was HUGE power supply caps without bleeder resistors among them, allowing dangerous voltages to build up. Because of the amount of energy stored in these ridiculously large caps (comparable to those in a huge power amp), the potential for disaster was likened to a hand grenade. Basically, the guy couldn't be trusted with high voltages and proper cap selection/configuration.

With the OP's early PPA build, he PROBABLY has a relatively safe amp which probably sounds wonderful (I would guess better than what can be sourced today for equivalent prices -- these can be GREAT sounding amps). However, it's not a bad idea to get it checked out by a competent tube tech. Especially that PSU section (bleeder resistors). The PSU caps in a PPA are going to be much, much smaller than those in Supra/SDS models.

Edits: 05/21/14   05/21/14   05/21/14