Picked up a black sparkle 99J on ebay just before Christmas. Price was attractive, probably in part because it was listed as a "Gulid 992"...whatever...
Of course it needs work... the coupling caps off of V1 are melted beeswax dipped paper jobs that pass around 20VDC, so they are getting pulled out today.
Aside from an incredible menagerie of cap types that really suggests the surplus market--wax caps, green Tropicaps, and ceramic case Tobe paper caps-- there are significant departures from the schematic that came pasted to the back panel.
Coupling caps from PI to grid are 0.47 instead of the .022 called out on the schematic. 6L6 cathode bypass cap is 20uf instead of the 100uf on the schemo--a rather low figure for bypassing a 210 ohm bias resistor!
All dropping resistors in the power supply are different from the schematic.
Clearly the same chassis was used for the 99J and the 100J, because it has a unused hole for an extra 12AX7 as employed in the parallel 12AX7 PI in the 100J (per the common "J100" schematic).
Speaker looks like an Oxford, alnico with a Guild logo badge on it.
I'll post a few pics in unmolested condition before I fix it up. My impression is that they grabbed any cheap surplus parts that were even close when building it.
Anybody running one of these amps? Love to hear some user comments. I have a good feeling about it, even though it does not play yet.
Love the forum, by the way!
Of course it needs work... the coupling caps off of V1 are melted beeswax dipped paper jobs that pass around 20VDC, so they are getting pulled out today.
Aside from an incredible menagerie of cap types that really suggests the surplus market--wax caps, green Tropicaps, and ceramic case Tobe paper caps-- there are significant departures from the schematic that came pasted to the back panel.
Coupling caps from PI to grid are 0.47 instead of the .022 called out on the schematic. 6L6 cathode bypass cap is 20uf instead of the 100uf on the schemo--a rather low figure for bypassing a 210 ohm bias resistor!
All dropping resistors in the power supply are different from the schematic.
Clearly the same chassis was used for the 99J and the 100J, because it has a unused hole for an extra 12AX7 as employed in the parallel 12AX7 PI in the 100J (per the common "J100" schematic).
Speaker looks like an Oxford, alnico with a Guild logo badge on it.
I'll post a few pics in unmolested condition before I fix it up. My impression is that they grabbed any cheap surplus parts that were even close when building it.
Anybody running one of these amps? Love to hear some user comments. I have a good feeling about it, even though it does not play yet.
Love the forum, by the way!