Just completed this new Rocket tribute, using Allyn's Pacific transformers and chassis, and it is a gem!
In my past four Rocket type builds, I have experimented with and implemented several different approaches to adding adjustable, additional levels of gain with the goal of maintaining the essential character expected of a Rocket. This build incorporates several of these and more, and omits several approaches others here have used.
1. Switchable 50pF or 50+500pF parallel treble caps.
2. Switchable .01uF or .01uF + .01uF CF caps.
3. Variable 0-250k PI input resistance (pot).
I've also gone with an adjustable treble bleed for the volume pot, using a tiny 100k pot with a 500pF cap, just for kicks, and to see if I could, and I used a Russian NOS mica cap (odd looking thing, isn't it?).
One change to the circuit is the use of NOS Russian PIO caps in the .047 and .022 (and my .01) positions, and the heretical use of a filter cap board (in for a penny, in for a pound), though I did return to the traditional chassis-mounted power tube cathode resistor. To bring the plate dissipation down a bit, I started with a 60 Ohm resistor, but may drop it down, perhaps to 57 Ohm or so.
This time around I didn't install an HT fuse for the OT, and hopefully this wasn't a mistake.
Grounds follow my previous distributed star arrangement, and the amp is exceptionally quiet.
There are spare turrets on the board for 2 different V1a bypass caps, and a jack installed at the rear panel, but no caps at this time (not really in love with what it does to my other Rockets).
It's already becoming the favorite of my Rocket builds, but then again, I am fickle.
This is the first build in which I've used Allyn's Pacifics. The tone is balanced, and warm, and delicious. I'll post photos now, and try to do a more complete job describing the amp's response later.
All you contributors here on TAG have made builds like this possible for me, and I thank you again for sharing to the group, and many of you, to me personally.
Cheers,
Greg
