Rocket Power Transformer Story - Revisited

[gktamps]

With the amp in which I've swapped OTs that I've been trying to adjust to get the tone of the most recent build with Allyn's Pacifics, yes - preamp and power tubes. After that, I've tried tube rolling new and vintage tubes through it.
I have not swapped tubes between the other builds, but those have several other variables. The two I've been discussing are the closest in most respects, except that;
RJs Pacific has a 5k primary; Allyn's a 4.3k. I would not have thought that enough of a difference, but the RJ Pacific build is much more aggressive, louder, and distorts earlier, among other characteristics.

[WRC34]

I have just finished up my Rocket build and used a Stancor 8356 PT.
My voltages were a little higher than I expected and I had to adjust my bias to bring it back into spec.
I used a MM Dynaco OT as well as the reccomended Hammond 158L choke.
I had to substitute a 68 ohm bias resistor in favour of the 50 ohm to get my tubes from redplating.
By my calculations I am running the El84's at 13w @42ma.

Drew, how much time did the Stancor P-8356 spend in your build? Did you give it a thorough workout with the volume cranked for any considerable period of time? Also, did you swap this PT out for any other reason than to obtain a lower plate voltage? (i.e. did it exhibit any "issues")

The reason I ask is I have one of these P-8356, unused. The specs look great for a 4xEL84 amp (270-0-270 @ 260mA) but I am having a really hard time trusting at it's puny size it will be able to handle the current draw of the power section at length without issue. Before building with it I would like to hear more about your experience using it.

[Mark]

With the amp in which I've swapped OTs that I've been trying to adjust to get the tone of the most recent build with Allyn's Pacifics, yes - preamp and power tubes. After that, I've tried tube rolling new and vintage tubes through it.
I have not swapped tubes between the other builds, but those have several other variables. The two I've been discussing are the closest in most respects, except that;
RJs Pacific has a 5k primary; Allyn's a 4.3k. I would not have thought that enough of a difference, but the RJ Pacific build is much more aggressive, louder, and distorts earlier, among other characteristics.

I have a Pacific transformer in my Rocket and with my Strat it’s breaking up with the volume control on two o’clock, the pot has a 10% taper from memory.

It’s very loud at that point.

[Colossal]

I have a Pacific transformer in my Rocket and with my Strat it’s breaking up with the volume control on two o’clock, the pot has a 10% taper from memory.

It’s very loud at that point.

Mark,

If I may ask, what are your B+, plate, and screen voltages?

Thanks

[Mark]

I have a Pacific transformer in my Rocket and with my Strat it’s breaking up with the volume control on two o’clock, the pot has a 10% taper from memory.

It’s very loud at that point.

Mark,

If I may ask, what are your B+, plate, and screen voltages?

Thanks

I can’t remember the screen grid and plate voltage but the rail is between 309 and 316vdc depending on the mains voltage.

[Colossal]

I have a Pacific transformer in my Rocket and with my Strat it’s breaking up with the volume control on two o’clock, the pot has a 10% taper from memory.

It’s very loud at that point.

Mark,

If I may ask, what are your B+, plate, and screen voltages?

Thanks

I can’t remember the screen grid and plate voltage but the rail is between 309 and 316vdc depending on the mains voltage.

Excellent, thank you. I remember it being quite low; the sweet spot for a Rocket.