Rocket mod - why didn't I do it sooner?!?

[Jackie Treehorn]

Last night I lowered the .047 output tube coupling caps to .022, sort of splitting the difference of AC30 and Rocket. It's so superior! Couldn't stop playing last night!

Also, used the Russian K40y-9's instead of the 716p's. I'm really blown away by how much better the Russian military caps are. The orange drops, and I mean sbe & Mallory, sound pretty flat in comparison. I've been experimenting with the MBM series, too, which also sound great- they sound less damped then the pio's, a bit more forward in the mids, too, if that makes sense.

It's one of those things that makes me wonder why it took so long to try...

[Smokebreak]

I'm interested to hear how this affected the amp(besides limiting bass of course)

[xtian]

Nice. Imma doit. I've always had to roll the Bass control way down. This will be interesting.

[xtian]

Yes, really nice. Much better tonal balance. Tone controls now sounds great at noon, with plenty of Bass still on tap. I put in Mallory 150s, since that's what I had.

No other perceived changes, seems to have same gain.

[Smokebreak]

Thanks. I'll give it a shot too. Are you running stock preamp cathode caps? 22uf i think?

edit: Yea, I like it. Not a huge change over here, but nice, more balanced. Still a lot of bass on tap. FWIW I'm running 1uf and 2 uf on cathodes, 100K Rp on V1 and just changed 500pf from ceramic to poly, with zwreck dropping string.

[xtian]

I'm using an on-off-on SPDT to choose from 22uF and 1uF bypass caps. Also have a VVR.

Here's my Rocket Dog build: https://tubeamparchive.com/viewtopic.php?t=17584

[Smokebreak]

Great looking build! Thanks for the posts guys.

[Jackie Treehorn]

I'm interested to hear how this affected the amp(besides limiting bass of course)

Well, trimming the bass is the main point. Before, I could only really run the bass from 0 and 3 and a half. Now, there's a lot more nice sounds to dial in. I think the K40y's add some swirl and harmonics, hard to really put my finger on it. I'll just say that the amp sounded great before, but the way it sounds now makes me want to just cuddle up with it and split a cigarette after I'm done playing.

[Bob S]

Yup - there's the reason RJ called the Rocket a fat bottomed girl.
Lotsa sparkle to be had too with a few value changes.
As already posted - V1 gain.
Cathode bypass caps.
Coupling caps.
Normster's Rocket Reverb had some good switchable features.

[Blackburn]

I used .033uf caps for the entirety of the inverter portion and really dig it like that. I always try to accommodate for excess bass response I get with my LP, but this can't be too drastic a difference. As is, I keep the bass pot around 8 or 9 o'clock. I like that Fat Bottomed Girl comment.