Who's playing with negative feedback and Xformer match values?

[Budda]

A little while ago, I decided to take my guitar in C standard and make an RV50 preset after watching a demo of the mk3 (I rarely ever watch demos that aren't Leon's). I was digging the vintage, doom/stoner vibe (potentially mis-labelled as I don't listen to much of either of those). Then I went "hey, let's try the input boost and get it a little juiced up" and now I have both old and current Mastodon-esque sounds in one preset. Sweet!

While the baby was napping, I decided to copy the boosted RV50 to a new scene and futz with power amp parameters. Specifically, I wanted to try tweaking with the 6CA7 tube type as a lot of users love the Plexi 6CA7. Well, my friends, this led to me playing with negative feedback (taken from another forumite who modded their JVM to be more recto-like), xformer match and grid bias. Between these 3 tweaks and the input boost, the voicing retained its overall character but the midrange changed and it sits differently. I have a feeling the two versions will complement each-other should I use them to track in future.

Who else has played around and found a cool second sound?

Scene 1: RV50 as is
Scene 2: add hall reverb
Scene 3: boosted with hall
Scene 4: boosted with room reverb
Scene 5: boosted 6CA7 (exported with hall on, reverb channel C for room)

 

[Tremonti]

Negative Feedback is one of my 10 go to global preset tweak knobs. It helps me bring stuff forward or sit back aways. Great under talked about parameter!

 

[tla]

Tried your preset, sounds great! I have often tried the Orange and struggled a little with the fuzziness, but this sounds nice. Got me playing some Blood and Thunder immediately
You can also experiment with adding a bit of XFormer Drive for some more growl.

 

[luke]

The amps in the Axe are based on the examples Fractal possesses. Analog amplifier parts vary, a mild adjustment of most parameters will probably still yield real world type results.

 

[spikey]

I'll give it a try, and thanks for the info!

 

[artzeal]

Setting the negative feedback on 0 for the Blues Jr is/was to my ears, pretty much a match for an Egnater Rebel 20. This amp also has two pairs of power tubes (EL84 and 6V6) that you can blend between. Making a second amp with 6V6 will accomplish that. Try different preamp tubes and undermatch the Xformer just a little to taste. I don't have the amp any more, so I can't compare how closely it matches up in Cygnus: but its a bit of satisfying fun playing in the FAS sandbox.

 

[Thomas Obester]

NFB is my go to parameter to change things, right after B/M/T, Input Drive/Trim and MV parameters.
Also Input dynamics, which I always set from 0 to 1 for every single preset, as it makes everything just better, even the most brutal hi gain sounds

 

[JWDubois]

Question. For amps like the JM45 and 65 Bassguy where the feedback value is 10, does that imply the power amp has unity feedback?

 

[Masterofsparks]

Setting the negative feedback on 0 for the Blues Jr is/was to my ears, pretty much a match for an Egnater Rebel 20. This amp also has two pairs of power tubes (EL84 and 6V6) that you can blend between. Making a second amp with 6V6 will accomplish that. Try different preamp tubes and undermatch the Xformer just a little to taste. I don't have the amp any more, so I can't compare how closely it matches up in Cygnus: but its a bit of easy and fun playing in the FAS sandbox.

Just sold my Rebel 20. Was the last actual amp I owned. Cool little amp.