Still struggling with the ac30tb model

Had to tweak my Humbucker presets a little after making the changes to the AC30TB block, that Cliff suggested, but I think the 808 and SDD pre-amp in front make the break-up in the amp. much smoother than before. Mt Strat presets, didn't change anything, just the amp. and they just sound better...chimier.
 
I am not among those who always that it is "awesome" just because it is new, but after trying the proposal from cliff, i must say that (in my opinion) it sounds better.
At least slightly different in a good direction, if the current model can be improved.
I will let people like Edo explain if it is definitavely better or not, and why.

I like it.

Personally, I also think that my core tone preset sounds slightly louder, which is probably a consequence of the new preamp comp value of 75% against 0%
 
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After using Cliff's recommend settings, I spent a good two hours noodling and playing. Sounds more open and clear to me now. Threw the SDD Preamp in front and kicked it up a notch.
 
The AC30 is definitely one amp block that I have spent more time messing with as compared to other models. getting something I liked then going down the rabbit hole, then coming back.. The suggestions made in this thread did produce very pleasing results. I am looking forward the bright model.
 
I dot mean to sound cocky, but if you knew me and my background, I graduated at Berkelee with full scholarship and won the guitar dept. award 3 times, I play guitar, bass, drums, piano and cello, i've directed orchestras, I've recorded and performed with a few major artists and for tv shows in Italy and have been playing in U2 tributes throughout Europe for 15 years, so I'm not a bedroom player inquiring about pre vs post delay!
Said that, I totally share your point of view, I agree that a big part of the tone is always in the player's hands, and clearly we're talking about achieving a similar tone with all limitations we might have (in the specific case of the edge, I should remind you that he uses about 20 guitars per show, each one for a specific song because one might have the bridge pickup slightly higher than another for a specific song etc, and of course a strat with rw fingerboard tuned 1/2 step down with 11's is going to sound different from a strat with maple fb in standard tuning with 10's), and I'm trying to get there using only 4-5 guitars..
The thing is that, like you say, edge of break up means that picking harder drives the amp, and my problem with the ac30tb model is that even picking harder, the clean attack is still predominant, and that is awkward. We're talking about a subtle thing here, one that the average guitarist / listener wouldn't even notice, but since I know what a great piece of gear the axe is and what it's capable of, I knew something was wrong within the Vox model and I'm glad cliff has confirmed this and is working on the fix - and that's beyond sounding like the edge or else, the ultimate goal is sounding great as opposed to good!
I definitely heard your skill in that clip and like I said I was already very impressed. :) I've had my similar quests with Mesa amps and usually it's about fine tuning the master although I realize in this case there is no master volume on the real amp.
 
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I spent the day looking into this. As it turns out the TB model is wrong because the cathode follower values weren't entered (Preamp Comp is 0.0). Unfortunately you can't just turn that up to fix it as the CF Ratio should be 1.96 and that's outside the allowed range. So the next firmware release will have this fixed and will expand the range to allow the required CF Ratio value. While I was at it I added a "Class-A 30W Bright" model and re-matched the existing models to our reference amp.

In the interim you can get close by setting Preamp Comp to 75%, CF Time to 3.7 ms and CF Ratio to 1.0. Xfrmr Match should be reduced as well since I realized that the typical Celestion Blue speakers have a lower voice coil resistance than I used in the calculations. Set it to 0.8 and adjust to taste from there. There's a bunch of other small changes I made but those will get you in the ballpark.

I had previously used the mismatch at 0.5 which helped, along with some other changes and the SDD in front of the amp. The suggestions above do help and may allow me to get rid of the SDD. Thank you.
 
I am not among those who always that it is "awesome" just because it is new, but after trying the proposal from cliff, i must say that (in my opinion) it sounds better.
At least slightly different in a good direction, if the current model can be improved.
I will let people like Edo explain if it is definitavely better or not, and why.

I like it.

Personally, I also think that my core tone preset sounds slightly louder, which is probably a consequence of the new preamp comp value of 75% against 0%

I'm in paris right now (U2 fans might guess why Lol), cant wait to get back and try the new improved settings tomorrow and report back!
 
I'm in paris right now (U2 fans might guess why Lol), cant wait to get back and try the new improved settings tomorrow and report back!

Edo, I should have known that's where you were. Just about to watch the show on HBO, in 30 minutes.

Look forward to your opinion on the changes suggested by Cliff. I think it definitely helped.
 
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Quick "noob" question... having changed those 4 parameters... when the new Firmware that fixes this issue is released, will I have to go in and "reset to default" those 4 parameters? or will they get reset by the update... I'm guessing the "former"? Never thought about it before...
 
I've finally got to try for a few minutes cliff's suggested / improved settings, and I must say, the attack / transient is still a bit "unnatural", but the overall sound and mosty feel is a big improvement in the right direction! Much happier than I was earlier, and at this point looking forward to the next fw that addresses the forementioned issues, hoping they all get fixed for good!
Also, I'd like to try the oh justin York ir's (exclusively for the 58 ir's), but since it requires cablab, and I read that cablab live is about to be released, is there an estimated release date yet?
 
I migrated away from the AC30TB model a while ago in favor of DC30 and Z38 models for my edge of breakup sounds. The AC30TB always sounded too compressed and squashy to me.
 
I spent the day looking into this. As it turns out the TB model is wrong because the cathode follower values weren't entered (Preamp Comp is 0.0). Unfortunately you can't just turn that up to fix it as the CF Ratio should be 1.96 and that's outside the allowed range. So the next firmware release will have this fixed and will expand the range to allow the required CF Ratio value. While I was at it I added a "Class-A 30W Bright" model and re-matched the existing models to our reference amp.

In the interim you can get close by setting Preamp Comp to 75%, CF Time to 3.7 ms and CF Ratio to 1.0. Xfrmr Match should be reduced as well since I realized that the typical Celestion Blue speakers have a lower voice coil resistance than I used in the calculations. Set it to 0.8 and adjust to taste from there. There's a bunch of other small changes I made but those will get you in the ballpark.

Thanks Cliff, sorry to ask a silly question but are the CF Time and CF Ratio the "Comp Time" and "Comp Ratio" in the pre-amp tab.
 
What Matt said. The problem is that the "AC30" can be one of dozens of different designs. The AC30 design was constantly changing. I don't think Vox even knew at one point what an AC30 was supposed to be. There are versions with EF86's, versions with Fender tone-stacks, versions with 100 nF coupling caps, versions with 47 nF coupling caps, versions with 300V plates, versions with 200V plates, etc., etc., etc.

Well this one should be the closest to the original then:
http://www.ebay.com/itm/1964-VOX-AC-30-VOX0001-/331610059430?hash=item4d357ff2a6:g:vFkAAOSwMmBVrU7B
 
The 1964 AC30 I had at the studio was surprising to me for many reasons. First of all I thought I'd break it before breakup... that's how loud it was. The low end is very interesting. In the room it was just like a 4x12 but when miked up I felt like it was almost compressed. The high end was very round and clear which is exactly what I wanted to get out of the combo. :) Cab Pack 18 is definitely my most successful non-4x12 IR shoot IMO.
 
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