Vox ac30, top boost vs. non top boost

[shaky town]

Hello friends,
I have a '64 AC 30 TB, and I read that some here prefer the non top boost. What the heck does top boost mean anyway, and why do some prefer the non boost? I looked inside and there were a bunch of those Mullard preamp tubes.
:bonk

[magnus02]

top boost means its totally undesirable... good news is i'll give you $100 paypal'd/shipped for it...

[bognermatchless]

Top Boost sounds awesome to me. Wouldn't change a thing about it.

[shaky town]

Undesirable? I don't think so. This amp head sounds amazing & gives my Dumble ODS fits (not really), they are different, but the Vox I thought for years was a non boost, but after looking closely at the serial #, I think it says TBRV after the number, and the reverb has never worked since I got it in '91 for $425. So, what the heck does top boost mean anyway?

[DANOCASTER]

TOP BOOST is an added gain stage in the brilliant channel w/ the addition of bass and treble controls for that channel

NON TOP BOOST is lower gain and the brilliant channel simply has a VOLUME control - just like the "normal" channel - except it's brighter and has less bass than the "normal" channel which I love

I find the NON top boost more to my own personal liking. They tend to accept pedals very well and I tend to like the more "medium" gain vox tones over the higher gain / glassier "Top Boost" sounds

both are good but different

if I was going for U2/ Edge tones - I'd go TB

if I was going for Tom Petty - I'd go NON TB

YMMV

[Gaetano Capuano]

Well saidTOP BOOST is an added gain stage in the brilliant channel w/ the addition of bass and treble controls for that channel

NON TOP BOOST is lower gain and the brilliant channel simply has a VOLUME control - just like the "normal" channel - except it's brighter and has less bass than the "normal" channel which I love

I find the NON top boost more to my own personal liking. They tend to accept pedals very well and I tend to like the more "medium" gain vox tones over the higher gain / glassier "Top Boost" sounds

both are good but different

if I was going for U2/ Edge tones - I'd go TB

if I was going for Tom Petty - I'd go NON TB

YMMV

[mcdes]

Nice bit of tongue in cheek action going on!! Ha

[scottcw]

Undesirable? I don't think so. This amp head sounds amazing & gives my Dumble ODS fits (not really)


You own a Dumble ODS and don't know what a top boost is? Priceless.

[mcdes]

You own a Dumble ODS and don't know what a top boost is? Priceless.

Bahahahahaha

[Coldacre]

the Top Boost is absolutely integral to the Vox sound, especially clean tones. its the reason why I play an AC30. I wouldn't own one without it.

[miklos]

hey shaky-hang on to those mullards-great tubes.i recorded with a early sixties ac30 tb one time at the request of the producer and have been hooked on vox ever since,i just got one of those ac30hwh and put a cab together with a couple of thse blue celestion 15watt spkrs--it sounds awesome but its not quite like that early 60`s tb i played.

[Anje]

TOP BOOST is an added gain stage in the brilliant channel w/ the addition of bass and treble controls for that channel

NON TOP BOOST is lower gain and the brilliant channel simply has a VOLUME control - just like the "normal" channel - except it's brighter and has less bass than the "normal" channel which I love

I find the NON top boost more to my own personal liking. They tend to accept pedals very well and I tend to like the more "medium" gain vox tones over the higher gain / glassier "Top Boost" sounds

both are good but different

if I was going for U2/ Edge tones - I'd go TB

if I was going for Tom Petty - I'd go NON TB

YMMV

Dan, I have a question about this TB / non-TB topic: I understand you prefer the non-TB amps, do you prefer the Normal or Brillant channel on those amps?
I'm not sure to understand correctly your sentence in bold above.
Also according to your experience, do you find the Normal channel of the TB amps to sound "as good" / the same as the Normal one on non-TB amps?

I've never compared TB / non-TB amps side to side to look at this, only AC30 I've had was an early 60's with added top boost; I would tend to think the TB amps could have the "best of both worlds" if the Normal channel on those just sounds as good as the non-TB amps?

[DANOCASTER]

Hopefully Moods ( who makes the wonderful Magic Amps ) will chime in on this, he knows more about Vox than anybody I've met BUT I'll try and explain what I know:

on the TB amp, the Brilliant channel has an extra tube gain stage as well as bass and treble controls

on a regular non top-boost AC-30 TB ( which came before the "add-on top boost" - which eventually became incorporated into the actual control panel ) - the "Brilliant" channel is similar to the "normal" channel. It has about the same amount of gain as the normal input but is voiced for more "brilliance" and sparkle and slightly less "thick". The normal channels of the two sound the same

that said - there are also 3 different versions of these amps - indicated by the last letter in the serial number ( either T,B, or N ) which indicates whether it's a "treble", "bass", or "normal" model.

My favorite of these ( of which I've had 3 at this point ) is the TREBLE model. So the Normal input is brighter than on most AC-30s and more useable as-is w/out the need for a treble booster, etc. Likewise - the brilliant input is now even more brilliant and is fantastic w/ semi-hollow Gretsch and Gibson guitars. Mine was perfect w/ a Casino for nailing old Beatles tones - much more so than a Top Boost would have been w/ all that extra gain on the brilliant channel

the cool thing is that it's very easier to change a couple values and tailor each input to your taste. I'm lucky to have PaulC as a friend and neighbor so I've been able to sit down w// him and play thru each input while he swaps out values until I find the perfect amount of bass / treble for each input

[Anje]

Understood, thanks for the great feedback.

[12strings]

Hi Danocaster, do you happen to know which component values for the voicing caps you ended up settling with for your AC30 Treble model?

I have one which I love, and would like to voice it a bit better for my guitars - a vintage Jazzmaster and a pine tele. Just curious what you ended up doing. Thanks!!

[DANOCASTER]

Hi Danocaster, do you happen to know which component values for the voicing caps you ended up settling with for your AC30 Treble model?

I have one which I love, and would like to voice it a bit better for my guitars - a vintage Jazzmaster and a pine tele. Just curious what you ended up doing. Thanks!!

I really have no idea. I went over to Paul Cochrane's house and he tweaked values while I played and we stopped when it was perfect for me

I wish I still had that amp !! I bought a smaller AC-10 that I just love and the volume is more manageable so I sold that AC-30

[Elliott Damage]

the extra gain of the top boost is desirable to most. killer amps. all the cleans, chime and crunch you need. you don't have to sacrifice anything.

[DANOCASTER]

the extra gain of the top boost is desirable to most. killer amps. all the cleans, chime and crunch you need. you don't have to sacrifice anything.

if you tend to use pedals a lot though - the NON TB amp takes pedals way better

[thegrapeguy]

I have a '64 non-top boost Bass version. I have spoke with guys that like the Bass version best. I have spoke with guys that like the Treble best and some that swear by the Normal version. I primarily play a Strat through this amp and it is primo for cleans. When I turn it up the Strat breaks up but not in the way that I like. My Les Paul breaks up in that crunchy old time kind of medium way. Kind of like an AM radio in a good way. I love that tone in particular.

The Strat in the Normal channel is very warm and rich and loves "spacy" chords but not super rythmic type playing especially with lower bar chords (can get too bassy). The tone control is not enough to thin it out. But the Brilliant channel does the trick and this is where I primarily do my clean Strat stuff.

I have never desired a top boost because I just love the transition from clean to dirty. I don't need any more dirt. I also know I could add top boost but I want to keep the amp original.

I just recently got a '60 Bassman and that is tone nirvana for dirty Strat sounds as well as bluesy cleans. I got caught up in that tone for awhile and I needed a clean Strat track for a tune so I revisited the Vox. Nothing equals that AC 30 for chimey cleans. My Les Paul through both amps turned up is quite equal in the crunch department.

I use my Vox through a '65 Vox closed back 2x12 (Celestion Silvers) which may explain some of the extra bassiness but with my Brilliant channel I am in heaven!

[chops612]

if you tend to use pedals a lot though - the NON TB amp takes pedals way better

I agree with Dan. I find the tone of the JMI era Normal channels the epitome of Vox tone. TB is cool without to much pedals, but is so much more gain relative that you can really take it overboard. Theres a punch and a fatness in the Normal channel circuit that the TB doesn't have. That being said, and old JMI non TB with the TB add on installed is a great option as you have the best of both worlds. A buffered splitter into two channels and finding the perfect balance yields killer results as well, vs channel jumping which changes the loading on the front end and runs both channels out of phase.

[12strings]

Hey Danocaster, thanks for your response. I would love to try out an AC10. I wish my neighbors were as cool as yours!!

My taste is stuck somewhere between a non top boost normal version and a non top boost treble version!