Chickenwings
Alnico 6/8
Re: Why is a vintage Vox AC30 sooo (((LOUD))) ?
Q: Why is a vintage Vox AC30 sooo (((LOUD))) ?
A: because they are awesome.
Q: Why is a vintage Vox AC30 sooo (((LOUD))) ?
A: because they are awesome.
Why is a vintage Vox AC30 sooo (((LOUD))) ?
- Thread starter SirJackdeFuzz
- Start date
Re: Why is a vintage Vox AC30 sooo (((LOUD))) ?
Ok , first post and an old thread revive. Sorry bout that.. Answer that the ac30 is so unbelievable loud compared to a higher powered marshall lies in that the ac30 has no negative feedback and no bass/mid/treble network eating up gobs of gain. Try removing it on your 50 or 100 water and you'll see.
Ok , first post and an old thread revive. Sorry bout that.. Answer that the ac30 is so unbelievable loud compared to a higher powered marshall lies in that the ac30 has no negative feedback and no bass/mid/treble network eating up gobs of gain. Try removing it on your 50 or 100 water and you'll see.
Myaccount876
Amira-Maker
Re: Why is a vintage Vox AC30 sooo (((LOUD))) ?
They're extremely efficient. Only two speakers, but boy does the AC30 really squeeze everything it can out of those speakers. It's also open-backed, giving a "room-filling" sound, rather than a one-way directional sound.
They're extremely efficient. Only two speakers, but boy does the AC30 really squeeze everything it can out of those speakers. It's also open-backed, giving a "room-filling" sound, rather than a one-way directional sound.
Lewguitar
New member
Re: Why is a vintage Vox AC30 sooo (((LOUD))) ?
I don't think a Tremolux compares to an AC30 in the volume department.
A real AC30 with Celestion alnico G12's is a really loud amp. Like Twin Reverb loud.
Loudest 30 watts I've ever owned.
The transformers are pretty large.
That must be one of the reasons.
And since the speakers are hooked up in series for 16 ohms you're using every inch of the windings on that big output transformer.
MY AC30 was the best sounding amp I've ever owned - but just to loud.
Also very, very heavy.
That thing weighed a ton.
A ton of tone.
I don't think a Tremolux compares to an AC30 in the volume department.
A real AC30 with Celestion alnico G12's is a really loud amp. Like Twin Reverb loud.
Loudest 30 watts I've ever owned.
The transformers are pretty large.
That must be one of the reasons.
And since the speakers are hooked up in series for 16 ohms you're using every inch of the windings on that big output transformer.
MY AC30 was the best sounding amp I've ever owned - but just to loud.
Also very, very heavy.
That thing weighed a ton.
A ton of tone.
MetalManiac
Li'l Junior Member
NecroPolo
New member
Re: Why is a vintage Vox AC30 sooo (((LOUD))) ?
It is all about the well-tailored frequencies it pushes. Considering the subjective perceived loudnes I'm pretty sure it felt to be the loudest amp I've ever recorded. The other thing is, it must be pushed really hard to reach the sweet spot.
It is all about the well-tailored frequencies it pushes. Considering the subjective perceived loudnes I'm pretty sure it felt to be the loudest amp I've ever recorded. The other thing is, it must be pushed really hard to reach the sweet spot.
Chickenwings
Alnico 6/8
Re: Why is a vintage Vox AC30 sooo (((LOUD))) ?
i was being nihilistic with this response.
AC30's are awesome but thats not actually the reason people say they are loud.
Its the speakers. Celestion Alnico blue speakers are very efficient (over 100 db) and also quite bright, so they not only can reproduce over 100 decibels of volume with only one watt of power ( a 3 db change such as that from a 97db speaker is perceived by out human ears as roughly half as loud) it is also quite bright and trebly - and our ears are more responsive to treble frequencies than bass frequencies.
So the rough equation works like this: a 30 watt amp thru a 100db speaker will give the same perceived volume as a 60 watt amp thru a 97db speaker.
Add to this, the trebly, cutting and harmonically rich nature of the cathode biased el84 based vox amp, and the fact the the extremely efficient speakers are trebly, cutting and harmonically rich, you have a recipe for something that to our ears is very loud.
However - run a vox ac 30 thru a pair of greenbacks (96db) and you have a different, much tamer beast entirely.
So, when people say things like vox ac30s are louder than marshall 100watt stacks, they are really not seeing the whole picture.
Take the marshall 100 watter and run it thru 4 or even 8 speakers. Its loud right? well yes, but you have to look at the speakers - classic marshalls like the jtm etc would quilte often be runing thru greenback speakers at only 96db of efficiency. The fact that there are 4 or even 8 of them makes very little difference because the speakers share the wattage load - they do not multiply it. The headroom of the speakers cabinet is increased so they do not distort or blow out, but the total volume capacity is the same due to the efficiency of the speakers - there is only so much volume they can output with each watt they get fed. Imagine how paint peelingly loud things would get if you run a 100 watt jtm thru quads of celestion blues!
There is a lot of myth and folklore that floats around in the world of guitars and amps. A watt is a watt regardless of what kind of tubes or what kind of transformers etc. If an amp has an RMS rating of 15, 30, 25, 50 or 100 watts then that is the end of the story. From there it is all up to the efficiency of the speakers to convert that wattage into decibels. However, our ears perceive decibels on a logarithmic scale and they also perceive treble frequencies more easily than bass frequencies. That, and the fact that it actually requires more wattage from an amp to reproduce a bass frequency so that it seems as loud as a treble frequency to our ears and there is the reason.
Its all about the speakers. The vox ac30s that people talk about have very efficient speakers.
i was being nihilistic with this response.
AC30's are awesome but thats not actually the reason people say they are loud.
Its the speakers. Celestion Alnico blue speakers are very efficient (over 100 db) and also quite bright, so they not only can reproduce over 100 decibels of volume with only one watt of power ( a 3 db change such as that from a 97db speaker is perceived by out human ears as roughly half as loud) it is also quite bright and trebly - and our ears are more responsive to treble frequencies than bass frequencies.
So the rough equation works like this: a 30 watt amp thru a 100db speaker will give the same perceived volume as a 60 watt amp thru a 97db speaker.
Add to this, the trebly, cutting and harmonically rich nature of the cathode biased el84 based vox amp, and the fact the the extremely efficient speakers are trebly, cutting and harmonically rich, you have a recipe for something that to our ears is very loud.
However - run a vox ac 30 thru a pair of greenbacks (96db) and you have a different, much tamer beast entirely.
So, when people say things like vox ac30s are louder than marshall 100watt stacks, they are really not seeing the whole picture.
Take the marshall 100 watter and run it thru 4 or even 8 speakers. Its loud right? well yes, but you have to look at the speakers - classic marshalls like the jtm etc would quilte often be runing thru greenback speakers at only 96db of efficiency. The fact that there are 4 or even 8 of them makes very little difference because the speakers share the wattage load - they do not multiply it. The headroom of the speakers cabinet is increased so they do not distort or blow out, but the total volume capacity is the same due to the efficiency of the speakers - there is only so much volume they can output with each watt they get fed. Imagine how paint peelingly loud things would get if you run a 100 watt jtm thru quads of celestion blues!
There is a lot of myth and folklore that floats around in the world of guitars and amps. A watt is a watt regardless of what kind of tubes or what kind of transformers etc. If an amp has an RMS rating of 15, 30, 25, 50 or 100 watts then that is the end of the story. From there it is all up to the efficiency of the speakers to convert that wattage into decibels. However, our ears perceive decibels on a logarithmic scale and they also perceive treble frequencies more easily than bass frequencies. That, and the fact that it actually requires more wattage from an amp to reproduce a bass frequency so that it seems as loud as a treble frequency to our ears and there is the reason.
Its all about the speakers. The vox ac30s that people talk about have very efficient speakers.
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Drunken Bowling
New member
Re: Why is a vintage Vox AC30 sooo (((LOUD))) ?
Okay, Gomer question of the night here....
What does THD stand for?
Okay, Gomer question of the night here....
What does THD stand for?
uOpt
Something Cool
Re: Why is a vintage Vox AC30 sooo (((LOUD))) ?
Comparing a 50 watts Marshall and an AC30 combo is problematic.
The Marshall has more bass and your ears are less sensitive there.
And the Marshall often comes with a closed 4x12cab. An open 2x12 screams right where you ears are more sensitive.
Plus they are ****ing loud.
Comparing a 50 watts Marshall and an AC30 combo is problematic.
The Marshall has more bass and your ears are less sensitive there.
And the Marshall often comes with a closed 4x12cab. An open 2x12 screams right where you ears are more sensitive.
Plus they are ****ing loud.
STRATDELUXER97
Stratoblaster Tone Meister
Re: Why is a vintage Vox AC30 sooo (((LOUD))) ?
Total Harmonic Distortion or Totally Hip Dudes!
Total Harmonic Distortion or Totally Hip Dudes!
Drunken Bowling
New member
Re: Why is a vintage Vox AC30 sooo (((LOUD))) ?
Thanks!
Thanks!
Re: Why is a vintage Vox AC30 sooo (((LOUD))) ?
My personal experience contradict this, I have a 64 ac30 that I have used with a single 1x12 scumback 65w M75 96 db sens spkr and it is still ample loud. I think the answer to why it is perceived as "comparatively" loud to many amps lies in the circuit and its comparatively high input sensitivity. No tonestack insertion losses and no negative feedback in the pwr amp.
I think the actual watts is not the answer but rather how strong signal that gets amplified with x watts that makes the difference. If I run say a hotter signal into my marshall that is compensated for the tonestack and negative feedback losses in my marhsall, say 20-30 db stronger signal it will be by large much louder than my ac30 and people around me will probably be running away or going def or both.
Removing the negative feedback alone will in many amps make a bigger difference than switching from say a "blue" to a "greenback". "Typically, in a guitar amp, somewhere around 6-10dB of negative feedback is used"
Quote from :
http://www.aikenamps.com/index.php/designing-for-global-negative-feedback
Removing the tonestack will a lot of times make an even bigger difference depending on the design.
I have read that the traditional FMV fender marshall vox treble bass mid tonestack typically has about 20db insertion loss!
My own tweaking subjectively supports this. I have removed both on some amps and all got substantially louder, much bigger difference than changing the speakers from greenbacks to blues golds or v30.
On a lowered powered amp this can make a huge difference. My friend has built a single end ac4 style amp without tone control and without negative feedback. I has just one master volume and it can be a pretty loud beast. On my 100w marhsall I like some negative feedback to control the bass and even things out. I don´t like quite as much NF as stock though. I find reducing NF can opens things up. Some amps have a global negative feedback pot that works in conjunction with the presence control and it can be very useful.
Some amps also has a "depth" knob that works by defeating the negative feedback in the lower register as opposed to the prescence that defeats negative feedback in the higher register.
I find variable NF is very useful, depending on room acoustics, volume and speakers it can be set to get into the zone. The lower the volume and gain the less NF i like.
Cheers!
My personal experience contradict this, I have a 64 ac30 that I have used with a single 1x12 scumback 65w M75 96 db sens spkr and it is still ample loud. I think the answer to why it is perceived as "comparatively" loud to many amps lies in the circuit and its comparatively high input sensitivity. No tonestack insertion losses and no negative feedback in the pwr amp.
I think the actual watts is not the answer but rather how strong signal that gets amplified with x watts that makes the difference. If I run say a hotter signal into my marshall that is compensated for the tonestack and negative feedback losses in my marhsall, say 20-30 db stronger signal it will be by large much louder than my ac30 and people around me will probably be running away or going def or both.
Removing the negative feedback alone will in many amps make a bigger difference than switching from say a "blue" to a "greenback". "Typically, in a guitar amp, somewhere around 6-10dB of negative feedback is used"
Quote from :
http://www.aikenamps.com/index.php/designing-for-global-negative-feedback
Removing the tonestack will a lot of times make an even bigger difference depending on the design.
I have read that the traditional FMV fender marshall vox treble bass mid tonestack typically has about 20db insertion loss!
My own tweaking subjectively supports this. I have removed both on some amps and all got substantially louder, much bigger difference than changing the speakers from greenbacks to blues golds or v30.
On a lowered powered amp this can make a huge difference. My friend has built a single end ac4 style amp without tone control and without negative feedback. I has just one master volume and it can be a pretty loud beast. On my 100w marhsall I like some negative feedback to control the bass and even things out. I don´t like quite as much NF as stock though. I find reducing NF can opens things up. Some amps have a global negative feedback pot that works in conjunction with the presence control and it can be very useful.
Some amps also has a "depth" knob that works by defeating the negative feedback in the lower register as opposed to the prescence that defeats negative feedback in the higher register.
I find variable NF is very useful, depending on room acoustics, volume and speakers it can be set to get into the zone. The lower the volume and gain the less NF i like.
Cheers!
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Edgecrusher
Well-known member
Re: Why is a vintage Vox AC30 sooo (((LOUD))) ?
You got your wires crossed on what you are reading. 100watts rms is measured at the output. Doesnt matter if gain is absorbed in the tone stack if its putting out 100 watts at the output its 100 watts. You cant get around this.
You answered your own question, in YOUR experience you PERCEIVE them as loud. Doesnt mean its actually so. Our ears naturally pick up on the high endy nature of the AC30 doesnt mean it is actually louder our ears just think it is.
You got your wires crossed on what you are reading. 100watts rms is measured at the output. Doesnt matter if gain is absorbed in the tone stack if its putting out 100 watts at the output its 100 watts. You cant get around this.
You answered your own question, in YOUR experience you PERCEIVE them as loud. Doesnt mean its actually so. Our ears naturally pick up on the high endy nature of the AC30 doesnt mean it is actually louder our ears just think it is.
Re: Why is a vintage Vox AC30 sooo (((LOUD))) ?
Thanks , it wasn't my question though. Sorry if i was unclear , I tried to describe why I think they are more often than not perceived "SOO LOUD" as the original post asks.
Thanks , it wasn't my question though. Sorry if i was unclear , I tried to describe why I think they are more often than not perceived "SOO LOUD" as the original post asks.
youngthrasher9
New member
Re: Why is a vintage Vox AC30 sooo (((LOUD))) ?
As others said, more mids, open back cab, and a very efficient minimalistic signal path. I've never played one, but it makes a lot of sense on paper.
As others said, more mids, open back cab, and a very efficient minimalistic signal path. I've never played one, but it makes a lot of sense on paper.
the guy who invented fire
Fuzzy. Guitars
Re: Why is a vintage Vox AC30 sooo (((LOUD))) ?
This thread is so funny...lots of good posts but also a bunch of posts that simply do not have much merit.
Anytime people mention an AC-30 and volume in the same sentence replys fly fast and furious about how the AC-30 is the loudest 30 watt amp ever and how a 30 watt Vox is louder than a 50 watt Marshall or Fender and all other such nonsense.
30 watts is 30 watts period, end of report.
On top of that a watt is nothing more than a measure of heat dissipation.
So, keep in mind one thing...YOU CAN NOT HEAR A WATT...what you hear are decibels and db's have much less to do with watts than you might think.
An AC-30 is a loud amp, no doubt about that. I played in a band for years with a guy that used an AC-30 and he only knew one way to run it...full up at all times and boosted with a TS-9! So I am fully aware of the sheer volume generated by an AC-30!
Why...here is why.
First off most of the time AC-30's these days have a pair of Celestion "blue bell" G12 Alnico speakers that are 100db's a pop. On top of that the new G12 Celestions have a serious peak in the upper midrange freqs that make them seem even louder due to the freqs being pushed forward.
On top of that the AC-30 itself is a pretty midrange heavy amp, again making it louder than you might expect if you are not used to it.
Those 2 or 3 things added together make the AC-30 be much louder than you might expect then if you just look at it with the mindset of it just being a 30 watt, 2x12 combo.
This thread is so funny...lots of good posts but also a bunch of posts that simply do not have much merit.
Anytime people mention an AC-30 and volume in the same sentence replys fly fast and furious about how the AC-30 is the loudest 30 watt amp ever and how a 30 watt Vox is louder than a 50 watt Marshall or Fender and all other such nonsense.
30 watts is 30 watts period, end of report.
On top of that a watt is nothing more than a measure of heat dissipation.
So, keep in mind one thing...YOU CAN NOT HEAR A WATT...what you hear are decibels and db's have much less to do with watts than you might think.
An AC-30 is a loud amp, no doubt about that. I played in a band for years with a guy that used an AC-30 and he only knew one way to run it...full up at all times and boosted with a TS-9! So I am fully aware of the sheer volume generated by an AC-30!
Why...here is why.
First off most of the time AC-30's these days have a pair of Celestion "blue bell" G12 Alnico speakers that are 100db's a pop. On top of that the new G12 Celestions have a serious peak in the upper midrange freqs that make them seem even louder due to the freqs being pushed forward.
On top of that the AC-30 itself is a pretty midrange heavy amp, again making it louder than you might expect if you are not used to it.
Those 2 or 3 things added together make the AC-30 be much louder than you might expect then if you just look at it with the mindset of it just being a 30 watt, 2x12 combo.
Edgecrusher
Well-known member
Re: Why is a vintage Vox AC30 sooo (((LOUD))) ?
This is true...But people keep saying x speaker is so many db's and to get the sensitivity rating on a speaker they usually measure the decibels at 1 meter with 1 WATT applied. Yes I know that when you double the wattage applied you increase the db's by 3 (which most ears will hear as only a small change in volume). Increasing the wattage only minorly increases volume in comparison to speaker senstivity (but we all knew this)
This is true...But people keep saying x speaker is so many db's and to get the sensitivity rating on a speaker they usually measure the decibels at 1 meter with 1 WATT applied. Yes I know that when you double the wattage applied you increase the db's by 3 (which most ears will hear as only a small change in volume). Increasing the wattage only minorly increases volume in comparison to speaker senstivity (but we all knew this)
crusty philtrum
Vintageologist
Re: Why is a vintage Vox AC30 sooo (((LOUD))) ?
Like everything, the end result is the combination of all the ingredients in the recipe.
But I'm inclined to think that a big factor is the EL84s without negative feedback. That creates a situation where the amp just gets more and more harmonically complex as the volume level is raised, making for a much wider sonic spectrum that sounds much bigger than an amp that uses negative feedback. The Top Boost channel also has more gain than any other channel used in the AC30 over the years.
I once built a Fender-based amp for a friend and installed a switch in the negative feedback loop. With the switch closed, the sound was basically what one might expect from a Fender amp with 2 x 6L6s, but with the switch open (neg. feedback removed from circuit) the sound became raw and wild and seemed much louder. But amps can only deliver a certain amount of power, limited by the tubes and power supply. It's the qualities of the sound that can make them seem restrained or wild. Maybe kinda like a recording of someone talking, and then shouting ... both recorded and played back at the same level, but the shouting will always seem louder.
Like everything, the end result is the combination of all the ingredients in the recipe.
But I'm inclined to think that a big factor is the EL84s without negative feedback. That creates a situation where the amp just gets more and more harmonically complex as the volume level is raised, making for a much wider sonic spectrum that sounds much bigger than an amp that uses negative feedback. The Top Boost channel also has more gain than any other channel used in the AC30 over the years.
I once built a Fender-based amp for a friend and installed a switch in the negative feedback loop. With the switch closed, the sound was basically what one might expect from a Fender amp with 2 x 6L6s, but with the switch open (neg. feedback removed from circuit) the sound became raw and wild and seemed much louder. But amps can only deliver a certain amount of power, limited by the tubes and power supply. It's the qualities of the sound that can make them seem restrained or wild. Maybe kinda like a recording of someone talking, and then shouting ... both recorded and played back at the same level, but the shouting will always seem louder.
Lewguitar
New member
Re: Why is a vintage Vox AC30 sooo (((LOUD))) ?
An AC30 with two Celestion G12 Alnico speakers is very loud when cranked. And they have to be cranked to get that sound.
Maybe with a Klon driving it, I would be able to keep the volume down a bit. I used to drive mine with either a DS1 or TS808 and I still had to crank the amp itself up to loud volumes - at least partially because it felt so good! :lmao:
Mine struck me as being louder than my 40 watt Pro Reverb and reminded me more of a Twin Reverb although it probably wasn't as loud as a Twin.
Not as loud as a 100 watt Marshall through a half stack either.
But if felt as loud as a 50 watt through a half stack - although it couldn't have been.
I guess the point is, an AC30 with G12 Alnico speakers gives the impression of being a very loud amp.
Louder than I usually get to play onstage.
Which is why I switched to Fender Deluxe Reverb Amps a long time ago.
BTW, I've seen Buddy Miller a few times with Emmylou Harris and he plays through two AC30's. His onstage volume always seemed fairly reasonable even though he got that cranked tone.
An AC30 with two Celestion G12 Alnico speakers is very loud when cranked. And they have to be cranked to get that sound.
Maybe with a Klon driving it, I would be able to keep the volume down a bit. I used to drive mine with either a DS1 or TS808 and I still had to crank the amp itself up to loud volumes - at least partially because it felt so good! :lmao:
Mine struck me as being louder than my 40 watt Pro Reverb and reminded me more of a Twin Reverb although it probably wasn't as loud as a Twin.
Not as loud as a 100 watt Marshall through a half stack either.
But if felt as loud as a 50 watt through a half stack - although it couldn't have been.
I guess the point is, an AC30 with G12 Alnico speakers gives the impression of being a very loud amp.
Louder than I usually get to play onstage.
Which is why I switched to Fender Deluxe Reverb Amps a long time ago.
BTW, I've seen Buddy Miller a few times with Emmylou Harris and he plays through two AC30's. His onstage volume always seemed fairly reasonable even though he got that cranked tone.
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