Better Gigging Tone. AD50VT.

[BaptissBlacktick]

I'm new to the forum, and I read with interest the FAQ on 'want to get better gigging tone' and thought I'd add my personal experience of this to those which Voxman posted.

I've got a Vox AD50VT and I used to practise in a band where the other guitarist had a Peavey Classic 30 valve amp. I used to be continually frustrated at practise, and also the couple of small gigs we did, that my amp seemed a) very 'directional' - i.e. could only be heard clearly if you were in a 'beam' directly in front of it and b) did not 'cut through' the mix as well as the classsic 30. I was frustrated that my 50 watt 'hybrid' amp was 'perceptively' not as 'loud' as a 30 watt valve amp. All the EQ and tweaking of settings just did not improve the situation. And whilst raising the amp on a chair or angling it towards me, meant I could hear it fine, anyone listening outside of the direct line of the speaker was getting a 'duller' version of the sounds.

In the end what worked for me was

a) opening up the back of the amp - as a bit of research on the web told me that the 'directional' sound projection is a characteristic of closed-backed cabs (my experience is that with the back off the AD50 you lose some volume out the front but your sound fills the room more evenly so you don't have to be so fussy about the relative position of you/amp/listener - plus its a handy place to put your footswitch and the power cable !) and

b) I replaced the stock speaker with a Celestion G12 Century neodymium speaker which basically gives you more volume per watt of output as it is a more efficient speaker than the stock 'unmarked' Celestion Seventy 80. It also has a more 'edgy' tone and both of these things helped it cut through better. This totally solved my problem and after these 2 mods my amp was more than capable of keeping up with the peavey valve amp - and in my opinion generally sounds better than it did before, too.

So I guess my experience was that getting a better tone is not just about tweaking EQ and - depending which Vox amp you have - there are other ways in which you can mod your amp to cut through the mix better. That said - I suspect that the modelling in the amp is designed to work with the 'flatter' and more predictable response of the closed back cab and seventy 80 speaker, so you could argue that the mods I have made have probably made the amp models slightly 'less accurate' than they were. So I guess it depends if you want to sound exactly like your hero but nobody can hear you, vs slighly less like your hero but at least you can be heard !

Would be interested to hear from anyone else who has solved the same dilemma in the same or different ways...

Cheers,
Andy

[retrobob]

Closed back, open back, insulation in the box or none, what’s the difference? Personal preference!
Open back distributes the sound on stage better, has more treble and midrange response, fills the room quickly. However stage distribution can also be accomplished by using the line out into your PA monitor mix.

Closed back has a more pronounce and tighter bottom, better for palm muted and staccato playing, you can increase the bass on an open back but you can't change the dampening effect (or lack of it in an open back).

Insulation inside a closed back speaker, it adds to the bottom end of the box and takes the boom out by dampening the resonance of the box caused by the size and materials the box is made from (trapping and limiting sound waves). Removing the insulation will make the box sound a little brighter, but may also add some undesirable resonant frequencies, and can make the box sound woofy (bass has no thud, like a dog with a low woof before it barks) or quaky (the bass is brittle, rings on the top).

Programs can be tweaked to help the sound simulation you’re looking for, but a closed back never sounds exactly like an open back and visa versa, because the speaker is responding differently. The speaker can travel more freely in an open back design, where a closed back decreases the time and distance the speaker can travel by dampening effect (air trapped in the box pushing back on the speaker).

Again this all boils done to your personal preferences, I prefer a closed back for better and more defined bass response (insulation in box). However there are times when an open back fills the bill nicely, especially on cleaner tones and modern country music. And sometimes a closed speaker box is improved by removing the insulation. Bottom line, experiment, find what works and suits your style best.

[Voxman]

Andy, thanks for the interesting post.

The wattage handling of the speakers is pretty much irrelevant and only indicates how much power the speaker can handle, not the volume it puts out. It's the sensitivity rating of the speakers that's important when in comes to volume output. The Seventy/80 is rated at 98dB sensitivity whereas the G12 Century is 102dB. That 4dB difference is huge - it's the equivalent of boosting your amp to the equivalent volume of an AD100VT going through a 98dB speaker! That and the increased frequency response range of the G12 Century is the biggest difference to your tone and projection - far more than the open backed mod, although I'm sure that has helped too.

Re EQ adjustment, unfortunately the AD50VT has no FX loop in which to put an external EQ, so (without doing the FX loop mod) you'd be restricted to the on-board EQ only.

For those of us with the VTX 'blues', these already come with the excellent G12 Century 'Neodog' speakers, and the power-amp was 're-tuned' in these amps to get the best out of these. The cabinet construction is birch-ply, which significantly improves the amps resonance and acoustic qualities. The AD series are chipboard, which tends to soak up and deaden tone.

So, I can fully understand the mods you've done to your AD50VT. The important thing is that you've found a solution that adapts the amp to your needs.

Conversely, my rig is entirely different to yours (& I believe Rob has a 'Blue' VTX too) For gigs, I use my AD120VTX with an AD212 extn cab - that's 4x12" 'Neodogs' - and I use an EQ and a BBE Sonic Maximiser in the FX loop. As you might imagine, with that power, projection & EQ control, I've never had the problems you've encountered. I also personally prefer the tighter bottom end from the closed back cabs - having played the AD120VT (open back) I found it got 'lost' & muddied in a band mix much in the same way you describe when cranking your pre-modded AD50VT - the VTX was brought out with the closed back, birch-ply cab, and new speakers specifically to remedy that issue.

The only problem I have is keeping my volume down!

BTW - ignore the 'hype' re 'flatter response speakers'. Vox tends to fit its own budget speakers now to save money. These are 'OK' for most folk (particularly non-giggers), but all amps will be significantly improved with better quality speakers. The Seventy/80 is a decent enough general purpose speaker but the G12 Century is much better, as you've found!

Rich

(PS - To both you guys, just a pointer - you both posted in a single 'blocks' of words - so I've put paragraph breaks in, as it makes it much easier for folk to read. )

[chill901]

hmm to butt in... an apologies for the hijack, but I used to have the AD50VT and thought exactly the same as you, it just didnt cut it (i jam a lot with a friend who as a very punchy fender deluxe 85) so it is interesting to hear the difference a new speaker made. I was just wondering whether you noticed much of a difference in the amp models themselves?

I used to love my AD50VT but was convinced for a while that i may have damaged the speaker. I say I, i think it may have been a 'friend' of mine who plugged one of those monsterous gt-3 boss contraptions into when jamming one day - he had a really heavy and bassy pantera -yuk- sound programmed into it that had buckets of bass to compensate for his tiny 1x8 SS combo of some sort and he played it through the UK70s amp model. Put simply it was bass overload and the speaker sounded like it was farting and not coping well, yet he continued to riff mindlessly. I didnt notice a difference for ages as I was into the habit of only using my v-stack modelling pedal on one of the clean channels for about 6 months after that, but when I finally went back to using some other amp models I found them to be awful past UK70s. The JCM800 had hardly any bite or gain to it (nowhere nearly as much as can be seen on youtube demos) and all of the ones after that sounded fizzy...

... is it possible that the speaker being damaged could cause the amp models to sound like this? Strange thing is however, the v-stack pedal always sounded fantastic. Maybe i just went off the ad50vt overdriven sounds in favour of this sound? (although I loved my tonelab after that... so maybe not). But i never had the volume up high on the v-stack so maybe it wasnt pushing the speaker so it didnt sound bad? I dont know how these things work... Is it possible that my speaker was a bit naff and that I hadnt gone off the sounds? Im thinking of getting the new VT30, do the amp models sound as good as they do in the tonelab or might i be disappointed given these experiences?

I wish I had held onto the amp now and put a new speaker in to see the effect. Another idea I had was to put in a new valve. Could the valve being worn out have lead to the sound quality i described? I did get a replacement but they sent me a 12AT7 by accident which i understand to be a lower gain valve so i didnt notice much when I popped that in. And also, when I sold it the guy came round and loved the thing, so maybe i simply grew out of the sound? Any ideas?

Rambling over. Thanks.

[BaptissBlacktick]

Thanks very much for the replies.

I'm certainly not 'advocating' the mods I made over any other, and I totally agree since everyone is starting from a different start-point (i.e. different amp/guitar/FX combination) and is trying to get a different end-point (i.e. different musical style/sound) in a different application (i.e. different gigging/practising circumstances) then there's no such thing as one size fits all.

Good to know I'm not alone in the experimentation & "finding what works for you" stakes !

[aaronob]

How would one go about opening up the back?

[rocketman]

Hmmm...well..I guess a guy could unscrew the back panel and take it off, (mine was still stuck on there good, kinda friction-fit) and then cut a large window out of it...leave a decent sized strip along the bottom part so you could put your cords, footswitch etc inside...and then screw it back on. I've been toying with the idea myself, as i can totally relate to the 'beam of sound' that BaptissBlacktick was talking about, and I'm not too thrilled about it. When i read posts on here saying that opening up the back will let you 'fill the room with sound easier' , that makes me wanna try it out. Kind of worried about possible negative effects on the sound though...since once you do it, it would be a real pain to reverse. I'd be interested in knowing how many ppl have done this...

[BaptissBlacktick]

Yep, rocketman, thats pretty much how I did it. Unscrew the back - don't worry it's safe as all the electronics are enclosed. I didn't want to destroy the original amp back in case I messed up, so what I did was I used 2 pieces of MDF and (using the original back as a template to cut out the control recess) I cut one piece to cover about 25% of the top section of the back of the amp, and another piece to cover about 25% of the bottom of the amp leaving a 50%ish 'letterbox' in the back of the cab. I painted them black, to match the amp and it looks pretty good. In terms of getting the back on and off, its easier if you loosen some of the bolts on each side of the amp which are there to hold the amp electronics 'housing' in the top of the amp. If you don't loosen those they have the effect of 'squeezing' the sides of the amp inwards, which makes it really hard to get the back on and off... Cheers, Andy.

[Napo]

Im thinking about this mod seriously. I use my Ad50VT for rehersals and gigging ( 50´s, 60´s rock&roll with my strat, Blues and Rock with my LP ). I use Tweed 4x10 and UK80´s mostly, no high gain settings, a little reverb, a little tremolo, no more than that. Not too much bass needed as well.

For what I´ve been reading, the " room filling" effect and lowering the " beam" it´s exatcly what I´m looking for. I´m going with the 1/3 open back, and leaving the original speaker ( 70/80 )

[MrMajstyk]

Follow up on this thread please!

I just bought a used AD50VT and am doing as much research as I can on it. Bought from GC the day they put it on the floor, so I don't get to pick it up til March 1. Until then I am doing a lot of research. I will be playing mostly oldies, rockabilly, etc thru it with my 64 Gretsch Tenneseean and my Strat. Mostly small and medium sized clubs.

I loved playing this amp in the store. Loved the clean settings!
And it seemed so much louder, but cleaner, than the other 50 watt amps I was looking at.

NAPO...you seem to play in a similar style as me...did you do the modificaction?