Vox Ac15HTV... Bargain!!

[Mark Burton]

[Didier]

Don't you just love Didier's black & white world ?

Dick

My world isn't in black & white, it's just the real world !

Didier

[keithmantle]

Gentlemen? please or you will be on the naughty step !!

[stuartcosgrove]

HI There,I have a Vox AC15 HTV and have experimented to get the vintage EF86 tone as close as possible.I dont believe you have to be as specific as a Berhinger Ultracurve Eq, you just need a basic BOSS RGE-10 band Eq device as used by Ronnie Gustafsson from the band '1961'.He has the best vintage Shads tone I have heard live!! I have the following chain: Guitar toAmtech Age 1 to TVS 1 used as preamp to Boss Eq to Vox AC15 HTV. You need to tone down the following frequencies:31,62,125HZ,4,8,16KHz whilst increasing db levels of 500Hz,1KHz,2Khz and you will achieve that tone!! I prefer the Age 1 to the TVS 3 in this situation as the echoes with the TVS3 sound too processed and I prefer to have complete control of the Eq myself.Let your ears do the work and have plenty of breaks to reconfigure and reset your listening sense and keep coming back to experiment till you are happy with your sound.If you listen to my old band playing 'THe Golden Sea' on 'Stradivarius' by 'The Epitones'. I think they have soundbites on Leos Den. Hope I have given some of you some food for thought!

[Twang46]

Don't you just love Didier's black & white world ?

Dick

My world isn't in black & white, it's just the real world !

Didier

My world has shades of grey as well

Cheers

Dick.

[fenderplucker]

Hi,

Here are two sound files (the second one to follow) done through a special preamp that had both 12Ax7 and EF86 channels, each matched for gain and frequency response and with the tubes biased exactly as in a Vox (and please don't pay too much attention to the playing, it was done by a friend of mine).

I can hear some obvious differences in the playing and levels from place to place, but I'm not sure I could pick which was 12AX7 or EF86??

I think that the differences that are clearly apparent when playing through the different channels of an amplifier are due to one (or both) of two main causes:

1. The EF86 has a different gain to the 12AX7. The "Normal" channel of an AC30/6 (12AX7) has a lower gain than the EF86 channel of an AC30/4, but the top boost channel has a higher gain (with the extra 12AX7 stage).

2.The EF86 channel of an AC30/4 (or AC15) is followed by simple top cut and sometimes bass cut ( labelled as "brilliance" in the AC30/4 and AC15/3) tone sections. This is similarly the case with the "Normal" and "Bright" channels of an AC30/6 (the bright channel having more bass cut). However, the top boost channel features a tone control section that results in a sharp dip in frequency response at around 900Hz unless both the bass and treble controls are turned to zero, in which case the frequency response is again fairly flat.

Both of these certainly affect the perceived sound, but it has little to do with whether the tube is EF86 or 12AX7. Either tube can be configured to sound the same as I think this demo shows (and the sound of a top boost channel with the bass and treble fully down is very close to that of an EF86 channel if the gains and top cut are adjusted to be the same). However I accept that many commentators are probably using the descriptors "EF86" and 12AX7" as shorthand for the sound of the different channels. Maybe this is where the disagreement in the above discussion arises?

Finally, both types of frequency response are needed to cover the whole range of Shadows sound: "flat" for the early tunes up to about Find Me a Golden Street, and top boost with a dip at about 900Hz for the later tunes.

Paul.

[fenderplucker]

Hi Again,

Here is the second sound file:

Paul.

[roger bayliss]

Paul thats something I have tried in the past and I too found the ef86 and the top boost can be made to sound the same by reducing the bass and treble to nought and adjustibg the volume so the gain is about the same. People often forget there are two 12ax7s in the preamp and plently of gain to be had and I know others have mentioned this before .. there is not a lot of difference really when set up like that save for perhaps a little more bass on the top boost side which can be easily EQ'd out and your sound files prove that