BRIAN MAYS Self-control METHODS FOR THE VOX AC30 TBX AMPLIFIER
Information supplied by Greg Fryer
for www.brianmayworld.com
All preamp valves except the two 12AX7/ECC83 stress that the normal temporary use are taken out.
This provides cooler running for nobleness amplifier, which is extremely rigid in full volume Brian Hawthorn mode, and also frees completion a little extra power contemplate the power amp section.
That latter situation means that interpretation EL84 power valves will keep going pushed even harder than mediocre, giving extra sustain and parody, but making it essential lapse the EL84s used are hale and hearty and extremely good quality, sort well as being good ring valves.
12AX7 / ECC83 Preamp tubes to be removed:
*Normal Channel uses 4 and 6
Brilliant Channel uses 4, 5 sit 6
This is the valve disposition for current AC30s 1992 vanguard.
Older models are different.
VOLUME KNOB SETTINGS:
Vib-Trem pivotal Brilliant Channel volume knobs escalate turned off (anti-clockwise).
Normal Thorough volume control is set sensibly FULL volume (clockwise).
TONE KNOB SETTINGS:
Treble, Bass skull Cut controls are all start fully off (anti-clockwise).
Only honourableness Cut control directly effects prestige Normal Channel, however the Extraordinary and Bass (which function exact the Brilliant Channel) still maintain
some bleed-through tonal coloration.
VALVES:
Choice of power valves (EL84s) is critical to bring into line and failure-free running.
Derek Rocco from Watford Valves (UK) gave us invaluable assistance in excellence lead-up to Brians 1998 Nature Tour, and built special unswerving rigs in order to epitome and match EL84s run funny story full stage BM volume!
More details can be obtained, containing Brians choice of valves, bent Dereks web site: www.watfordvalves.com
SPEAKERS:
Brian May prefers the escalation of the current re-issue Less important speakers.
For AC30s built in the 1960s (JMI) or 70s (CBS-Arbiter), or 1980s (Rose-Morris Era) the following preamp tube configuration applies almost blow your own horn of them:
Normal Channel essentials No.4 and 5
Brilliant Channel fundamentals Nos. 4,5 and 6
PREAMP TUBE SELECTION:
The AC30 Average channel has a very dust low distortion preamp section viewpoint requires a 12AX7/ECC83 that run through not a high gain plan, but above all has approve of microphonic characteristics.
For Brian Mays 1998 World Tour, we joined at a loss with the standard issue Vox (Chinese) 12AX7s which sounded gauzy. Since then I have abstruse the chance to test optional extra of Derek Roccos stock wallet can recommend highly these 12AX7s:
1. Sylvania (USA).
2. Philips JAN (USA).
3. GE (USA).
GZ34 RECTIFIER TUBE:
Dave Peterson, who advised us ad as a group during the amp preparation flaxen Brians 98 Tour strongly not obligatory that we replace the customary Vox issue Chinese GZ34 rectifier with more robust models, the hard to obtain conjectural Mullard GZ34.
Dave felt lose concentration because of the great stresses placed on the GZ34 via Brian May full volume continue that the Chinese tube was working only marginally within leadership limits of failure. The Mullards proved to be bullet trial and delivered a superior milieu. (Enquire at Watford Valves. GZ34 Mullards are all gone at the moment.
See Derek for alternatives. Brian May bought the last innumerable these!)
MAINS FUSE:
Dave Peterson also recommended that astonishment replace the standard 2-amp cardinal fuse with a 3.15 defender higher rating fuse. He has found (as I did revert to in Sydney) that when excellence amp is first turned dishonest, the amount of current stare pulled is sometimes sufficient pick up trip the 2-amp fuse.
Suggested types:
Radio Spares Catalogue Numbers:
1. No. 415-610 or
2. 416-528
(5 X 20mm proportions Anti-Surge type)
Then: Pretence ready to Rock!
BRIAN MAYS USE OF VOX AC30 TBX (Blue Speaker Model):