Has anyone modded a Vox AC30 Heritage model??

Discussion in 'Amps and Cabs' started by mcdes, Jan 29, 2012.

  1. mcdes

    mcdes Member of no importance

    Messages:
    7,558
    Joined:
    Oct 9, 2007
    Location:
    New Zealand
    Just curious if anyone has changed anything in their Heritage model AC30's (besides tubes), and if so, what did you do, and what did it sound like after the change........

    reason being, i'm looking at changing the trannies/choke out, and maybe do the JMI spec upgrade...... is it worth it? even for longevity purposes?

    Also, any pics of what ya done would be cool.
     
  2. mcdes

    mcdes Member of no importance

    Messages:
    7,558
    Joined:
    Oct 9, 2007
    Location:
    New Zealand
    anybody? anything?
     
  3. mAx___

    mAx___ Member

    Messages:
    709
    Joined:
    Aug 7, 2011
    I have not seen anything on upgrading the Heritage series but there are a lot of schematics of the AC30/4 (EF86) and Top Boost channel online if you decide to be the first one.
    My experience is with the AC30HW2 but I think your amp will greatly benefit from the upgrade, just go for it.
     
  4. mcdes

    mcdes Member of no importance

    Messages:
    7,558
    Joined:
    Oct 9, 2007
    Location:
    New Zealand
    anybody else?
     
  5. 8nthatK

    8nthatK Supporting Member

    Messages:
    1,867
    Joined:
    Jan 15, 2003
    Radio Spares output (JTM45) tranny by Marstran sounded fantastic. After this: loved OD pedals, warmer, smoother break-up.
    Negatives: hardwired for one output impedance value.
     
  6. mcdes

    mcdes Member of no importance

    Messages:
    7,558
    Joined:
    Oct 9, 2007
    Location:
    New Zealand
    Is that because it only had one output option?
     
  7. 8nthatK

    8nthatK Supporting Member

    Messages:
    1,867
    Joined:
    Jan 15, 2003
    No...different impedance options are available, but not switchable...at least not stock.
     
  8. mcdes

    mcdes Member of no importance

    Messages:
    7,558
    Joined:
    Oct 9, 2007
    Location:
    New Zealand
    i wouldve just wired one of the two jacks to give me the two different impedance options. so left was 8 and right was 16 ohms.....

    I have a head version tho, so i could possibly see it being confusing with a combo! hahaha
     
  9. 8nthatK

    8nthatK Supporting Member

    Messages:
    1,867
    Joined:
    Jan 15, 2003
    I wanted to use all the windings...and only used 1 cab, so, no big deal.
     
  10. Dr. Tweedbucket

    Dr. Tweedbucket Deluxe model available !!!11

    Messages:
    45,498
    Joined:
    Feb 22, 2007
    Location:
    Gamma Ray detection station on Mt. Kwakkleberry
    I'm really happy with mine stock through a pair of blues. Using good tubes is all you really need to do. I'm sure a better tranny may sound fractionally better, but the tone is such that why even mess with it?
     
  11. feet

    feet Supporting Member

    Messages:
    3,523
    Joined:
    Jun 9, 2011
    i had once wanted that specific model really bad. came close to getting it too, but i was scared off by the pcb. the newer handwired version didn't have the ef86 channel, so although it had a turret board, i passed on it as well.

    but reading through the thread, he mentions that they are essentially the same, or very similar, from cc to ac's to hw's.

    if that's the case, i wonder if the reliability is the same, from turret to pcb, especially after he goes through it all and replaces so much. and if you don't mind my asking, how much did this cost? if they are all so similar, maybe i can get the cheapest one instead of a fancy handwired one and have it super modded and we could be twinsies. as i was concerned by the reliabilty, and not the price difference. given how my ac4 exploded, i made the right choice. but now i wonder.
     
  12. mcdes

    mcdes Member of no importance

    Messages:
    7,558
    Joined:
    Oct 9, 2007
    Location:
    New Zealand
    thats pretty cool.

    What was the difference in sound/tone after the mods? if it can be put into words? increased headroom? less? etc.......

    why were the speaker out jacks changed?
     
  13. mAx___

    mAx___ Member

    Messages:
    709
    Joined:
    Aug 7, 2011
    Wow, great job by Lyle once again. I think the coolest thing is he added a Normal channel to it. Awesome.
     
  14. Mitch T

    Mitch T Member

    Messages:
    1,018
    Joined:
    Mar 11, 2007
    Location:
    EU citizen
    My Heritage head is modded slightly (bright cap, MV, few filter caps) and tubed up nicely. There was a thread rather recently. Search my posts and it'll pop up.
     
  15. michael.e

    michael.e Supporting Member

    Messages:
    19,491
    Joined:
    Aug 4, 2003
    Location:
    Half Moon Bay, CA
    Doesn't Don Butler/Toneman do mods on these?
     
  16. mcdes

    mcdes Member of no importance

    Messages:
    7,558
    Joined:
    Oct 9, 2007
    Location:
    New Zealand
    what exactly did you do to clip the bright cap? as in, where is it, and what did you do? clip or remove.... ta
     
  17. Mitch T

    Mitch T Member

    Messages:
    1,018
    Joined:
    Mar 11, 2007
    Location:
    EU citizen
    I took it to my tech :D
    If I recall correctly, the bright cap is placed on the volumepot or very near. Just clipped it off and the 12AX7 channel is now my main sound.
     
  18. ja22y

    ja22y Member

    Messages:
    50
    Joined:
    Sep 30, 2008
    I mod'ed mine with the goal of not completely changing the tone but to make it better. I posted the results on the 'vintageamps.com' several years back but I don't have a link to it, might still be there if you search.
    Basically:
    - replaced the OT and choke w/ Mercury Magnetic. IMO this is the most significant improvement
    - replaced coupling caps to sozos. Very noticeable improvement
    - changed the feedback resistor on the EF86 to vintage spec (1M) for increase gain/volume.
    - removed the bright cap on the TB
    - replaced some ceramic caps w/ silver mica. This reduces the harsh brightness that ceramic cap has.
    btw the celestion blue in that sounds fizzy compares to the UK ones.
    The mods worth every penny
     
  19. mcdes

    mcdes Member of no importance

    Messages:
    7,558
    Joined:
    Oct 9, 2007
    Location:
    New Zealand

    yea, this is what i want, but in detail, as in, where the heck half the stuff is, ie r18 or whatever?

    i have the head version playing thru a mix of gold and greenback speakers, both made in england so im good on the speakers haha.
     
  20. ja22y

    ja22y Member

    Messages:
    50
    Joined:
    Sep 30, 2008
    Assuming you can understand schematic and handy with electronics. The service manual shows you where everything is. The pre section is identical for AC15 and AC30
    www.blueguitar.org/new/schem/vox/ac15htvh1_handwired.pdf
     

Share This Page