Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com

Schematic for AC4HW1

Discussion in 'Glowing Bottle Tube Amp Forum' started by maj34, Aug 31, 2017.

  1. maj34

    maj34 Tele-Meister

    209
    Nov 19, 2013
    Calgary
    Does anyone have a source for amp schematics? I'm hoping to get my hands on the schematic for the AC4HW1.
     

  2. Wally

    Wally Telefied Ad Free Member

    Mar 17, 2003
    Lubbock, TX
    Since it is handwired, one can rather easily draw the schematic.....that is if one reads schematics and has the amp in front of them.
    You could use the old AC4 and the Vox Top Boost circuit as references. They integrated that TB circuit into that simple little amp.
    Do you have the amp....or are thinking you want to build one? I don't find the schematic during a quick search.
     

  3. maj34

    maj34 Tele-Meister

    209
    Nov 19, 2013
    Calgary
    I have the amp. Just being hopeful. Might trace it out this weekend and if I do I'll post it back here.
     
    Wally likes this.

  4. Wyatt

    Wyatt Tele-Holic

    782
    Nov 3, 2004
    Vox won't release schematics for any "in production" amp.
     
    ZackyDog likes this.

  5. JD0x0

    JD0x0 Friend of Leo's

    Age:
    27
    Feb 22, 2009
    New York
    Why do you need it? Repair? Mods? Full build?

    They dont seem to be available for the current production ones.
     

  6. maj34

    maj34 Tele-Meister

    209
    Nov 19, 2013
    Calgary
    Well, I'm thinking about modding it.

    I should really be thinking about selling it: was planning to sell the AC15C1 but I don't like the AC4 nearly as much as my AC15C1. The biggest problem is the massive amount of mids. I know Vox is mid-rangey anyway, but I find the AC4HW1 to be much more middy and I cannot dial it out with the on-board EQ.

    I really like how I can dial it in with a Boss GE7 though - so I was wondering if I could design a band pass or even a treble bypass to accomplish something close to what I'm doing with hte GE7.
     
    Last edited: Sep 1, 2017

  7. Wally

    Wally Telefied Ad Free Member

    Mar 17, 2003
    Lubbock, TX
    In your situation, I would leave the amp as is and use the external EQ. At some point, I would consider getting a different speaker. Read: for me, a different speaker is mandatory. Not a Celestion, either. IF the Eminence GB Legend GB12 is available in 16 ohms,that is a good full range speaker. The Red Coat Private Jack is nothing like the Legend GB12. The Private Jack is a very 'middy' speaker....as many Celestions are, ime. A Weber Blue Dog in either ceramic or Alnico would give that amp another approach.
     

  8. maj34

    maj34 Tele-Meister

    209
    Nov 19, 2013
    Calgary
    Interesting. I still consider myself new to the amp and speaker game. But I've bought about a 6-7 amps now, and they all have Celestions. And I always find them middy. Actually own 3 tube amps now and all 3 have stock greenbacks. But the AC4HW1 is the only one with an extreme amount of mids I don't like - so I hadn't been blaming the speaker, but I suppose I could compensate for it with the speaker.
     

  9. Silverface

    Silverface Poster Extraordinaire Platinum Supporter

    Age:
    65
    Mar 2, 2003
    Lawndale CA
    That's a pretty good clue right there. Most Celestions are inherently mid-forward. Buy a speaker cabinet with the same impedance (or hopeful at least some of those amps have impedance switching) and run completely different voiced speakers as Wally recommended.

    Do you have that many amps for collecting purposes (i.e. they're vintage pieces), are they completely different (except for gigging amps and a backup) - or did you buy them "tone chasing"?

    If the latter One thing I suggest - I suggest it regardless - is to have a good tech and talk to him about voicing the amps the way you want. A good tech will 1) tell you honestly if "you can't get there from here", tweak the things that are tweakable, keep your amps current as far as service and save you money buying unnecessary equipment.

    You may already be doing this - but if not I hope it helps.
     
    Wally likes this.

  10. Wally

    Wally Telefied Ad Free Member

    Mar 17, 2003
    Lubbock, TX
    I prefer a speaker that is more or less neutral. Just my opinions..... IF the amp can create low end, the speaker should be able to show that. If the amp can create mids, the speaker should show that. IF the amp is mid-scooped, the speaker should not cover that up by yielding dominant mids and no lows. If the amp is bright, the speaker should show that. I like to fine tune the tone with the amp's pots and the guitar's controls. IF a speaker simply wants to do mids with no bottom and no high end, that is a speaker for which I personally have little use. Others/mmv.
     
    maj34 likes this.

  11. maj34

    maj34 Tele-Meister

    209
    Nov 19, 2013
    Calgary
    I should've said I've bought and *sold* about 6-7 amps - and 3 remain. I really don't need that many. I just play around the house and out in the garage.

    It's been part tone chasing, partly just enjoying the learning/listening/experimenting experience. I really consider playing guitar and playing with guitar gear to be two different hobbies and I enjoy them both. So even though a tech might do it better, studying and modding these things myself are part of the fun. I have lots of electronics experience - from designing PCBs to working in 600V cabinets so it's nice to have crossover from the dull things I do at work sometimes to having fun with the same skill set.
     
    asnarski likes this.

  12. 3-Chord-Genius

    3-Chord-Genius Friend of Leo's

    Apr 3, 2015
    Winchester, VA
    Those mids sound simply fantabulous in a live band setting, though. I discovered this myself.
     
    Bacha009 and ZackyDog like this.

  13. Teletoaster

    Teletoaster Tele-Meister

    259
    Aug 24, 2013
    Earth 01
    I think you should spend some time with the EQ and the Gain and Master as well. They are highly interactive and you can dial back the mids and get it pretty trebly sounding by turning the knobs.
     

  14. maj34

    maj34 Tele-Meister

    209
    Nov 19, 2013
    Calgary
    Yeah, I've heard a lot of people say that. But if I were designing the amp I would have voiced it more like the AC15C1 - with more bass and clarity, because the customer base for this amp is probably shifted towards the home player.

    It's possible that I can dial things in better. But I'm very familiar with top boost circuit from the AC15 and most importantly I know you can kinda do a mid-scoop by boosting the treble/bass and lowering volume a touch. But even with bass/treble on 10, my AC4HW1 has way more midrange than the AC15C1.

    AC4HW1 with Bass@10 and Treble@10 equals AC15C1 with Bass@3 and Treble@3.

    If I use a EQ pedal and take off 10-12dB from 400-1200Hz, the AC4HW1 is much closer to the AC15C1. And this is unrelated to the speakers and cabs. I used some jumper cables and fed each amp into the other's cab to prove that it's all in the amp itself.

    For this reason, I probably should either stick with the foot pedal EQ, or sell it and carry on with the AC15... probably the latter.
     

  15. Teletoaster

    Teletoaster Tele-Meister

    259
    Aug 24, 2013
    Earth 01
    You mustn't forget the Gain and Master! Both have a significant influence on the midrange in different settings...
     

  16. ZackyDog

    ZackyDog Tele-Afflicted

    Age:
    53
    Aug 24, 2014
    PNW
    My amp tech was fixing my input jacks last month. After scouring the www, he deduced that only an authorized VOX service center would have access to the schematic.

    I use a Celestion Blue alnico in mine; it's the only way I can get the true/classic/original VOX tone.

    vox.png
     

  17. 3-Chord-Genius

    3-Chord-Genius Friend of Leo's

    Apr 3, 2015
    Winchester, VA
    That's the issue I had with the AC4C1-12 and the AC4TVH - they were my only amp, so they had to perform double-duty, as stage amps and as home amps. They sounded great with a band, but in the house they sounded flat and mid-rangy. I will say that when I cranked the AC4TVH (through an Egnater 12" cab) it sounded glorious... but really too loud for the house.
     

  18. Silverface

    Silverface Poster Extraordinaire Platinum Supporter

    Age:
    65
    Mar 2, 2003
    Lawndale CA
    ...wha'? uhhh...where am I? I think I fainted! :lol:

    It's *really* refreshing to read that. SO many players are distracted and focused on gear details, tweaks, twiddly-things and it affects their playing. It takes a huge amount of effort for "gear tweakers" to push gear-related thoughts *completely* out of their minds when playing, but it makes the playing experience exponentially better in every way!
     

  19. Bacha009

    Bacha009 TDPRI Member

    37
    Jan 19, 2014
    Minneapolis
    Hey ZackyDog do you have 16ohm Blue in there? I ony have 8ohm one, I am just getting the HW1 now and excited to hear it with Blue. If it sounds much bette than greenback, I might look for a 16ohm Blue. The Stock OT does not have multiple taps?
     

  20. ZackyDog

    ZackyDog Tele-Afflicted

    Age:
    53
    Aug 24, 2014
    PNW
    Yes, I have a 15/16 ohm Celestion Blue alnico. As far as I know, the OT doesn't have multiple taps.

    It does have an output speaker jack, but that is also 15/16 ohms, and it defeats the internal speaker when you use it.
    See page 5 for details.
     

IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.