Breaking in the Speaker

Vox AC15HW1I’ve often heard people talk about how their headphones or guitar speakers really “opened up” or became more “dynamic and alive” after breaking them in.  

I recently had the opportunity to borrow a virgin, unplayed Celestion G12M Greenback speaker, which is the same speaker as in my Vox AC15HW1 hand-wired

Celestion G12M GreenbackSo, I thought it would be interesting to do a swap-in comparison with my current G12M, which has probably about 100 hours of playtime on it, at both bedroom and gigging levels.

Honestly, I was not blown away.  I thought the differences would be really obvious, but they’re pretty subtle. 

Have a listen:

And here’s a little pictorial of swapping the speaker.   After removing its screws, the speaker is still stuck in there.   There’s a thin layer of cork between the speaker and the cabinet, which either has adhesive applied to it, or has just kinda bonded with the cabinet interior.   It needs a little coaxing to get out of there.  I’m using a 15" utility bar to gently pry free the speaker. 

Read the rest of this entry

What’s In The Cabinet?

What’s in an amp cabinet?   As it turns out, quite a lot.  In this video I do an experiment with the same two AC15 amps as in my last video– the AC15C1 Custom, and the AC15HW1 hand-wired.

G12M-GREENBACK-8Both amps use the same Celestion Greenback G12M speaker, and these two here have each been played about the same amount, so they should be “broken in” evenly.  Now, by disconnecting the wires from the two speakers, and routing them through an AB box to the external speaker output of one the amps, I can isolate a single amplifier circuit, and hear it through both cabinets in turn.   In this way, we can first listen to the AC15C1 amp circuit through its own cabinet, and then listen to that same AC15C1 amp circuit through the AC15HW1 cabinet.   Switching back and forth really highlights the different sound character provided by the two cabinets.

2011-02-08-VOX-AC15-high-frequency-diffuser-004Why so different?  The AC15HW1 cabinet is obviously larger, which provides a bigger resonant cavity.  It’s also built with birch plywood which is lighter weight and perhaps more resonant than the denser MDF used in the Custom.   Another important difference is the high frequency diffuser used in the AC15HW1 which really softens the high-end.  In the video, I also experiment taping a makeshift little diffuser over the AC15C1 cabinet to see what happens.

Vox AC15 Comparison

In this video, I review and compare these two excellent Vox AC15 amps, the AC15C1 Custom, and the AC15HW1 hand-wired.

These amps are similar in many respects:

Celestion Greenback G12MVox AC15HW1 Tubes

  • same Celestion Greenback G12M speaker
  • same preamp and power amp tube complement (3 12AX7’s and 2 EL84’s)
  • same two channels: Normal and Top Boost.
  • same tone cut and interactive EQ controls
  • same weight – 48 pounds. Handwired is larger but birch plywood is lighter than MDF
  • same AC15 legacy and tradition
  • However, there are some obvious differences:

    Read the rest of this entry

    Oh, For the Love of an AC15

    Vox AC15C1 Wow.  Yesterday, I had a chance to play a session through a new Vox AC15C1.  Really dynamic and responsive to play.  Great character and presence, and a really nice break up when you dig in.

    My usual session amp, a late-eighties solid-state Fender Stage 185, is increasingly unsatisfying to play- seems I can never find the right level of brightness in a band setting.  Cranking up the presence, or tweaking the treble tends to make it harsh before it becomes pleasant.  The clean channel is pretty nice, but the drive/boost channel tends to feel a bit fizzy.  

    Vox AC15HW1 Vox has just released a new hand-wired series, including the AC15HW1, pictured left.  After my experience with the AC15C1, I’m anxious to hear whether the use of top-shelf components, hand wiring, tube rectifier, birch cabinet, ruby tubes, can make the already great sounding AC15 even better.

    I also really like the ability to kick in extra gain with the new hot/cool foot switch, and the the OP mode switch to drop to 7.5W for nighttime playing.

    The only things missing from the hand-wired series are the tremolo and reverb.  One tune in yesterday’s session, Glen Phillips’ excellent laid back version of I Want A New Drug, calls for a bit of tremolo- but every time I tried kicking in the AC15C1’s trem, I just found it distracting and reached back to flick down the knob- perhaps I was just overdoing it, but I think I can probably live without it :)   And while the AC15C1’s reverb is very warm, smooth and pleasant- I rarely use reverb.  And I must say, if you turn the verb knob up over about 10%, it just sounds huuuuge, like you’re playing inside a water tower.

    Warning- explicit photos follow:

    Vox AC15HW1 Turret Board Wiring Vox AC15HW1 Ruby Tubes

    Full disclosure- I work for Korg R&D, which owns Vox.  So perhaps I’m a little biased towards Vox, over other alternatives (employee discount, woo-hoo!)

    UPDATE 3/22/2011: I did eventually buy that AC15HW1, and it is a thing of beauty.  I borrowed Chuck’s AC15C1 again and made a video comparing the two.