#1
So I have a stock AC15C1. Had it for 2 weeks now. I love the clean tone from it, or at least, the valve sound. That's what bugged me about my Marshall MG15DFX. It had an awesome rock bite to it, but it was so muddy and undefined. Just noise, really. But the tone was there and it played well with my SG. I couldn't actually find any other cheaper amp that sounded anything like it. Not a Line 6 or an Orange 15W or a Fender.


Fast forward... 6 years.. and I get a beautiful example of a Vox AC15C1. Mainly purchased because the AC30 was a staple amp of the Foo Fighters. Foo's got me into guitar and turning that into a serious hobby. I was also told that AC15's and Proco RAT's are a match made in heaven.

So I buy the amp, pair it with my RAT and it does sound nice. It really does. But there's a problem, that no matter what settings I dial in, no matter what I try, it just sounds muted. Defined, but muted. It lacks that kind of hard-rock gain. Things like slides, octaves, harmonics don't ring and crash and buzz like they used to. I figured I needed a Distortion pedal and spent the best part of today checking stuff out. I went to all the guitar shops in town and tried their stuff out on Tube amps. The Boss OS-2, Blackstar LT Distortion, Hardwire SC2 Valve Distortion and a Marshall BluesBreaker.


It was the Marshall BB that sold me. Ran that through a Fender Valve amp on full clean tone and played a Gibson SG Melody Maker - the closest match to my Epiphone SG which I play mainly on Bridge Pickup. It sounded EXACTLY what I wanted. That awesome gain, but not metal sounding, hard, hit you in the face Rock Power chords coming thick and fast CRUNCH. I could dial it back and hit treble and get Led Zeppelin, or whack some bass on for a bit of QOTSA / TCV.

I took it home and eagerly plugged in. Neighbours were away. But to my dismay it's got the SAME problem as the ProCo RAT. Too muddy, too bassy. But if I roll off the tone cut it sounds too thin. Still no gain either way. Slides are no longer a flick of the wrist but a laborious effort. Octaves sound flat. Harmonics dink instead of ring.


Tomorrow, I'll upload a video that should try and explain what I mean by this. All I wanted was a Valve amp that would give greater clarity to the Marshall Rock tone. I guess I should have tried the JCM 2000 DSL401, I tried the 60W JCM 2000 in the shop and loved it. Whoops.

But I want to stick with the Vox. I do like the sounds I can get from it. I love the way it looks. I just want it to play nice with a OD pedal.

Is the Bright Cap Mod going to be my saviour? I feel like the lower-end volume is just too muffled and muted. But living in a block of flats, cranking this amp isn't going to work out for me either.


Thanks.
#2
have a look at this thread for some ideas:
https://www.ultimate-guitar.com/forum/showthread.php?t=1674484

I've got an AC30 and my favorite OD (out of the ones I own) is the Fulltone Fulldrive 2 MOSFET.
I also have 2 tubescreamers, but the FD2 is my favorite.
The tubescreamers are brighter than the FD2, perhaps that may help you?

A big part of the classic Vox sound is the Alnico Blue speaker.
But those cost around $300, but IMO, it makes a big difference.

I run an Alnico Gold (50 watt version of the Alnico Blue) and a G12K-85 in a 2x12 cabinet.
Stock tubes were ok but not that great.
Upgraded to JJ tubes all around.
Another big improvement IMO.

Theres a video here that may give you some ideas for settings.
The AC15 part starts at around 2:20
www.musiciansfriend.com/amplifiers-effects/vox-custom-ac15c1-15w-1x12-tube-guitar-combo-amp/423619#productDetail

I can't speak for the Bright Cap Mod as I haven't done it myself, but its easy to do and easy to reverse it if you can solder.
Just remove it instead of cutting it out.

Edit:
You may also want to consider building an isolation cabinet.
With that you can crank your amp without annoying your neighbors.
Isolation Cabinet Building - Google Search
Last edited by CodeMonk at Apr 9, 2015,
#3
My understanding is that AC's should never sound muffled. 15's should be quite mid-heavy and bright, and break-up should be easy to onset. On top of that, the RAT (or at least my box) takes out some low-end.

Are you setting the AC to be boosted by the dirt box? The AC should be right before the onset of break up, then engage the pedal. Have the pedal volume at unity and the dirt level at the saturation you desire.
Last edited by Will Lane at Apr 9, 2015,
#5
Are you sure its not your SG thats causing the problems? Epiphone pickups are notoriously muddy and muffled.

I'd recommend to bring your sg to the shop and trying it out with the Fender + BB combo you liked. that should let you know if that the issue.

Also, Are you sure you don't have the tone cut rolled in? That can really change the overall sound.
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#6
Quote by boblittle
Are you sure its not your SG thats causing the problems? Epiphone pickups are notoriously muddy and muffled.

I'd recommend to bring your sg to the shop and trying it out with the Fender + BB combo you liked. that should let you know if that the issue.

Also, Are you sure you don't have the tone cut rolled in? That can really change the overall sound.



When I was at Music 47 I played an Epiphone Les Paul then a different vender Gibson 335 Copy both through a Boss OS-2 into a Vox AC15C1. They sounded great.

When I was at Music City I played an SG Classic (knock-off) into a Peavy Tube Amp through Blackstar LT Disto and Hardwire SC2 Disto. They sounded good.

Then at Guitar Centre I played a Gibson SG style Melody Maker through a BluesBreaker pedal into a Fender tube which sounded FANTASTIC.


I've done some side by side tests. Things like rubbing my palm across the strings over the pickups to give a scratchy noise just aren't there at all on the Vox. Not even on the Top Boost channel. But on my Marshall MG15 I can get those scratchy sounds easily. Like I said, harmonics ring out and scrapes, scratches, palm-muting, and in general notes just ring out louder and with more impact.

I'm ringing an amp repair shop on Monday to see if he recommends sorting the tubes out or what he recommends.

Cheers, keep the suggestions coming
#7
Quote by Chaoslava
I've done some side by side tests. Things like rubbing my palm across the strings over the pickups to give a scratchy noise just aren't there at all on the Vox. Not even on the Top Boost channel. But on my Marshall MG15 I can get those scratchy sounds easily. Like I said, harmonics ring out and scrapes, scratches, palm-muting, and in general notes just ring out louder and with more impact.
Something surely sounds wrong. Might be more than the tubes. Did you buy it used or new?
#8
Quote by 311ZOSOVHJH
When I read your story I kept thinking maybe you need to do some tube swapping

It definitely should not have a muffled tone.

Yeah, this sounds a lot like a crappy preamp tube to me.
#9
Quote by Will Lane
Something surely sounds wrong. Might be more than the tubes. Did you buy it used or new?



I did buy it used. A nice chap brought it round, this isn't the kind of thing I can pick up as being wrong from a first impression. It's taken nearly two weeks of figuring out why it doesn't sound quite right.

If it's a broken pre-amp... is there any recourse? Can I get it repaired or replaced? I've been speaking to a different chap and he says it may be the pre-amp...
#10
Just replace the tubes yourself.
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#11
i would get some new tubes in.

its funny, because i haven't ever heard anything bad on a recent vox tube amp (AC15/30 and variations). they are pretty solid and you know what you are getting.
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#12
This might be a silly comment but it's related to a problem I had for a few weeks when I got my ac30c2.

The tone cut on your amp works a bit like the tone knob on your guitar. It doesn't add anything, it simply removes highs as you turn it.

Therefore, if you find your sound too muted, you'll want to make sure that the tone cut knob is at 0 (all the way to the left). I thought that it worked like a "one knob EQ" where left was bassy and right was trebly but it's sortof the opposite.

Also another silly question but how do you use the tone knob on your guitar?


I love my AC30C2. But if I had to make one criticism is that it can get a bit too bright and piercing if not tamed correctly. It's only a problem at gigs when the amp is at ear level and even then it's manageable
#13
Quote by flexiblemile
This might be a silly comment but it's related to a problem I had for a few weeks when I got my ac30c2.

The tone cut on your amp works a bit like the tone knob on your guitar. It doesn't add anything, it simply removes highs as you turn it.

Therefore, if you find your sound too muted, you'll want to make sure that the tone cut knob is at 0 (all the way to the left). I thought that it worked like a "one knob EQ" where left was bassy and right was trebly but it's sortof the opposite.

Also another silly question but how do you use the tone knob on your guitar?


I love my AC30C2. But if I had to make one criticism is that it can get a bit too bright and piercing if not tamed correctly. It's only a problem at gigs when the amp is at ear level and even then it's manageable



Had the tone cut at 0 and it still sounds crap. It must be the tubes... Got this message from the seller:


"Hi mate sorry to hear you re having problems. I never had any issues but I did play it at lower volumes so maybe i didn t notice. You have to change the tubes in valve amps quite frequently and I never have so that s probably the problem."

"Hi mate had it for about 3 years and I never changed the tubes. I d say it was due a change of tubes because depending on how you use them they need changing annually."


So... yeah.. probably needs new tubes. Annoying coz I just spent £58 on Distortion pedals now I need another.. how much? For Tubes? Haha.. Christ.
#14
3 12AX7's. Not too expensive. You might could isolate which tube is causing the issue if it's just one, but having spare tubes is always nice (that goes for power tubes as well).
Last edited by Will Lane at Apr 11, 2015,
#17
my general experience is that it could be the room you are playing in, the volume, and as a whole, keeping the master down too far on a tube amp generally can make it sound more muffled.

i feel like this is more true with lower gain smaller wattage tube amps than high wattage amps with channels and masters (such as a DSL you mentioned).

i think most with an AC series will tell you, if you crank it, it sounds way more awesome. i mean thats true with a lot of things, but particulary something like a voc AC. not saying they dont sound good at lower volumes.

i have commonly found that i over compensate in low volume bedroom environments to "brighten" it up and then at a band practice my amp is SUPER ICE PIKCLY trebly gross thin, tinny mess. totally change the EQ and gain.

back to bedroom - MUDDDDD.
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Last edited by ikey_ at Apr 14, 2015,
#18
Quote by ikey_
my general experience is that it could be the room you are playing in, the volume, and as a whole, keeping the master down too far on a tube amp generally can make it sound more muffled.

i feel like this is more true with lower gain smaller wattage tube amps than high wattage amps with channels and masters (such as a DSL you mentioned).

i think most with an AC series will tell you, if you crank it, it sounds way more awesome. i mean thats true with a lot of things, but particulary something like a voc AC. not saying they dont sound good at lower volumes.

i have commonly found that i over compensate in low volume bedroom environments to "brighten" it up and then at a band practice my amp is SUPER ICE PIKCLY trebly gross thin, tinny mess. totally change the EQ and gain.

back to bedroom - MUDDDDD.


I'll agree with this, with one exception.
The best sound I ever got out of my AC30 was in a friends basement, which also at that time, doubled as my bedroom.
The walls were all cemented in rock.
Looked EXACTLY like this:


Best sound I EVER got out of my amp, even to this date.
I probably had the master at around 5 - 7 and the channel volumes around 2 - 3
My version allows you to blend the channels and I usually run the normal channel at around 2.5 and the Top Boost channel at around 3 - 3.5
Depends on the room though.


Quote by Chaoslava
Gone and bought 2 JJ EL84's and 3 EH 12AX7's Can't wait!
I think my amp had EH tubes stock, I went with JJ's all around.
Was a change that worked very well for me.
Last edited by CodeMonk at Apr 14, 2015,
#20
Quote by 311ZOSOVHJH
Probably because the walls were not flat

Less reverb. Sound waves were not bouncing all over the place.

Good idea actually.

Could be I guess.
I just remember it sounding awesome in that room.