I can say this now: The Vox AC4C1-12 is a terrible amp.

TheCheapGuitarist

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For several months I refused to say it, because I spent my hard-earned $$ on one (beige). It look great. Sounded terrible. And the ironic thing was that I thought I was moving up from my AC4TVH, but that amp actually sounded better. So for the longest time I forced myself to embrace the trebly tone with absolutely no bottom end, and (probably) decent mids that were simply stomped all over by the treble.

The problem: not the 12" speaker, swapping other speakers into it did not help matters. It's the shallow cabinet design. You simply cannot make an a cab that size produce good bass response. Tubes? Nope, swapped those out at as well, only resulting in differing amounts of preamp gain.

So now that I no longer have this amp, and have no need to lie to myself about how "good" it was, I can now say that it's a terrible amp. Second place: The Vox Night Train NT-15. I tried to love that amp also. Sounded terrible.
 

VintageSG

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The AC4C1-12 isn't brilliant, but it isn't terrible either. It is severely cab limited. You're right. It's the shallow cab design, plus the fact it isn't 1/3rd open back.
A new back, cut from 9mm ply with room for the driver to breathe really helps. Why Vox decided to make it a closed back is probably an ecumenical matter.
A little late now, but should you ever chance upon one for chump change, try it with the back off.

My AC4, with the back modified, now lives happily with my son.
 

MuddyWolf

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Do you mean ac15? I know of no ac12.
I played one in a music store in the 90s with an alinco blue speaker and it sounded awesome. But I think you need a gibson or an all mahogany guitar to have it sound right. I didn't get because it was heavy for 15w and for similar money at the time the Marshall 4010 ate the vox's lunch.
 

RetiredUnit1

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Do you mean ac15? I know of no ac12.
I played one in a music store in the 90s with an alinco blue speaker and it sounded awesome. But I think you need a gibson or an all mahogany guitar to have it sound right. I didn't get because it was heavy for 15w and for similar money at the time the Marshall 4010 ate the vox's lunch.
I think he means this one
 

MuddyWolf

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Yeah, chopping the top boost circuit out of another amp is bound to be bad. No wonder it's too bright. Plus the 7080 speaker is bright and harsh until you hit it hard for at least a couple hours with a good 30 watts. 4 watts is never gonna get it there. Sounds like an avoid to me.
 

TheCheapGuitarist

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(I edited the title of this thread with the correct name of the amplifier.)

The amp looked and sounded like a small suitcase. Also, I love the top boost circuit in Vox amps. I had the AC10C1 and the AC15C1, both of which I loved. But in those cases, the high-end was counterbalanced by good solid low end. Not the case with the AC4C1-12.
 

arlum

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Why would they build a Vox AC that's always in "Top Boost"? My understanding is that Vox developed the "Top Boost" for those take the lead moments when you really needed to cut through the mix. I can't think of any situation where a guitarist would want that in play at all times. Even if a player did, for whatever reason, they'd still need the dampening effect of the original Alnico Blue speaker to control the high end. The circuit needs all the other parts to sound like the circuit was designed to sound like.
 

Dismalhead

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Why would they build a Vox AC that's always in "Top Boost"? My understanding is that Vox developed the "Top Boost" for those take the lead moments when you really needed to cut through the mix. I can't think of any situation where a guitarist would want that in play at all times. Even if a player did, for whatever reason, they'd still need the dampening effect of the original Alnico Blue speaker to control the high end. The circuit needs all the other parts to sound like the circuit was designed to sound like.
I don't ever use the top boost on my AC15C1 because I like those Vox sparkly cleans, but from what I understand it's more popular than the regular input. I think the AC10 is top boost only.
 

gusfinley

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What was you master volume normally set to on the AC4C1-12?

The main weakness of the AC4C1 series is the incorporation of a treble bypass cap on the master volume. When I first got mine (AC4C1-BL w/ 10" speaker) I immediately found it sounded "not quite right" and found a schematic with the bypass cap on the master volume. I literally tore the cap out with some pliers and it immediately sounded better.

I have also messaged a few people who have been selling these on local ads and mentioned the bright cap mod. The few who have removed the bypass cap from the master volume have removed the amp from sale and decided to keep it.
 

Mike_LA

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It's the shallow cabinet design. You simply cannot make an a cab that size produce good bass response.

You have hit the nail on the head AND also explained the wonder of the pathfinder 15r. I have both and it's the speaker and cab size of the pathfinder that sound sooooo good and so much better than the AC1.
BTW I have an AC4C1 for sale .......
 

TheCheapGuitarist

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yep, needed a decent sized 12" external cab and you'd have been set.
play music!
It did sound a little better through an Egnater 1X12 cab (they make great cabs at great prices, by the way), but that negated the whole point of owning a combo amp.
 

TheCheapGuitarist

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What was you master volume normally set to on the AC4C1-12?

The main weakness of the AC4C1 series is the incorporation of a treble bypass cap on the master volume. When I first got mine (AC4C1-BL w/ 10" speaker) I immediately found it sounded "not quite right" and found a schematic with the bypass cap on the master volume. I literally tore the cap out with some pliers and it immediately sounded better.

I have also messaged a few people who have been selling these on local ads and mentioned the bright cap mod. The few who have removed the bypass cap from the master volume have removed the amp from sale and decided to keep it.
I didn't do any mods to the A4C1-12, but I did to the AC4-TVH that I had previously, and it improved the tone greatly. The mod kit came with a different preamp tube, a capacitor, and something else (can't remember what). I wish I'd kept the AC4TV but I thought going to the C1-12 would be an improvement...
 

TheCheapGuitarist

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Do you mean ac15? I know of no ac12.
I played one in a music store in the 90s with an alinco blue speaker and it sounded awesome. But I think you need a gibson or an all mahogany guitar to have it sound right. I didn't get because it was heavy for 15w and for similar money at the time the Marshall 4010 ate the vox's lunch.
Yeah, I goofed on the thread title. AC4C1-12. This one. It's an amazing LOOKING amp.

1662483076433.png
 

gusfinley

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I have been tempted to buy an AC4C1-12 on the used market, but have been very happy with my AC4C1-BL since removing the bright cap on the master volume (and then converting it to a handwired circuit). I also have an JMI-style AC15 which is only about 4 inches larger in the "frontal" dimensions than the AC4C1-12 and another AC4 "heritage" that I built into a Pathfinder 15 cabinet - I certainly don't need another AC4 (but I do have an AC4 "parts bin" build as one of my immediate projects). I think I have a problem.
 




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