AC30 / 15 speaker swap

MtB

When Vox made the speaker swaps on these amps from vox / Celestion blues to greenbacks / GSH-1230s were there any changes made to the circuit (tone caps for example) as well?

Cirrus

What particular era are we talking here? If there are two AC15/30s of the same make and model the speaker selection will have no bearing on the circuit, but a '60s JMI could have a number of different circuit variants, likewise a '70s vox sound ltd, TB, CC, C, HW, heritage....

MtB

I'm suggesting an AC15C1 or AC30 CC2 and to swap out the standard speakers for Blues - would they then sound the same as the "x" models, that came with blues as standard.

Cirrus

Well, the c and cc series are different, and both had ac15 and ac30 models.

but yes, an ac30c2 that you subsequently put celestion blues in will sound the same as a store bought ac30c2x.

ICBM

It might not, because the Vox OEM Blues are supposedly different from the direct-from-Celestion ones. But it will sound in the same ballpark.

The odd thing about the C and CC series is that I much prefer the AC15C to the AC15CC (which I didn't like at all) but I prefer the AC30CC to the AC30C.

siraxeman

They were before the chinese started to use the correct H1777 cones. Since then (apparently...vox forum) they sound identical.

ICBM

siraxeman said:

They were before the chinese started to use the correct H1777 cones. Since then (apparently...vox forum) they sound identical.

Aha! I am out of date .

Bygone_Tones

fwiw on modern speakers Im pretty sure the H1777 stamp is there for cosmetic purposes only, basically because guitar players want to see something stamped on the cone, and it is probably not linked to any specific factory (English vs Chinese etc). I remember dr.decibel telling me this a while ago.

the H1777 on a modern celestion blue is a "vintage correct" cone stamp. A replica of the stamp found on the early 60's vox blue cones. Also the reason they are prefixed with a 53 is because there are not 53 weeks in the year. The prefix on the original vox blue cone was a variable number said to represent the week of the year the cone was made.

they do this on some of the other heritage series speakers too such as the 014 cone on the 55Hz G12H. just a replica stamp of the old 60's pulsonic cones.

In my experience people tend to think they are recones if they cant see a stamp on the cone somewhere. This might be another reason they want a stamp to be visible.

Also if you look at any celestion recone kit the real part number is on the outside edge and is not visible once installed into the speaker, it is usually a code starting with the letters 'SP'.

MtB

I've been looking at a AC15c1, but already have a celestion blue kicking around at home and I wanted to know that if I take the stock speaker out and replace it with the blue I will get the Vox AC sound. That's to say I don't then want to find out that I need to swap out a tone cap or two because that's how Vox had to modify the tone circuit to get a green to sound like a blue (so to speak).  

ICBM

No, there is no difference in the amp circuits.

If you have the Blue anyway that's exactly what to do.

MtB

Perfect. I'd guess putting a blue in there would also increase the perceived clean headroom of the amp - so to speak - with the sensitivity of the blue being 2dB higher than the green.

Cirrus

It will make clean sounds seem louder, once the amp is cranked all the way up there's not much in it because although the blue is louder, it starts compressing sooner too so above a certain point it's not going to get much louder.