The Scumback J75 Speaker Upgrade


Lately I’ve been trying to get my Avatar 45 to sound much better than what it has been. Don’t get me wrong, it’s a great amp for sure, but there has just been something that irks me about the tone I have been getting with it. I thought that getting some different speakers for the 2 X 12 Avatar Cabinet could be the solution.

I have been using two Celestion speakers in the 2 X 12 Avatar cabinet. A G12H 30 and a G12M 25 Greenback. Now these speakers are supposed to be great, but I just don’t really like them for what I am looking for. To me, the mids have a cardboard sound to them when cranked, and the top end is slightly harsh to my ears.

The Solution

Lately I’ve been reading about the Scumback speakers and have really wanted to try them out. I decided to order a Scumback J75 which is a combination of an H and G type Celestion speaker. Kinda the best of both worlds from what I have read.

The Scumback J75 I purchased is a 65 watt speaker, and I decided to put just one of them in the 2 X 12 cabinet to see how that sounded.

The amp is an Avatar JTM 45 watt, but I think the actual wattage is similar to a Marshall JTM 45 which is rated around 35 watts I believe. My point being is that one 65 watt speaker will be enough power running it by itself.

Avatar also wired the cabinet for various different combinations which was also great. The Avatar 45 also lets you select between 4, 8, and 16 ohm settings.

Putting just one Scumback 65 watt speaker in the cabinet has really opened up this amp and I am much happier with it. The only drawback to using one speaker I have found is that there is not as much headroom. I could always put another J75 or maybe M75 in the cabinet if I wanted to achieve more headroom.

I have to say though that I really like the sound of this one speaker, and of course putting 2 speakers in there would change the tone to some degree.


To me the Scumback is tighter sounding with much nicer highs. The harshness is gone and the mids are very nice and do not have that cardboard quality that the Celestions to seem to have. It seems to sound the best when the amp is turned all the way up. The Avatar also has a built in Attenuator which actually works really well. Any attenuation will suck some tone, but I often find that with minimal attenuation a very nice tone can be achieved.

Watch the Video


Amp Settings



So that’s my take on this Speaker change. I am completely happy with it and Jim at Scumback Speakers is very easy to deal with and has great customer service. If you’re interested in his speakers, you can check them out here.

For the Avatar 45 check here.

11 thoughts on “The Scumback J75 Speaker Upgrade”

  1. John … if you’ve left the other speaker in the cab, but unconnected, try removing it.

    This will give your Avatar cab a detuned port, and with closed back cabs like the Avatars, it can sound really great.

    Kevin O’Connor is a real advocate of this, and goes into quite a bit of detail about it in his speaker cab book (

    • Hi Richard, I actually did remove the other speaker after reading about this and I think it sounds really good. That’s what you’re hearing in this video. Thanks!

  2. Hello John,
    I like the sound you have managed to get. I’m not a big fan of the Celestion’s midrange boxiness either.
    If you have the chance, try an Eminence Swamp Thang in the other port. They tend to sound like an older Electro Voice EVM12. Bill M. uses them for bench testing his Fender Blues Jr. mods. I put one in a Randall 50 watt tube combo and absolutely love it. Fantastic speaker for slide work! John

  3. Not to bad John, I dig what your saying about the celestions, ever try some vintage greenies ? Pulsonic cone era? Night and day from new issue , check out Micky moody of. Juicy Lucy fame , he’s got some sick tone in this vid , got your vids and there great learning tools man, use em all the time , keep up the good work .

  4. Hi John….just wondering why your moved away from the terrific sounds you achieved with the vibrolux blackface you were using. Is it because you’ve changed guitars to the Les Paul Standard? I’m thinking that the vibrolux was really complementing you playing the best. This one sounds good too though…….

    • Hi Tim, I have not moved away from the Vibrolux. I still love it but I like to keep looking for new tones. I have multiple guitars and both amps do something completely different. Still learning it. Not having reverb is different as well and the Avatar has a lot of different settings to choose from. The Vibrolux has one. Staying still in my comfort zone results in never moving forward to me. Thanks!

  5. Hi John,

    I’m looking into purchasing the Avatar 45 amp. I’ve listed to your videos and like the tone you’re getting. My question is, can you get nice saturated overdrive at lower volumes with this amp, like at bedroom levels? I’m just wondering how much volume plays a part in the tone. I know the louder the better, but I’m hoping it won’t sound lifeless at lower volumes.

    Jim K.

    • Hi Jim,

      This is not a bedroom amp. It’s similar to a JTM 45 and the louder the better with the sound. You can turn it down with the attenuator but most all amps sound lifeless at low volumes.

Comments are closed.