JTM45 clone or 1987x for bass (and occasionally guitar)

pintspiller

I use a Sound City 50+ as my gigging amp with the cover band I am in. It does the job really well. I had thought of going down the DI route so i wouldn't have to carry my head and 4x10, but having to carry a couple of subs instead didn't seem like I was saving much of a trade-off!

Anyway, I got a 2203 a few years ago for a band that didn't get beyond a couple of rehearsals that is too heavy to carry to be honest and isn't as loud or suitable for bass as the Sound City.

A Carlsbro 40CT (modified to JTM45-style preamp) has come up locally, as has a 1987x (PPIMV mod). I have been considering both and am looking for opinions on use as primarily as a bass amp.

I have the opinion that the Carlsbro may be more suitable, but will have to be bought for cash. I may be able to trade my 2203 for the 1987x, which will mean I will still have a Marshall.

ICBM

The 1987x will be much better for bass than a JTM45 in my opinion. More power, headroom and punch, and less sag.

If you want to really make it good, convert it to 1986 spec - those still sound great for guitar too, in fact better than the 1987 in my opinion. (And Paul Kossoff's.)

pintspiller

@ICBM thanks for your feedback. The Marshall is the one I would prefer to go for. I like to own at least one Marshall as it makes me feel more like a rock star. Lol. I assume using the low input and considering alterations to the negative feedback circuit may make it more suitable for bass?

Is there any advantage to removing the master volume mod?

The owner of the Carlsbro doesn't know much of how the amp was modified for JTM45. I assume it still has the SS recto and lowerpowered transformer (you said in a previous discussion of mine that the difference was choice of iron between the 40s and 60s in the Carlsbros).

I hope the guy will take the Super lead and give a good allowance towards the Plexi.

ICBM

pintspiller said:

@ICBM thanks for your feedback. The Marshall is the one I would prefer to go for. I like to own at least one Marshall as it makes me feel more like a rock star. Lol. I assume using the low input and considering alterations to the negative feedback circuit may make it more suitable for bass?

Just use the second channel. All the differences in the circuits of the 1986 and 1987 are on Channel 1, in the tone stack, and the coupling caps between the PI and the power section - the NFB is the same on both models.

pintspiller said:

Is there any advantage to removing the master volume mod?

No, just turn it up full for bass.

pintspiller

It's sold. They hadn't updated it on Facebook. Grrr!

pintspiller

I bought the Carlsbro. Nice wee amp. Reasonably clean sounding, breaks up earlier than my Sound City 50+. Should do the trick.