BIG sounding 18 watt

[hebaton]

I've been wanting a Marshall type sound at manageable levels ( who hasn't )
I did have an 18 watt some time back but always felt it didn't sound "big" enough or, didn'T feel like enough "weight" behind the note if that makes any sense..
Would there be a way to make it sound "heayvier" not in the sense of more gain but in term of perceived wieight ?
Would a bigger OT acieve that ?

THanks !

[LOUDthud]

What did you use for speakers ? I bought a Marshall 4x12 cabinet that had these speakers with small magnets. They had a tone similar to what I'm used to, but efficiency was low and they didn't have what I call low frequency Slam on power chords.

[Phil_S]

Build the 36-watt. 4 power tubes instead of 2. I think, if I was considering the 36-watt, I'd build a JTM 45 circuit instead with a pair of EL34's. I really don't think either will address your wants here. I think the speaker change is a better idea.

[Stevem]

You’re talking about an amp having punch or not.

To have punch you need to move air and a good amount of it.

To move air the best way to do that is with multiple speakers.

In terms of the way the Human ear work in regards to SPL here’s the way it works .

In general playing thru 2 speakers instead of one will double the SPL level your ear gets hit with.

If you wanted to get that same doubling of SPL by way of your amps wattage you would have to make your 18 watt amp into a 180 watt amp which would be quite expensive!

[sluckey]

I put an Eminence BIG BEN 15" in my 18W amp mainly because the old Ampeg cab I'm using came loaded with a 15" CTS. No regrets. It has the big sound you may be looking for. Ain't gonna be any speaker breakup with an 18W amp though.

https://sluckeyamps.com/18w/18w.htm

[Littlewyan]

If you just want to save volume I would really consider whether it's worth building an 18W. You'll only save roughly 3/4db and you're right, they just don't sound as big. I have a JTM50 with EL34s and a 50W Lead with 6V6s. The lead sounds good but the breakup is a bit different and I still have to use an attenuator with it. So maybe invest in a good attenuator, there's a good design on the Marshall forum for one.

[LOUDthud]

So maybe invest in a good attenuator, there's a good design on the Marshall forum for one.

Can you provide a link or some suggestion of the thread title ?

[Helmholtz]

If you wanted to get that same doubling of SPL by way of your amps wattage you would have to make your 18 watt amp into a 180 watt amp which would be quite expensive!

Sorry, no.
It only takes doubling the power (+3dB) to double SPL.

[jabguit]

A change of 10 dB is accepted as the difference in level that is perceived by most listeners as “twice as loud” or “half as loud”. To produce an increase of +10 dB you need to increase power (watts) by a factor of 10.

[Helmholtz]

A change of 10 dB is accepted as the difference in level that is perceived by most listeners as “twice as loud” or “half as loud”. To produce an increase of +10 dB you need to increase power (watts) by a factor of 10.

Correct.
Doubling SPL (+3dB) does not double loudness.
It takes 10 times (or +10dB) SPL to double loudness.
Reason is the logarithmic sensitivity of the human ear.

[cdemike]

So maybe invest in a good attenuator, there's a good design on the Marshall forum for one.

Can you provide a link or some suggestion of the thread title ?

I think the attenuator in question is the JohnH attenuator; the associated thread is here: https://www.marshallforum.com/threads/s ... ing.98285/

Agree with the speakers mentioned before. If you can afford some 55hz-type Greenback speakers , I think that'd be a quick way to add some meat to the sound. Heavy magnet will be tighter, but IMO the medium magnet will likely sound thicker at the expense of low end "thump." I prefer heavy magnet speakers, but I also regard medium magnet speakers' high end as fizzy.

Beyond the speakers question, I don't think there's anything intrinsic to the 18W design that would necessarily prevent it from sounding bigger, and I especially don't think EL84s lock you into a smaller sound (no one ever said Brian May has a small sound). That said, if you prefer your sound to emphasize preamp overdrive over power amp overdrive (i.e., to keep the power section from compressing), you could add post-phase inverter master volume. If that moves you in the right direction but you want more, my suggestion would be to first switch to solid state rectification. Past then, you could increase your reservoir and screens filtering. A more radical solution would be switching to 6V6's given how sensitive EL84s are. However, I would likely move in that order ahead of bigger changes to isolate which variable requires modification.

[nuke]

I've been wanting a Marshall type sound at manageable levels ( who hasn't )
I did have an 18 watt some time back but always felt it didn't sound "big" enough or, didn'T feel like enough "weight" behind the note if that makes any sense..
Would there be a way to make it sound "heayvier" not in the sense of more gain but in term of perceived wieight ?
Would a bigger OT acieve that ?

THanks !

Which 18-watt amp did you have (or build)?

18 watts can sound crazy "big", depending of course, what you mean by "big" or weighty.

What are you playing, and what amp and speaker does that sound the way you want?

[Phil_S]

Been thinking about this. I recall someone on another forum many, many years ago built a 1W marshall style amp using a dual triode for the power tube. As I recall, he ran it through his 4x12 cab repoeting very good results in getting that "big" amp sound. He claimed it was enough oomph to work with a bass player and a drummer. I'm sure it was not 50W or 100W output, but he said it moved enough air. See what SteveM said. Skip the technical stuff. His main point is very much on target. You need to move more air. More speakers and large diameter speakers will go a long way.

Style of cab may also make a difference. Any takers on a Theile-Small style cab?

I wonder, though, is the 18W a square peg in a round hole? Sometimes what you have just isn't what you really want and it makes sense to get something else, or in addition to what you already have.

[Matthews Guitars]

I have a 20 watt Marshall Lead & Bass 20, model 2061, made in 1973. I've also had the reissue of the same amp, the 2061X.

Both feel and sound AS BIG as my real 100W 1969 Plexi. Just a little less brutally loud but every big as big and fat in tone as the 100 watter.

The 2061 is a simpler amp but it's a plexi thru and thru, if you ask me.

The 2061 has become hands down my favorite amp. It gets the lion's share of my play time.

[Bergheim]

IIRC, the 18 watt is cathode biased? I recently built a low power cathode biased amp with 6L6GC's (250V B+ and 8k OT, for about 10-12 watts output) and no matter how I tweaked it, it sounded fizzy and flat. Even did the zener mod on the power tube grids to eliminate bias shift during overdrive and it took away some of the fizzy swirl, but still way too fizzy for my taste.
Running out of ideas, I converted to fixed bias, and the overdrive character became much bigger and powerful, almost like a cleaner, more organic overdrive. Before the conversion, it felt like the guitar signal was entirely masked by the overdrive, while with fixed bias I can hear the guitar attack and dynamics, even far into power tube distortion.