5150 I, II, and III - Tightness Question

[TheGreatGreen]

So it's pretty common knowledge that when the 5150's design was updated to the 5150 II, the lead channel was "tightened" which has been a bit of a controversial thing over the years. Some people note that the sound became more articulate and manageable, but some people think this update caused the II to sound a bit "choked" compared to the original, describing the newer circuit as having a "half-cocked wah" kind of sound going on.

From James Brown himself on reverting the 5150 II's lead channel back to 5150 lead channel specs:
"you can take your amp to a qualified service center, and they can remove C17(470pF) and replace it with a 470K and 0.0022uF capacitor in parallel (or they can just tie a 470K and an additional 0.0015 uF cap across C17, without removing C17). Then they would change C2 from a 0.001uF capacitor to a 0.022uF capacitor. The result is that the attack is a bit floppier and thicker sounding, and the gain is much heavier sounding and not as tight/chunky."

What I'm wondering is where the 5150 III falls in regards to this. Does the 5150 III have the same low end tightening components as the 5150 II? Less? More? What about the Stealth 6L6 and EL34 versions?

 

[the4thlast1]

The 5153s are more similar to the 5152 than the original 5150. Tightness is very close although the newer stealth versions have a depth control so you might get a bit more low-end with those. Ive had them all accept for the EL34 5153.

 

[WarHed]

5153s are quite different from a circuit perspective. Tighter than the II - higher corner the frequency at the start of the preamp, and higher gain from biasing the cold stage a bit warmer. The tightness setting is also gain dependent, in the 5150 and 5152 the tightness decreases with increasing gain, and increases in the 5153. There's probably a point in the gain setting where they match, but the adjustment is slightly dynamic which changes gain control response things a little between the I and II vs the III.

Another big difference James Brown doesnt mention is the 50k mid pot in the 5150 and 25k in the 5152. Changes the mids texture quite a bit, but doesnt affect the tightness

 

[fek]

I have had the 5150, 5152, 5153 EL34 50W, and now the Stealth 50W. I like less low end and dial in for a mix so I keep the bass control lower when I dial in an amp. The 5152 is no longer here (wish it was) but that one is probably my favorite out of the ones I have owned. I found the OG to be too boomy for me but others love that about it.

The 50W Stealth is still growing on me so it could overtake the top spot. On the Stealth I keep the bass under 11:00 and the Resonance on the back at about the same. I boost the blue channel with a TS9 to smooth it out a little bit.

 

[TheGreatGreen]

5153s are quite different from a circuit perspective. Tighter than the II - higher corner the frequency at the start of the preamp, and higher gain from biasing the cold stage a bit warmer. The tightness setting is also gain dependent, in the 5150 and 5152 the tightness decreases with increasing gain, and increases in the 5153. There's probably a point in the gain setting where they match, but the adjustment is slightly dynamic which changes gain control response things a little between the I and II vs the III.

Another big difference James Brown doesnt mention is the 50k mid pot in the 5150 and 25k in the 5152. Changes the mids texture quite a bit, but doesnt affect the tightness

That's really interesting. So with the 5150 III, at minimum gain knob settings, you actually let more low frequencies from the guitar into the mix, and they get tapered off as the gain gets turned up? Neat.

Have you found the 5150 III to have the same kind of "half cocked wah" sound at certain settings as some people describe the 5150 II as having?