69 Super Lead mod suggestions

michaiel · Post by **michaiel** » Fri Mar 18, 2005 3:24 pm

I want to get more gain out of my 69 super lead p2p kit. i dont want to add another tube and i dont want EVH brought into this....
thanks

Flames1950 · Post by **Flames1950** » Fri Mar 18, 2005 3:30 pm

One thing you could try is changing the 100K plate resistors on the first preamp stage to a larger value (220K is as high as I've seen.) I had never tried this due to other people describing the overdrive as "buzzy" but I recently modded a silverface Bassman to McIntyre Bluesmaker spec, which uses the 220K's on the plates, and it sounds pretty good, lots of hot overdrive. You can try any value in between too, you're not limited to 100K or 220K only.
You don't have to replace both 100K's, you can do it to just one channel or the other.
I've seen hints that a very few early split-cathode Lead amps had an 820ohm/330uF on one side of the first stage, and an 820ohm/.68uF instead of the usual 2.7K/.68uF for the other side. I've wondered how that would sound. Maybe you can tell me.

michaiel · Post by **michaiel** » Fri Mar 18, 2005 3:35 pm

great!! thanks

Billy Batz · Post by **Billy Batz** » Fri Mar 18, 2005 7:21 pm

It sounds great when you have a number of gain stages but a 1959 has 2. It will probably sound a bit buzzy. Start with 150k in the input.

Dax · Post by **Dax** » Fri Mar 18, 2005 8:44 pm

Use a 100K feedback resistor, and take the purple wire to the 4 ohm tap, this will add some dirt. Also, change the first stage cathode cap to 330uf, i think the stock value is 250uf. It is the very first cap at the left of the board with the 820 ohm resistor bridging it.

Dax

Flames1950 · Post by **Flames1950** » Fri Mar 18, 2005 8:50 pm

The 250uF cap is already so big that you'll hear little to no difference between it and a 330uF.
Dan, maybe that's why the McIntyre Bassman mods sound OK with the 220K plate load, it runs through three gain stages before hitting the cathode follower. I've just never felt the need to get more gain out of a stock Marshall, whether two or four input, so I never tried it to a Marshall.

Billy · Post by **Billy** » Fri Mar 18, 2005 9:24 pm

I dont think its as dramatic as people say but going to 220k on an amp like a 1959 can sound a little 'hard.' Cascade a few stages with much of the gain potential used and it will soften up. That seems to be the case with the Dumble. The Dumble is weird though. Its still kinda hard sounding but its smooth at the same time. Very difficult to explain. The SLO is similar but only uses the 220k on the first of 4 gain stages. I dont mind it in Fenders as much. My Fenders are 3 stage preamps though. Like the reverb channel on BF Fenders without the effects. Theres a lot of gain potential in those.

I would also suggest raising the NFB resistor to 100k though its probably that already. I also agree the 250u to 330u mod isnt likely to change much. Both those caps are so below the frequency of the guitar its only effecting frequencies that have a subtle influence at best. Look at the 820 ohm cathode resistor on stage 2. It may or may not be bypassed by a .68uF cap. If it isnt try that right away. A .68 will have a midrange emphasis. Bypasing it with a 330uF is common as well and may get you more gain. You could even bypass it with something like 1u or 5u for an even frequency responce. All these things arent likely to make a 69 flabby or muddy. Its so thin and tight anyway. Worst case scenario you have to dial down the bass and up the treble a bit more but that will only get you a tighter sound along with your increased gain.

Dax · Post by **Dax** » Fri Mar 18, 2005 10:41 pm

Ah, I think thats what i meant, swapping the .68 for the 330uf not the 250. Brainfart