S.I.R. 100W SuperLead Schematic pt. II

[dukeamps]

Well that's it, sometimes its best to leave alone and just have fun with what you have

Nah, I’m here to learn about amps and mods, so I’ll give it a go. I started with 2 2k7/.68 stages though and in my experience if you have bright cap on both (470k+470p/470k is same as a 1M pot with 470p bright cap at 8ish) it will squel at higher settings already. Then adding 3k3/.47 on third? Like, wow?

Ok, if you do this spec, make sure you have the wires coming from the gain pots going over the board to the tubes, that they are shielded, then that you have a 150k or 220k from the middle lug to ground on the first gain pot, and don't go any higher than 4 or 5 with the gains. You could probably get away with MV on 3, also make sure your pickups are not microphonic.

[gluke]

I got «a version» of it up and running. It is still borderline unstable though. Will try to record some clips tomorrow.

[gluke]

"A version" of that latest spec....

WTTJ
https://www.youtube.com/watch?v=-9iilZFkCas

A wise man once said: "sometimes its best to leave alone and just have fun with what you have"

[dukeamps]

"A version" of that latest spec....

WTTJ
https://www.youtube.com/watch?v=-9iilZFkCas

A wise man once said: "sometimes its best to leave alone and just have fun with what you have"

I wonder who it was that said that lol

So i think its getting a bit out of control but still sounds not too bad, if you want, change the second stage to 5k7 ,22u

PS, before you do the 5k7.22u change, you could parallel a 100k with the NFB resistor to tighten the amp up a bit.

[CoffeeTones]

"A version" of that latest spec....

WTTJ
https://www.youtube.com/watch?v=-9iilZFkCas

A wise man once said: "sometimes its best to leave alone and just have fun with what you have"

Sounds like some blocking distortion to me. Gonna need to dump some gain and / or use large value grid stoppers to clean that up. Not worth it IMO.

[snakepit86]

"A version" of that latest spec....

WTTJ
https://www.youtube.com/watch?v=-9iilZFkCas

A wise man once said: "sometimes its best to leave alone and just have fun with what you have"

the previous version of your mod was it i think, the Welcome solo 2

[dukeamps]

"A version" of that latest spec....

WTTJ
https://www.youtube.com/watch?v=-9iilZFkCas

A wise man once said: "sometimes its best to leave alone and just have fun with what you have"

the previous version of your mod was it i think, the Welcome solo 2

Yep, the other mod was sounding great and very close to the original AFD tone, but i suppose he wants to learn about amp modding too. Nothing wrong in that.

[gluke]

"A version" of that latest spec....

WTTJ
https://www.youtube.com/watch?v=-9iilZFkCas

A wise man once said: "sometimes its best to leave alone and just have fun with what you have"

the previous version of your mod was it i think, the Welcome solo 2

Yep, the other mod was sounding great and very close to the original AFD tone, but i suppose he wants to learn about amp modding too. Nothing wrong in that.

Well, you know when you go from something that is good sounding and stable into something that is a challenging unstable squiling mess, then there is always 30 sec of "what the hell was I thinking". But I just wanted to hear what that combo of catodes sounds like. In order to make that spec work I will have to rewire everything going to and from the pots. I'm off course way to impatient to do that, so I just wired up a layout I thought might work with those catode values. It didn't. As CT points out it had a few side effects...

But I have already taken "some of that tone" and tried to add it to that previous spec and it is kinda cool too. So it's like two steps forward and one step back and then one step to the side.

[gluke]

I wonder who it was that said that lol

I think I'm into a new routine where I take half of what you recommend and then apply it half assed and usually gets me sort off half way there...... go figure. I tend to get sidetracked a bit easily though and then decide try two, three other things at the same time....

[gluke]

Ok, if you do this spec, make sure you have the wires coming from the gain pots going over the board to the tubes, that they are shielded, then that you have a 150k or 220k from the middle lug to ground on the first gain pot, and don't go any higher than 4 or 5 with the gains. You could probably get away with MV on 3, also make sure your pickups are not microphonic.

I'm maybe not the biggest fan of the way his mods sound, but I think the Lee Jackson mod videos is a good representation of how these guys would do these mods in the 80s, especially the use of shielded wire for everything going over from the pots to the tube sockets.

https://www.youtube.com/watch?v=VZor5pDOy3Q&t=1194s

[dukeamps]

Ok, if you do this spec, make sure you have the wires coming from the gain pots going over the board to the tubes, that they are shielded, then that you have a 150k or 220k from the middle lug to ground on the first gain pot, and don't go any higher than 4 or 5 with the gains. You could probably get away with MV on 3, also make sure your pickups are not microphonic.

I'm maybe not the biggest fan of the way his mods sound, but I think the Lee Jackson mod videos is a good representation of how these guys would do these mods in the 80s, especially the use of shielded wire for everything going over from the pots to the tube sockets.

https://www.youtube.com/watch?v=VZor5pDOy3Q&t=1194s

[gluke]

A few shielded cables later and it's up and running!

Will try to make some clips later.

[gluke]

Ok, if you do this spec, make sure you have the wires coming from the gain pots going over the board to the tubes, that they are shielded, then that you have a 150k or 220k from the middle lug to ground on the first gain pot, and don't go any higher than 4 or 5 with the gains. You could probably get away with MV on 3, also make sure your pickups are not microphonic.

It's actually quite ok now. I can run the gains up to 6 no problem. The P90 goes a bit bonkers, but that's expected.

[gluke]

Here we go again (forgive my sloppy playin, I was under a bit of time pressure here as it's still loud ass føkk):

WTTJ
https://www.youtube.com/watch?v=rzLypB9aJeU

WTTJ Solo1
https://www.youtube.com/watch?v=8PiKK6vMvG4

[CoffeeTones]

So much gain, the amp is choking and sounding un-natural. My suggestion is to go back to your best spec and tune the slope resistor, TS treble cap, peakers and bright cap till you get the mids and highs right. It may take something other than 250 or 500pF and 33k in the TS as well as non traditional values in other peakers. Keep in mind, the outliers within the 20% tolerance spec at least. You could also start testing partially bypassed cathodes to voice the amp. As particular as you are wanting to be, and with all you have tried, these become viable options. Plus you learn more as you go. How the power supply and dropping string is arranged is a big part of voicing too. I remember something said about the tone stack possibly being a hybrid. Don't recall where the B+ was taken from, to power the extra tube.