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

[CoffeeTones]

Could be just the recordings, but it needs more bottom and has a nasty spike in the high mids. Try and keep the camera about 5m away from the amp.

I have now changed to 33k slope instead of the 39k I had left installed from the previous mod. It has less high / mid spike and more bottom now, but could probably use even more bottom. I was about 2.2m from the amp, with the phone. I have used ceramic caps as plate snubbers, so maybe changing those would reduce that upper end thing they add. Are you using mica caps there? You know where I can get more low end based on the PM I sent you.

[dukeamps]

Could be just the recordings, but it needs more bottom and has a nasty spike in the high mids. Try and keep the camera about 5m away from the amp.

I have now changed to 33k slope instead of the 39k I had left installed from the previous mod. It has less high / mid spike and more bottom now, but could probably use even more bottom. I was about 2.2m from the amp, with the phone. I have used ceramic caps as plate snubbers, so maybe changing those would reduce that upper end thing they add. Are you using mica caps there? You know where I can get more low end based on the PM I sent you.

I didn't get a PM.

[CoffeeTones]

Sent another. The first PM went to my out box the other day, dunno why it disappeared.

[Unique]

That sounds pretty good Coffee! At times it sounded like some harsh highs coming through, but that could be due to your phone, or possibly you have, what sounds like to me, a slightly microphonic tube in there somewhere. But that's hard to tell from a recording. I just hear what sounded like some traits of that coming through. All in all, I think your pretty darn close, if not there, and the amp sounds really good. It has all the right character in there, even with it being recorded with a phone, you hear it. I bet it sounds better in person. Good job!

Thanks

A couple of things I may change.

1. I have a 39k slope resistor from a previous mod. I left it in just to see if it worked out. That adds highs and pulls lows compared to 33k. Can cause ice picks in some specs. That is the only odd ball part in the spec. Surely I will change that value.

2. Ceramic plate snubbers in place. Mica should be smoother. May change those out some day.

Can't change these parts easily, but the amp has all Xicon film resistors which have a harsh sound that can also sound microphonic. Not likely I'll go through the trouble.

Phone recordings always accentuate the highs of any sound.

I wouldn't overdue it on the changes, it sounds pretty darn good. I mentioned a possible bad tube because the highs weren't harsh the whole time, it's like they came and went, and from my experience, this is usually a bad preamp tube.

Only you can hear it in person, maybe tweak something and see how it sounds, and then move to the next if needed. I would start with your tubes though. One dead give away for a not so great sounding tube is if all the bad sounds seem to go away after playing for about 45 minutes. Even bad tubes sound good once they get good and hot. Also, a tube may not be a 'bad' tube per se, but one that just doesn't have good highs. Just my two cents, you would know better having the amp in front of you. Besides that, from what I could hear, it sounded really good.

[Unique]

ok so a little trip to memory lane...
i was searching for some recordings and im revisiting an not so old spects of mine

https://soundcloud.com/shenierhandmadet ... al_sharing


compared it to the original recording and WOW, Lynchbacks are the shit, they sound like a big greenback old greenback

That sounded pretty good, are you still using that spec?

[Unique]

No need to answer that, I just read it in the next post.

[CoffeeTones]

I wouldn't overdue it on the changes, it sounds pretty darn good. I mentioned a possible bad tube because the highs weren't harsh the whole time, it's like they came and went, and from my experience, this is usually a bad preamp tube.

Only you can hear it in person, maybe tweak something and see how it sounds, and then move to the next if needed. I would start with your tubes though. One dead give away for a not so great sounding tube is if all the bad sounds seem to go away after playing for about 45 minutes. Even bad tubes sound good once they get good and hot. Also, a tube may not be a 'bad' tube per se, but one that just doesn't have good highs. Just my two cents, you would know better having the amp in front of you. Besides that, from what I could hear, it sounded really good.

I did change the 39k slope. Pretty sure it was for the better. I need to roll some tubes, because I do hear what you are describing. Already did some chop stick testing, and nothing was evident. I'm using plenty of shielded wire, so It is probably a preamp tube or a bad pF cap. I'll try to post more clips in a few days, for more opinions.

[Unique]

I wouldn't overdue it on the changes, it sounds pretty darn good. I mentioned a possible bad tube because the highs weren't harsh the whole time, it's like they came and went, and from my experience, this is usually a bad preamp tube.

Only you can hear it in person, maybe tweak something and see how it sounds, and then move to the next if needed. I would start with your tubes though. One dead give away for a not so great sounding tube is if all the bad sounds seem to go away after playing for about 45 minutes. Even bad tubes sound good once they get good and hot. Also, a tube may not be a 'bad' tube per se, but one that just doesn't have good highs. Just my two cents, you would know better having the amp in front of you. Besides that, from what I could hear, it sounded really good.

I did change the 39k slope. Pretty sure it was for the better. I need to roll some tubes, because I do hear what you are describing. Already did some chop stick testing, and nothing was evident. I'm using plenty of shielded wire, so It is probably a preamp tube or a bad pF cap. I'll try to post more clips in a few days, for more opinions.

I'll be looking forward to hearing them!

[dukeamps]

https://www.youtube.com/watch?v=IR2cyXdRP6Q&t=1s

G12H55Hz speakers

[dukeamps]

Here is one for you to chew over, A mix of speakers, G12M + G12H both BlackBacks. Sm57 on the G12H, and SH 421 on the G12m.

https://soundclick.com/share.cfm?id=14414529

[Unique]

Here is one for you to chew over, A mix of speakers, G12M + G12H both BlackBacks. Sm57 on the G12H, and SH 421 on the G12m.

https://soundclick.com/share.cfm?id=14414529

That sounded pretty darn good, and it was cool to hear a #36 mod with different speakers and mics.

[dukeamps]

Here is one for you to chew over, A mix of speakers, G12M + G12H both BlackBacks. Sm57 on the G12H, and SH 421 on the G12m.

https://soundclick.com/share.cfm?id=14414529

That sounded pretty darn good, and it was cool to hear a #36 mod with different speakers and mics.

[CoffeeTones]

https://drive.google.com/file/d/1EVXl1h ... sp=sharing

[lespaul6]

Has anyone figured out how to do the 34 without using a ppimv and without having to have the master on 8 and the gain on 2? I found the schem posted in the mid 700 pages.. thanks

[CoffeeTones]

Which scheme are you using? It's possible to do #34 with the master on 2 and the gain on 7 or 8, without a PPIMV. It's hard to give out much info, because too many folks want to start amp companies with other people's work. The Fender / Marshall / Jose trend continues, I guess. There's a guy who sells mostly other people's and company's mods, while pretending to be an expert authority. Sure, he changes a cap or two, sometimes throws a snubber cap here or there. Hard to believe people eat this sort of thing up.