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

[BRMSlash]

Thanks. I don't think the link worked correctly, so I'm not sure what speaker you're suggestion. However, I'm very happy with my Scumback H75-PVC's and not really looking to upgrade. I've already spent too much on speakers for my liking and need to clear out my spares to recoup some cash.

There are a couple more things I want to try on my amp though. First up I want to try lowering my PI B+ cap to soften up the tone slightly. Secondly, I might try a 50n to 1n cap after the rectifier like some of the older and newer Marshalls to see if it does anything noticeable to the high end.

[Unique]

"crickets..."

I guess everyone must have figured out #36, huh?

[BRMSlash]

Too busy going to reunion concerts Tickets just went on sale over here. Can't wait to February. Video clips off the net look like they're almost back to 1990's quality sound wise

[BRMSlash]

Back to amp matters. I've ended up pretty much at "stock" filtering now, with basically 50u's at each node. I re-tried various configurations and the higher filtering just seemed to tighten up the bass better. There was a change in sound which I attribute to settling in of the electrolytics, as the initial stiffness seems to have gone after a few weeks.

Also, just for laughs, I decide to use a different guitar this time. Here's a clip using my Epiphone Reissue 1962 Sorrento.

http://sclk.co/s8029u

[herbvis]

Too busy going to reunion concerts Tickets just went on sale over here. Can't wait to February. Video clips off the net look like they're almost back to 1990's quality sound wise

Ive seen them twice so far on this tour. I think they are actually better now than in the 90's. The only better time to see them would be the 80s imo. I cant believe how good they were. Slash's playing melted my brain! He has been playing his ass off on this tour and definately deserves his guitar god status. And Axl sounds fantastic!!! Worth every dollar spent and then some.

[BRMSlash]

Yeah, it looks like they've really kicked things up a notch!

[BRMSlash]

Re-intonated my guitar and played the usual riff sequence, plus some extra.
http://sclk.co/s802we

[herbvis]

Sounds pretty cool. Nice and smooth

[dukeamps]

Re-intonated my guitar and played the usual riff sequence, plus some extra.
http://sclk.co/s802we

I think your clips with the CL80 speakers sounded better

[BRMSlash]

Thanks herbvis. I agree, however I still feel there's a very slight treble buzziness going on. I think it may be due to the single 15k in the B+ between output tubes and phase inverter. Whereas Marshall typically uses two resistors. My base amp is a Ceriatone AFD35, so there is only room for one resistor.

I decided to do some calculations, and it turns out that a single 15k, dropping 100V, is required to be around 5W (depending on the de-rating factor for limiting temperature rise). Where as by sharing the voltage drop over two resistors, each one needs to be around 2W. It may not look pretty, but I'll have to try mounting two resistors in series, vertically to fit the horizontal space.

[BRMSlash]

Thanks duke, but I felt the CL80's weren't quite right for me. Maybe some vintage ones would be nicer?

[rockgod212]

sounds pretty good.....

[BRMSlash]

Tried a 4n7, 2n2 & 1n in the B+ after the rectifier diodes. I ended up liking 2n2 there, but it did muffle the clarity slightly, so ended up removing it.

Also tried putting in two resistors instead of the single one in the B+ between output tubes and phase inverter. There was maybe a very slight difference, but nothing significant. I also tried bumping up their values, which did help reduce the buzz slightly, but sacrificed a little head room.

I also tried some c0g multilayer ceramics in the peaker and mixer positions instead of the mica's. They sounded pretty good, although slightly different to the mica's.

Treble cap tweaking is next on the agenda...

[herbvis]

Its too quite around here these days lol. Heres a quick sample. It was done in a hurry
http://www.soundclick.com/bands/default ... tent=music

[rockgod212]

always sounds great herb, same spec?

a bit off topic, but I have a new project. a 59 flame top LP. its looking good so far.