Page 767 of 775
Re: S.I.R. 100W SuperLead Schematic pt. II
Posted: Sat May 06, 2023 12:04 pm
by CoffeeTones
RG58 - appears to be solid instead of stranded core conductor, 22 AWG. .195" diameter, about 31pF per foot, high working voltage rated, insulation is not great and will melt easily if heat applied too long. I'd try to seek out some coax with Tefzel or Teflon insulation, tinned and stranded copper core 22 - 20 AWG. You assume the risk. If you choose to do the mod, do it as best and safely as possible.
Re: S.I.R. 100W SuperLead Schematic pt. II
Posted: Sat May 06, 2023 7:07 pm
by Antonio
CoffeeTones wrote: ↑Sat May 06, 2023 12:04 pm
RG58 - appears to be solid instead of stranded core conductor, 22 AWG. .195" diameter, about 31pF per foot, high working voltage rated, insulation is not great and will melt easily if heat applied too long. I'd try to seek out some coax with Tefzel or Teflon insulation, tinned and stranded copper core 22 - 20 AWG. You assume the risk. If you choose to do the mod, do it as best and safely as possible.
Thanks for the heads up, Coffee!
Here in Brazil there is no suitable cable for hot shield.
I'm thinking of asking a friend to bring this cable from Europe, it looks good!
https://www.tube-town.net/ttstore/coaxi ... g-187.html
What do you think of this one?
Thank you so much!
Re: S.I.R. 100W SuperLead Schematic pt. II
Posted: Sun May 07, 2023 9:57 am
by CoffeeTones
The capacitance per foot is low, so you would need to use one foot to get about 20pF for the hot shield effect IMO.
Your linked description doesn't make clear the material of the center conductor (Staku stranded wire). From random data sheets, RG187 appears to be plated steel, stranded center conductor. Tinned or silver plated, pure copper is preferred IMO.
32 - 36pF per foot is better since you really shouldn't need a one foot piece from input to V1. (6 - 8 inches would provide about 18 - 24pF).
Re: S.I.R. 100W SuperLead Schematic pt. II
Posted: Sun May 07, 2023 7:46 pm
by Antonio
CoffeeTones wrote: ↑Sun May 07, 2023 9:57 am
The capacitance per foot is low, so you would need to use one foot to get about 20pF for the hot shield effect IMO.
Your linked description doesn't make clear the material of the center conductor (Staku stranded wire). From random data sheets, RG187 appears to be plated steel, stranded center conductor. Tinned or silver plated, pure copper is preferred IMO.
32 - 36pF per foot is better since you really shouldn't need a one foot piece from input to V1. (6 - 8 inches would provide about 18 - 24pF).
Great to hear that, Coffee!
I'm going to look for a cable that meets those specifications you gave me.
Thank you very much!
Re: S.I.R. 100W SuperLead Schematic pt. II
Posted: Mon Jul 17, 2023 12:02 pm
by blacklabel
Hi guys, it's been a while since I've been back here, lately I've only played on mesa mk III and V
I would like to ask you: has anyone recorded any new takes of #34?
I would like to play it again and it would be nice to have someone to talk to (miked sound only)
Re: S.I.R. 100W SuperLead Schematic pt. II
Posted: Wed Sep 06, 2023 9:40 am
by dukeamps
Re: S.I.R. 100W SuperLead Schematic pt. II
Posted: Sun Sep 17, 2023 12:44 pm
by dukeamps
Re: S.I.R. 100W SuperLead Schematic pt. II
Posted: Sun Sep 17, 2023 12:50 pm
by CoffeeTones
Are you posting the spec?
Re: S.I.R. 100W SuperLead Schematic pt. II
Posted: Sun Sep 17, 2023 12:52 pm
by dukeamps
CoffeeTones wrote: ↑Sun Sep 17, 2023 12:50 pm
Are you posting the spec? LOL
it was something like 4 10ks and something else, oh yes a 47p bright lol
Re: S.I.R. 100W SuperLead Schematic pt. II
Posted: Sun Sep 17, 2023 12:52 pm
by CoffeeTones
This fall weather is bringing back the amp fever!
Re: S.I.R. 100W SuperLead Schematic pt. II
Posted: Sun Sep 17, 2023 12:56 pm
by dukeamps
CoffeeTones wrote: ↑Sun Sep 17, 2023 12:52 pm
This fall weather is bringing back the amp fever!
I just might fire up the soldering iron again too lol
Re: S.I.R. 100W SuperLead Schematic pt. II
Posted: Thu Oct 26, 2023 2:50 am
by dukeamps
Re: S.I.R. 100W SuperLead Schematic pt. II
Posted: Thu Oct 26, 2023 3:52 am
by dukeamps
Re: S.I.R. 100W SuperLead Schematic pt. II
Posted: Thu Oct 26, 2023 7:10 am
by CoffeeTones
Man, that's the wrong angle for a gut shot.
Re: S.I.R. 100W SuperLead Schematic pt. II
Posted: Thu Oct 26, 2023 7:22 am
by dukeamps
