The improvement with the resistors is more dramatic than the vcaps, tho to be fair, the vcaps supposedly need 400 hours on them and I have about 150 or so. My 211 amp now has base that is controlled, deep, and rich. Voices etc. have lots of air. It's all very very musical now. Who is Ned Kelley?
Rather than drill through the stock wood side panels I just cut some nice teak 9-ply 3/8" plywood I got from a local hi-end wood place - they sold it 2' x 4' sections. So, it looks quite nice and gives the side some nice grain to look at instead of that that stock red stained stuff.
First, make sure the caps are drained so you don't kill yourself. I did not try to solder inside the amp and took out the two boards boards instead. The first amp was a tad scary and it took me awhile. You can manage to get both boards out of the amp and the wires will get a little wangled. You might have to desolder the one wire that goes to the power tube from the output transformer.
Then carefully draw a map where every wire goes to and from and check it like 5 times. Most locations on the power board are labeled - take lots of pictures. Then start removing and replacing the wires - and each wire I installed was maybe 1"-3" longer than the stock to make it easier to install the boards. The second amp was a lot easier to do - I found that installing everything on the tube board first made it easier, and then connecting it up to the power board. Oh, I did need to lengthen the wires from the torroid to the power board by about 2"-3" to make working with it all easier.
Mark some wires with tape and mark the board with black dot with permanent marker - leave these breadcrumbs. Use compressed air and solvent to clean up the flux and keep it all clean and pretty.
I actually did all the work with the boards on top of the (bottom of the) amp (of course, it's all upside down). The replacement wire is Chis Venhaus' solid core copper air teflon series. 24g for the rca connection, 21g for most of the wiring, and 18g for the higher current runs and to the speaker binding posts.
The only soldering inside the amp are the 5 wires from the output transformer to the binding posts. Do this with the boards removed. Everything else is external.
Wire from the IEC is Venhaus' 12g twisted pair soldered to the stock switch and I also installed a cryo'd fuse holder -but it stays under the bottom lid - no easy access to it.
The resistors are all recommended by Nick at HiFiCollective - enormously helpful and patient with my questions. I can give you that list, but they are all location and purpose specific. My list would only be helpful if your 845S is the same as my 211, which it likely is in most, if not all, areas. I found a schematic of the 211 amp online which Nick used for his recommendations - relating that schematic to the real thing was quite time consuming though. I don't know jack about circuits etc, I'm basically a solder by number guy.
I don't really know what to expect by replacing the bridge rectifier - Nick said it was a good idea and recommended some diodes for me and he has a build schematic on the website. I'll be doing that next.
If I had a complaint at this point it would be that the leading edge attack was soft - perhaps more time on the caps will help, and maybe the new rectifier will provide cleaner power. Oh, I also ran the twisted pair from the stock rectifier to the 211, replacing the crappy thin stock wire. The tubes should be now getting as much power as they want - perhaps that's the boost in base response I'm now getting.
I don't know how to post photos here and I did not take any of my finished product. I do have to venture back inside to install an XLR input connection - so I'll take some. And, I still need to install the resistors etc in the second amp. If you are in the SFBay area, let me know.
Rather than drill through the stock wood side panels I just cut some nice teak 9-ply 3/8" plywood I got from a local hi-end wood place - they sold it 2' x 4' sections. So, it looks quite nice and gives the side some nice grain to look at instead of that that stock red stained stuff.
First, make sure the caps are drained so you don't kill yourself. I did not try to solder inside the amp and took out the two boards boards instead. The first amp was a tad scary and it took me awhile. You can manage to get both boards out of the amp and the wires will get a little wangled. You might have to desolder the one wire that goes to the power tube from the output transformer.
Then carefully draw a map where every wire goes to and from and check it like 5 times. Most locations on the power board are labeled - take lots of pictures. Then start removing and replacing the wires - and each wire I installed was maybe 1"-3" longer than the stock to make it easier to install the boards. The second amp was a lot easier to do - I found that installing everything on the tube board first made it easier, and then connecting it up to the power board. Oh, I did need to lengthen the wires from the torroid to the power board by about 2"-3" to make working with it all easier.
Mark some wires with tape and mark the board with black dot with permanent marker - leave these breadcrumbs. Use compressed air and solvent to clean up the flux and keep it all clean and pretty.
I actually did all the work with the boards on top of the (bottom of the) amp (of course, it's all upside down). The replacement wire is Chis Venhaus' solid core copper air teflon series. 24g for the rca connection, 21g for most of the wiring, and 18g for the higher current runs and to the speaker binding posts.
The only soldering inside the amp are the 5 wires from the output transformer to the binding posts. Do this with the boards removed. Everything else is external.
Wire from the IEC is Venhaus' 12g twisted pair soldered to the stock switch and I also installed a cryo'd fuse holder -but it stays under the bottom lid - no easy access to it.
The resistors are all recommended by Nick at HiFiCollective - enormously helpful and patient with my questions. I can give you that list, but they are all location and purpose specific. My list would only be helpful if your 845S is the same as my 211, which it likely is in most, if not all, areas. I found a schematic of the 211 amp online which Nick used for his recommendations - relating that schematic to the real thing was quite time consuming though. I don't know jack about circuits etc, I'm basically a solder by number guy.
I don't really know what to expect by replacing the bridge rectifier - Nick said it was a good idea and recommended some diodes for me and he has a build schematic on the website. I'll be doing that next.
If I had a complaint at this point it would be that the leading edge attack was soft - perhaps more time on the caps will help, and maybe the new rectifier will provide cleaner power. Oh, I also ran the twisted pair from the stock rectifier to the 211, replacing the crappy thin stock wire. The tubes should be now getting as much power as they want - perhaps that's the boost in base response I'm now getting.
I don't know how to post photos here and I did not take any of my finished product. I do have to venture back inside to install an XLR input connection - so I'll take some. And, I still need to install the resistors etc in the second amp. If you are in the SFBay area, let me know.