K-amps said:
Did you have trouble finding the Silver plated coppers bars?
Here is a SKU to get you started.
88865K117
Call that up and follow the tree back to expand your selection if you like.
Regards
Anthony
Grounding Questions
OK, I'm getting ready to connect the inputs and outputs.
I've got a power star ground (star gnd#1) at the front of the case but I have not grounded any inputs or outputs yet and that is what I'm looking to do.
Do you connect the ground of the RCA jacks to a separate signal star ground somewhere else and then from there to the GND on the board? Or you connect RCA ground directly to the input board, then to a star gnd #2, then to speaker binding posts?
What about output GND, looks like the output stage/ board needs no ground connections, so just connect RCA ground to speaker binding post GND to star gnd #2?
lots of possiblities....
OK, I'm getting ready to connect the inputs and outputs.
I've got a power star ground (star gnd#1) at the front of the case but I have not grounded any inputs or outputs yet and that is what I'm looking to do.
Do you connect the ground of the RCA jacks to a separate signal star ground somewhere else and then from there to the GND on the board? Or you connect RCA ground directly to the input board, then to a star gnd #2, then to speaker binding posts?
What about output GND, looks like the output stage/ board needs no ground connections, so just connect RCA ground to speaker binding post GND to star gnd #2?
lots of possiblities....
rabstg said:
#1 Why not?
#2 How would you run the wires? Is it the looks that bother you or are there electronic reasons you don't like it? If you look at the amp as a whole you can see that the wires are very easy to follow. This isa three channel amp though in the picture one of the board is not mounted at the time of the photo. It is now.
#3 The caps are held in place with douple sided foam tape between them and the bottom of the chassis. The bolt that you see for the star ground "sandwitches" the caps between the copper plate and the bottom. They do not move at all. Maybe over time, I don't know.
Why would soldering the caps to a perf board offer better connection than soldering to the plate? I pre-tinned the plate at high temp before I soldered the caps to it. I have been thinking about doing a PCB for this but I have to wonder if 1 or 2mil of copper on a PCB would equal the 1/8" plate. My logic says it won't. Pehaps you can explain so that I can understand.
Thanks, Terry
#1 Why not?
Because it is VERY difficult to get a good reliable connection to a solid bar and any vibration / movement could cause the terminal to break. Also if you lose a cap, it would be extremely difficult to remove / replace on such a setup.
#2 How would you run the wires? Is it the looks that bother you or are there electronic reasons you don't like it? If you look at the amp as a whole you can see that the wires are very easy to follow. This isa three channel amp though in the picture one of the board is not mounted at the time of the photo. It is now.
Looks do bother me, if it looks neat it is “usually” safe. Also some long stretches of wire are unsupported.
#3 The caps are held in place with douple sided foam tape between them and the bottom of the chassis. The bolt that you see for the star ground "sandwitches" the caps between the copper plate and the bottom. They do not move at all. Maybe over time, I don't know.
Double stick tape is not a “long term” mechanical mount. If the bolt does go through to the bottom that is an excellent hold down method! It is not visible in the photo’s.
Why would soldering the caps to a perf board offer better connection than soldering to the plate? They don’t, but perf board does not require the heat to unsolder bad caps potentially unsoldering good ones also. I pre-tinned the plate at high temp before I soldered the caps to it. I have been thinking about doing a PCB for this but I have to wonder if 1 or 2mil of copper on a PCB would equal the 1/8" plate. My logic says it won't. Pehaps you can explain so that I can understand.
Your plate IS a better electrical connection but Far more difficult to make a proper mechanical connection. Solder is not for support or stability. Solder is only for electrical connectivity. The solder would easily crack or the terminal of the cap break if the amp were jolted hard as in a fall. Installation and electrical connection should be viewed as separate items. The hold down bolt is excellent. The star grounding is excellent. The wiring could use some work to be neater and better supported / secured but in the bigger picture not too bad. But I would still suggest not using snap in caps on bar stock.
Again, my comments are stated to make it better. I am not trying to discourage or embarrass. I only TRY to offer a friendly, different point of view.
Because it is VERY difficult to get a good reliable connection to a solid bar and any vibration / movement could cause the terminal to break. Also if you lose a cap, it would be extremely difficult to remove / replace on such a setup.
#2 How would you run the wires? Is it the looks that bother you or are there electronic reasons you don't like it? If you look at the amp as a whole you can see that the wires are very easy to follow. This isa three channel amp though in the picture one of the board is not mounted at the time of the photo. It is now.
Looks do bother me, if it looks neat it is “usually” safe. Also some long stretches of wire are unsupported.
#3 The caps are held in place with douple sided foam tape between them and the bottom of the chassis. The bolt that you see for the star ground "sandwitches" the caps between the copper plate and the bottom. They do not move at all. Maybe over time, I don't know.
Double stick tape is not a “long term” mechanical mount. If the bolt does go through to the bottom that is an excellent hold down method! It is not visible in the photo’s.
Why would soldering the caps to a perf board offer better connection than soldering to the plate? They don’t, but perf board does not require the heat to unsolder bad caps potentially unsoldering good ones also. I pre-tinned the plate at high temp before I soldered the caps to it. I have been thinking about doing a PCB for this but I have to wonder if 1 or 2mil of copper on a PCB would equal the 1/8" plate. My logic says it won't. Pehaps you can explain so that I can understand.
Your plate IS a better electrical connection but Far more difficult to make a proper mechanical connection. Solder is not for support or stability. Solder is only for electrical connectivity. The solder would easily crack or the terminal of the cap break if the amp were jolted hard as in a fall. Installation and electrical connection should be viewed as separate items. The hold down bolt is excellent. The star grounding is excellent. The wiring could use some work to be neater and better supported / secured but in the bigger picture not too bad. But I would still suggest not using snap in caps on bar stock.
Again, my comments are stated to make it better. I am not trying to discourage or embarrass. I only TRY to offer a friendly, different point of view.
Hi Troy,
Thanks for the suggestions. As to the mounting of the caps, as I said they are sandwitched between the plate and the chassis bottom. You cannot move them at all. The bolt does indeed go through the bottom plate. I have seen many "snap-in caps" merely soldered to a PCB and the only thing that is holding them is the little prongs. It's hard to believe that is more secure.
I understand that screw type would be better but I bought 25 of these little 80V, 15000uF caps and they work quite well in my P101. I still have 17 left so I plan to use some of them in the Krell Klone. If you really think a PCB is a better ground plane/ Star ground, I will certainly give it some thought.
About the wiring, I have thought about adding some tie-wrap mounts in there to support the long stretches better. Maybe I'll go ahead and do that in the near future.
Again, Thanks for taking the time to help me. I really appreciate it.
Blessings, Terry
Thanks for the suggestions. As to the mounting of the caps, as I said they are sandwitched between the plate and the chassis bottom. You cannot move them at all. The bolt does indeed go through the bottom plate. I have seen many "snap-in caps" merely soldered to a PCB and the only thing that is holding them is the little prongs. It's hard to believe that is more secure.
I understand that screw type would be better but I bought 25 of these little 80V, 15000uF caps and they work quite well in my P101. I still have 17 left so I plan to use some of them in the Krell Klone. If you really think a PCB is a better ground plane/ Star ground, I will certainly give it some thought.
About the wiring, I have thought about adding some tie-wrap mounts in there to support the long stretches better. Maybe I'll go ahead and do that in the near future.
Again, Thanks for taking the time to help me. I really appreciate it.
Blessings, Terry
Baloney! When assembling just place a star lockwasher on both sides of the plate were ever a critical screw passes through. I have done this for years and never had a screw or terminal come loose, ever. Most if not all manufadturers also do this. Replacment of one or all the caps is also not that difficult as the whole bank of caps comes out just by loosening the clamp screws in the mounts. This way just one bad cap, or all of them can easily be replaced.
Mark
Now, now Mark... Calm down and re-read the post.....
I said to SOLDER a cap to bar stock....
I also use star or "dragon tooth" washers on screw caps when connecting to bar staock.. It is my perferred method.
Both Terry and Mark... Peace my brotha's!
It's all good.
I said to SOLDER a cap to bar stock....
I also use star or "dragon tooth" washers on screw caps when connecting to bar staock.. It is my perferred method.
Both Terry and Mark... Peace my brotha's!
It's all good.
eugenio said:
Anche io, duro, no ?
scherzo soltanto.
The coils are from a company closing shop, 2.5mH, price was less than bare bell wire.
A bit fat considering they'll go on 2 rails, at 7 amps bias voltage will drop less than 2V, which makes up for the added weight.
i just took a voltage for an example, the original Krell has 50V PS rails.
Toshiba's SA970/SC2240 are very linear in the 1 to 40 mA range for hFe, 3-20mA for Vce(sat), bandwidth and noise level are excellent in that range.
A thing to consider is that the designer surely spent a lot of time tweaking current values, by listening and modifying.
Great pictures, Anthony.
Thanks Jacco, My Krell Clone is on hold until I can get some spare cash for the Transistors, Trade anyone for Power Supply Capacitors?
My Power supply and chassis is completed, When I get the Driver and ouput Transistors I can finish it up finally...
Anthony
Anthony-
I swapped to TO-3 from the TO-220 looking package (I think its a TO-264 package), so have a bunch of them in flat TO-264 packages available, assuming I can't use this in the upcoming Leach Amp, I'd be happy to swap them for some of your very nice caps.
I've got these avail- Onsemi MJL21193, 94, 95, 96. Unopened in orig. rail packaging. How many and what type do you want?
Still waiting for an answer to my ground post everyone!
I swapped to TO-3 from the TO-220 looking package (I think its a TO-264 package), so have a bunch of them in flat TO-264 packages available, assuming I can't use this in the upcoming Leach Amp, I'd be happy to swap them for some of your very nice caps.
I've got these avail- Onsemi MJL21193, 94, 95, 96. Unopened in orig. rail packaging. How many and what type do you want?
Still waiting for an answer to my ground post everyone!
lgreen said:
I need the following:
MJE15033OS x 8
MJE15032OS x 4
MJL21194OS x 6
MJL21193OS x 6
2SC3955 or replacement x 2
3W 27V Zeners x 4
Regards
Anthony
lgreen said:
If you have 2 star grounds i dont think you can call it central anymore.
IMO:
unless a board has a ground plane, it should have signal ground and power ground.
Input ground goes to signal ground on the board, from there it is connected to central star ground.(not chassis ground)
For input signal i use teflon insulated silver plated coaxial wire, if this is connected to a separate star ground signal wire length is longer and has a disruption halfway.
That is what i like about thick bus bars for star ground, all the traffic comes from all directions to quiet down there, without feeding back through wires to other ground surfaces.
Has anyone tried Apexjr's Silver over Teflon 12 ga wire? I got some it looks nice and is cheap, but am pondering on what the best application would be, signal, power or both...
I've used most of Steve's Silver plated Teflon insulated wire including the co-ax and twisted sheilded pair.
Now I order in bulk and that is all I use. Price is great and it solders really well.
I've made interconnect and speaker wire with it. I also use it to repair broken stuff and build new.
I even used some to repair the wiring harness on my 72 Suzuki GT750 yesterday because of the high temp insulation.
The twisted sheilded pair is GREAT for balanced signal cable, and the co-ax is great for single ended. I've also rewired many electric guitars with it and the owners have been amazed at how much quieter their guitars are.. One guy complained about a drip sound after I rewired his guitar.. I asked him to play for me, and it turned out to be the tics of the second hand from the watch on his LEFT hand. He now takes off his watch to play and loves the sound of his guitar.
In short good stuff for the price.
Now I order in bulk and that is all I use. Price is great and it solders really well.
I've made interconnect and speaker wire with it. I also use it to repair broken stuff and build new.
I even used some to repair the wiring harness on my 72 Suzuki GT750 yesterday because of the high temp insulation.
The twisted sheilded pair is GREAT for balanced signal cable, and the co-ax is great for single ended. I've also rewired many electric guitars with it and the owners have been amazed at how much quieter their guitars are.. One guy complained about a drip sound after I rewired his guitar.. I asked him to play for me, and it turned out to be the tics of the second hand from the watch on his LEFT hand. He now takes off his watch to play and loves the sound of his guitar.
In short good stuff for the price.
Yup, looks pretty good quality, I tried a automtic wire stripper on it and the blades just slipped off the insulation... teflon is interesting 😀.
K-amps said:
Seen that, looks very attractive, thinking of ordering 100ft, same with the 10ga. And i gotta have those 1.5''x1.5'' feet.
i am using this as speakercable.
1/2" diameter, silverplated, double shields, 7 times 0.03" strand core.
Bi-cabled, core of one cable connected to the shields of the other for the +, same for the -
I can only recommend everyone to use teflon insulated wire for internally wiring the Krell's.
Teflon is also great material for valves and top of the range for a lot of other applications, wonderfull material.
My dad bought Teflon foil rolls by the tons from DuPont for production, i used to make all kind of stuff from Teflon foil as a kid.
(old fart)
