I've got some huge Russian K40Y-9 .22uF 1000v caps that I want to try out in my SSE. They are too large and heavy to try mounting in the allotted space.
George, on your TSE page you write the following:
Note the "upgrades" link is broken on your site.
My question is, for off-board installation of coupling caps, is the off-board cap location and routing of the connections from the caps to the board critical? Should they be located far away from any particular section of the board? Like "as far from the power as possible" , or "as far from the input section as possible?" I'm going to need to mount them to the side of my chassis and I want to get the location right the first time. Of course in my case I am talking about C11 and C21.
By far, the shortest run is from the board to the front of my chassis, on the side of the board where the input terminals are.
George, on your TSE page you write the following:
Note the "upgrades" link is broken on your site.
My question is, for off-board installation of coupling caps, is the off-board cap location and routing of the connections from the caps to the board critical? Should they be located far away from any particular section of the board? Like "as far from the power as possible" , or "as far from the input section as possible?" I'm going to need to mount them to the side of my chassis and I want to get the location right the first time. Of course in my case I am talking about C11 and C21.
By far, the shortest run is from the board to the front of my chassis, on the side of the board where the input terminals are.
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The TSE has a mosfet buffer between the coupling cap and the output tube. This means that the cap sees a 470K (TSE) or 1 Meg (TSE-II) load, so the cap is not required to pass varying amounts of AC current.
The SSE does not have this buffer, so the type of cap can make a bigger difference on the SSE, especially if driven near, or into clipping.
All on my PC boards and just about every board made in the last 50 years uses plated through holes to make connections from one side of the board to the other. Do NOT attempt to drill out the board holes to accommodate a larger diameter wire that is found on some caps. That will break the connection inside the board......this was another extended remote troubleshooting experience that didn't get solved until the builder mailed me his dead board. Can't find this one without an oscilloscope.
I have not tried it, but you should be able to remote mount the coupling caps. I would keep them away from AC line wiring and the power or output transformers. Somebody said that they had to insulate the metal case on their Russian caps, don't remember the details though.
Many builders have used some expensive boutique capacitors in their amps, and some claim great results from trying different caps.
There have been a few people who have had trouble with leakage current in expensive wax based caps causing runaway, or sudden death of an output tube. I would avoid using any wax based capacitors in any tube amp that gets warm. This was an issue in the 40's and 50's and still is today, regardless of where the wax comes from.
The SSE does not have this buffer, so the type of cap can make a bigger difference on the SSE, especially if driven near, or into clipping.
All on my PC boards and just about every board made in the last 50 years uses plated through holes to make connections from one side of the board to the other. Do NOT attempt to drill out the board holes to accommodate a larger diameter wire that is found on some caps. That will break the connection inside the board......this was another extended remote troubleshooting experience that didn't get solved until the builder mailed me his dead board. Can't find this one without an oscilloscope.
I have not tried it, but you should be able to remote mount the coupling caps. I would keep them away from AC line wiring and the power or output transformers. Somebody said that they had to insulate the metal case on their Russian caps, don't remember the details though.
Many builders have used some expensive boutique capacitors in their amps, and some claim great results from trying different caps.
There have been a few people who have had trouble with leakage current in expensive wax based caps causing runaway, or sudden death of an output tube. I would avoid using any wax based capacitors in any tube amp that gets warm. This was an issue in the 40's and 50's and still is today, regardless of where the wax comes from.
Thanks for your reply, George. The plated through holes for C11 and C21 on my board have miniature binding posts installed to facilitate easy swapping of the coupling caps. So glad that I decided to do that now. The binding post holes can probably accommodate 12 gauge solid core by the looks of them. Not that I need anything close to that!
The K40Y-9 caps are PIO and have a pretty good reputation. I replaced the coupling caps in my EL34 push-pull amp with some and it made a significant difference in sound quality. Although, the random Chinese caps that came in the stock amp were probably bottom of the barrel, 50 cent jobbies, so anything would have been better.
I've been listening to the amp long enough now to have a general feel for the sound. C11 and C21 are these right now. Time will tell if the PIOs will sound better - or if I will even notice.
And yes, the K40Y-9 have a conductive shell. I've wrapped them in electrical tape and they'll be secured to the wooden chassis with non-conductive retainers of some sort. Probably plastic zip-ties.
I've got some giant Sprague .22uF 600v orange drops here I can try too, but by most accounts the Russkies are better.
The K40Y-9 caps are PIO and have a pretty good reputation. I replaced the coupling caps in my EL34 push-pull amp with some and it made a significant difference in sound quality. Although, the random Chinese caps that came in the stock amp were probably bottom of the barrel, 50 cent jobbies, so anything would have been better.
I've been listening to the amp long enough now to have a general feel for the sound. C11 and C21 are these right now. Time will tell if the PIOs will sound better - or if I will even notice.
And yes, the K40Y-9 have a conductive shell. I've wrapped them in electrical tape and they'll be secured to the wooden chassis with non-conductive retainers of some sort. Probably plastic zip-ties.
I've got some giant Sprague .22uF 600v orange drops here I can try too, but by most accounts the Russkies are better.
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K40Y-9 PIOs installed.
It sounds great. Need to do a lot more listening to decide if there is an obvious difference or not. It is easy to fool oneself with this stuff, but it does sound like the top end is cleaner or "sweeter" to me.
One thing is for certain, the amp is still dead silent with no signal so at least I didn't make a mess of it.
It sounds great. Need to do a lot more listening to decide if there is an obvious difference or not. It is easy to fool oneself with this stuff, but it does sound like the top end is cleaner or "sweeter" to me.
One thing is for certain, the amp is still dead silent with no signal so at least I didn't make a mess of it.
Anytime I'm messing around with an amp or anything that requires subjective testing, I make only ONE change at a time, and do so in a manner that can be undone. Then leave it alone and listen for a few days or weeks. If you are not sure, put it back the way it was. If there is no immediate "yuck" then the change was not a major upgrade and you can then decide whether or not to reinstall the mods.
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