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Post by killerq on Nov 8, 2020 4:11:00 GMT
Hey, All, Forgive my ignorance, but i appreciate your help in advance. I have rolled many 6SN7 tubes on my ember 2, and never had an issue. It’s amazing. Today, I got an adapter that goes from 2 6J5 tubes to a single 6SN7 connector that Incan plug right into my ember 2. I have two “ Matched Pair RCA 6P5 6P5G Foil Getters Shoulder ST Shape” tubes in it. Here are detailed pics of the adapter and the tubes: imgur.com/a/PMkfZqUThe problem is that, even through the volume level seems just the same as my other tubes, when I use the adapter, the bass seems distorted. Not overly loud and distorting, but like it can’t recreate the sound properly and it is distorted. Could it be that since I am using the double adapter than I now have to change some jumpers because the ember can’t drive the tubes properly or something like that? I hope these end up working out. Thank you!!’ |
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solderdude
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Post by solderdude on Nov 8, 2020 15:13:20 GMT
I have no experience with these tubes.
Best to take this up with Jeremy.
He may have toyed with it.
Looks like these tubes are outside of the adjustment range of the Ember.
Have you experimented with the input cap settings ?
Some tubes need different settings.
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Post by killerq on Nov 8, 2020 18:18:18 GMT
I have no experience with these tubes. Best to take this up with Jeremy. He may have toyed with it. Looks like these tubes are outside of the adjustment range of the Ember. Have you experimented with the input cap settings ? Some tubes need different settings. I have only played with the gain and the resistance jumpers. I’m using Planars. Which cap setting should I try? It’s on default now. |
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solderdude
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Post by solderdude on Nov 8, 2020 20:37:18 GMT
In the manual you can find the various settings.
Just try all of them and see if any of them works well.
You can't damage anything.
When setting the jumper while the amp is on be sure to remove the headphone plug.
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Post by killerq on Nov 8, 2020 20:56:38 GMT
In the manual you can find the various settings. Just try all of them and see if any of them works well. You can't damage anything. When setting the jumper while the amp is on be sure to remove the headphone plug. Good to know. As long as I remove the headphones, can the gain and resistance jumpers be switched while the unit is on as well? |
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Post by killerq on Nov 8, 2020 22:15:15 GMT
SO, I have found some new settings that get rid of the bass distortion with my new adapter.
Settings are: BP-C, wo/am, low gain.
After using these new settings, I went back to my KenRad single 6SN7 tube, and the there's NO hum - the background noise was pretty much pitch black, wow. I have never heard this quiet of a noise floor on a Tube amp. Also, this is using really sensitive Dan Clark Aeon 2 Closed Planar Magnetic cans. Love it!
But, back to the adapter - although the distortion is gone, there is still a large amount of hum. If touch the body of the amp, the hum drops, but is still bad (even though everything is plugged into the same power strip). I suppose I can pick up a pair of cheap metal body 6p5 or 6j5 tubes so I can a/b test the hum.
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Post by killerq on Nov 9, 2020 0:12:19 GMT
I just tried one of these ground eliminators just to test that possibility. The him did not go away. When I unplugged the rca cables so that nothing was connected, the him actually got worse. Buuuuuut, I solved it!!!! The ONLY thing I found was to touch BOTH rca cables connectors with one end of the foil abs then touch the other end of the foil to the tops or both tubes. The hum is 99.95 % gone. As a matter of fact, I really have to concentrate to even hear it. Here’s the image imgur.com/a/mZSWy2KSo, I suppose I can experiment with how little of foil I actually need to accomplish this - I just wanted to mention it right away since I was so excited. Any thoughts on a better solution? A new, discreet ground wire somewhere on the unit instead ? |
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Post by killerq on Nov 9, 2020 13:39:00 GMT
In the manual you can find the various settings. Just try all of them and see if any of them works well. You can't damage anything. When setting the jumper while the amp is on be sure to remove the headphone plug. Good to know. As long as I remove the headphones, can the gain and resistance jumpers be switched while the unit is on as well? You’ll see that I found a solution - hopefully the ground wire idea is an OK fix and doesn’t mean the amp is defective. |
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Post by killerq on Nov 9, 2020 16:17:40 GMT
Is it true that the pad where the standoff is in the upper left corner of the ember 2 board acts as a ground? If so, this should work for me. I would assume that touching both RCA Cable ends together is the same as ground. Here’s a pic. imgur.com/a/AgjmR2M |
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Post by mvneufeld on Nov 9, 2020 17:31:19 GMT
The hum from your 6P5Gs is caused by RF interference. It's pretty common with the twins like 6J5s, 6P5s, and 6C5s. 6F8Gs can hum, too. To fix it you need to build a Faraday cage. You can use copper mesh or try chicken wire. I started with copper mesh cages, but discovered that chicken wire worked well enough while allowing me to gaze fondly at my tubes. ;-) Here's a pic of my chicken wire cage: i.postimg.cc/3Nsb7jg5/IMG-3432.jpgNote the ground running into the standoff as you mentioned. If you want to try copper mesh, it's cheap on Amazon - search for 99.9% Pure Copper Wire 40 Mesh |
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Post by killerq on Nov 9, 2020 18:02:35 GMT
The hum from your 6P5Gs is caused by RF interference. It's pretty common with the twins like 6J5s, 6P5s, and 6C5s. 6F8Gs can hum, too. To fix it you need to build a Faraday cage. You can use copper mesh or try chicken wire. I started with copper mesh cages, but discovered that chicken wire worked well enough while allowing me to gaze fondly at my tubes. ;-) Here's a pic of my chicken wire cage: i.postimg.cc/3Nsb7jg5/IMG-3432.jpgNote the ground running into the standoff as you mentioned. If you want to try copper mesh, it's cheap on Amazon - search for 99.9% Pure Copper Wire 40 Mesh I’m not sure it’s RF in this case. Even when I move the amp or cover the setup entirely in a foil cage, the hum is still there. As soon as i take a small wire or piece of thin foil (the size of a pencil) and connect the two RCA grounds to the glass, it goes away 100% |
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Post by mvneufeld on Nov 9, 2020 21:02:33 GMT
The only other thing I can think of is maybe you have a ground loop. The easiest way to do fix a ground loop is to power everything through a single AC socket.
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solderdude
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Post by solderdude on Nov 9, 2020 21:10:28 GMT
Is it true that the pad where the standoff is in the upper left corner of the ember 2 board acts as a ground? If so, this should work for me. I would assume that touching both RCA Cable ends together is the same as ground. Here’s a pic. imgur.com/a/AgjmR2MI believe Jeremy had one of the stands grounded. It's the same ground as RCA ground. Sounds a bit like a grounding issue. There is no one solution but asks for some experimentation. Also the tube construction is one very big antenna picking up hum as well as RF. Hard to say what's causing the issue in your particular case. |
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Post by killerq on Nov 9, 2020 21:56:34 GMT
The only other thing I can think of is maybe you have a ground loop. The easiest way to do fix a ground loop is to power everything through a single AC socket. Everything is on the same socket. |
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Post by killerq on Nov 10, 2020 1:48:53 GMT
I just tried several cages. No luck. This simple strip of foil is literally the only thing that works. It’s a 100% silent noise floor now. Hmmm imgur.com/a/tTwHjAF |
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