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Post by musicman on Jun 4, 2015 0:43:31 GMT
JGlatz, the 7193's have arrived. They were delivered on Saturday, but I was not home to sign for them, so on Monday gave the signed slip to the postal worker, he turned it in that day. No tubes, Tues none today, had a talk with the postal worker,and he advised me to go to the main post office and pick them up, he said he had seen them go two weeks before they were put out for delivery, I know government. At any rate these KenRads were made in 1943 for the Navy and were essentially new. The boxes were original and in fair condition. I had been listening to my Ken Rad VT231 all week, put in the new 7193's and after about three hours listening, having dinner and going back for more, these are very hard to tell the difference, if any from the vt231. Lot's of bass, mids are sweet, vocals very articulate, and the highs are ample. I am going to see if he has another set of these and then unplug my internet connection for a few months! Listening to Patrica Barber now, and her Taste of Honey is one the best I have heard. Heard some triangles and talk about clear as a bell, amazing. Sound stage is some of the widest I have heard on the Ember. The sound is very "open"if that makes sense. Chris Botti's trumpet is suburb, no smearing on the high notes, they just jump out at you. Eva Cassidy's voice on How will it end just goes on forever, you just keep waiting for it to snap, but just goes up and comes back down in one piece. Sorry, so much to listen to, so little time. By the way now that I have the metal chassis plates,with the FrankenEmber these tubes look even better. Almost like they were made for each other. Enough, have to get back to music. Thanks for listening.
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Post by richard51 on Jun 4, 2015 1:24:30 GMT
thanks for your impressions musicman...My adapter was shipped to me 5 days ago,but was a defect, the chineese seller said that he will ship to me another one......I waited with my kenrad 7193 for the adapter... If i read you correctly the 7193 are at worst on the same level than the 6sn7 tubes...perhaps a little better...thanks for your time....
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Post by musicman on Jun 4, 2015 1:33:07 GMT
What I meant was that these particular tubes, Ken Rad 7193 compared very favorably to my Ken Rad 6sn7 vt231, tube. With the adapter, and these 7193's I should be happy, until Jeremy gets the 650 filters done, then back at it again.
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Post by richard51 on Jun 4, 2015 1:41:40 GMT
The Ember is our paradise never lost... thanks
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JGlatz
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Posts: 26
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Post by JGlatz on Jun 4, 2015 3:01:35 GMT
Hey Musicman,
when I got my 7193 KenRads they were new in the original boxes. So new that I had to almost tear the box to get the tube out. I have never not been able to figure out how to get a tube out of the box but these were kicking my butt, like they were designed around the tube. Anyway it took a couple of days for things to break in. Listen for the bass to tighten up and the soundstage to expand a little more. Even the highs will become a little more clear. On a side note, when you posted your picture how do you get it to be so big? When ever I try and attach a picture it shows like a postage stamp.
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Deleted
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Post by Deleted on Jun 4, 2015 4:06:57 GMT
It depends how big the original image is & where you host it.
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solderdude
Administrator
measureutternutter
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Post by solderdude on Jun 4, 2015 5:11:22 GMT
Why in the mk-I version the bias changes at the variation of the volume potentiometer? Also, doing the mod in the mk-I version to avoid the scratches (adding a 10 k resistor in series with the wiper of the volpot ) will change the behaviour or the bias will be altered anyway? The reason for this change in tube current itself has to do with the bias voltage (the voltage between grid and cathode) which is self regulating. This is something else as the bias voltage that sets the internal output voltage at around 1/2 suplly voltage. Because the circuit works on a very low voltage (lower than usual) you have more than 'normal' electrons flowing from the cathode to the grid. The more electrons flow through a resistor (100k with caps in) the higher the voltage drop over that resistor. This (together with the cathode resistor) sets the tube current (not output current) Without the input cap the resistor the grid 'sees' is between 0 Ohm (vol completely down) to 1k (volpot in the middle setting) or max 9k Ohm. Because of this the current IN the tube will differ from when a 100k is used. Of course the output voltage biassing is done automatically so the amplifier itself will always be set optimally (for max symmetrical output voltage swing) but internally the tube will run under a different current. With different types of tubes the current also can differ over a very wide range. This is taken care of by the auto bias circuit. In the mk-II there is another series resistor which ensures the grid always 'sees' 10k minimum and this gets rid of the 'scratch' (which basically is a change in tube current) and brings it down to very low levels. This also means the tube current varies less internally.
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Post by musicman on Jun 4, 2015 13:34:34 GMT
Hey Musicman, when I got my 7193 KenRads they were new in the original boxes. So new that I had to almost tear the box to get the tube out. I have never not been able to figure out how to get a tube out of the box but these were kicking my butt, like they were designed around the tube. Anyway it took a couple of days for things to break in. Listen for the bass to tighten up and the soundstage to expand a little more. Even the highs will become a little more clear. On a side note, when you posted your picture how do you get it to be so big? When ever I try and attach a picture it shows like a postage stamp. Mine had the same boxes. They have an inner sleeve that wraps around the tube, and is then inserted in the box. I usually open both ends of the box and push the tube through,instead of trying to pull it out. Did this more times than I care to remember back in the sixties as a tech in the Navy. Back then, they were just changing over to solid state, funny thing, I was in the tech school, just got through tube theory, and then when we started solid state, the first thing the instructor did was say, everything you learned about tubes forget it, things be different here. I know you have learned about electron flow, just think of it as hole flow instead of electron flow, the class went to the bar that night, "hole flow" first we have to accept electrons that we can not see, flowing through a solid piece of wire, not we have to "see"holes following through itl Bar made a big profit that night.
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Post by musicman on Jun 4, 2015 14:20:50 GMT
Hey Musicman, when I got my 7193 KenRads they were new in the original boxes. So new that I had to almost tear the box to get the tube out. I have never not been able to figure out how to get a tube out of the box but these were kicking my butt, like they were designed around the tube. Anyway it took a couple of days for things to break in. Listen for the bass to tighten up and the soundstage to expand a little more. Even the highs will become a little more clear. On a side note, when you posted your picture how do you get it to be so big? When ever I try and attach a picture it shows like a postage stamp.
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Deleted
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Post by Deleted on Jun 4, 2015 14:48:01 GMT
So, does that contraption sound better than your single VT-231, or not?
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Deleted
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Post by Deleted on Jun 4, 2015 14:50:37 GMT
Listening to Patrica Barber now, and her Taste of Honey is one the best I have heard. Heard some triangles and talk about clear as a bell, amazing. Is this the version on her Café Blue album? If so, what do you think of Nardis? That's my go-to demo track for jazz. Awesome!
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Rabbit
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Post by Rabbit on Jun 4, 2015 14:53:30 GMT
It looks like something from Dr Who.
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Deleted
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Post by Deleted on Jun 4, 2015 15:03:33 GMT
It looks like something from Dr Who. Aye & not the cutie assistant either.
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jaxz
valued member
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Post by jaxz on Jun 4, 2015 16:09:50 GMT
Looks really good musicmanThe metal chassis have more height related to acrylic? I don't know if has been covered but I want to know what exactly input capacitors do and how they alter the sound bypassing it. Thanks! The metal chassis plates and the acrylic are the same height. The metal plates give it a little more weight and it does not slide as easily, bypassing the input caps does not have much if any effect on signal, they help eliminate the volume pot scratchiness. Some pots make a little noise when turned, pretty normal, with the input caps in the circuit the noise from the mechanical link in the pot is eliminated. I tried both ways, with the caps bypassed, I could hear a little scratchiness when turning the volume pot, but did not hear any benefit so left the caps in the circuit. I did not think I would like the metal chassis plates as much as I do. In my opinion when the demo is sent around for reviews they should be included. Makes a much nicer package, there are other amps out there that look similar to the Ember, but not with the metal plates. The other open frame amps are all plastic and do not look nearly as nice as the matte black plates on the Ember. Thank you. I have a slightly scratch volpot but only when used from FiiO X5 line out. The volpot, when Ember is feed from the ODAC or AudioGD NFB15, is dead silent. I dont know what's happening.
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JGlatz
valued member
Posts: 26
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Post by JGlatz on Jun 4, 2015 18:51:22 GMT
Hey Musicman, when I got my 7193 KenRads they were new in the original boxes. So new that I had to almost tear the box to get the tube out. I have never not been able to figure out how to get a tube out of the box but these were kicking my butt, like they were designed around the tube. Anyway it took a couple of days for things to break in. Listen for the bass to tighten up and the soundstage to expand a little more. Even the highs will become a little more clear. On a side note, when you posted your picture how do you get it to be so big? When ever I try and attach a picture it shows like a postage stamp. Mine had the same boxes. They have an inner sleeve that wraps around the tube, and is then inserted in the box. I usually open both ends of the box and push the tube through,instead of trying to pull it out. Did this more times than I care to remember back in the sixties as a tech in the Navy. Back then, they were just changing over to solid state, funny thing, I was in the tech school, just got through tube theory, and then when we started solid state, the first thing the instructor did was say, everything you learned about tubes forget it, things be different here. I know you have learned about electron flow, just think of it as hole flow instead of electron flow, the class went to the bar that night, "hole flow" first we have to accept electrons that we can not see, flowing through a solid piece of wire, not we have to "see"holes following through itl Bar made a big profit that night. It appears that over time the inner sleeves have fused to the outer box they would not budge. By the way Swabby thanks for your service. Us jarheads really appreciate you guys giving us a lift around the world...
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