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Showing content with the highest reputation on 04/21/2023 in Posts
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and yet the audio precision actually reports .0008 % thd at 1khz. so much for that being worth anything. sure looks like about 10 volts per microsecond slew rate. pretty grim at higher voltage levels. winding transformers correctly really is not that hard. too bad the lundhal transformers won't fit inside the box. hmm, there is that size thing again. (usa_love) what really gets me is the really poor soldering job, probably there is a significant failure rate of topping products in the field. And yet led lit sails that makes you think there are tubes inside. my guess is that the koss box sounds better than this, for roughly the same price. quoting from someone who knows how to actually make transformers like this.. quote In a transformer winding, inter-turn capacitance is generally negligible compared to inter-layer capacitance. We can approximate the winding self-capacitance within a small factor by considering only the capacitance between winding layers, approximating the layer to a conductor sheet. The highest capacitance arrangement is when each layer is wound in opposite directions, so left to right on the first, right to left on the next. That's because the first turn of the first layer is opposite the last turn of the next layer, so there's twice the voltage per layer between those turns. As the energy stored in the self-capacitance goes as the square of the voltage, this more than offsets the lower voltage difference at the other side of the windings. A lower capacitance can be obtained by winding each layer in the same direction, returning between layers, so left to right, then left to right again. The voltage between layers is now uniform at the per layer voltage. end quote transformers made this way have to be partially done by hand. no winding machine currently available does this. its why esl63 replacement transformers are $500 each.4 points
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Throw it out and start again? I mean this truly terrible stuff but I stripped it down yesterday and yeah... I can see why Topping has a reputation for failing a lot as this was probably soldered by people not being paid a whole lot. Some joints have barely any solder on them and there is flux everywhere. The transformers are clearly styled after the Stax SRD-7 units (down to the color of the wires) but who knows how they are actually wound. It is quite tricky and expensive to wind a really low capacitance transformer. The back of the Stax socket board and yup, straight links to the socket from the bias and the transformers. Look how dirty this thing is, it is covered in muck. Sorry for the shit pictures, I didn't want to drag out a better camera for this. This is not good... Here is what I'm doing to my own unit as I ripped off the Stax connector PCB: This simple board just adds some high voltage resistors to the bias line, adds output protection resistors (also HV units) and zeners to clamp the output so it can never go over 1150Vppss. The board is designed to go on the smaller pins of the socket so this could be fitted to the amp with the original board in place if the connectors are just cut off.4 points
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Jest before I stopped playing with it last night I took some measurements, I fed it a 10kHz squarewave, 1Vpp from a function gen and while it was a pain to get a good ground in there, we are not dealing with high speed signals either. Here is the input to the amp: Nice enough squarewave but here is the output of the amp, set to my usual listening level: This was one leg of the output of the transformer, here is the other: Yeah.... this isn't great, is it? Might be the worst I've ever seen but I naturally forgot to measure the primary of the transformers and I've already started to rip the unit apart. I may do that later.1 point
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Taking away a balcony door on the top floor rental of a home in the Sunset District. Replacing old door with a window. My boss is a stickler for matching the height to the existing window, down to the 1/16". That's the hardest part, especially since the existing window is nothing like the new one. Turned out great. Once the painter is done it'll look like it's always been that way.1 point
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If The Moon Turns Green Diana Panton 2011 https://album.link/i/1443526888 Example: Lovely female jazz voice. I have been away from jazz vocals for a while. I think I need a little more in my life. This did nicely.1 point
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We Get Requests Oscar Peterson Trio 1964 https://album.link/i/1443078246 Example: You know, it is just required listening now and then. Still strikes me as one of the most beautiful jazz albums ever made. Just overhearing it for a few seconds compels me to cue up the album and 40 minutes later, I am happier than I started that time. Thx Oscar and friends.1 point
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This is how the night went... I picked him up at his jobsite after work. He does not drive, and usually rides with his Uncle. We just made small talk as I drove him to his home to shower and change clothes. I chatted with his Uncle while that took place. I think his Uncle was more excited than anyone. When he was ready we went to a local (Daly City) Greek spot for Gyros. He had never experienced a Gyro, and he absolutely loved it. While having our Gyros, I directed the conversation straight (no pun intended) to his sexuality. I wanted to get that out of the way. He was a bit embarrassed as we talked openly, but was very forthcoming. He is a virgin, and has never really been attracted to girls. He does seem to be a bit confused about exactly what his sexuality is, as he's also never done anything with another guy. He just said that he feels good whenever he's around me. He definitely has Father figure feelings toward me, but is confused regarding the other. He did say that he thought I was very handsome, to which I joked "well of course, you do have good eyesight", and that managed to get a chuckle from him. He's such an innocent young man. Warm and friendly with a curiosity about everything. I do enjoy being around him. But I'm certain that in no way do I want to be his first sexual encounter. We've agreed that we will be friends for now, and I've offered to slowly introduce him into the gay community. Then he can better determine where he fits in. I'm about 95% sure that he's gay. But want him to take all the time he needs to figure that out for himself. I'm also determined to steer him toward guys his age. Your first sexual experience is extremely important in setting the tone for future relationships. And those would be easier if they involved similar ages and stages in life. I realized that I do feel very protective toward him. And maybe a Father figure/mentor will not only be beneficial for him, but myself as well. We ended our outing watching Mario at the theater, where he did snuggle into me a bit, and I didn't discourage that. Very innocent, but kind of cute.1 point
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Agreed, Craig. I used to love to pour through my dad's copies of Mad.... To this day, I still remember one cartoon that I repeated to my son. A kid is bugging his dad and keeps saying something like, "Dad lookit....lookit what I'm doing....lookit, lookit, lookit....!" And the dad then retorts, "I'm lookiting!!" Don't know why that stuck with me, but I still use it occasionally.....1 point
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