dsavitsk

In addition to a regulator for the PS, a CCS plate load for the first stage will decrease distortion, a CCS cathode load for the second stage will also decrease distortion, and using a MOSFET instead of the awful 6080 will decrease output impedance, lower noise, and decrease distortion. It will also allow you to eliminate the 6080 heater power supply which is the most likely source of noise, and the source of tons of heat that needs to be dealt with. A first stage biasing scheme that does not involve an RC filter will also do good things. While we're at it, a 6SN7 gives you too much gain for nearly every headphone out there. That means that you are attenuating and then amplifying, which is a source of both noise and distortion. There are a number of ways to lower gain - the easiest might be simply eliminating the cathode bypass cap (this also increases plate impedance, so whether it can drive HF into the next stage will be an issue, but it is probably fine, but it has the benefit of getting rid of that RC filter). You can also find a lower mu tube, or perhaps a pentode with a low impedance plate load to lower gain. Or you could use a step up transformer on the input. I've now replaced every part of your amp

250V refers to plate to cathode voltage. Because the tube is biased up by the preceding stage, the voltage across the tube is considerably lower than 250V. Even if Blackgates were better than other caps, and even if they are still good, a small regulator using about $4 in parts will sound better. On that note, there is a lot that can be done to improve the circuit with minimal effort/expense.

Did you know him by his crocs?

$1400 seems high for $80 worth of transformers. Doubtful. But even if there is, there will be considerably more across your head.

No pictures, but looking for something we'd never had, we went out for Nigerian food last weekend. It was very good.

There is nothing about that article that convinces me that the cloud is not just someone else's computer. Clearly it is bigger than mine, and more redundant. But everybody who makes that "joke" understands that. And contrary to the article, history suggests that scaling things up in size does not increase the attention to detail.

Steve and I cut a window out of the wall today so I can put in a ~12" deep medicine cabinet. In the process, we got a good look at the structure of the wall which is steel lath, about an inch of concrete, and then some plaster. Overall, a very messy experience. The wall ate my oscillating tool, but we got through with an angle grinder. The first pic shows the tile, and the wall before the cut (that's the existing hole from the old cabinet) the second is the piece we removed.

Happy Birthday!

Those leads look awfully close to shorting.

Looks cool. But I've never understood why the solid state world threw out the inductor baby with the tube bathwater. Adding even a small choke to your filter will pay huge dividends on high frequency harshness that the bridges add, that the R-cores pass, and that those big caps do a poor job filtering out.

I think you'll be disappointing with them. Try the AlNiCo's instead - they feel more natural.

I wouldn't charge a penny over $3850

I don't know. I like Greene & Greene as much as the next guy*, but those seem a bit overworked. And they would not match many speakers in terms of design. * not really, actually

https://furnituremaker.com/portfolio-item/rafter-tail-speaker-stands/

Hiss is not due to an impedance mismatch per se. It is caused by current moving through electronic parts, and it can be exacerbated by having too much gain which amplifies it. The reason one might see it more with low impedance headphones is that they are often louder for a given voltage. https://en.wikipedia.org/wiki/Johnson–Nyquist_noise https://en.wikipedia.org/wiki/Shot_noise

Sorry for your loss, Kerry.

I don't like the feel of foam at all, but I especially don't like how it holds heat. And I find the smell from foam or latex unpleasant. Barring finding something novel, I think we'll likely end up with a run of the mill mattress with a foam free topper for now. Then perhaps get the fancy mattress at some later date.

Rubber is on the not-wanted list. I am not sure that what I want actually exists in an affordable state, but that's nothing new.

Yes to springs, but nearly all of them have layers of foam, too. We're looking for something made with cotton, wool, etc. I can only find one, and I can't afford it. I'm wondering if there is anything else out there.

Is anyone aware of any reasonable mattresses made without foam - latex, petroleum, soy, or otherwise?

Sounds like they are expecting your power to be 120V, and that it runs lower. Even a surge on a different circuit could lower house power overall. Our power runs at 123V in the winter, and around 110V in the summer (108 when the dryer is on). Pick up one of these to watch it over time.

This is often due to a 1/4" knob on a 6mm shaft. If that's the case, a layer or two of masking tape on the shaft will add about enough thickness.