audio-talk

A layer of hash has been removed as it was last time.

I have to ask. Did the layer of hash come back when you put the electrolytics back in last time?

All good. Was at Croft. Well not all good still loads to work on. Almost got the Mx5 to where I wanted it. (Much cheaper to turn into what I want than the Boxster would be). Being driven around by someone who knows what he is doing puts a stake in the ground what the car will do. I doubt getting clo...

Lots of progress today. I missed it till now as I was away driving in circles again all day.

Well I am not fighting for that valve . But a flat load line does wonders.

I was thinking 200v 25ma but I agree more would be better.

Why have you drawn a 6k load line for the interstage?
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Ok, so maybe el84 would be a better choice. Just wanted an excuse to mention E130L, I think its a great valve that no one seems to use.

I haven't run the numbers, but I wonder if the el34 in pentode driving the interstage might give you extra gain and a simpler drive for the 6072a, so you might be able to miss the 5687. Also, el84 might do most of the work of a el34 as its only driving the gm70 grid instead of a loudspeaker. Also an...

I would hazard to suggest the el34 would be better than a DHT, far less microphonic as a driver valve. Why not just do what Phil does, make your existing amp the driver, replace the output TX with the interstage, then just add the gm70 output stage. At least as a prototype.

I think they can, though, I would think you might want to run that o/p stage b+ via a variac partly for the valve, and partly for room temperature. 125W in winter, maybe a bit less in summer (+ 60W heater power as well). In the amps I built Colin way back, that Andrew has now, I used a similar circu...

Oh, and I was quoting Mr Sowter "Junior". I used the past tense as he has now retired and Sowter Transformers sold.

Wound components these days are not wound for 243 volts as theyre imported and we said to the rest of europe our voltage is 230. But it isnt. No wound components from cheap sources have any reserves. More true for chokes you want to use as choke input. Mr Senior Sowter is right. Well, to be picky, ...

Yep its often ignored that the entire AC component of the rectified sine wave is applied directly across the choke (the coupling cap being a short at AC). The effect of that instantaneously being stopped at some point in the 100Hz cycle when its turned off is never going to be trivial. Brian Sowter ...

Yep, anywhere from 600v-1200v and a GM70 in A1 is just a "simple" way of getting a bit more Set power. Once you get over the heater requirement its a nice more powerful cross of a 211 and a 845. I think a 7k load works well with it, but its generally ok with anything from 5k to 12k.

However after calculating distortion at youre operating point 2nd h is only 3.9%.

Just to put this in perspective, when I talked about high 2nd I was thinking 0.5% at most. Beyond that I would start to consider it a guitar effects box.