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Alles klar!Kann night spreche in gutte Deutsch auch. Tut mir leid.

Thank You Helm.
Have another newbie question then, as follow:
From a triode perspective the grid leak it count just as load for previous source ? Otherwise, the valve didn't care if the signal...

Understood. 12AX7 btw.

This is the first pole, the second one will be determined by input capacitance of the valve itself in conjunction with series resistance and input impedance whatever the signal is shunted to the...

I did not expect to improve into tonal way, just to have more consistency over volume pot position. I cannot manage a bypass cap over pot in a way to keep consistent tone from low to loud volume....

Think freq reponse will be more consistent preserved over volume control range. Does it works ? Thanks

Thank You.
I.m trying to figure a "better" volume control with better frequency characteristic over a more consistent impedance. A second order in this position also hope to get some tonal benefits....

Thanks, I can measure , but just edited for an additional question,please:

...if is changed it will be disturbed by operational input voltage condition swing ?

Hello,
I wonder what is happen from a biasing point of view if one triode , say 12ax7, is cathode biased through fixed resistor say 2,2 k, for a certain potential point, say 1.6 V, but I put in the...

Hi , yes 600. I used a magnastat iron and there are only tips I have. As a remark, I saw the wafer melted litle bit. Ordinary plastic perhaps...? Maybe is better to use a pot with more thermal...

Two pots soldered with all my best skills can do... one hit, one miss. Something get loose as pushed gentle the pot get intermitent operation. Maybe some of you guys can do it but for sure is not...

Hello.
I wanna modify some 24 mm pots from soldering lugs to soldering pins one mounted directly to PCB. The only way found, due to layout and pot size ,was to cut completely the lugs and to solder...

Hello,
I have a job in progress restoring an old Dynacord Bass-King. I just noticed the bass control is not quite functional as should be jumping to huge boost the bass after fraction of knob turn....

I just work into a '63 Dynacord Bass-King. Rectified alcohol and ear sticks (a lot) works for me. Be careful at any holes which are not solder sealed as the dirty liquid can leak on the other side...

As can see there is a path to the v1 plate to ground through 500pF cap , so maybe big 2M resistor is matter. You can fit one 1M resistor in top of more common 1M pot and then get half of max signal...

Take a look at this: GW Instek, gag-810.Analog basic one, 200 bucks around, very happy with it.
https://www.gwinstek.com/en-GB/products/detail/GAG-810_GAG-809

...btw talking about speakers...something for mythbusters..:)

https://m.youtube.com/watch?v=P4grDEC_Uj0

https://m.youtube.com/watch?v=CDy2dwPQAFs

https://m.youtube.com/watch?v=GIjyiIjvXFk

I don't think they made transformers, but they received transformers from one of their suppliers. I.m pretty sure no one supplier ship to Marshall transformers like that but pretty much well packed...

Those screen draw (sometimes) current at startup...a lot, why ?
I asked just to share opinions about possible scenarios by the other techs experience as for me no one power tubes I used till now...

..and Yes, it was confirmed. It is a bad tube. I swapped it to the other side of the rail. After some successful starts up yesterday, today it was time to smoke its 1k/ 5w screen grid resistor into...

....like this ? :)
https://m.youtube.com/watch?v=_2raNqztPX0

Thanks, I will swap it on other position and hope to confirm the tube is bad.

Hello,
I recorded a issue to one of my power tube from a new 6CA7 matched set. At start up one of the screen resistor it start to burn. It is happen just at first startup after the amp stayed off...

It is something which intrigues in Rod Elliot floating paraphase description , as: "The second form is shown shown below (version 2), and it works by using the second valve as a unity gain inverter,...

The "wattage" is expression of power and is related by the heat dissipated by the speaker coil in You instance. You have to determine this as maximum admissible condition. Maybe some guys know how...

That is correct

Sure, I.ll need to do the amplification of paraphase more than unity by a factor. That meant less local feedback. In consequence the feedback resistor should be bigger, That is correct ? I used 470k...

Can be introduced in simulation a build-out resistor to balance the output impedance as M Blencowe suggested, please?
...