Tube Amp Archive

That's about right. I would add the Rk to the Ra to calculate the max current as 282V/110k=2.56mA, and draw that load line. Since you know Rk, assume cathode voltage Vk is -2.5V, calculate current Ik=-2.5V/10k=0.25mA, and spot that point on the -2.5V grid line. Next assume Vk is -3V and calculate I...

I've had a look again and I think I get it now. If: The max plate voltage is 282v The max plate current is 2.82ma The plate is biased at about 250V and 0.3ma The Quiescent power dissipation from the plate is about 75mW The grid must be about -2.75v Rk = V/I = 2.75/0.0003 = about 10K Voltage gain is ...

I've recently read up (Robert Megant) on how to design tube amplifier stages and as an exercise I'm going through some common circuits bit by bit calculating the operating point, gain, dissipation etc of the various stages. I started on the express (kelly 90) this morning and while V1a and V1b seem ...

I'm finishing off a tweed clone and when testing it I find I have to be so much more aware of my string attack otherwise the dynamics sound awfull twang pop etc (my playing not the amps fault). Especially on a fairly recently aquired tele for some reason. in fact after years of only playing high ou...

To me, touch sensitivity is like a tweed Champ driven just to the point of breaking up. Maybe about half volume. Or maybe full volume but driven with the vloume control on your guitar turned down to 4 or 5. When you dig in to the strings, it growls and breaks up, and when you ease off the string at...

So Its about maintaining headroom in the preamp stage.
So is tube distortion, low volume and response a possibility? perhaps by adding more preamp stages that are just starting to simultaniously hit the sweet spot

Strange...

I don't know how. but this seems to have posted up twice.
Mods. Please delete this one if appropriate.

I don't know how. but this seems to have posted up twice.
Mods. Please delete this one if appropriate.

As I read more about valves and amp design I keep coming across references to touch responsive valves and amps but I haven't found a decent explanation of what technically makes an amp more or less responsive. I seem to find with my single ended 5w kit amp (Ampmaker SE-5A) that if I crank the gain b...

As I read more about valves and amp design I keep coming across references to touch responsive valves and amps but I haven't found a decent explanation of what technically makes an amp more or less responsive. I seem to find with my single ended 5w kit amp (Ampmaker SE-5A) that if I crank the gain b...

Cheers for that Glen. I found the album on Spotify too and had a listen through while I was walking the dogs. Nice playing and a great reference for the TW. I also found a video of you on Youtube comparing two TW's and that was great to see how you worked the guitar volume to get the tone. I hoping ...

I've only recently stumbled accross the whole trainwreck thing and I'm seriously considering starting a build.
I was just wondering out of interest and reference what tracks or albums might have been recorded with one? any one know?

I'm obviously doing my sums wrong. I'll have to look into that. Been in the UK, and transformers been heavy choice seems a bit limited. Barry from Ampmaker.com has some custom made in the UK which seem fairly cost effective. There's a 275-0-275V 36W that looks about suitable and there's also an outp...

So, If I'm doing mu sums right to get a B+ 0f 410vdc I would need a PT with a secondary voltage of 450-0-450 would that be right?
[IMG:507:253]http://i51.photobucket.com/albums/f368/JammyBStard/TrainwreckA1aPowercircuit_zps7bed8a32.png[/img][/quote]