The Amp Garage

Isn't it the same as the 50L6, 35L6, etc? I've used the 50L6. Sounds alright. Not production, but there are plenty to be had at a reasonable price. The 35L6 has a lower heater draw so when push comes to shove the other variants can make more power. The tube being uncommon depends on how you look at...

Link says that it was deleted.

No transformer but some say power tube distortion may actually be from the PI. So how do you simulate the power tubes effect on the PI when clipping? Have not tried it, I doodle so many circuits but never get to try most of them.

You do not have a resistor to ground on the second triode's grid. When switching you most likely will get a pop unless you put a 4.7M (as an example) after the capacitor on the first triode's plate. Going straight in from the first stage into the second might be a bit too much signal level. You can ...

Try a little NFB. Without it the output section works more as a current source as compared to a transistor amp that acts as a voltage source. What that means is that at the resonance of the speaker the amp tries to put more power into the speaker than if there was NFB. The one negative would be any ...

A standby switch (depending on arrangement) would be between the first node capacitor and the center tap of the OT along with the rest of the amp. One standby switch shutting off the current to the output transformer center tap shuts off current through the both windings... Note that OT primary and...

...Certainly not any worse than an amp with a standby. I agree that the scenarios are similar but query your certainty that the proposed application is no worse than standby. Consider that an OT’s primary inductance may be many times greater than that of a typical HT choke, and that with signal, th...

I have been thinking about it. You can keep the power on both OT's all the time. Two poles from the plate to the two primaries. A pole for the output winding to speaker. When you break the plate to primary contact the current stops suddenly and when it makes the other winding it starts suddenly. Cer...

So what happens if you change the values in a PI? Surely it changes the nature of that design. I am guessing that you can not just compare one PI with the other without seeing what changes to the values do to that PI. Well you can, but then you are only getting half the story.

No need to use a 34, use an 84 instead. Much cheaper tubes and for power supply requirements. Need three to five times the number of tubes to get the same amount of gain. Heck, why not use a smaller output tube, say a 6AK6? miniscule heater amperage, cheap enough tube. Just need a lot of 7-pin sock...

No need to use a 34, use an 84 instead. Much cheaper tubes and for power supply requirements. Need three to five times the number of tubes to get the same amount of gain. Heck, why not use a smaller output tube, say a 6AK6? miniscule heater amperage, cheap enough tube. Just need a lot of 7-pin socke...

Reminds me of a quickie I drew up.

On my to-do list. I will have a lot more time next year so it should get done. I would like to try a couple of different flavors, simple https://i.imgur.com/mDq2d9x.png?1 Probably can use a voltage divider before the FET. And a little more. https://i.imgur.com/IWns2V7.png?1 https://i.imgur.com/qZw9s...

Tony Bones wrote: ↑Sat Sep 28, 2019 12:58 am

printer2 wrote: ↑Fri Sep 27, 2019 10:43 pm [...], tie the diode pins to the plate.

Or the cathode.

Meant cathode, sorry, brain locks up some days.

The tail end of the transformer bucks some of the hum in the amplifier. Just connect to the center tap (which is not at the center ) and it will work like any other SE OT.