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[kodabmx]

I finished the Stupendous amp 🙂

 

[prairieboy]

Nice work. And really, two uses: an amp and a space heater! 🙂

 

[Duke58]

Stupendous!

What design is it? Are those 6CL6 output tubes?

 

[boywonder]

I'm not sure how that works, I think they are stamped in. Frontpanel express can do them too
http://www.frontpanelexpress.com/products#studs

They are typically called PEM studs or PEM fasteners....and they come in many sizes and shapes to press into different thickness materials and metal/plastic etc.


Technically they are "press-in" fasteners

McMaster-Carr

 

[kodabmx]

Nice work. And really, two uses: an amp and a space heater! 🙂

Thank you. The black screws are in the mail 🙂
Right? Still not as hot as the light bulb MOSFET amp though 😀

Stupendous!

What design is it? Are those 6CL6 output tubes?

It's The Stupendous 6P1P 4PP amplifier!

It uses 8 6P1P triode strapped per channel and makes 8W of class A power.

 

[Bas Horneman]

Rh84 for a friend

 

[Jeroen211]

Which UGTs are so small that they fit inside?

 

[K.A.B]

Damn Bas that was slick but were have you hide the input?

 

[Hearinspace]

Simple put, parallel feedback is applied in parallel with input signal (think of inverting amp using opamp, where one resistor goes from the source, another one goes from the output).

Would that include plate to grid (Schade) feedback?

 

[Bas Horneman]

Which UGTs are so small that they fit inside?

Got them from Triode Electronics TO-9105-1. Very small. But capable. That's the reason I built a RH84. It has some tricks to make a small output transformer sound bigger.

 

[Bas Horneman]

Damn Bas that was slick but were have you hide the input?

There is going to be a raspberry pi based volumio with hifiberry dac inside...So an all in one streamer and amp.

 

[stevenrotterdam]

Hi Bas
Do you think it is worth te trouble to repurpose the output of a stereo radio with EL95 as an amp?

 

[K.A.B]

There is going to be a raspberry pi based volumio with hifiberry dac inside...So an all in one streamer and amp.

Nice, yes there are lots of new options to connect things and less with cable everywhere.

 

[Adolf Corkscrew]

Measuring a lab prototype. KT66 push-pull, around 35 watts of power with fairly low distortion.

 

[v4lve lover]

3X EL34 regulated power supply

A friend of mine finally found the time to build some of the boards i drew back in ''19 for a tube regulated power supply with 3X EL34 or KT88.


Control is a EF184, The circuit is proprietary.

 

[Diabolical Artificer]

A friend of mine finally found the time to build some of the boards i drew back in ''19 for a tube regulated power supply with 3X EL34 or KT88.

Specs?

 

[v4lve lover]

About 300mA continuous max, tubes need 150V headroom or so to provide that.



Output adjustable between 150-400V


Maximum dissipation in the trioded EL34 is a hair over 80W for the three.


Ripple is under 500uV.

 

[v4lve lover]

More pictures, tube regs are fun

Heres another picture, friend got it to work.



Works well, without any filtering in the supply output noise is measured at around 2mV RMS into a 150mA constant load. With about 5VRMS ripple in.


Could have been better, i designed in a Zener reference that is noisier than a VR tube such as the 85A2

 

[Wavebourn]

Would that include plate to grid (Schade) feedback?

Yes, it is parallel feedback. And it's input resistance similarly to Miller capacitance is calculated as the feedback resistance divided by amplification factor of the stage.

 

[kodabmx]

When you want sets of speakers at the same time 😛

EDIT: taken with Note 20 Ultra. Not bad for a _phone_, eh?