My new old amp project: SE46 monoblocks

When I google, quite a few schematic popped up and they are quite different. Can you give me a link for the schematic that you use?

Thanks
 
Thanks

This is a really simple circuit. One SRPP stage driving the SE triode tube. No negative feedback at all.

I just print out the file, let me read a little, I am sure I have questions for you. I am not that familiar with tubes, so it's going to take a little bit of time.

What is the output power of your amp? What kind of speaker you are using?
 
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This is a really simple circuit. One SRPP stage driving the SE triode tube. No negative feedback at all.

I just print out the file, let me read a little, I am sure I have questions for you. I am not that familiar with tubes, so it's going to take a little bit of time.

What is the output power of your amp? What kind of speaker you are using?
Yeah, it doesn't get much simpler than that!

Power output is better measured in milliwatts... maximum output of my amps is ~1 watt per channel on a good day, but the spec'd 45 would give you a smidgen more power than that. You need very efficient speakers. Mine are single driver, full range field coils from Feastrex.
 
Yeah, it doesn't get much simpler than that!

Power output is better measured in milliwatts... maximum output of my amps is ~1 watt per channel on a good day, but the spec'd 45 would give you a smidgen more power than that. You need very efficient speakers. Mine are single driver, full range field coils from Feastrex.

I think the power is too low for me. I was expecting like 5 to 7W like a normal SE amp.

Thanks anyway.
 
Is SET means single ended tube?

I have the idea of parallel two big tubes to get the necessary power. My speaker is not that efficient. Not too many high end speakers are efficient and they usually are 4ohm.
 
Is SET means single ended tube?

I have the idea of parallel two big tubes to get the necessary power. My speaker is not that efficient. Not too many high end speakers are efficient and they usually are 4ohm.
Single ended triode

There are some nice high efficiency options out there. It's kind of a niche.

By the way SEP would be single ended pentode (el, kt, 6l6 etc)
 
I don't know what you mean you are "opposite" me.

I am thinking about in terms of equivalent circuit and noise. Here is what I think according to my understanding:

OPT is used to match the load ( speaker impedance) to the PLATE resistance of the output tube. I draw the typical circuit of SE triode and the equivalent voltage divider:

SE power supply.jpg

The left side is the triode with plate going to the OPT, the other side of OPT to +B( shown as battery). The turn ratio is N1 to N2. The OPT will present an impedance equals to the plate resistance rp to the plate of the triode.

Now look at the right drawing, I just draw the ripple voltage Vr. Since the impedance of the primary is equal to the plate resistance, the ripple voltage ACROSS the primary of the OPT is 1/2 X Vr. The ripple voltage at the load end will be (1/2 X Vr X N1)/N2 as shown in the writing.

Now lets put in some numbers.

Let Vr=1V
N1:N2 = 100:1

So the ripple voltage across the primary of the transformer is 1/2 X Vr= 0.5V

Since N1:N2 is 100:1, ripple voltage at the load is 0.5V/100= 5mV. That's a lot of ripple noise in my book.

I am not familiar with tubes and transformer, you can correct me and put in some real numbers and see what is the output noise.

Of cause it is understood it's more critical for preamp tubes as it's going to be amplified by the output stage.
 
Cripes Jeff, this old tune again?! Maybe you should start your own thread about your own amazing amps that you built THE RIGHT WAY instead of crapping on everyone else's threads and pointing out their HUGE PROBLEMS and their WRONG PARAMETERS...

I'm guessing your amps sound very nice. A single ended 46 can do that. Please tell us more about them... in another thread.
I really love to do a SE amp, I am just afraid that it might not loud enough for me. I already have the speaker, it's not like I can go buy another pair. I think 7 or 8W will be good enough, not 1 or 2W.

I am not giving up yet, I am thinking about paralleling tubes, but then the problem is how much DC current I can realistic pass through the OPT without saturating the transformer and destroy the sound. I read something about using transistor to remove part of the bias current, but then, it's not a true tube amp anymore. I am still at the thinking stage.
 
Theory and calculation is very important for SS amp design, why is it different for tubes? As long as you are matching the impedance of the primary to the plate resistance, you will get the divider effect and ripple will go to the speaker. 5mV is a lot at the speaker and you will hear it.

I don't mean I don't trust you, but if you have been it this for 30 years, you got to work on the theories, why don't you share some insight backing up with theory.

What is the reason you cannot parallel tubes with SE amp? People parallel tubes in push pull, we parallel transistors in SS amp. In fact, the more you parallel, the better it sound. My design has 9 pairs of output transistors and it is sweet. AND there is theory behind why the more the better, not just "it is".
 
Thanks for at least explain a little more, whether I agree or not, at least I know where you come from.

I design my own amp, I read a little about the Spectral DMA200, I stop when I read the spec. My amp is so much lower THD than what they are boasting. They claimed 0.015% THD into 4ohm. My amp is 0.0035% at 20KHz at 112W output into 4ohm. That amp is faster, but I don't know what it's for!!!! Mine already do 30V/uS slew rate, 1.5uS rise time and about 300KHz BW. What more do you want for an AUDIO amp that never see anything over 20KHz!!!! I am very happy with my SS amp, it beats the Nakamichi Stasis PA-7 designed by Nelson Pass that is almost the same as his famous Threshold S300. With more detail, sound stage and separation. That PA-7 or S300 already a $4000 amp quality. You should look at my thread on "My Amplifier" that I have blow by blow posting the construction and final FFT plot on the THD at 1, 5, 10, 12, 15 and 20KHz. Below 10KHz, it's less than 0.002% THD. At 12W, the THD dips down to 0.0009% at some frequency. This is my first even amp designed, from theory to final amp. My open loop damping factor ( not negative feedback) is over 200, with closed loop, it must be way over 600 to 1000 theoretically.

My speaker is JM Lab Spectral 913.1, I don't know the exact sensitivity, I remember it's in the low 90 db. So it's not going to be sensitive enough for SET with 1 to 3W. I spent $3000 on this pair of speaker and I really like it already. I am not going to spend $10000 on another pair to beat this pair. More importantly, I don't like horn speaker. No offense, I hate Klipsh horn speakers type. Even if I buy another pair, it's going to be either JM Lab Utopia, Sonus Faber or Martin Logan that is even less sensitive.

Enough for these talk. Big Red already not happy we hijack the thread already.
 
I used to think THD is not important until I research into speaker cables. THD is everything. I think people that claim THD is not important likely to have inferior speaker cable. I have a long thread on speaker cable and distortion. Speaker cable is everything. 10ft of Monster cable raise the THD from 0.006% to 0.14%. If you don't have a good cable, you'll never get the benefit of an ultra low distortion amp.

I might be new in audiophile, But I have been a senior engineer and manager of engineering for 30 years designing with transistors, IC design and all different things. I also designed tube guitar amps with channel switching, power scaling. So please don't talk to me as if I am a green horn. I owned two US patents solely under my name and I published papers in America Institute of Physics Review of Scientific Instruments.

There is a lot more to electronics than just by try and experience. You can have 30 years of experience OR you can have 3 years experience repeating 10 times. Theory is everything, you have to have solid grounds to stand on. No GNFB is ONLY your opinion, there are plenty of people disagree with you. All I know is My amp has better clarity, more separation and better sound stage than the Famous Stasis amp designed by Nelson Pass that has no GNFB. AND it is a quite expensive amp. I am not going to say I know it all as I don't. But I did accomplish a big mile stone on my very first design.....based on theory and surprisingly, proofed with listening. My amp comes alive.

Years of experience in ultra low noise, microwave and HV design taught me to conclude that those who think it's black magic is very likely they don't know enough to explain it. You work long enough with so many PhDs like me, you'll see the other side.....that EVERYTHING can be explained IF you know enough. I designed RF circuits of multi GHz from paper and simulation to real circuit ONE TIME THROUGH with performance, Smith Chart plot almost identical to my simulation. It's the knowledge that matter. If you cannot explain it out, you just don't know enough.



EDIT:

Back to the speaker cable, I have a long thread on testing, comparing and building speaker cable and the difference in sound due to speaker cable.http://audiokarma.org/forums/index.php?threads/effect-of-speaker-cable-on-thd.764633/

The different in changing the speaker cable is staggering. With the old multiple monster 12 gauge cable, I could not tell the difference between the Stasis amp and my amp. BUT with the new cables I made, the difference came out clearly. It's all scientific, and then proof by listening.
 
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This has taken a strange turn.

Red, I've got some new altecs in. I've been run into 2a3s lately, but I'm going to have to sub back in 45s just to see how things sound. Your amp are a good reminder of what a simple circuit and simple tube can do.
 
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