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New 20 watt amp from Schitt Audio


EmilC

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https://firstwatt.com/pdf/art_diy_sony_vfet_pt1.pdf

 

Because they had so much demand for it diyaudio held a lottery and I was lucky enough to win one. Possibly requesting a SE SIT design from Nelson over 3 years ago had something to do with it. There was a second lottery for the SE 2SK28 a few weeks after my 2SJ28 offering. There will be kits for those already possessing the SIT's of which I have an extra pair of 2SJ28's I bought from the original seller in Hong Kong many years ago when they were available. PM me if interested when the kits become available in the store. I built one of the first PP V-fets when they first were available. I bought the SE kit I believe in March but only finished it last month due to health issues. 

 

Not familiar with the Slewmaster. Send info to me please.  

 

https://firstwatt.com/pdf/art_diy_sony_vfet_pt2.pdf

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Honestly I do not think many have taken the trouble to measure how much power they are actually using. Not complicated and easy to do with just a volt meter and a little math. I rarely exceed one watt and that is on peaks. Nelson Pass has made a lot of money selling from his relatively small secondary company called Firstwatt for a reason and the majority of buyers do not have horns. One thing that makes a 25watt class A amplifier desirable is that over 25 watts of class A power you have a small heater in the room. Class A amplifiers run hot. 

7 minutes ago, Area 51 said:

I guess the Schiit amplifier-I assume it's the 20 watt (10+ class A) Aegir-mentioned in the the title of this thread qualifies? It's interesting, not everyone agrees 10 watts of class A power is enough-even for Klipsch Heritage speakers. Well, it is a subjective experience, isn't it?

 

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7 minutes ago, henry4841 said:

Honestly I do not think many have taken the trouble to measure how much power they are actually using. Not complicated and easy to do with just a volt meter and a little math. I rarely exceed one watt and that is on peaks. Nelson Pass has made a lot of money selling from his relatively small secondary company called Firstwatt for a reason and the majority of buyers do not have horns. One thing that makes a 25watt class A amplifier desirable is that over 25 watts of class A power you have a small heater in the room. Class A amplifiers run hot. 

 

Will you please explain how one would calculate watts used, particularly so that peaks could be included? I'd be interested in finding that out for my system.

 

I've been stymied by the changing mix of frequencies in music, and the different impedances that different frequencies present.

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2 minutes ago, Dave MacKay said:

Will you please expain how one would calculate watts used? I'd be interested in finding that out for my system.

The easy not too complicated way which is not exactly precise but close enough without getting too technical is to take your volt meter on AC, turn your music up as loud as your ever listen and measure across the speaker terminals on peaks. Then using ohms law square that figure (multiply it by itself) and divide by the resistance (ohms) of your speakers. Then you will roughly have the wattage your are using. Maynard on this forum as 'tube fanatic' has stated the precise way of measuring but the differences between the easy way and the precise way is just minimal. I would have to do some searching to find that way but I expect there are others that will post that way before I do. Either way I believe you will be shocked on what a small amount of power you are actually using. Nelson Pass has power meters that are very precise in his listening room in the lab using conventional speakers and they rarely go over a few watts on peaks when many say turn them down some. The wattage war manufacturers want you to believe is a fallacy to sell their products. More has to be better right. Audiophiles understand quality watts are more important.   

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2 hours ago, henry4841 said:

The wattage war manufacturers want you to believe is a fallacy to sell their products. More has to be better right. Audiophiles understand quality watts are more important.   

Hence my wish to see Amplifiers rated in DB WATTS rather than watts.

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2 hours ago, henry4841 said:

The easy not too complicated way which is not exactly precise but close enough without getting too technical is to take your volt meter on AC, turn your music up as loud as your ever listen and measure across the speaker terminals on peaks. Then using ohms law square that figure (multiply it by itself) and divide by the resistance (ohms) of your speakers. Then you will roughly have the wattage your are using. Maynard on this forum as 'tube fanatic' has stated the precise way of measuring but the differences between the easy way and the precise way is just minimal. I would have to do some searching to find that way but I expect there are others that will post that way before I do. Either way I believe you will be shocked on what a small amount of power you are actually using. Nelson Pass has power meters that are very precise in his listening room in the lab using conventional speakers and they rarely go over a few watts on peaks when many say turn them down some. The wattage war manufacturers want you to believe is a fallacy to sell their products. More has to be better right. Audiophiles understand quality watts are more important.   

Thanks. I've been trying to correlate the -80 dB to +16.5dB that my Yamaha R-N803 receiver displays for volume to what I see on my SPL meter. But I haven't been successful.

 

I recognize that the dB numbers shown on the receiver aren't dBA (i.e., sound presure level) but are instead a measure of the receiver's electrical output. I also noticed that a 96 dB range is what woud be expected of a 16 bit value.

 

I expected that max volume would be at 0 dB and that everything lower than that would represent how much attenuation was in force (restriction from full power) so that all numbers would all be negative. But since my receiver goes -80 to +16.5 dB that didn't make sense.

 

I then thought that perhaps 0 dB was set to max power before a certain level of distortion. If that were the case, any numbers above 0 dB would have increasing levels of distortion. 

 

That seemed sensible, but I couldn't get the numbers to work.

 

When I deconstruct the receiver's published max power specs at different impedences (e.g., 100W at 8 ohms, 140 watts at 4 ohms) using watts = volts^2/impedence, I get different voltages for the max power (28.3V RMS @ 8 ohms but 25.3V RMS @ 4 ohms). Peak-to-peak that would equate to 40V or 36 V. I had expected that the voltages would have been the same.

 

I had thought I'd hook up the receiver to an 8 ohm resistor and measure the voltage at different volume levels when I input a signal (like a sine wave). However, the biggest 8 ohm resistor I have is rated at 50W which would only be good for 20 volts peak-to-peak (i.e., 14 volts RMS). That won't let me turn up the volume too high on the receiver; in fact I wouldn't even get out of the negative numbers.

 

Any suggestions?

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51 minutes ago, Dave MacKay said:
51 minutes ago, Dave MacKay said:

When I deconstruct the receiver's published max power specs at different impedences (e.g., 100W at 8 ohms, 140 watts at 4 ohms) using watts = volts^2/impedence, I get different voltages for the max power (28.3V RMS @ 8 ohms but 25.3V RMS @ 4 ohms). Peak-to-peak that would equate to 40V or 36 V. I had expected that the voltages would have been the same.

 

I had thought I'd hook up the receiver to an 8 ohm resistor and measure the voltage at different volume levels when I input a signal (like a sine wave). However, the biggest 8 ohm resistor I have is rated at 50W which would only be good for 20 volts peak-to-peak (i.e., 14 volts RMS). That won't let me turn up the volume too high on the receiver; in fact I wouldn't even get out of the negative numbers.

 

Any suggestions?

Yeah, put some music on and forget that stuff. 

 

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7 hours ago, Dave MacKay said:

 

 

I had thought I'd hook up the receiver to an 8 ohm resistor and measure the voltage at different volume levels when I input a signal (like a sine wave). However, the biggest 8 ohm resistor I have is rated at 50W which would only be good for 20 volts peak-to-peak (i.e., 14 volts RMS). That won't let me turn up the volume too high on the receiver; in fact I wouldn't even get out of the negative numbers.

 

Your 50 watt resistors should work fine for short periods. Just watch the temp of them. 

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Bullshit, spoken with conviction, is still not better than the truth..................unless, of course, you are the Salesman!
Relax big guy. This is just fun stuff to play with......but most of us here know our systems capabilities and when we are locked in the sweet spot it's like a magnifying glass. Some things are just flat out noticeable. This was my experience and I've gone back and forth on it more than several times to confirm it because I really didn't want to believe it. Is it night and day? No but it's detectable enough that I actually have a preference in which one of the PC's I own that I use with certain pieces of gear.

Would I spend a significant amount of money on a PC? Absolutely not.

Sent from my SM-G991U using Tapatalk


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On 11/20/2021 at 7:26 PM, henry4841 said:

https://firstwatt.com/pdf/art_diy_sony_vfet_pt1.pdf

 

Because they had so much demand for it diyaudio held a lottery and I was lucky enough to win one. Possibly requesting a SE SIT design from Nelson over 3 years ago had something to do with it. There was a second lottery for the SE 2SK28 a few weeks after my 2SJ28 offering. There will be kits for those already possessing the SIT's of which I have an extra pair of 2SJ28's I bought from the original seller in Hong Kong many years ago when they were available. PM me if interested when the kits become available in the store. I built one of the first PP V-fets when they first were available. I bought the SE kit I believe in March but only finished it last month due to health issues. 

 

Not familiar with the Slewmaster. Send info to me please.  

 

https://firstwatt.com/pdf/art_diy_sony_vfet_pt2.pdf

 

 

Thanks!

 

I somehow missed this version of the Vfet amps. When you mentioned he put out a single ended version I was hoping he was driving the load with the drain not the source, follower stages will not have nearly the magic.

 

The version I built was the CCS was loading the drain not the source, and so output was taken from the drain not the source like the Vfet part 2 amp. It sounds like a ballsy bored and stroked 300b on ntiro. I will try and find the schematic for you if you don't have it.

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6 hours ago, captainbeefheart said:

It sounds like a ballsy bored and stroked 300b on ntiro. 

I have a SE 300b amplifier I built and the SE V-fet does sound much like it but I would leave out the bored but then I like the SE 300b sound. My 300b amplifier is the last one I would part with. The V-fet and SIT single ended amplifiers are 300b sound for those that would only consider a SS amplifier. Many still have misconceptions about tubes. 

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On the whole power cable subject. Let's do a thought experiment. You own a $799 Aegir amp. I'll assume that you are not going to spend $1,000 on a power cable. Let's say you spend $100. You are saying that Schiit did not design a power supply quiet enough for their amp. Either a) they are not competent or b) they cheaped out to the tune of $100. I am going to claim that Schiit could spend $20 and affect their amp as much as that $100 cable might, seeing as how they have the ability to upgrade internals versus just play with wire. But they didn't. Or maybe they did all that could be done. If you believe option a) then you bought an amp designed by someone who you believe could not design a power supply! If you believe option b) then you think spending $100 on the wire has more effect than anything Schiit could have done with transformers, capacitors, etc. for the same price.

 

Let's repeat the experiment. You bought a $7,500 McIntosh amp. Same argument...

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7 hours ago, henry4841 said:

I have a SE 300b amplifier I built and the SE V-fet does sound much like it but I would leave out the bored but then I like the SE 300b sound. My 300b amplifier is the last one I would part with. The V-fet and SIT single ended amplifiers are 300b sound for those that would only consider a SS amplifier. Many still have misconceptions about tubes. 

 

Think about this for a minute. The two Vfet amps you have take the output from the source ala follower output stage like most SS output stages. With a 300b amp that's not the case, they are not going to be follower output stages, to get the full 300b sound you need to take the output from the plate, hence the load in the plate circuit. That is exactly why I got excited when Nelson showed that cheaters version with standard Mosfets with the load on the drain this time unlike the Vfet amps with the load on the source, just like a real 300b tube amp taking the output from the plate. I highly suggest you try version with the load on the drain as it will be the most "tube" like sound. There are other amps Nelson has made with the output taken from the collector/drain, some have light bulbs as drain loads instead of a CCS that I have built that sound great but the output is more pentode like than triode like which is why the circuit I showed is so unique and about as close as you will ever get to a SET sound with SS components.

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2 hours ago, Pondoro said:

 

On the whole power cable subject. Let's do a thought experiment. You own a $799 Aegir amp. I'll assume that you are not going to spend $1,000 on a power cable. Let's say you spend $100. You are saying that Schiit did not design a power supply quiet enough for their amp. Either a) they are not competent or b) they cheaped out to the tune of $100. I am going to claim that Schiit could spend $20 and affect their amp as much as that $100 cable might, seeing as how they have the ability to upgrade internals versus just play with wire. But they didn't. Or maybe they did all that could be done. If you believe option a) then you bought an amp designed by someone who you believe could not design a power supply! If you believe option b) then you think spending $100 on the wire has more effect than anything Schiit could have done with transformers, capacitors, etc. for the same price.

 

Let's repeat the experiment. You bought a $7,500 McIntosh amp. Same argument...

 

I talked to Tom at Schiit about this, here is what he had to say.

 

 

schiit.png

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I generally don’t read long posts but “thong” caught my eye and grabbed my attention. So with these new power cables how long are you able to sit in the “sweet spot” wearing only a thong? You might also find an association between quality power cords and hemorrhoids - 
Ah, so that's why you hang out here....

Sent from my SM-G991U using Tapatalk

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41 minutes ago, captainbeefheart said:

 

I talked to Tom at Schiit about this, here is what he had to say.

 

 

schiit.png

Well, he said they didn't comment and then he commented. But it does not surprise me that the manufacturers generally do not comment on these accessories. Why tick off the highest spending customers? I will say it for the manufacturers: if you buy a power cable to filter your power you are insulting the designer of the amp. 

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