High Power SET?

[82 Cornwalls]

36 minutes ago, richieb said:

There’s a reason Nelson Pass uses the name First Watt for his “skunk works” amplifier designs - 

 

Dick Olsher famously remarked that “The first watt is the most important watt.” This sentiment has also been expressed by others as “Who cares what an amplifier sounds like at 500 watts if it sounds like crap at one watt?” With this in mind, I created First Watt in 1998 as a "kitchen-table" effort, exploring unusual low power amplifiers with an emphasis on sound quality.

[henry4841]

2 hours ago, richieb said:

The F3 I’m currently listening to is a NP singe stage I believe. And like much of the gear ‘round here it sounds “okay” -

My first thought was the F3 is a 2 stage but after looking at the schematic you are right single stage from what I see. It has been years since I built that amplifier. I still have the boards but used the case and PS section for another FW project. Nelson is big on less is better, fewer parts. The F3 is similar to the J2 and F8 in that they all use power J-fets. 

[henry4841]

1 hour ago, 83 LSIs said:

 

Dick Olsher famously remarked that “The first watt is the most important watt.” This sentiment has also been expressed by others as “Who cares what an amplifier sounds like at 500 watts if it sounds like crap at one watt?” With this in mind, I created First Watt in 1998 as a "kitchen-table" effort, exploring unusual low power amplifiers with an emphasis on sound quality.

You will find that Firstwatt amplifiers have a sound very much like a tube amplifier but in SS. 

[Marvel]

Here is a schematic for parallel 6c33 tubes. A single channel with 3 tube... I don't know if it's for audio or heating your house.

 

 

 

 

[Marvel]

I had a lovely pair of 2a3 monoblocks, which produced some of the best sound out of my La Scalas.

[richieb]

1 hour ago, Marvel said:

Here is a schematic for parallel 6c33 tubes. A single channel with 3 tube... I don't know if it's for audio or heating your house.

 

 

 

 

Good find Marvel. And yes, it does keep you nice and toasty while listening. A two-fer I suppose - 

[richieb]

1 hour ago, henry4841 said:

My first thought was the F3 is a 2 stage but after looking at the schematic you are right single stage from what I see. It has been years since I built that amplifier. I still have the boards but used the case and PS section for another FW project. Nelson is big on less is better, fewer parts. The F3 is similar to the J2 and F8 in that they all use power J-fets. 

I also had the J2 but let it go.  I’ve owned the F3 longer than any amp I’ve owned.  They are very similar although the J was bit more powerful , 25 vs 15 for the F.  

[henry4841]

10 hours ago, richieb said:

I also had the J2 but let it go.  I’ve owned the F3 longer than any amp I’ve owned.  They are very similar although the J was bit more powerful , 25 vs 15 for the F.  

After more thought on the subject of Firstwatt being single stage amplifiers, many of them are. The F3 was designed many years ago and since then in many of his designs they do have an extra circuit consisting of a couple of J-fets but used as a buffer with no gain. A buffer is an impedance matching circuit matching the source and the amplifier better. Electronically those amps could be considered a single stage as far as the sound is concerned. A buffer has very little if any affect on the sound and is a very desirable component between the different equipment stages in the audio chain. My principle volume control device is a stand alone buffer called the Firstwatt B1 V2. I use it more than a preamp to control the volume with my Lascala's not needing the extra voltage gain of a  preamp. 

 

Firstwatt is simple circuit amplifiers using just as few parts to get the job done. What many consider delivering the best sound. Less parts, wanting to hear the source and not components. 

[henry4841]

11 hours ago, Marvel said:

Here is a schematic for parallel 6c33 tubes. A single channel with 3 tube... I don't know if it's for audio or heating your house.

 

 

 

 

Am I correct in thinking the reason for more current being run in a SET output stage being better control of the bass speaker? Higher damping factor? There is certainly more expense with all those output circuits and a beefy more expensive power supply transformer and circuit  to deliver enough current to run those dang tubes. 

 

You would have a small heater with all those output tubes. Not seen that often in SET amplifiers. Many may consider it just being an advertising tool without contributing that much to the overall sound. But then I have never heard a dual or triple parallel output stage SET amplifier to compare it to my other SET amplifiers. 

[tube fanatic]

15 hours ago, 83 LSIs said:

 

I was listening to some jazz the other day and was curious, so I got the SPL meter out and did some calculations. My average power was @ 1/20 of a watt.

Indeed!!!  As many are aware, I have always been an advocate of using flea power amps with Klipsch speakers.  
 

Push pull triodes are considered the ultimate way to go among many audio folks.  My personal preference has been to parallel tubes (whether SET or SEP).  It is possible to achieve very low distortion levels in single ended operation by proper choice of operating point and circuit design.

 

Maynard

[82 Cornwalls]

1 hour ago, henry4841 said:

Am I correct in thinking the reason for more current being run in a SET output stage being better control of the bass speaker? Higher damping factor? 

 

You probably have me on ignore, but I mentioned a few posts up that output impedance is cut in half with 2 paralleled tubes. Half output impedance = double damping factor.

 

In my experience paralleled tubes also give the impression that the tubes have been working out at the gym and yet still retain their SE like nimbleness.

[henry4841]

13 minutes ago, 83 LSIs said:

 

You probably have me on ignore, but I mentioned a few posts up that output impedance is cut in half with 2 paralleled tubes. Half output impedance = double damping factor.

 

In my experience paralleled tubes also give the impression that the tubes have been working out at the gym and yet still retain their SE like nimbleness.

I do not have anyone on ignore, I just have not been following the thread that closely. If I had seen what you posted I would not have said what I did. 

[Shakeydeal]

51 minutes ago, 83 LSIs said:

 

You probably have me on ignore, but I mentioned a few posts up that output impedance is cut in half with 2 paralleled tubes. Half output impedance = double damping factor.

 

In my experience paralleled tubes also give the impression that the tubes have been working out at the gym and yet still retain their SE like nimbleness.

 

I only have one experience with paralleled tubes and that was the Audio Mirror mono blocks I bought from richieb. I really wanted to like those amps but in the end, their tonal balance was on the thin and bright side in my system. I had to pass them on to someone else.

 

[Schu]

On 1/4/2024 at 3:17 AM, Shakeydeal said:

 

I still say if you long for high power while maintaining one tube per channel, look to the 805 or 845.

or a 2A3

[Shakeydeal]

2 minutes ago, Schu said:

or a 2A3

 

Good one....😀

[richieb]

I’m not sure how the 2a3 will satisfy someone “longing” for a high power SET? A great sounding tube/amp, yes, high power? Not so much - 

[hanksjim1]

On 1/2/2024 at 6:44 PM, richieb said:

Not a broadcast tube but the Russian 6C33 military based tube is a formidable candidate

Here's a link to a set in Seattle from a very reputable seller, if anyone is interested...

 

https://seattle.craigslist.org/est/ele/d/renton-6c33b-set-tube-amplifier/7700350408.html

 

 

[capo72]

1 hour ago, hanksjim1 said:

Here's a link to a set in Seattle from a very reputable seller, if anyone is interested...

 

https://seattle.craigslist.org/est/ele/d/renton-6c33b-set-tube-amplifier/7700350408.html

 

 

Interesting build, but hard to get past the, ahhh....ummm.....asthetics.

[Shakeydeal]

Agreed!