henry4841

I installed a bigger horn because the bigger the horn the better the sound. My thoughts and I do like to experiment. The Cornwall is an excellent speaker but it has a much smaller horn then a LaScala. I also have years of experience having owned my LaScala's since '86 and listened with them stock until a few years ago. Room placement is more of a problem with K'horns the LaScala, at least until Klipsch sealed the back of the K'horn. Until then I had no place to put them because of my listening room. Never had a reason to step down to a Cornwall. In fact after purchasing my LaScala's I have never considered any other speaker for my prime listening. Before then I was changing speakers on a frequent basis searching for better.

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

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.

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.

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

There are not that many low wattage Class A SS amplifiers to choose from. Right now I am using the SE V-fet Nelson Pass project with around 10 watts and I an not loosing anything with it. I have built the ACA amplifier but it has been years since I listened with it. Tubes and transistors clip very differently so I am going to say 10 watts with a class A SS amplifier. Quality watts are more important than quantity watts when it comes to our horn speakers. At the present time I am listening with an outstanding A/B amplifier project called the Honey Badger with 150 watts a channel. I do have it biased so that the first few watts are class A so I am probably listening with just a few of it's watts in class A. It is a fantastic design that would be thousands in an retail amplifier. Driving a Ferrari on the interstate 55 MPH is what I liken it to but it sound excellent.

The truth of power needs with heritage speakers many do not understand or believe. I could live with a 2 watt amplifier but I have found that 5 watts is the sweet spot in a tube amplifier for my needs. The advantage of 5 over 2 watts is just in the bass. More solid. Brook amplifier with klipsch speaker filled auditoriums in their day.

The shade feedback amplifier Nelson presented at one of the BAF conferences is a 50 watt class A amplifier that will require a lot of heatsinking. In other words expensive. There were many diyer's on the diyaudio forum that had a hard time getting it to work. A few did manage to do so but it is a challenge. If someone designed and tested a smaller lower wattage one I would be interested and would love to see the schematic. The BA-1 and BA-2 are two of the best diy ones out there and are not that complicated to build. I have both. Well actually a modified F4 with 2 less output devices then the single board BA-2 and using the BA-3 front end where I will not have to have a linestage with a lot of gain.

The F5 was not to my liking. Too reveling with my reveling horns. Many like the M2 along with myself. It is a keeper for me. One you may want to consider is the BA-1. It is one of my favorite amplifiers. I built the one board output version with 3 pairs of output devices instead of 6 pairs. The BA-1 is the single ended version. careful matching of the output devices are necessary for a better sound. I bought the pairs of output mosfets in tube of 25 which insures you will get better matching. My thoughts are with 6 output devices Nelson has presented the diy XA30 with the BA-2 which is PP. Much like the F4 with more output mosfets.

Which diy Pass A amp did you build? I have built most all of them including the Zen versions as well. I recently finished my SE Vet amplifier I won on the lottery. Fantastic sounding amplifier that sounds like my many SET amplifiers. Mine is the first build using the 2SJ28 V-fet.

I am a devoted Nelson Pass follower and read and watch most every I can find that he has done and does. He has said that there is a difference and improvement in sound with boutique cables but minimal. Where the rubber meets the road has the most benefit, the amplifier. Sure one can dive into the world of seeking the next fraction of and inch but that will cost much more for just a bit of difference. He also says hearing is a very complicated subject that we do not fully understand and no two people hear exactly the same much as no one has the same fingerprints. He used a friend to test his amplifiers before he died that could hear the difference between negative phase 2nd harmonics and positive phase 2nd harmonics. A feat I would never be able to hear. Something most would never be able to hear unless one has exceptional hearing and probably training to do so. Engineers see things different then the average person. Becoming an audio engineer is not an easy task and is to be admired as I do. Take the "Crash course electronics and PCB design by Udemy" and get a taste of what is involved becoming and engineer. https://www.udemy.com/course/crash-course-electronics-and-pcb-design/ I am glad we have an engineer on this forum giving his opinions being most engineers do not have or take the time for social media platforms. One side will never win when talking about what one hears and the other does not. Reminds me of talk between vinyl vs digital. I prefer vinyl thinking I can hear a difference between the two.

I hear LaScala's are PA speakers a lot and it is a crock of s**t. Same drivers and horns are K'horns with a 2 fold vs a 3 fold horn as in the K'horn. So why in the world would anyone think they are just PA speakers and K'horns are home speakers. Possibly because they were introduced as a PA speaker by PWK but found favor among serious listeners wanting to save a few bucks over K'horns. Missing something like 1/3 octave on the bottom end but these days with cheap subs it is no big deal. If you have to crank them up before they come alive it is in the crossover. I am using a simple 1st order crossover ditching the autotransformer using discrete L-pads for attenuation and mine fill the room at the lowest volume one can listen with. You hear this a lot with those that buy the steep crossover networks from Al. Using steep networks one has to crank them up before they come alive. PWK favored simple 1st order networks at the beginning and used an autotransformer due to the low powered amplifiers for the time to save a few milliwatts.

I have always felt when someone has a preconceived opinion before buying something and then shelling out big bucks for it they will make themselves believe it will sound better. Even if expensive cables do improve the sound it will be minimal at best. In other words money better spent on something else. That being said I have no problem with someone spending their money on whatever they choose if it makes them feel better.

For rust vinegar. You my need to remove plate and soak. I have cleaned many a shop tool soaking in vinegar.

Most of the time something real simple, bad connection at crossover or attachment cables. First thing to always check first.

Tubes rule no matter the hype. Try a SET tube amplifier if wanting a different jaw dropping experience. If you must go SS look at one of the SIT amplifiers from Nelson Pass.

What you are looking for is a single ended class A SS amplifier. Unless mistaken all single ended tube amplifiers are class A. Admittedly most all SE class A amplifiers use output devices with curves like pentode tubes except the SIT amplifiers from Nelson Pass, Firstwatt. Static induction transistors (SIT) have curves much like triodes.

I'm old and forgetful and you are determined to be right so I will not comment further. Chances are in your favor that I confused the big mosfet 50 watt class A project of Nelson's with shade feedback with the F7 with current feedback. I still think Nelson said current feedback was old tube technology but I could be wrong again. I would have to watch some of his old BAF conferences to refresh my memory and to me it is not worth the trouble trying to be right. How one treats another person is more important then being right.

Positive current feedback is used in the F7 along with a touch of negative feedback. I built a version of the F7 using the lateral mosfets and positive current feedback using some members at diyaudio guess at how Nelson designed the circuit. The original schematic of the F7 has not been released. Being such a simple circuit it was not that hard to do. Wasn't my cup of tea so I tried it for awhile and removed the boards and replaced with some others. Page 4 of this article describes some about Nelson's choice of positive current feedback. Same as used in old tube circuits. https://firstwatt.com/pdf/prod_f7_man.pdf

This has been discussed before but I thought to list it again. This SE tube amplifier has positive reviews from a number of talented reviewers on youtube and is moderately priced even with a price increase this year. Not a lot of money for the sound you will get if one wants to experience the sound of a SET tube amplifier. https://www.amazon.com/BOYUU-Hi-Fi-Stereo-Amplifier-Single-end/dp/B07L4GL63N/ref=sr_1_9?crid=25UQUN38C3ZCY&keywords=tube+amplifier+stereo&qid=1636029815&sprefix=tube+amplifier%2Caps%2C209&sr=8-9

If I am not mistaken the F7 uses those lateral mosfets where degeneration resistors were not necessary. That positive current feedback is old tube technology Nelson resorted to to improve the amplifier. Nothing wrong with either feedback systems if used with discretion but you will find negative feedback more common. Again if not mistaken positive current feedback in tubes was to make a pentode sound like a triode. Forgive me if I am wrong and I will blame it on age. I find a good SET tube amplifier has more than adequate bass and does not need to apologize to anyone but I have found SS to have better bass tighter bass but again what is most important for serious listening are the mids. If it does not sound good better bass will not matter and that is where SET's shine.

Just remember what PWK said about music (Music lives in the mids) and tubes are excellent there. Better bass is to had with a PP tube amplifier but for reach out and touch performant presence a SET amplifier is where it's at. That said a proper designed PP SS amplifier will be an excellent choice as well but you as a rule have to spend much more on a SS PP amplifier then say with a modestly priced PP tube amplifier for that effect. Best performance is generally best achieved with class A with either one.

Much like fishing lures. Many times they catch more fisherman then they do fish. Sure are pretty though. Klipsch now uses older technology polyester vs polypropylene caps because they are plenty good enough. Some even consider them better sounding.

To block DC. In tube amplifiers there are large amounts of DC on the plates of tubes and they must not get to the grids of the next tube. Necessary evil.

I love my tube amplifiers for the kind of music I enjoy but I agree with what SWL says for those heavy rock music lovers. As above not saying tubes do not sound good with heavy rock but SS does rock better. That is with a good PP SS amplifier.