henry4841

If I had to guess reading about the output transistors used in the Technic I would say the output stage is a form of a class A/B PP circuit judging by the power rating. The front end appears from what is stated as being digital much like your computer or DAC.

Reading this review the amp uses a type of mosfet transistor on the output stage. https://twitteringmachines.com/review-technics-stereo-integrated-amplifier-su-r1000/ The transistors used are called Gallium nitride field effect transistor. https://en.wikipedia.org/wiki/Gallium_nitride#:~:text=These transistors are built by,superior electrical performance of GaN. Another way of making a field effect transistor, mosfet. One would have to see a schematic to comment further but my thinking calling it digital is an advertising marketing tool. Perhaps they mean the stages in front of the output stage being digital. Schematic would tell the truth.

I have a pair of open baffle speakers and the efficiency is high on mine 95db if memory is correct but I know of no open baffle speaker that can match the efficiency of a pair of heritage Klipsch speakers. Does not mean that there possibly could be some but I am not aware of any. Does not really matter that much though, even with 95db speaker, I had plenty of power using 2 watt SET tube amplifiers and they got plenty loud. What I missed in my open baffle setup is the detail that my LaScala's produce. That and the quickness of horns. I prefer horns myself but with sound it is so subjective so there will always be disagreements.

Should sound great but sound is subjective. Mark Levinson makes fantastic amplifiers. A great amplifier like a Mark Levinson will sound excellent on any speaker system.

Would you rather have an A, B, C or D on a test? Class A is class A, the purist form of amplification. There is a reason it is the first letter of the alphabet when it comes to amplification, none better. The audio signal is not manipulated as in the other forms. Can one hear the difference? Only if your hearing is good enough. That being said I have some class D amplifiers that sound really, really good. I could live with one of them. Class D amplification is for the masses now and in the future but purist will still seek class A.

Try a tube preamp with your SS amp. It will give you a touch of 2nd harmonic that SS amps sometime lack. Audio amplification is entertainment, art, as well as science. Most input tubes have very little current being run through them so replacement will not be needed for years.

$5000 And usually a waiting list to get a Firstwatt product.

I googled and found the same site and was going to post the link but you beat me to it. New to me and thanks for letting us know. There is a lot of activity of members at diyaudio.com building amplifiers using those Tokin SIT's but I have not been following the threads having both the PP and SE version of a SIT amplifier. The transistors alone are selling for $100+ on Ebay. I also did not know Nelson was sitting of enough of the Tokin's to offer a production SIT-4. Sneaky grey headed fox. The SIT transistors he had made for $300,000 years ago are no longer being produced. The company closed. These SIT amplifiers by Nelson Pass are destined to be a classic desirable amplifier 20, 30+ years from now. He is one of a kind. He will service any amplifier made by him at a minimal cost after the warranty has expired. Even the old Threshold amplifiers or yesteryear. Transistors made 50 years ago are in demand and work as when produced.

The difference with Nelson and the other audio engineers is he shares some of his knowledge with the electronic audio geeks.

Correct. Fix the known problem now, RCA inputs, and chances are really good that is the only problem.

I was not aware there was going to be a SIT-4 from Firstwatt. Last I heard Nelson's stock of SIT's that he had produced were depleted. Is there going to be a new product using NOS V-fets from the 70's? I know of no company producing static induction transistors for the public. My understanding is they are still being produced strictly for the military though. There was a rich guy producing SIT's in Japan before the tsunami but his factory was destroyed. From Firstwatt's webpage. https://firstwatt.com/wattsnew.html Watt's New? 2/5/23 FW Product availability: As we run low on the SemiSouth SiC Jfets and SITs without replacements, we are discontinuing the F8 and SIT-3. F7 is still available, and new product is under development.

I was the first builder of the PP SET amplifier at diyaudio.com. I also am the one who asked Nelson for a SE V-fet design and he agreed to design one. It took a few years but he did produce it. Also I have built the majority of Nelson Pass diy projects including nearly all of the Firstwatt clones. Nelson Pass 74 year old groupie. If you like the sound of the ACA you would love the sound of the Burning Amp #1 SE amplifier with multiple output devices. https://firstwatt.com/pdf/art_ba1.pdf The Burning Amp #2 has a lot in common with the Pass Labs amplifiers. Similar to the F4 with an extra output stage if memory is correct with a front end circuit added where it will operate without a high output linestage that the F4 really needs for full output.

I have built both of the V-fet offerings from Nelson Pass. V-fet is just another name for static induction transistors, SIT. One amplifier being single ended and the other PP. SIT transistors are extremely fast first used for radar applications.

Wayne Colburn of Pass Labs presented this project at this years Burning Amp Festival in California. https://burningampfestival.com/videos/ Worthy project for anyone seeking excellence in sound on a beer pocket book. Not a lot of electronic skill is needed to build a project like this mainly just stuffing circuit boards. Decent soldering skills and the ability to follow directions is all that is required. It will be a while before the kit is readily available but you may want to follow the thread at diyaudio.com and buy one when available. https://www.diyaudio.com/community/threads/pearl-3-burning-amp-2023.404054/ If you look at the price of a Pass Lab phono stage $12,075 for the XP-27 and $4,500 for the XP-17 you will understand the quality of sound you can expect from a phono stage designed by Wayne Colburn. I am almost certain the diy project will not sound exactly like the XP-27, I am sure there are some tricks left out, but if built correctly should be really close. The boards given out at the festival are being built mostly as the 2 chassis XP-27. Why not go for the best.

The F3 is a better amplifier than the ACA. I have built them both. The ACA is a simple circuit amplifier designed by Nelson as a diy project for a beginner amplifier builder to get a taste of what a class A mosfet amplifier sounds like. The F3 uses what is called power J-fets which also the more modern Firstwatt J2 uses. If you want more details of the F3 circuit you can look here. https://firstwatt.com/pdf/art_zv9.pdf The Zen 9 from 2006 is the same circuit retailed as the F3. Both are very good sounding but if hearing good enough you will hear a difference in the F3.

There are Y-cables that split the input signal as well as what Peter P quoted. Not the best way but will work.

Just to add, LaScala's have been marketed for home use for around 4 or 5 decades. One would think good engineers would know what is expected for home use after decades being sold for that purpose. The Jubilee speakers have roots in pro use as well.

They make Y cables to split the source input enabling the use of a sub with the tube amp mentioned. Not the best way but it will work. For me bigger horn bigger sound and the LaScala has a larger horn than the Cornwall. Give them some time. There is nothing like horn bass.

Like yourself, I do not care for bluetooth or usb but both are something many would consider necessary before considering purchasing a turntable. I gave receivers to my grandkids in college and the first thing after speakers they bought was bluetooth where they can stream from their phone. Chinese I am sure but most electronics are these days.

A few days ago I got an email about this new turntable from Parts Express. Looks good. Perhaps a member will pick one up and give review. https://www.parts-express.com/Dayton-Audio-TT-1BTW-Belt-Drive-Turntable-with-USB-Bluetooth-Audio-Technica-AT-VM95E-Cartri-300-363?quantity=1

Good review from a member. Hard to go wrong at that price. The tubes add a touch of 2nd harmonics which is always a good thing in my opinion.

On a tight budget give these some consideration. Positive reviews and on youtube. Do not expect decades of use or $5K sound though. No personal experience. https://www.parts-express.com/Dayton-Audio-HTA100-100-Watt-Stereo-Hybrid-Tube-Amplifier-with-Bluetooth-300-3848?quantity=1 https://www.parts-express.com/Dayton-Audio-HTA200-200-Watt-Stereo-Hybrid-Tube-Amplifier-with-Bluetooth-300-3850?quantity=1

The data sheet says all a designer or tech needs to know though.

https://www.ebay.com/itm/196010265116

Capacitor talk in a thread on this forum seldom ends well.