I used a generic 12v zener diode rated 1w from Amazon. If you want to get from mouser or digikey then I would say anything rated 1w 12v zener is good enough like - https://www.digikey.com/en/products/detail/onsemi/1N4742ATR/977261
Until early this week, I have been listening to music through my Quad ESL speakers driven by this Lovoltech amp. Even though the original idea was to use it as a summer amp to beat the heat, I had not been feeling the need to switch over to my big biamped JBL speaker system. One thing I did, though, was to insert my prototype LU1014D preamp in front of the left channel power amp to listen to the LU1014D preamp/power amp combo.
My normal Sony VFET preamp by itself barely provides enough voltage to drive the follower amp to a reasonable volume level with the Quad speakers, so a voltage amplifier stage is welcomed for the power amp. Plus, I would like to use the LU1014D follower amp in my biamped JBL system and the LX-Mini crossover would not be able to provide enough voltage out to drive it.
Of course, there are other voltage gain stage options, but I like the idea of using power devices for voltage amplifiers. In my SIT follower amps, I have used Sony VFET voltage amplifiers. I think I was seduced by Sakuma's amplifier designs when I was a youth. It may not be the best technical reason, but I recall someone saying it's just entertainment, so I don't sweat it.
I listened to the LU1014D preamp/amp combo in the left channel with the just the follower amp in the right channel for about a week. Aside from the ability to crank that channel up, I can't swear to any difference in sound. There were times when I thought I heard more subtle detail, but it could be my imagination. I guess I'm not surprised as the LU1014D preamp's distortion is fairly low and the harmonic distortions are similar.
I pulled the preamp and amp out of my system to make some measurements on the preamp/amp combo. I was interested in the frequency response since the preamp's output impedance is not super low at about 1.2k ohms. Frequency response graph shows a small decrease of a few tenths of a dB at 20 Hz and 20 kHz compared to just the follower amp by itself, so I was happy with that. Harmonic distortion increased slightly at all power outputs which is what I expected. hese measurements confirm my listening experience.
My normal Sony VFET preamp by itself barely provides enough voltage to drive the follower amp to a reasonable volume level with the Quad speakers, so a voltage amplifier stage is welcomed for the power amp. Plus, I would like to use the LU1014D follower amp in my biamped JBL system and the LX-Mini crossover would not be able to provide enough voltage out to drive it.
Of course, there are other voltage gain stage options, but I like the idea of using power devices for voltage amplifiers. In my SIT follower amps, I have used Sony VFET voltage amplifiers. I think I was seduced by Sakuma's amplifier designs when I was a youth. It may not be the best technical reason, but I recall someone saying it's just entertainment, so I don't sweat it.
I listened to the LU1014D preamp/amp combo in the left channel with the just the follower amp in the right channel for about a week. Aside from the ability to crank that channel up, I can't swear to any difference in sound. There were times when I thought I heard more subtle detail, but it could be my imagination. I guess I'm not surprised as the LU1014D preamp's distortion is fairly low and the harmonic distortions are similar.
I pulled the preamp and amp out of my system to make some measurements on the preamp/amp combo. I was interested in the frequency response since the preamp's output impedance is not super low at about 1.2k ohms. Frequency response graph shows a small decrease of a few tenths of a dB at 20 Hz and 20 kHz compared to just the follower amp by itself, so I was happy with that. Harmonic distortion increased slightly at all power outputs which is what I expected. hese measurements confirm my listening experience.
Attachments
I don't know. I don't use those pins, but instead just solder a short length of wire to each pad. I preheat the Al board with hot air and then use an iron for the soldering.
There's probably something useful in this thread.
https://www.diyaudio.com/community/threads/assembling-the-lu1014d-ims-to-247-adapter.373273/page-2
There's probably something useful in this thread.
https://www.diyaudio.com/community/threads/assembling-the-lu1014d-ims-to-247-adapter.373273/page-2
Yes, the pins came from Samtec, who were the distributor. They were not available from the usual sources, Mouser, Digikey, etc... They had a minimum order of 300, I think. Which worked for the group buy.
https://www.diyaudio.com/community/threads/assembling-the-lu1014d-ims-to-247-adapter.373273/page-2
Yes, the pins came from Samtec, who were the distributor. They were not available from the usual sources, Mouser, Digikey, etc... They had a minimum order of 300, I think. Which worked for the group buy.