Hi Folks,
I was just gifted a pair of the SemiSouth JFETs. I am looking to build something with them, and my #1 choice would be F2J. There was PCB for the F2J for sale on Diyaudio Market place a few years ago, and just requested if they had any more. My fall back plan would be adopting the Zenlite circuit to use the SemiSouth SiC Jfet. I am comfortable building Vacuum tube circuit as a hobby, but I never built a Solid State amp, so this is new territory for me. I figure the IRFP240 and the SiC Jfet are both Enhancement-mode devices, the only thing I need to figure out is setting the positive voltage bias at the gate, finding the correct amount/type of light bulbs to set the current, and find the correct V+. Am I looking at this too simply? Is this a good Idea ? I'm am hoping to find the F2J PCB. I've included the circuit from the zenlite diy article.
I was just gifted a pair of the SemiSouth JFETs. I am looking to build something with them, and my #1 choice would be F2J. There was PCB for the F2J for sale on Diyaudio Market place a few years ago, and just requested if they had any more. My fall back plan would be adopting the Zenlite circuit to use the SemiSouth SiC Jfet. I am comfortable building Vacuum tube circuit as a hobby, but I never built a Solid State amp, so this is new territory for me. I figure the IRFP240 and the SiC Jfet are both Enhancement-mode devices, the only thing I need to figure out is setting the positive voltage bias at the gate, finding the correct amount/type of light bulbs to set the current, and find the correct V+. Am I looking at this too simply? Is this a good Idea ? I'm am hoping to find the F2J PCB. I've included the circuit from the zenlite diy article.
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The R100 operates at a lower Vgs than the IRF parts, so you would likely want to replace R1 with a variable resistor, say 10 kohms
and adjust it gradually as it warms up.
and adjust it gradually as it warms up.
The SemiSouth JFETs work great in https://www.diyaudio.com/community/...j2-on-steroids-or-not-your-fathers-j2.343073/
Good dual duty as a space heater. 🙂 A winter rig.
Good dual duty as a space heater. 🙂 A winter rig.
Babelfish F8 is great with both SJEP or IRFP150 in output
it's not that simple as Papa's Real McCay, but - hey - I'm not yet grown up (enough)
it's not that simple as Papa's Real McCay, but - hey - I'm not yet grown up (enough)
Thanks Papa for your quick response, I will do that as plan B. The 2 other suggestion is also very good, but my "Kung Fu" in SS design and building is not very good. I need to get more experience before I tackle those circuits. Besides, I'm a Vacuum tube guy, I appreciate the simple circuit, but more importantly the glowing lights.
Has anybody used these power supplies from Antek ? https://www.antekinc.com/ps-4n80-400w-80v-power-supply/
I decided to do F2J with light bulbs and looking for a 80V power supply. The other option is build from scratch using https://www.antekinc.com/as-4458-400va-58v-transformer/ for a mono amp. I figure the first option is prepackage, and I don't have to source the parts. For option 2, can anybody recommend PS caps without breaking the bank ? I'm looking at anything above 20000uf at 100v .. So far the caps cost in the 30 to 50 US dollar each . There is also some Chinese brands like JCCON that is in the 10 to 15 dollars, but its an unknown quality. Any suggestion ?
I decided to do F2J with light bulbs and looking for a 80V power supply. The other option is build from scratch using https://www.antekinc.com/as-4458-400va-58v-transformer/ for a mono amp. I figure the first option is prepackage, and I don't have to source the parts. For option 2, can anybody recommend PS caps without breaking the bank ? I'm looking at anything above 20000uf at 100v .. So far the caps cost in the 30 to 50 US dollar each . There is also some Chinese brands like JCCON that is in the 10 to 15 dollars, but its an unknown quality. Any suggestion ?
Option #1. I've used Antek transformers on all my amplifier builds with zero issues. 100v caps are very limited regarding choices, cost is out of my budget.
Are you very sure you want an F2J? I built an ALEPH J using a pair of SemiSouth 100's, using the DIYStore ALEPH J PCB's and codyt's part selection, is one of my favorite amp's.
Are you very sure you want an F2J? I built an ALEPH J using a pair of SemiSouth 100's, using the DIYStore ALEPH J PCB's and codyt's part selection, is one of my favorite amp's.
When I wanted to build my F2J boards were scarce…then this thread popped up:
https://www.diyaudio.com/community/threads/f2-and-f2j-pcbs.314829/
Here’s a newer run I think:
https://www.diyaudio.com/community/threads/f2-f2j-clone-pcb-and-ps-boards.366925/
I’d reach out to kinku or post a WTB in the swap meet to see if any boards shake loose.
If you can’t find a PCB floating around in there I’d try doing it on perf board like vitalstates:
http://www.vitalstates.org/diy/amplifiers/vsl-amplifiers.htm
Its well documented and I think he even has a diagram of how he connects everything on the back side of his boards. I was actually preparing to do it myself right before I found boards.
Good luck…BTW, I still love my F2J monoblocks after years of living with them.
https://www.diyaudio.com/community/threads/f2-and-f2j-pcbs.314829/
Here’s a newer run I think:
https://www.diyaudio.com/community/threads/f2-f2j-clone-pcb-and-ps-boards.366925/
I’d reach out to kinku or post a WTB in the swap meet to see if any boards shake loose.
If you can’t find a PCB floating around in there I’d try doing it on perf board like vitalstates:
http://www.vitalstates.org/diy/amplifiers/vsl-amplifiers.htm
Its well documented and I think he even has a diagram of how he connects everything on the back side of his boards. I was actually preparing to do it myself right before I found boards.
Good luck…BTW, I still love my F2J monoblocks after years of living with them.
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Elwood625, To answer your question I not sure if I want to build the F2J, I was actually going to do something even more simple. A F2j but use lightbulbs as a current source. I will look into the Aleph J, and do some research in the Semi South Conversion. Will it be the same circuit as the J2 that was mentioned in the thread ?
Chromenuts, Thanks for the resource threads, I did reach out to Kinko in one of the WTB threads, and I also missed out on F2J board by a member. I need to get something done by April. I will also look at the perf boards.
Chromenuts, Thanks for the resource threads, I did reach out to Kinko in one of the WTB threads, and I also missed out on F2J board by a member. I need to get something done by April. I will also look at the perf boards.
https://www.diyaudio.com/community/threads/firstwatt-j2.151909/post-5999278
https://www.diyaudio.com/community/threads/firstwatt-j2.151909/post-5996957
https://www.diyaudio.com/community/threads/firstwatt-j2.151909/post-5899908
For a tube guy, the output stage should look familiar.
🤓
Patrick
https://www.diyaudio.com/community/threads/firstwatt-j2.151909/post-5996957
https://www.diyaudio.com/community/threads/firstwatt-j2.151909/post-5899908
For a tube guy, the output stage should look familiar.
🤓
Patrick
No. The ALEPH series of amplifiers uses an ALEPH Current Source circuit. The ALEPH J build guide has a description of the circuit, I would NOT do it justice explaining it.
Here is the thread for the SemiSouth version: https://www.diyaudio.com/community/threads/semisouth-aleph-j.176857/
Attached are the ALEPH J PCB and the SemiSouth version together and the SemiSouth version alone.
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Thanks guys for the pictures and threads. Very Helpful ! I'm trying to get my amp done before April. Though my job at a Museum, I met a gentleman named Mike Mazzola, It turns out to be the same Mike Mazzola from Semi South. He is a really Nice, Cool and passionate guy. We are working on Museum Experience for Innovation Day comparing a drop in Tube replacement using SiC Jfet for guitar Amplifiers. There will be guitar playing demo, guest playing guitar to comparing the sounds of Tube Vs SiC Jfet
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output tubes - for best results, they need low impedance drive
ask George, he devised funny Power Drive, with reason
ask George, he devised funny Power Drive, with reason
elwood625, you convinced me to do the ALEPH J with the SemiSouth, I liked the fact that there is a DIY Store PCB for it, DIY 4U Universal Chassis, I even have the Dual 18v 300Va transformer, Much lower cost Power Supply Caps. I ordered board and Chassis from the DIY store. I think I have most of the transistor that are need, I need to go over my parts bin.
I went though the long read on the thread you sent on the ALEPH J SemiSouth conversion, by Codyt, he did lots of work and testing various parts. There was also various input from Nelson Pass and others. I will attempt to redraw the circuit on the way I will implement it, and hopefully get some feedback from the DIY community. What really helped was the build guide of the Aleph J , It put me to ease on how to set it up.
Funny that you mentioned George, I've actual have his universal driver board that I got over a year ago. I heard that he has suspended sales on all his boards at this moment. But the picture SiC Jfets "Tube" substitute was developed by the fine folks who developed the Semi South SiC Jfet. One of the engineers is a guitarist, and during "Innovation Day" in April there will be three Fender Tweed Champ build kits from Mojotone. For the demonstration there will be Champ amp with a 6V6 and one with the SIc Jfet. The proof is in the listening. I have not heard the SiC Jfet, so I'm excited to listening to it during Innovation day.
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You won't be disapointed. You should start posting in thee ALEPH J SemiSouth thread during your build.
ALEPH J w/ SemiSouth gerber files here.
https://www.diyaudio.com/community/threads/semisouth-aleph-j.176857/post-6625249
https://www.diyaudio.com/community/threads/semisouth-aleph-j.176857/post-6625249