If you mean this one:
All FET class A preamplifier JC-80 PCB ! | eBay
Then I would ask Jims Audio about it. They've been very helpful towards me in the past.
Those are the ones I have bought. Stanton from Jim's Audio is a very reliable person. You can also source the 109/389 parts from him. They're used but tested and original parts. The Caddock will most probably cost you around 80$ since the minimum purchase from them is qty 10.
Jim's audio will supply the BOM and schematic
Ciao!
@ticknpop Help, please! pinnocchio has questions re your blowtorch.
@kamis Thanks (again!)
@pinnocchio Thanks for the rail current reading.
Stanton is not merely reliable, he is a customers fondest dream!
I am so close to getting the Kubota together. Its parts are widely available and it is easy to build. I am taking the time to match back there as well as within the JC-80 itself. All of this in an attempt to make the JC-80 more amenable to DIY and easier to build. Offers to share private component caches are greatly appreciated but I am resolutely sticking with careful matching of 170/74 and thermal bonding if at all possible.
The earlier plans for the power supply(ies) allow mix and matching at various price perf levels if I can just get the parts in one place at one time. The current info strongly suggests there is an excellent chance the Kubota will serve well for a single channel.
Hi Wolfsin,
Stanton and I go back a couple of years. I know him very well. I'm sorry to hear you had a bad experience.
If you don't want to have to source parts for power supply but would like to try something different later on, you could go on the Twisted Pear Audio site and buy their Placid HD Bipolar PSU
Placid HD Bipolar Power Supply
It is a complete kit and very good shunt regulator.
Ciao!
That is a great deal but I would be careful of fake parts... That is the reason why I bought them directly from Caddock.
Although they could be 100% genuine
The price is amazing though!
Hi pinnocchio,
>>Stanton and I go back a couple of years. I know him very well. I'm sorry to hear you had a bad experience.
The bad was his competition, NOT Stanton. It was all about IP so it is easy for everyone to get riled about that.
There are quite a number of JC-80s in Hong Kong but I only know of a couple in North America based on the boards we are both using. I know I will end up with spare parts when I am finished. After I have matched the polystyrene caps for the cap multipliers I will have enough left over for three additional pairs of JC-80 boards that I will give to aspiring fanatics to simplify their search (if they sound as good as expected). The really expensive parts (caddocks, toshiba duals, r-cores) I am doing my best to source correctly on the first try.
So far this has been enjoyable, if protracted, and I am expecting to have the power supply chain for the first channel before EOM.
>>Stanton and I go back a couple of years. I know him very well. I'm sorry to hear you had a bad experience.
The bad was his competition, NOT Stanton. It was all about IP so it is easy for everyone to get riled about that.
There are quite a number of JC-80s in Hong Kong but I only know of a couple in North America based on the boards we are both using. I know I will end up with spare parts when I am finished. After I have matched the polystyrene caps for the cap multipliers I will have enough left over for three additional pairs of JC-80 boards that I will give to aspiring fanatics to simplify their search (if they sound as good as expected). The really expensive parts (caddocks, toshiba duals, r-cores) I am doing my best to source correctly on the first try.
So far this has been enjoyable, if protracted, and I am expecting to have the power supply chain for the first channel before EOM.
I used the JC 80 boards and built Blowtorch , but had to offboard the servos and locate the output stage voltage divider resistors under the board as the JC 80 board isn't the same as the Blowtorch, also several other cut tracks or mods but it worked out reasonably well - better than trying to hardwire one.
Mounted it in an SAE mk 1b metered preamp chassis with a meter buffer board and new jacks, switches, and volume control ( the ultra expensive stereo TKD pot)
Pinocchio i have 2sk216 / 2sj79 , 2sk2013 /2sj313, and E101 and E102 jfet current sources for Borbely regulators if you need . I have both original kits from Erno and Jim's audio version - Erno's parts are somewhat different than the Jim's audio version due to availability )
Mounted it in an SAE mk 1b metered preamp chassis with a meter buffer board and new jacks, switches, and volume control ( the ultra expensive stereo TKD pot)
Pinocchio i have 2sk216 / 2sj79 , 2sk2013 /2sj313, and E101 and E102 jfet current sources for Borbely regulators if you need . I have both original kits from Erno and Jim's audio version - Erno's parts are somewhat different than the Jim's audio version due to availability )
That would be the Dale mil-spec resistor, RN60 series.
>>Although they could be 100% genuine (caddocks)
The fun part will come toward the end, assessing blame :-( For now I am trying to keep my skepticism in check. Just received a matched quad from Israel. Only matched 9610/610 and opa2134 remain on the shopping list. I have likely shopped too hard so if the result fails expectations I'll only have self on list.
>>Although they could be 100% genuine (caddocks)
The fun part will come toward the end, assessing blame :-( For now I am trying to keep my skepticism in check. Just received a matched quad from Israel. Only matched 9610/610 and opa2134 remain on the shopping list. I have likely shopped too hard so if the result fails expectations I'll only have self on list.
I have the 216/79 and 2013/313 that I had bought for Jim's Borbely Shunt and JC-80. Are your 216/79 matched? My Borbely Shunt and JC-80 have been working for about a year now.
Ciao!
Hi Wolfsin,
You can buy the 610/9610 from this seller with confidence. I've bought many things from him.
Tech DIY Company Store
I've used Dale RN60 resistors on all the board plus the Caddock 820
Ciao!
Hi John,
What were the main differences between the Blowtorch and the JC-80?
Thanks!
Unless you are truly a fanatic, I would recommend the JC-80 approach. It is easier to get successful parts for (V series jfets for example), lower distortion, and ease in making something that will serve the task. In any case, these boards are not original for either the JC-80 or the Blowtorch and several 'shortcuts' have been taken in fabricating them. For example, the Blowtorch boards are made from Teflon. There are other differences as well.
We still use the JC-80 topology, for example, the new Constellation preamp, that just won 'preamp of the year' in TAS. So, it is not much of a compromise in the real world.
We still use the JC-80 topology, for example, the new Constellation preamp, that just won 'preamp of the year' in TAS. So, it is not much of a compromise in the real world.
What an amazing history for this design. Congrats on the latest award.
Some of the most time consuming work is quickly approaching here: matching and thermal bonding of the singles to replace the dual Toshibas in the BOM. A couple of years ago small aluminum widgets were available for that purpose but those sources have gone dry. I propose fabricating copper holders that would serve the same purpose but be more amenable to 'roll yur own'. I am unsure how much of the purpose is thermal bonding and how much is cooling. Any word about how hot these will get in a JC-80, pinnocchio?
Some of the most time consuming work is quickly approaching here: matching and thermal bonding of the singles to replace the dual Toshibas in the BOM. A couple of years ago small aluminum widgets were available for that purpose but those sources have gone dry. I propose fabricating copper holders that would serve the same purpose but be more amenable to 'roll yur own'. I am unsure how much of the purpose is thermal bonding and how much is cooling. Any word about how hot these will get in a JC-80, pinnocchio?
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