JC-80 eBay PCBs

Status
Not open for further replies.
Now there are no more Blackgates to waste money on did Wolfsin ever try Casa de Feijuada in Rio? Or Bolinha in Sao Paulo. Nothing like several glasses of old Cashasha afterwards. Met the audio society of Rio there - mostly European ex- pats - a long time friend is a member - taxes kept most good audio equipment out of the Brazilian market for decades, but it's getting a little better. Boa Noite.
 
Last edited:
Perhaps I should be more specific. On the JC-80 board itself there are basically three cap types, large value electrolytics, small value SMD (in servo), and the cap multiplier fellows (polystyrene). On the Kubota there are six electrolytics (Elna Silmic II) and a pair of WIMA MKP2. Finally, on the rectifier and caps board there are 10x Nichicon 2200ufd FW(M) electrolytics currently. It is the smaller value caps at the output of this last board, just before the ~35vDC enters the (say) 4 foot shielded power cable to the Kubota, and possibly where it will enter right at the pair of WIMA MKP2s. I have a dozen extra 0.47ufd polystyrenes but they seem large in both value and size for that use.

The question really comes down to this: before and after the DC power transmission cable are there special precautions to be taken?
 
The JC 80 boards use both electrolytics and film caps on the output of the cap multiplier. I believe John's original intention was just the film cap only on the output of the cap multiplier to keep the da of the electrolytics from smearing the signal - try removing it and see if it improves the sound.
 
Pinnocchio, you are asking the wrong person. This is the way it works: John and Erno designed JC 80 and regulator boards, Tim makes money off John and Erno's work, and John gets to answer the build questions about it, but makes nothing on it. What's wrong with this equation? (nothing if you are Tim). Tim does seem clever enough to update the designs in a few areas such as obsolete device substitution - not exactly the original design, but 99% is there.

Now you know why John called his later efforts Vendetta. I suspect John feels like a Xexox machine he's been copied so often and why Tim and Mark Levinson aren't likely on John's Christmas card list.
 
Last edited:
Pinnocchio, you are asking the wrong person. This is the way it works: John and Erno designed JC 80 and regulator boards, Tim makes money off John and Erno's work, and John gets to answer the build questions about it, but makes nothing on it. What's wrong with this equation? (nothing if you are Tim). Tim does seem clever enough to update the designs in a few areas such as obsolete device substitution - not exactly the original design, but 99% is there.

Now you know why John called his later efforts Vendetta. I suspect John feels like a Xexox machine he's been copied so often and why Tim and Mark Levinson aren't likely on John's Christmas card list.

100% i agree with you. stanton is ignorant of lot of electronic basics. he is a nice Pcb maker and nothing more than component dealer. Please read the earlier threads on John' JC 80/ JC 2 threads.
When i asked him questions - he becomes very defensive. his component choices are no better than novices like us except that he does not read much what information is posted here - you can get more than enough information in Blowtorch thread on every aspect. Yet it does not handhold for making a preamp.
My 2cents
Kannan
 
I don't mind answering 'reasonable' questions here. The JC-80 has not been made for several decades, at least with me around. The boards that are being made are NOT exactly what we did then, nor what we would do today. However, they are a good starting point to make an excellent preamp circuit.
 
That iz three cents worth, Kannan 🙂 The only issues with that thread are broken links and its length; otherwise excellent. Stanton was totally clueless about the cap multiplier and reduction from 30 volts to 24 volts, for example. We all need to face the difficulties associated with technological progress. The JC-80 made enough of a leap in this regard that its fame continues. Integrated circuits offer simplicity but lack the control aspect so dear to the hearts of true fanatics.

Please share your response from Stanton, Do, and the effects of 'popping' those electrolytics. If you pm your address I will mail you four of the polystyrene multiplier fellows that you might wish to use in place of the electrolytics.

@tickhpop I hate to see you with nothing to do but dream of Rio 🙂 My Sao Paulo feijoada favorite was the Rubyiat on Praça da República. Wednesday and Saturdays only in those days.

I honestly wish I had been able to ask better questions here. Perhaps when I get the power issues resolved and really get into the JC-80 some serious questions will come to mind. For now I will do my best at matching, search for heatsinks I can get through the door, and lash up one channel.
 
Pinnocchio, you are asking the wrong person. This is the way it works: John and Erno designed JC 80 and regulator boards, Tim makes money off John and Erno's work, and John gets to answer the build questions about it, but makes nothing on it. What's wrong with this equation? (nothing if you are Tim). Tim does seem clever enough to update the designs in a few areas such as obsolete device substitution - not exactly the original design, but 99% is there.

Now you know why John called his later efforts Vendetta. I suspect John feels like a Xexox machine he's been copied so often and why Tim and Mark Levinson aren't likely on John's Christmas card list.

ticknpop, I'm fully aware of this and agree that it is John's IP and I respect that 200%. I was just trying to help out and maybe get an answer.

I do appreciate John's help and presence in this thread.

That said, my intentions were never to hurt anyone's feelings toward the subject and I do dig what you're saying.

Cheers!
:cheers:
 
Pinniccho,
Not picking on you, just using your question to point out John's being nice in helping the JC 80 board buyers . So far it hasn't gotten me complimentary Blowtorch boards. Besides I like to go to the Montreal audio show and can't risk alienating the local population. Spend too much time at Schwartz's, the Copacabana bar across the street from it, and Wanda's looking for Bob Cordell anyway.............

I don't know if there's much else we can talk about now that we've got the power supply sorted out.
Everyone here knows enough to use non- ferrous metal film or bulk foil resistors, teflon, polystyrene, or polypropylene caps, match semiconductors, use good attenuators and switches, teflon insulated silver or good quality copper wire - the only difference may be which gods we pray to before turning on the power switch for the first time.
 
Last edited:
Pinniccho,
Not picking on you, just using your question to point out John's being nice in helping the JC 80 board buyers . So far it hasn't gotten me complimentary Blowtorch boards. Besides I like to go to the Montreal audio show and can't risk alienating the local population. Spend too much time at Schwartz's, the Copacabana bar across the street from it, and Wanda's looking for Bob Cordell anyway.............

I don't know if there's much else we can talk about now that we've got the power supply sorted out.
Everyone here knows enough to use non- ferrous metal film or bulk foil resistors, teflon, polystyrene, or polypropylene caps, match semiconductors, use good attenuators and switches, teflon insulated silver or good quality copper wire - the only difference may be which gods we pray to before turning on the power switch for the first time.

Are you passing by this year's audio show in Mtl? I go every year to see the latest trends and some friends. It is a nice audio show. I just hated the two Marriott hotel years... To cramped in the rooms... Wanda's nice... ;-) Haven't been there for years and years but it use to be a decent place to "talk".

Ciao!
Do
 
the only difference may be which gods we pray to before turning on the power switch for the first time.

In years past I favored the crew on Mt. Olympus but in light of recent events I'll count on our resident bon vivant and Do to down a couple at the audio show in honor of John and to luck in this build.

I am trying to assess the cost of aquiring the parts and whether they are even available.

Mission accomplished thanks to John et. al. Answer for total cost with power supply "neither JC-80 or Blowtorch . . . a mixture of the two, better than the JC-80, and somewhat less than the Blowtorch." is around $350 carefully shopped with radial rusky polystyrene bypass caps.

The perfect storm has hit the markets for audiophile electronics. Consumers have benefited but musicians, the recording industry, and audio designers not so much. What happened? The shift from discrete to integrated circuit components, shifts in musical 'tastes' (or lack thereof), a huge repository of great performances, the ease of making bitPerfect copies, the internet, third-world labor wage advantages and lack of local opportunities, 'open source', persistence of selling at prices much below those at which supply and demand equate, and . . .

How could something as virile as megawatt stereo fall into such a state so quickly? What are the prospects for recovery? Is mono the future or will it be 17.2 'in the head' audio implants? Do subwoofers cause premature joint failure? All topics for other threads.

'gardz & thanks all, Dick
 
Wait until all the lead free solder breaks down in 5 years and the only semiconductors avaiable commercially are surface mount and the Diyaudio swap pages have NOS jfets and mosfets hoarders making thier retirement a little easier selling off thier stash.
 
I beleive botique semiconductor manufacturer will come up for those Hi End Audio requirements. Like Nelson Pass is getting specific Power FET ( Si Carbide stuff) manufactured. As far as Old Toshiba JFETs - you will get them even after next 5 years for a cost. Also who knows- some new semiconductor or ICs which will run in calss A will come up for audio might emerge as an alternative?
 
I beleive botique semiconductor manufacturer will come up for those Hi End Audio requirements. Like Nelson Pass is getting specific Power FET ( Si Carbide stuff) manufactured. As far as Old Toshiba JFETs - you will get them even after next 5 years for a cost. Also who knows- some new semiconductor or ICs which will run in calss A will come up for audio might emerge as an alternative?

One thing for sure, people always find a way! When there's a will, there's a way!
 
One question was never resolved in my mind. ticknpop suggested that in the original design the electrolytics paralleling the polystyrene caps were to be omitted. We never heard from John one way or the other. Assuming no paralleling caps, the values I plan to use are shown in the attached schematic. Are the values for the bypass caps appropriate?
 

Attachments

Status
Not open for further replies.