what did you do for those SMD resistors/caps on the back of these JC-80 PCB's ?
what IC's you used for Servo?
kannan
Seller IP?
It is, AFAIK, accurately specified in the BOM Stanton emals with each pcb.
It is, AFAIK, accurately specified in the BOM Stanton emals with each pcb.
Hi dirkwright,
If you have just bought the PCBs then you can also look at this one...
Ventus EZ Headphone Driver
Everything is included!
Sorry... a little off topic... My bad...
Do
The headphone amp is just the PCB, but I just ordered all of the parts from Mouser.
The Kubota power supplies are complete kits.
Now I need to find a way to fit into the USB amp I'm building.
I just checked, everything is in the BOM that Stanton emails out. You have all the resistor values in the bom and the package type as well in the third column.
Do
Owen has raised the bar again! As usual, after just a few hours, his pcbs are unobtaniums. He has scaled up 'the wire' into a behemoth whose specs are frighteningly good. It can be partially populated and used as a headamp that remains class A to deafening levels.
http://www.diyaudio.com/forums/soli...gh-perfromance-lpuhp-16w-power-amplifier.html
His BAL-BAL is my gold standard headamp today. I hope the JC-80 can change that soon. Wolfsin's checkin' his BOM and matchen' 'em twice, gunna find out who's . . .
http://www.diyaudio.com/forums/soli...gh-perfromance-lpuhp-16w-power-amplifier.html
His BAL-BAL is my gold standard headamp today. I hope the JC-80 can change that soon. Wolfsin's checkin' his BOM and matchen' 'em twice, gunna find out who's . . .
Unobtainiums drive me nuts. After living in Brazil where every week another item was 'em falta' I can begin to appreciate the pains of 'planned economies'. Hunting (and gathering) parts from around the globe has its charm. All the colorful stamps and trips to the post office to sign for registered parcels containing 99cent items are kinda' fun. I am thankful it is not (yet) food :-( End rant!
It should be noted that modern Brazil is much, much bettter and I loved it then.
It should be noted that modern Brazil is much, much bettter and I loved it then.
Unobtainiums drives me nut too... You're not alone!
I know why you love Brazil... Those cute women with their dancing outfit! I bet they would enjoy music on that JC-80!
Do
Busted BOM - not first time
OK, heeeere's an example. The BOM specifies 1.5ma crd. DK is clueless when you search for crd but mouser gets you to the part quickly. Only $2.48 but you need four and there is another crd, of a different current in the BOM. That is $20 in parts even if you do not try to match. The alternate is listed as LM334 + 33R resistor. Great, for 87 cents each and a pool of resistors you have cut the price to $7, have one fewer part to order, and can likely offset variations in the lm334 by those in the resistors. While matching you notice that this 'alternate' results in 2ma. Now your mind starts running. Which is the correct value? Does it matter as long as both are matched? Maybe this is great for a vanishingly small audience but . . .
One might say I signed up for this. Well, yes, but by sellers seeing IP in their BOMs this goes on and on. Open source allows the light of day to sanitize them, at least in theory.
@Diminic Really now, Wolfsin izNearly 70 yearzOld (but was 30 in Brazil)
OK, heeeere's an example. The BOM specifies 1.5ma crd. DK is clueless when you search for crd but mouser gets you to the part quickly. Only $2.48 but you need four and there is another crd, of a different current in the BOM. That is $20 in parts even if you do not try to match. The alternate is listed as LM334 + 33R resistor. Great, for 87 cents each and a pool of resistors you have cut the price to $7, have one fewer part to order, and can likely offset variations in the lm334 by those in the resistors. While matching you notice that this 'alternate' results in 2ma. Now your mind starts running. Which is the correct value? Does it matter as long as both are matched? Maybe this is great for a vanishingly small audience but . . .
One might say I signed up for this. Well, yes, but by sellers seeing IP in their BOMs this goes on and on. Open source allows the light of day to sanitize them, at least in theory.
@Diminic Really now, Wolfsin izNearly 70 yearzOld (but was 30 in Brazil)
OK, heeeere's an example. The BOM specifies 1.5ma crd. DK is clueless when you search for crd but mouser gets you to the part quickly. Only $2.48 but you need four and there is another crd, of a different current in the BOM. That is $20 in parts even if you do not try to match. The alternate is listed as LM334 + 33R resistor. Great, for 87 cents each and a pool of resistors you have cut the price to $7, have one fewer part to order, and can likely offset variations in the lm334 by those in the resistors. While matching you notice that this 'alternate' results in 2ma. Now your mind starts running. Which is the correct value? Does it matter as long as both are matched? Maybe this is great for a vanishingly small audience but . . .
One might say I signed up for this. Well, yes, but by sellers seeing IP in their BOMs this goes on and on. Open source allows the light of day to sanitize them, at least in theory.
@Diminic Really now, Wolfsin izNearly 70 yearzOld (but was 30 in Brazil)
Wolfsin, maybe it is me smokin' grass or somethin'
but which bom are you refering to? I don't remember any current regulator diodes in my JC-80 buildNearly 70... You're still a baby!
Ciao!
Do
Hi Wolfsin
check for same parts else, I had bought Current Regulator Diodes for 1 $ or less. however check whether LM334+Resistor replacement a good idea ? with John. Some of these parts had been selected for low noise.
kannan
It could be worse
@Dominic Not the JC-80 (that leaves only the Kubota) but there is at least one bug in the former (at least my version).
A favorite witicism goes as follows: Hardware degrades from too little maintenance while software degrades from too much. Even directly from the hands of the original designer things are iffy before QC and frequently worse after :-( What's the chance following translation? I am surprised things are not worse.
Now comes the innocent noob and buyz a kit to avoid this. Does (s)he carefully measure each resistance or stuff the board and solder? And when it doesn't (work, sound right, smell ok) or does (cause lights to dim, catch fire, attack the dog) whoze2sue unless John designed it?
@Dominic Not the JC-80 (that leaves only the Kubota) but there is at least one bug in the former (at least my version).
A favorite witicism goes as follows: Hardware degrades from too little maintenance while software degrades from too much. Even directly from the hands of the original designer things are iffy before QC and frequently worse after :-( What's the chance following translation? I am surprised things are not worse.
Now comes the innocent noob and buyz a kit to avoid this. Does (s)he carefully measure each resistance or stuff the board and solder? And when it doesn't (work, sound right, smell ok) or does (cause lights to dim, catch fire, attack the dog) whoze2sue unless John designed it?
Now I understand better why John Curl shuns the headaches involved in offering bare PCBs and/or schematics for people without enough knowledge and experience to build properly working units.
When someone offers a complete kit, with support to builders – it's a different story.
Given the fact that the major parts for the JC-80 are out of production, probably such a complete kit isn't and will not be available.
When only PCB with schematic and BOM are offered, people should know what they are getting into and should estimate their ability to build properly working units with what they receive from the seller. Especially when the schematic and BOM are confidential, so they cannot consult other members on the forum.
When someone offers a complete kit, with support to builders – it's a different story.
Given the fact that the major parts for the JC-80 are out of production, probably such a complete kit isn't and will not be available.
When only PCB with schematic and BOM are offered, people should know what they are getting into and should estimate their ability to build properly working units with what they receive from the seller. Especially when the schematic and BOM are confidential, so they cannot consult other members on the forum.
Well put, @Joshua_G Certainly John's reluctance is totally justified, consultation in this case has been hampered, but the seller has really tried to cooperate. Do(minic) is the only living testimonial that it actually can be built.
Please don't get me wrong. This has been fun. I have built other (kits, pcbs) in past and most had some kind of glitch. Until Do came along I could not determine even the current requirements. That makes power supply design a challenge.
Initially I hoped to offer a unified BOM but now must limit that to power chain. Will any of this encourage others to give it a try with the uncased cost of components (carefully shopped) approaching $$$ per channel? John's Blowtorch looks cheaper every day.
Please don't get me wrong. This has been fun. I have built other (kits, pcbs) in past and most had some kind of glitch. Until Do came along I could not determine even the current requirements. That makes power supply design a challenge.
Initially I hoped to offer a unified BOM but now must limit that to power chain. Will any of this encourage others to give it a try with the uncased cost of components (carefully shopped) approaching $$$ per channel? John's Blowtorch looks cheaper every day.
for everyone interested but worried that finding parts could be hell on earth (and it is), I'm currently thinking of helping out and get everything except heatsink and mkp capacitors as JC-80 kits.
I would need to know how many would be interested and how many boards each. Then I would also need to figure out pricing and availability for everything...
I would just be helping out to get the parts not offering any warranty on the stuff.
If the logistics are not too crazy then I could do it... Not making any promises here!
Ciao!
Do
I would need to know how many would be interested and how many boards each. Then I would also need to figure out pricing and availability for everything...
I would just be helping out to get the parts not offering any warranty on the stuff.
If the logistics are not too crazy then I could do it... Not making any promises here!
Ciao!
Do
Go Do!
This is the best news since Stanton assured me that "You would not be regretted with JC-80, but like all the rest of JC designs, the performance is quite decided by the quality of power supply." While still hopeful that Stanton was not being overly optimistic, the devil lurks in the power supply IMO. What plans do you have there?
This is the best news since Stanton assured me that "You would not be regretted with JC-80, but like all the rest of JC designs, the performance is quite decided by the quality of power supply." While still hopeful that Stanton was not being overly optimistic, the devil lurks in the power supply IMO. What plans do you have there?
Hey Super Wolfsin!
I'm using the Borbely Super Shunt per JC-80 and it has given me extremely satisfactory results. I have also used the AMB o22 with excellent results. I have yet to try Salas shunt reg which I have but not build it yet...
I'm not going to piece the Borbely Super Shunt since it was even harder to get parts for it but definitely wouldn't mind getting parts for the AMB o22 for those interested. It is always a question of shipping cost in the end...
The σ22 Regulated Power Supply
I will post pictures of my JC-80 and Borbely Super Shunt later on.
Ciao!
Do
I'm using the Borbely Super Shunt per JC-80 and it has given me extremely satisfactory results. I have also used the AMB o22 with excellent results. I have yet to try Salas shunt reg which I have but not build it yet...
I'm not going to piece the Borbely Super Shunt since it was even harder to get parts for it but definitely wouldn't mind getting parts for the AMB o22 for those interested. It is always a question of shipping cost in the end...
The σ22 Regulated Power Supply
I will post pictures of my JC-80 and Borbely Super Shunt later on.
Ciao!
Do
ItzA New Day
Sorry I missed your comments in the heat of frustration @kannan_s. The noise issue is something I am reading about in a Walt Jung article. The LM334 can be also be wired using a pair of resistors so its current flow is unaffected by temperature. I should have admitted to having aspecial interest in lm334 in addition to being cheap.
I am over my rants and tantrums. Awakened with a great idea on how to fab the copper temp bonding parts.
Sorry I missed your comments in the heat of frustration @kannan_s. The noise issue is something I am reading about in a Walt Jung article. The LM334 can be also be wired using a pair of resistors so its current flow is unaffected by temperature. I should have admitted to having aspecial interest in lm334 in addition to being cheap.
I am over my rants and tantrums. Awakened with a great idea on how to fab the copper temp bonding parts.
to CRD or not CRD... That is the question!
Did you only buy the Kubota boards or the full kit? In the full kit the CRDs are included.
The only thing I changed was all resistors and large filtering caps.
I guess I missed a part somewhere...
Ciao!
Do
Did you only buy the Kubota boards or the full kit? In the full kit the CRDs are included.
The only thing I changed was all resistors and large filtering caps.
I guess I missed a part somewhere...
Ciao!
Do
My goals, from the beginning, included finding low cost, available, parts for the whole project. Only the regulator portion of the Kubota is needed when the r-core, rectifiers and caps are located externally, hence the Kubota pcb only (available from same seller as JC-80). My pet peeve is BOMs that do not align (missing, inconsistent, not matched to silk screen, version mismatch) with other parts. IP keeps many of these alive.
My cache of SERIOUSly NOS Dale 1% resistors arrived today. They were declared surplus 7/18/88! A single value, 36.5R, can be used with all the lm334s (paralleled in the higher current case). Later I can add trimmers to achieve tempco=0 should drift rear its ugly head. I really enjoy the matching activities and it makes me feel SERIOUSly fanatical
The only real compromise to date wuz the Caddocks. John would likely view this entire enterprise as compromised but, as he has pointed out, what's a fanatic to do?
My cache of SERIOUSly NOS Dale 1% resistors arrived today. They were declared surplus 7/18/88! A single value, 36.5R, can be used with all the lm334s (paralleled in the higher current case). Later I can add trimmers to achieve tempco=0 should drift rear its ugly head. I really enjoy the matching activities and it makes me feel SERIOUSly fanatical
The only real compromise to date wuz the Caddocks. John would likely view this entire enterprise as compromised but, as he has pointed out, what's a fanatic to do?
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