Has anyone had problems with their Shuntky and Pumpkin?
I'm a fully qualified and accredited Electronic Engineer so I know how to solder and read circuit diagrams.
I took very great care when I was building the Shuntkys. However, one of them still sparked slightly when I powered it up for the first time. No damage was done but it was a bit alarming. I can only put it down to traces of copper remaining between the pads and the top layer on the earth plane.
I've subsequently investigated it under the microscope and can see absolutely no reason for the flashes - as I said NO damage was done. After the flash everything worked perfectly.
I've fully adhered to Zen-Mods recommendation of raising all the components above the board, about 1mm in my instance. One flash was next to C17A / C18A and the other around the 10V zeners D2 / D3 / D4 and D5. They occurred separately as I didn't fit the fuses until I was happy that the input circuitry was OK.
I'm still waiting for some MOS-FETs so there are no active devices nor heatsinks fitted after the zener chain. JP1 and JP1A are also currently not fitted.
The unregulated DC at the supply side of the fuses is approximately +/- 58.5V
I'm a fully qualified and accredited Electronic Engineer so I know how to solder and read circuit diagrams.
I took very great care when I was building the Shuntkys. However, one of them still sparked slightly when I powered it up for the first time. No damage was done but it was a bit alarming. I can only put it down to traces of copper remaining between the pads and the top layer on the earth plane.
I've subsequently investigated it under the microscope and can see absolutely no reason for the flashes - as I said NO damage was done. After the flash everything worked perfectly.
I've fully adhered to Zen-Mods recommendation of raising all the components above the board, about 1mm in my instance. One flash was next to C17A / C18A and the other around the 10V zeners D2 / D3 / D4 and D5. They occurred separately as I didn't fit the fuses until I was happy that the input circuitry was OK.
I'm still waiting for some MOS-FETs so there are no active devices nor heatsinks fitted after the zener chain. JP1 and JP1A are also currently not fitted.
The unregulated DC at the supply side of the fuses is approximately +/- 58.5V
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I'm always checking all boards for shorts between upper GND plane and rest pads .
but - as I'm humble human
, mistakes are possible , but certainly not purposely .
say that I can find one of ~25 (Shunty) to be problematic
if you have further problems with pcb , I'll send another one
but - as I'm humble human
, mistakes are possible , but certainly not purposely .say that I can find one of ~25 (Shunty) to be problematic
if you have further problems with pcb , I'll send another one
I might take the fuses out and sustitute them with resistors for testing just in case I have one of the suspect boards. I certainly don't wan't to have to go fault finding and have to go through the pain of replacing matched components.
I am surprised that you are experiencing problems with commercially produced boards.
I'm on the hunt at the moment for a CNC PCB milling machine. When I can spare £1000 I might just buy one. Far better than DIY etching.
Only one was a problem, the other one was 100%.
I am surprised that you are experiencing problems with commercially produced boards.
I'm on the hunt at the moment for a CNC PCB milling machine. When I can spare £1000 I might just buy one. Far better than DIY etching.
Only one was a problem, the other one was 100%.
just realized that we - while still talking about 
- aren't in Pumpie thread .......
maybe regular thread is better place ; that little drek certainly isn't sole one capable to drive bal F4 nutz
http://www.diyaudio.com/forums/pass...amp-ordered-steen-official-making-thread.html
- aren't in Pumpie thread .......maybe regular thread is better place ; that little drek certainly isn't sole one capable to drive bal F4 nutz
http://www.diyaudio.com/forums/pass...amp-ordered-steen-official-making-thread.html
Zen Mod did you notice that I have listed the part numbers for the heatsinks for the Shuntky and Pumpkin. The heatsinks are less than Euro 3.00 each for the bigguns and less tha Euro 2.00 for the small ones. P&P is also very reasonable. I know that several people have had problems sourcing the correct 'sinks for the board layout.
all valid points ;
I have slight problem - I know for at least 5 better places to make pcbs , but all of them aren't situated locally ; that demands - besides all other complications - that I must smuggle them in my country , to keep costs down .
taking also in account complications with payment ........
considering amount of pcbs I make and sell this way , there is no space for "taking operation to higher level "
so - I'm making them locally and I must check each one manually 😕
yes , thank you - I take a note , and will implement that in Cook Book
in time when it was written , there wasn't a problem to source them by these types ; I bought mine locally , even if I had to wait 3 weeks for delivery
I had to buy them from Germany. It seems that no-one in the UK sells the smaller heatsink. Farnell sell the bigger one.
No sparks when I fired up my two shunties and two pumpkin boards 🙂
But much sparkling joy when I heard them combined with F4!🙂🙂
Hear pumpkin with F4 and you begin to dance......🙂🙂🙂
But much sparkling joy when I heard them combined with F4!🙂🙂
Hear pumpkin with F4 and you begin to dance......🙂🙂🙂
In the F4 thread Zen Mod shows a variant without J-FETs, pumpkin drives directly t he output stage.....
I'm currently building both SHUNTKY PUMPKIN and F4. It's cost wife so far so it's been a bit slow. I did build the BORBELLY so I've got a few buidling bricks to check my final result.
Still trying to sort out how to mount the MOS-FETs as my PCBs are single sided. I may just take the plunge and buy some double sided ones.
Still trying to sort out how to mount the MOS-FETs as my PCBs are single sided. I may just take the plunge and buy some double sided ones.
It's been a while. My main supplier (RS-Components) was out of stck of IRFP510s. So a lull in the build.
However, after the initial fireworks from the first Shunky it is now producing a clean +/- 36V. Second shuntky will have to wait as Im off to Padstow to see girlfriend after wife of Shuntky left me.
I'll be treading a bit more cautiously this time.
However, after the initial fireworks from the first Shunky it is now producing a clean +/- 36V. Second shuntky will have to wait as Im off to Padstow to see girlfriend after wife of Shuntky left me.
I'll be treading a bit more cautiously this time.
I'm really not keen on the Borbelly Pre-Amp. It does colour the sound in my ears. It is a welt built amplifier - I'll probably stick it on E-Bay once tI've built and evaluated the Pumpkins.
Maybe I just haven't got valve ears.
Maybe I just haven't got valve ears.
Papa Borbely is , without doubts , Papa - too ;
but - I don't like his way of cascoding Jfets , I always have impression that they're starving ( voltage vise )
to be more precise - my ears have impression ,and my reason ( Ratio) is trying to decipher that
but - I don't like his way of cascoding Jfets , I always have impression that they're starving ( voltage vise )
to be more precise - my ears have impression ,and my reason ( Ratio) is trying to decipher that
Well. An update at last.
Seems like IRFP510s are in short supply so had to wait three months for them. They have now arrived.
Despite early sparks from the Suntky's - prior to fitting any components in the regulator. The finished boards worked with no more sparks.
Heatsinks were a problem to source but I eventually got them from Germany. Zen Mod is going to include the supplier and part numbersf in the next issue of the cookbook.
Shuntkys tested and set up. Next job is the Pumpkins.
I really dont like the Borbelly Vlave Line Amps that I built. They colour the sound above and beyond what I call acceptable. This might be a subjective comment as some of you will like the valve sound.
Seems like IRFP510s are in short supply so had to wait three months for them. They have now arrived.
Despite early sparks from the Suntky's - prior to fitting any components in the regulator. The finished boards worked with no more sparks.
Heatsinks were a problem to source but I eventually got them from Germany. Zen Mod is going to include the supplier and part numbersf in the next issue of the cookbook.
An externally hosted image should be here but it was not working when we last tested it.
Shuntkys tested and set up. Next job is the Pumpkins.
I really dont like the Borbelly Vlave Line Amps that I built. They colour the sound above and beyond what I call acceptable. This might be a subjective comment as some of you will like the valve sound.
Cook Book edited with few notes on last page ;
heatsink related info , supplemented by Andy5112405 and few small things ....
heatsink related info , supplemented by Andy5112405 and few small things ....