I have a couple of Folded PCBs left, and some of the parts listed in the first post. If your interested, please Private Message me your requests and an email address.
I am not certain of the part substitute, I would leave that question to Salas.
Will work. May show a bit harder subjective HF or not. Its about a small difference for more reg Zo HF rise trend due to the 9540's higher parasitic capacitance.
You are welcome. Overload spec is 16V pk-pk non clipped sine wave output as is. No worries.
You are welcome. Overload spec is 16V pk-pk non clipped sine wave output as is. No worries.
Thats not too shabby at all, quite a bit of headroom indeed. My build will be slow as I fit in around day to day living of course but itll make the anticipation ever sweeter.
I think I can drum up the parts for you. Nothing ready to fly off the shelf, but I think I got all the parts needed. If you want any of the other items in the first post send me a PM. thanks.
Are there any parts value substitutions I can make that will reduce my losses on the RAW PSU board please?
I have a recycled torroidal transformer from a Sony amp. It's very nice, but outputs 2x 31.5v AC
Although Salas has assured me that this should be OK, I am understandably keen to reduce my losses as much as possible to get closer to the desired 46v DC output from that board.
Many thanks
Lucas
I have a recycled torroidal transformer from a Sony amp. It's very nice, but outputs 2x 31.5v AC
Although Salas has assured me that this should be OK, I am understandably keen to reduce my losses as much as possible to get closer to the desired 46v DC output from that board.
Many thanks
Lucas
Use links or 1 Ohm RD (drop resistor) on the raw boards, no more Ohms. After you will have biased the FSP, measure its rail value. If the raw DC input is 7V-15V higher than FSP rail (i.e. reg out), no worries.
Thanks Salas, links it is! I was thinking about 0R1 resistors, but if links work, then that's best.
What are your thoughts on the audible effect of bleed resistors that remove the DC from the caps on switch off to make the PSU safe to work on after a passage of time?
I generally use a loose Dale 5W 10R to drain caps before working on a used PSU, but I guess the safest is to build them in of course.
What are your thoughts on the audible effect of bleed resistors that remove the DC from the caps on switch off to make the PSU safe to work on after a passage of time?
I generally use a loose Dale 5W 10R to drain caps before working on a used PSU, but I guess the safest is to build them in of course.
Small value resistors vs links can maybe take some EMI edge off the charging cycle without forming significant RC time yet. That's the difference.
When becoming 5-10-15-20 Ohm then its for dropping excessive transformers really. Somewhat slower but cleaner also, because its a real filter now too.
The double 10K resistors on the Raw board's sections are bleeders. They are shown in the PDF guide's generic supply too. I don't think they affect subjectively.
They are designed to smoothly drain about 10mA from each reservoir, but the main bulk is going to be drained by the regs CCSs before the LEDS extinguish during power down.
When becoming 5-10-15-20 Ohm then its for dropping excessive transformers really. Somewhat slower but cleaner also, because its a real filter now too.
The double 10K resistors on the Raw board's sections are bleeders. They are shown in the PDF guide's generic supply too. I don't think they affect subjectively.
They are designed to smoothly drain about 10mA from each reservoir, but the main bulk is going to be drained by the regs CCSs before the LEDS extinguish during power down.
Hi Salas,
I've just assembled the PSU board with links (not resistors), and I'm getting 43vDC out exactly, so I may have to run my RIAA at 36v to give the shunts 7v to burn. Will that be OK do you think?
For clarity, I have barely begun buying the parts for the main boards. That's next!
I've just assembled the PSU board with links (not resistors), and I'm getting 43vDC out exactly, so I may have to run my RIAA at 36v to give the shunts 7v to burn. Will that be OK do you think?
For clarity, I have barely begun buying the parts for the main boards. That's next!
Thanks Salas. Very reassuring!
I have the K369 quad from the group buy, and matched K170s I have from way back (all good and tested!). The K117GR fets are from eBay, but I don't think they are faking those cheapies are they? The 2SA970BL is also eBay, but a good source from the UK.
Caps and resistors to buy mostly. Thinking PRP, Vishay and Mundorf (basic for shunt regs and Supreme for DC blockers.)
I have the K369 quad from the group buy, and matched K170s I have from way back (all good and tested!). The K117GR fets are from eBay, but I don't think they are faking those cheapies are they? The 2SA970BL is also eBay, but a good source from the UK.
Caps and resistors to buy mostly. Thinking PRP, Vishay and Mundorf (basic for shunt regs and Supreme for DC blockers.)
Yes they unfortunately fake those too. An Australian member that built a very nice valve preamp had all sorts of problems recently with K117GR fakes in SSHV2 HV power supplies for instance. When he replaced them with good ones all ills solved instantly. Show us a macro photo from your K117GR, many times we can say if fake just by looking. We could in that case too. Its not the end of the world if bad though. You may either ask Tea if he can spare a couple out of his minikits quota, or use two lowest IDSS K170BL within 1mA tolerance between them from your stash.
