Search found 5487 matches

by jack
Tue Aug 22, 2017 8:52 pm
Forum: Everyones Projects
Topic: 6B4G - The Resurrection Shuffle
Replies: 414
Views: 161086

Re: 6B4G - The Resurrection Shuffle

Merlin Blencoe's power supply book is out of print now (seen Jack is looking for a copy on DIYAudio) but Merlin once posted it was because there were so many errors in it he wasn't happy with it... There's not even a PDF around :( I never trust most stuff in books, unless it's AoE. I forget stuff a...
by jack
Tue Aug 22, 2017 3:09 pm
Forum: Everyones Projects
Topic: 6B4G - The Resurrection Shuffle
Replies: 414
Views: 161086

Re: 6B4G - The Resurrection Shuffle

Been looking at the maths required to calculate R and C snubber values for mains TX secondaries and how to measure interwinding capacitance and transformer leakage inductance accurately so that reasonable calculations can be made :shock: I'll need to blow the dust out of the scope and sig gen then....
by jack
Tue Aug 22, 2017 1:35 pm
Forum: Everyones Projects
Topic: 6B4G - The Resurrection Shuffle
Replies: 414
Views: 161086

Re: 6B4G - The Resurrection Shuffle

Been looking at the maths required to calculate R and C snubber values for mains TX secondaries and how to measure interwinding capacitance and transformer leakage inductance accurately so that reasonable calculations can be made :shock: I'll need to blow the dust out of the scope and sig gen then....
by jack
Tue Aug 22, 2017 1:19 pm
Forum: Everyones Projects
Topic: 6B4G - The Resurrection Shuffle
Replies: 414
Views: 161086

Re: 6B4G - The Resurrection Shuffle

Been looking at the maths required to calculate R and C snubber values for mains TX secondaries and how to measure interwinding capacitance and transformer leakage inductance accurately so that reasonable calculations can be made :shock: I'll need to blow the dust out of the scope and sig gen then....
by jack
Mon Aug 21, 2017 8:33 am
Forum: Assorted Stuff
Topic: Dacs, kits or bought?
Replies: 33
Views: 23864

Re: Dacs, kits or bought?

I think you need to look at more than the length of the I2S tracks, for example, what the output from the microprocessor looks like jitter-wise. Using the Soekris DAC I'm working on as an example: the DIY version has I2S isolation/reclocking on its inputs, prior to the microprocessor but on the OEM...
by jack
Mon Aug 21, 2017 8:09 am
Forum: Assorted Stuff
Topic: Dacs, kits or bought?
Replies: 33
Views: 23864

Re: Dacs, kits or bought?

...no need to reclock. It depends on what you mean by "no need"; generally, providing you constrain the length of your I2S connections it will work but there are SQ improvements to be had with jitter reduction via something like the DIY fifo reclocking solutions that are available, pionee...
by jack
Mon Aug 21, 2017 7:03 am
Forum: Everyones Projects
Topic: The Bastard
Replies: 9
Views: 7374

Re: The Bastard

The first (and only) turntable I made had a platter of phosphor bronze that I turned from a casting on a Myford ML7. It was my 6th form DT project. I also made the oil-damped unipivot arm, that went with it - still have bits of that, 40 years later... FWIW, turning a platter is very very tricky to g...
by jack
Mon Aug 21, 2017 6:20 am
Forum: Assorted Stuff
Topic: Dacs, kits or bought?
Replies: 33
Views: 23864

Re: Dacs, kits or bought?

Another vote for Raspberry Pi with a DAC hat and max2play - I use the IQaudIO Pi-DigiAMP+ or Pi-DAC+. In the Pi-DAC+ they use the TI/Burr-Brown PCM5122 - 32bit @ 384kHz - see http://iqaudio.co.uk/audio/8-pi-dac-0712411999643.html - the Pi-DigiAMP+ includes a 35W/chan class D amp too and is based on ...
by jack
Sun Aug 20, 2017 1:28 pm
Forum: Assorted Stuff
Topic: Nothing In Particular
Replies: 16439
Views: 4671063

Re: Nothing In Particular

Have a look at the Aneng AN8008. Astonishing value for money and genuine TrueRMS - many reviews out there including eevblog and detailed ones from Mark Henessey, a BBC lecturer . The 8002 is also worth considering and has slightly different characteristics. Paid about 14 quid for mine on Banggood - ...
by jack
Sun Aug 20, 2017 11:41 am
Forum: Assorted Stuff
Topic: Nothing In Particular
Replies: 16439
Views: 4671063

Re: Nothing In Particular

Not to say I wouldn't like one of these to play the precision game, but it would be just the collector of test kit impulse http://www.keysight.com/en/pd-1000001297%3Aepsg%3Apro-pn-3458A/digital-multimeter-8-digit?cc=GB&lc=eng If you bide your time, who knows what will turn up... I sold all of m...
by jack
Sun Aug 20, 2017 10:36 am
Forum: Assorted Stuff
Topic: Nothing In Particular
Replies: 16439
Views: 4671063

Re: Nothing In Particular

in my paupers defence though I wonder what benefit there is watching a square wave on a 500mhz scope over watching the same square wave on a humble 60mhz scope, in this hifi amp example..... Transient response, ringing, overshoot, rolloff, frequency response, HF oscillation (can be in the 10s or 10...
by jack
Sun Aug 20, 2017 9:06 am
Forum: Everyones Projects
Topic: GK-71 - economical build.
Replies: 497
Views: 173736

Re: GK-71 - economical build.

Or just host stuff within a Google doc and instead of an embedded image post the link to a Google doc (accessible to anyone who has the link). That's probably the way forward until a competitor to photobucket springs up. For NEONIXIE-L (which I own & manage) I have set up a Google Drive with pe...
by jack
Sun Aug 20, 2017 8:01 am
Forum: Everyones Projects
Topic: 6B4G - The Resurrection Shuffle
Replies: 414
Views: 161086

Re: 6B4G - The Resurrection Shuffle

What's that Q1 thing in the circuit above ? It is indeed a Mosfet - the "Maida" regulator is not an invention of Morgan Jones - it's named after Michael Maida - who wrote an application note back in the 1980s - see http://www.ti.com/lit/an/snoa648/snoa648.pdf - he was at National Semicond...
by jack
Sun Aug 20, 2017 6:29 am
Forum: Everyones Projects
Topic: 6B4G - The Resurrection Shuffle
Replies: 414
Views: 161086

Re: 6B4G - The Resurrection Shuffle

Oops! just realised sorry Jack if separate shunt regs for each valve, then it only needs to be 310V at 150mA capability. I'm a silly b'stard. :lol: That's pretty much within the capabilities of the current boards - you'd need a second extension board as, using 1N4734As, the maths shows an adjusted ...
by jack
Sun Aug 20, 2017 5:53 am
Forum: Everyones Projects
Topic: GK-71 - economical build.
Replies: 497
Views: 173736

Re: GK-71 - economical build.

Oh poop. Catching up here is first I realised my photobucket restricted. Would cost $39 a month to get back what was free. Sooner or later a competitor will blow photobucket out. Until then. I have no solution. It's a major pain in the scrotum. Some forums I use have switched to imgur and there are...