From original users, I would have said 3mths for 3mA Duraglit and discerning users. More than 1 yr for the 0.5mA versions. That's allowing for the odd night when you forget to switch off the device.
The first thing you notice when the cell runs down is the noise increases. But Duraglit is so much quieter than lesser devices that many users didn't even notice that.Other stuff, like gain, changes too but this is what you notice first when the cell is nearly dead.
I think 3mA is a sensible max current to run for a C-cell and will continue to recommend that except for Golden Pinnae .. I mean specially discerning users like Bill.
You really only need to get noise & THD sufficiently below vinyl noise to obtain the improvements in World Peace and a Better Sex Life I describe in my document
Richard,
I play at the most 100 LP's per annum, I wonder who is doing more that that ?
One hundred LP's means 100 hrs of available power supply.
When the Duraglit supply is remotely synchronised with a small relay to the TT, the smallest battery will do the job, but certainly a C cell will function for even more than a year.
When swtiched on/off by hand, multiply these 100 hrs by a large margin like 10 times to inlude idling time and forgetting every now and then to switch the thing off, and you will need 1000 hrs of power supply.
For a 3 mA version, this will consume 30% of the energy in a C cell.
Still at 70% capacity, voltage will hardly be changed for a good alkaline C cell battery.
So in my case, a year will be easily met and the 3 months you mention do seem very pessimistic.
Hans
That’s an excellent result and a good enough reason in my book to go with the large base caps.
Just sayin', someone coming upon this might have some work to do to sort things out.
(ancient-year-end-folklore-symbol)
Today it was over 40 degrees locally, so I had to stay inside where it was a bit cooler but also too hot to do a sensible thing.
I decided to scan various sections and threads on diyaudio to find many of the same posters all over the place.
I wonder how to combine such an impressive presence with quality time for the family, read newspapers or even to listen to LP’s.
But I’m probably just caught in the heat.
Hans
I decided to scan various sections and threads on diyaudio to find many of the same posters all over the place.
I wonder how to combine such an impressive presence with quality time for the family, read newspapers or even to listen to LP’s.
But I’m probably just caught in the heat.
Hans
The 3 mths life was in our R&D Dept where the vinyl playing system was in constant use and I was a bit fussy. But the owner of the first 3mA Duraglit, an avid record player, did indeed go for more than a year before changing C-cells (at my insistence)
Remember, this is the late 70s & early 80s where vinyl was still the pre-eminent music medium
______________
Friends, syn08 & Bonsai, I urge you to make up a Duraglit each and use it. This has documented beneficial effects on World Peace and I'm certain will resolve any negative differences in opinion between friends. It may even improve your sex life
A secondary use apart from the above major & most worthwhile aims is to act as a practical LN MC head amp reference while you attempt to equal its real life performance with a mains powered device
I suggest the 3mA version though even that would give insufficient battery life before you complete this onerous task
What would you think, I already did (no case and raw power supply yet). Short of some hum (normal, since there is no shielding at all) sounds as good as anything else I have, as usual I can't tell any difference.
Attached is a photo, takes 50mA @100mA both channels for the solar cells, for my Benz Micro Gold MC (12ohm 0.4mV) the optimum current is lower, @1mA. Noise is 0.44nV/rtHz flat, input shorted. Feeding the output in an Anthem AVM20 MM input.
I am happy to report that the MC did not care about feeding a virtual ground, FR is just fine (I have a test LP for that). This is one precious lesson learned from this exercise, not sure if it's worth finalizing this project, since I already have enough idle HPS series preamps, don't need another one.
Attachments
With great respect for the short time it took you to built such a neat looking Duraglit with fully isolated remote PSU, it’s also nice to hear that sonically the virtual ground topology seemed not to pose any drawback.
So no signs of “muddy sound” but in line with most other positive virt gnd experiences that were reported.
Thank you for sharing.
Hans
Any numbers/graphs you can share?
Maybe this partly answers my question
John Curl's Blowtorch preamplifier part III
Hans
Only 38 here. We hid in a museum.
I just spend too much time on the internet! Really must get on with soldering. And checking the signet mk111E I bought as a low mass MC.
Mostly impresses me when mega-contributers have succesfull companies, busy keeping up with demand, but still time to post at all hours of the day. Often productive in diying at the same time. My projects take a year+ generally. I can sometimes long for retirement, but I really need work for a rythm.
Cheers!