Hi Matt,
a "black edition" transformer could "snuggle up" on the black LS-HPULN's site giving a nice appearance
Thanks for your ideas - I'll put it on our "improve-list".
I don't believe that this answer makes you satisfied... I'll need some days to clear that.
What do you mean with "threaded inserts"? A kind of included nut in the epoxy?
Best regards
Stammheim
a "black edition" transformer could "snuggle up" on the black LS-HPULN's site giving a nice appearance
Thanks for your ideas - I'll put it on our "improve-list".
I don't believe that this answer makes you satisfied... I'll need some days to clear that.
What do you mean with "threaded inserts"? A kind of included nut in the epoxy?
Best regards
Stammheim
Hi Michael,
the thread is potted in the epoxy, the transformer is mounted from below with a bolt which goes into the thread.
You find some nice examples here:
In praise of Canterbury windings power amp transformers | pink fish media
Scroll down.
Are not these all black ones really beautiful?
Matt
the thread is potted in the epoxy, the transformer is mounted from below with a bolt which goes into the thread.
You find some nice examples here:
In praise of Canterbury windings power amp transformers | pink fish media
Scroll down.
Are not these all black ones really beautiful?
Matt
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Hi Michael,
another thing I would change:
AFAIK, for the right connecting of two pairs of secondaries you would want FOUR different colors and not TWO.
The most other manufacturers use four colors for two pairs:
http://www.avellindberg.com/pdf/avel_y23_range.pdf
Matt
another thing I would change:
AFAIK, for the right connecting of two pairs of secondaries you would want FOUR different colors and not TWO.
The most other manufacturers use four colors for two pairs:
http://www.avellindberg.com/pdf/avel_y23_range.pdf
Matt
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Guys,
you might have already noticed: Special offers everywhere!
Intro:
In search of "best possible" music reproduction there are plenty of things, you will listen to and work with after a time. Some of them will be sold again, some of them will accompany you for a time, while increasing your own experience.
Getting deeper in technical aspects, the DIY-enthusiast will often find something to optimize, to improve it and to reach a better lever of music playback.
Optimizing power supplies is always desireable:
An audio circuit is always as good as it's power supply - it's output signal consists 100% of the supplied power!
Usually a transformer is used to supply the power supply with AC, what entails following challenge:
Something, that is neglected in our eyes is "transformer ringing", which is a really complex issue to deal with - a snubber circuit needs to be used between transformer and power supply, which "compensates" transformer's ringing. A lot of maths and measuring is necessary to get results, one can use to calculate an individual "snubber" matching the transformers parameters.
The good news: A circuit called "Quasimodo" was developed by Mark, also member here at diyaudio, to make it possible to everyone to "calculate" the snubber, that reduces / avoids transformer ringing. With a time invest of 5 minutes using Quasimodo.
The improvement is not theory only, it is measureable from the first moment connecting the snubber.
So what is the offer now?
Each HPULN-PS-order placed on friday, the 23rd of November 2018, UNTIL SUNDAY will include a Quasimodo PCB for free!
Best regards
Stammheim
you might have already noticed: Special offers everywhere!
Intro:
In search of "best possible" music reproduction there are plenty of things, you will listen to and work with after a time. Some of them will be sold again, some of them will accompany you for a time, while increasing your own experience.
Getting deeper in technical aspects, the DIY-enthusiast will often find something to optimize, to improve it and to reach a better lever of music playback.
Optimizing power supplies is always desireable:
An audio circuit is always as good as it's power supply - it's output signal consists 100% of the supplied power!
Usually a transformer is used to supply the power supply with AC, what entails following challenge:
Something, that is neglected in our eyes is "transformer ringing", which is a really complex issue to deal with - a snubber circuit needs to be used between transformer and power supply, which "compensates" transformer's ringing. A lot of maths and measuring is necessary to get results, one can use to calculate an individual "snubber" matching the transformers parameters.
The good news: A circuit called "Quasimodo" was developed by Mark, also member here at diyaudio, to make it possible to everyone to "calculate" the snubber, that reduces / avoids transformer ringing. With a time invest of 5 minutes using Quasimodo.
The improvement is not theory only, it is measureable from the first moment connecting the snubber.
So what is the offer now?
Each HPULN-PS-order placed on friday, the 23rd of November 2018, UNTIL SUNDAY will include a Quasimodo PCB for free!
Best regards
Stammheim
Hi Michael,
so far never experienced "transformer ringing".
When does it happen?
Is it audible or only something what can be measured?
Can you please shed some light on this?
Thanks
Matt
Transformer Ringing and Mark Johnson
To add to Stammheim, Mark Johnson's Quasimodo is outstanding and quite ingenious. He also did painstaking research into the ringing characteristics of many different diodes. Here.
Commercial products using a transformer LPSU is often susceptible to ringing.
This is because, unfortunately, many fast rectifier diodes have poorly controlled turn off characteristics and they turn off abruptly or extremely rapidly i.e. with large dI/dt. Abrupt diode turn-off dI/dt manifests as a large voltage across the leakage inductance of the transformer which is the stimulus which causes transformer secondary circuits to begin oscillatory ringing.
The snubber removes the ringing. I've seen Nelson Pass agree on this.
The cost of a CRC snubber is negligible, it makes no sense to ever omit snubbers. The genius of Quasimodo is that it figures out the optimum snubber for you in a few minutes, without doing complicated math or simulation which would be unbearable for mere mortals.
Denis
To add to Stammheim, Mark Johnson's Quasimodo is outstanding and quite ingenious. He also did painstaking research into the ringing characteristics of many different diodes. Here.
Commercial products using a transformer LPSU is often susceptible to ringing.
This is because, unfortunately, many fast rectifier diodes have poorly controlled turn off characteristics and they turn off abruptly or extremely rapidly i.e. with large dI/dt. Abrupt diode turn-off dI/dt manifests as a large voltage across the leakage inductance of the transformer which is the stimulus which causes transformer secondary circuits to begin oscillatory ringing.
The snubber removes the ringing. I've seen Nelson Pass agree on this.
The cost of a CRC snubber is negligible, it makes no sense to ever omit snubbers. The genius of Quasimodo is that it figures out the optimum snubber for you in a few minutes, without doing complicated math or simulation which would be unbearable for mere mortals.
Denis
Thanks @dtossan
@Stammheim:
Hi Michael,
when I order fully assembled and tested regulator boards I do not want to diy an extra Quasimodo board.
Further:
An oscilloscope is necessary to work with the Quasimodo.
More and more manufacturers do implement snubber circuits into their products.
What do you think about?
IMO, this is the better way to go than offering an external diy Quasimodo board.
Matt
@Stammheim:
Hi Michael,
when I order fully assembled and tested regulator boards I do not want to diy an extra Quasimodo board.
Further:
An oscilloscope is necessary to work with the Quasimodo.
More and more manufacturers do implement snubber circuits into their products.
What do you think about?
IMO, this is the better way to go than offering an external diy Quasimodo board.
Matt
MPAudio offers complete regulator boards with onboard rectifiers and offers a range of suitable transformers.
So what is the reason not to implement the snubber circuit?
Matt
@dtossan
Many thanks, great comment.
Matt, regarding your first statement: What would you want instead?
Although I recommend taking actions to avoid transformer ringing, it's just an option, that people CAN do, or not.
So as HPULN power supplies have the option for a snubber on board, the PS also works without the snubber placed.
Most customers also get an MPAudio transformer, so the snubber is already customized matching the transformers characteristic while manufactured.
Customers, that use their own transformers are free to decide, if they want to use the snubber finding out the necessary resistor's resistance (both necessary capacitors are also included, but not published in this case) with Quasimodo, or just leave it out.
Best regards
Stammheim
Many thanks, great comment.
Matt, regarding your first statement: What would you want instead?
Although I recommend taking actions to avoid transformer ringing, it's just an option, that people CAN do, or not.
So as HPULN power supplies have the option for a snubber on board, the PS also works without the snubber placed.
Most customers also get an MPAudio transformer, so the snubber is already customized matching the transformers characteristic while manufactured.
Customers, that use their own transformers are free to decide, if they want to use the snubber finding out the necessary resistor's resistance (both necessary capacitors are also included, but not published in this case) with Quasimodo, or just leave it out.
Best regards
Stammheim
Hi Michael,
just for clarification:
When ordering LSIB-HPULN and your transformers I do not need the extra Quasimodo board to prevent transformer ringing?
The snubber circuit is then onboard?
And there is no onboard snubber circuit for LS-HPULN?
In this case I would need the extra Quasimodo?
Correct?
Thanks
Matt
just for clarification:
When ordering LSIB-HPULN and your transformers I do not need the extra Quasimodo board to prevent transformer ringing?
The snubber circuit is then onboard?
And there is no onboard snubber circuit for LS-HPULN?
In this case I would need the extra Quasimodo?
Correct?
Thanks
Matt
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