Why audiophools love LT1083/84/85 ? - Page 1
Forum section: electronics / projects

author: BravoV
author_rank: Super Contributor
timestamp: February 12, 2020, 06:10:27 am
content: At least here locally, the goons here love it so much, the LT1083, LT1084 and LT1085 Low Drop Out voltage regulator, that drives it's price crazily high, and also officially by Analog (Linear Tech) its discontinued.->https://www.analog.com/en/products/lt1083.html#product-overviewTechnically, apart from the phool's believe of course, is it really special ?Say compared to other brands comparable LDOs ?

author: moffy
author_rank: Super Contributor
timestamp: February 12, 2020, 06:19:01 am
content: Looking at the data sheet and its response to a step load current change with Cadj=1uF, it is pretty good.

author: poorchava
author_rank: Super Contributor
timestamp: February 12, 2020, 07:17:31 am
content: Same thing as NE5532 opamps.<audiophile bashing >Because these LDOs sound the best! The scene seems wider... (or somethng....)</audiophile bashing>In Poland we have a saying: don't go into discussion with an idiot. He's gonna drive you to his level and beat you with experience.

author: Vovk_Z
author_rank: Super Contributor
timestamp: February 12, 2020, 02:00:07 pm
content: Quote from: BravoV on February 12, 2020, 06:10:27 am- compared to which one? There isn't any large choice of powerful (3-7 A) integral regulators.

author: SiliconWizard
author_rank: Super Contributor
timestamp: February 12, 2020, 02:13:38 pm
content: Quote from: Vovk_Z on February 12, 2020, 02:00:07 pmIndeed. Didn't know those were so popular, but for the OP? don't hesitate to list alternatives that can provide that much current with those regulation characteristics and a drop-out voltage <= 1V. Not that many either.It's actually NOT discontinued yet, it's just flagged as NRND for the LT1083, and AD suggest using the LT1084 instead, which is in active production so far.High-power LDOs are not that many on the market and if you have a decent list of equivalents, some may be interested here.

author: moffy
author_rank: Super Contributor
timestamp: February 13, 2020, 01:29:47 am
content: The LM1084 has very similar characteristics to the LT1084. Looks like the LT1084 was their answer to the LM1084. LM1084 is cheaper, but in their data sheet they don't show the dynamic response with Cadj=1uF. I suspect it would be very similar to the LT1084.

author: magic
author_rank: Super Contributor
timestamp: February 13, 2020, 07:56:26 am
content: Micrel (Microchip) has some high power integrated LDOs, not sure how their perfarmance compares to this one.

author: BravoV
author_rank: Super Contributor
timestamp: February 13, 2020, 08:18:42 am
content: Quote from: Vovk_Z on February 12, 2020, 02:00:07 pmStill doesn't explain the "special" factor that differs like night & day to other regulators with external power passing components.Also as miniaturization is not a priority in this subject, as its just the linear power supply section that usually also comes with big ass step-down transformer encased in a huge box.

author: Someone
author_rank: Super Contributor
timestamp: February 13, 2020, 08:25:21 am
content: Quote from: BravoV on February 12, 2020, 06:10:27 amUnusual corner case high voltage and big current LDO, no mention of capacitor stability problems.Quote from: moffy on February 12, 2020, 06:19:01 amIts ok and typical of good LDOs, very comparable to other parts in the space. Look carefully! they slew the load step to make it look better.Quote from: magic on February 13, 2020, 07:56:26 amThey have some but not quite with the same dynamic performance, STMicroelectronics are probably a better example.

author: SiliconWizard
author_rank: Super Contributor
timestamp: February 13, 2020, 03:00:22 pm
content: Quote from: moffy on February 13, 2020, 01:29:47 amYep, they are pretty similar. The LT1084 might be marginally better on some specs but I wouldn't trust the datasheets to elicit that clearly, and direct testing would be required. And yes, the LM1084 is much cheaper (at least currently). Maybe the price tag on the LT1084 makes it look "better" to amateurs? (Classic case of high price tag = looks like high quality) Still, this is a good LDO (even if a bit pricy), so it wouldn't qualify as bullshit. Maybe more just a costly habit (knowing that a few bucks for an high-power linear power supply won't make any difference to your expenses anyway...)I actually don't know for sure which came first? Weren't LM* parts initially National Semiconductor parts (which was bought by TI relatively recently) anyway? I don't know the history between NS and LT exactly, that would be interesting though if someone has more info on this.Still not a lot of options for high power LDOs, and beside the price tag point, using the same "favorite" part over and over is a pretty common behavior even among seasoned engineers. And again apart from the price tag, there's nothing much we can say against this part. And chasing to save a buck on designs that would cost hundreds is kind of ridiculous too, so I don't really see a problem here.

author: moffy
author_rank: Super Contributor
timestamp: February 13, 2020, 03:08:48 pm
content: Yes, the LM(linear monolithic) parts were National Semiconductor before purchased by TI. I would go with the LM's being first as LT were relative late comers compared to NS.

author: sam[PS]
author_rank: Contributor
timestamp: February 28, 2020, 03:06:30 am
content: That is pretty much like asking "why did the chicken cross the road ?".As a general answer to any question starting with "why audiofool love XXX ?", i would probably look at cognitive bias much more than any electronic/engineering parameters. Remember they themselves often like emphasize that it's not about the numbers, and really most of the time it's not. But it's not about the ear neither (double blind ear test anyone ?).So a discontinued/hard to find part tick a classical rare=best bias for sure.A very similar chip do exist but this one is higher priced tick another bias.An easier solution would work about as good (just a good ripple filtering) but this one is harder to build so less often found, tick the exotic appeal bias....Buy the way if anyone really caring about the sound quality of their system is reading this, i sell special lt1084 hand picked and then broken in with a special secret protocol that enhance the quality for an unequaled bass frequency authority and astonishing high frequency details for just 200$ a piece or 500$ for a paired couple.Just my 2cts...