The true experimental tweak thread

[Superdad]

With my recent tweak of the isolated Wavio board powered by LPS1 I'm in audio heaven. Voices are shocking (bar the occasional bad recording) and often when I'm listening I jump at the realism - mistaking parts of the audio as if they are coming from outside or from somewhere in my apartment.

 

Funny you should mention that as my old (but really hard to beat) Hovland/Swenson NOS PCM1704 DAC (discrete output stage, multiple choke-filtered supplies, etc.) has a LuckIt WaveIO, and last week I noticed there is room in the chassis for an LPS-1. So I am hoping this weekend to wire one in to power the WaveIO.

Glad you did it first and liked the results. Thanks for reminding me!

 

--Alex C.

 

P.S. And yes, Lucian is a terrific guy. Too bad he takes forever to develop new products. I think WaveIO is still his only available product.

[Superdad]

9 hours ago, Cornan said:

 

AFAIK attenuators have no negative impact to SQ except for the additional connection. They are quite transparent. You will normally find them in passive preamps for example which is normally a better choise than an active preamp if you want to limit the affects on the sound signature.

 

Oh, that is a very broad generalization and not one to be taken without questions.  Even leaving aside active preamps entirely, there is a whole world of discussion and debate about various attenuator topology, design, and materials.  Enough for a very lively and long separate thread.  

 

With my Hovland buddies we started building stepped attenuators back in the late 1970s/early 1980s.  (In fact, we were Caddock's very first audio industry customer, and we did crazy things like series/parallel 4 resistors per step on critical top steps in a 24-postion unit.)  Here's a couple of old pics:

 

And here is one of the very first 47-postion stereo Slagleformers recently produced by Dave Slagle.   This may be the ultimate attenuator as it has a very low output impedance, is capable of driving long cables, and can even provide a few dB of gain.

 

I recently got a nice case and big knob for it and just need to make the time drill/mount/wire it.

[Superdad]

On 4/27/2017 at 7:35 AM, Cornan said:

 

 

A truly floating PSU means that the AC mains safety ground is totally isolated from the DC output.  The AC mains safety ground (input) is connected to the chassi instead of to the DC output. With a truly floating PSU you can safely connect several psu´s in series without putting your life at risk. With a truly floating output 100% of the leakage loops and ground loops is gone in that path. For example a LPS-1 is not truly floating. It do have a 100% isolated output but it is not 100% isolated towards the safety ground. Connecting the SMPS feeder supply to your BK 1604A will turn the LPS-1 into a truly floating PSU. Connecting the Gophert to the LPS-1 will turn the LPS-1 into a truly floating PSU.

 

 

 

That is incorrect Cornan.  The UltraCap LPS-1 output is 100% "floated."  There is no connection between its output and the mains at all, and you can put them in series (or even center-tapped series for bipolar, +/- supply).

It floats like a battery (without the drawbacks of battery)--that is the whole point of the sophisticated engineering hoops we jumped though to make the design. 

[Superdad]

On 6/17/2017 at 3:05 AM, Cornan said:

Listened all night. I now know for sure that this is my best sound up to date in my A setup! The treble is glorious, the bass notes deep and firm and midrange very natural sounding. Dynamics, 3D/air, room sense and instrument placements are all top notch. Both MQA and FLAC sounds great! I wish I had words to describe how good it sounds right now. I am speachless and really happy right now! ? I wonder how it will sound with more burn-in? I cannot wait!

 

Fitzpleasure!? 

 

(Or how about some nice early Elbow?)

[Superdad]

On 6/29/2017 at 10:45 AM, mozes said:

I am suspending my LPS-1s from the ceiling due to lack of space.

 

Wow, you guys are wacky!   Pictures please....

[Superdad]

On 7/7/2017 at 0:19 PM, mozes said:

Then here you go guys ...

 

Holy Mozes!!  

[Superdad]

1 hour ago, Middy said:

Something nice and stopped the wife worrying.... 4d scan of the boy. 

Just a proud dad showing off so apologies. 12 weeks to go...

 

Oh my!  CONGRATULATIONS!!  

 

Is this your first?  Take good care of you wife.  And remember, while she may scream and curse at you during labor-- that's nothing compared to what she is really feeling.  

[Superdad]

5 minutes ago, Cornan said:

 

Great to see that you're back Alex! ? I hope they've got the fires under control now! 

 

Unfortunately not.  See my update from this morning:

At least i we now have power and internet for the moment.  Guess that means I'll be battling the wildfire of my neglected e-mail inbox.  

[Superdad]

10 minutes ago, Cornan said:

Just got a delivery confirmation of my ISORegen. Two days before promised delivery date. Great work @Superdad! 

Looking forward! ?

 

Yeah, I have been going round-the-clock for many days leading up to this week.  90 units headed to the post today.  That's all the ISO REGEN "singles."  Thursday is the big day for all the ISO REGEN/LPS-1 bundles, about 70 of those.  After that, we will have just about 25 open orders that were promised for the 26th--but they will be delayed to Tuesday, the 29th due to small parts. 

 

September 1-4 is a holiday weekend and I'm taking it!  Headed to the beach with old friends.  Can't wait.  

My assistant leaves for 10 days at the end of next week too.  Definitely have to give her a bonus check before she goes.  Partially for her outstanding work (she even takes stuff home at night to work on), but largely just for putting up with me during high-stress times!  (Actually I am a really nice boss and never get upset with others--just with myself.)

 

Hope everyone enjoys their ISO REGENs.  Thanks again to you all!

--Alex C.

[Superdad]

On 5/3/2018 at 12:40 PM, Cornan said:

 

Hi Micael:

I just want to confirm that I understand correctly your use of the two Stammheim LT3045 boards.  In the above photo it appears that you are using those fine low-noise supplies just to “energize”/charge your UltraCap LPS-1.2 unit (which itself is of course based on LT3045s at its output).  

That seems tremendous overkill as the active bank of the LPS-1 (the one connected to the output at any given moment) is never connected to the presently charging side (the whole point of our design).

What you are doing is akin to saying that charging a battery with cleaner power results in better output voltage from that battery when you take it and install it in some device!  And you should be aware that what gets fed into the “charger” port of the LPS-1.2 then goes though an expensive ($26/pc.) buck/boost DC-DC switching regulator module, in turn charging one 70Farad bank of ultracaps, while the other bank is actually connected to the load—first through a TI TPS7A4700, then into the specially paralleled pair of LT3045s.

 

Really you could feed our LPS-1.2 the most nasty dirty power imaginable, and it’s output will measure the same (versus “clean” charger power) via every PS performance metric.

[The only exception to this is that it is best for the charging supply to have as little high-impedance AC leakage as possible since the transistors we use as switches for bank alternating—as opposed to large mechanically clicking relays—do have a few picoFarads of capacitance which can allow some high-impedance to pass.  (Low-impedance leakage has always been 100% blocked by our units.). And as is widely known since last year, preventing any high-impedance leakage from entering the UltraCap supply—from any SMPS charger—is a simple matter of just being sure that the charger’s DC zero-volt “ground” is shunted to AC mains ground. And that is already done with the UpTone-branded 7.5V/4.8A/36W charger that ships with every LPS-1.2.]

 

So I respectfully suggest that perhaps you can find a better use for those pretty blue heatsinked Stammheim supplies elsewhere in your system. 

[Superdad]

On 6/7/2018 at 7:17 AM, Cornan said:

 

If you want to power both FMC input and output with best results with a valuable option I would recommend that you buy this two-way independant LPSU https://www.ebay.com/itm/50VA-50VA-HIFI-Linear-power-supply-2Way-LPS-50W-50W-DC-5V-9V-12V-15V-18V-19V-24V/132431179122?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

 

 

Given that the output voltage regulators of that supply have their tabs bolted to the same chassis plate, the DC output zero-volt “grounds” are going to be common to each other.  Thus using this supply to power a pair of FMCs will defeat the galvanic isolation of the optical connection—the whole point of the FMC scheme.

[Superdad]

10 hours ago, Cornan said:

Works great out of the box but will get hot and create a lot of EMI that you will need to deal with by dressing nearby sensitive components and cables in copper or shielding.

 

Toroidal transformers do not generate that much heat...

 

Sorry but much of what you wrote about R-core versus toroidal transformers is incorrect.

For example, temperature rise is much greater inside a torrid because the core is not exposed at any point so there is no surface area for it to dissipate.

 

Leakage flux from an R-core is extremely small due to balanced windings cancelling out stray flux.

Plus R-core efficiency is higher than a toroidal trans.

 

And those are just the superficial advantages...

 

 

 

[Superdad]

34 minutes ago, Cornan said:

I am now all into photography and haven't improved much on my audio side. I'm quite happy where I'm at in the audio world but have much more to improve and explore in the visual world.

All the best!

 

Thanks for popping in to say hello Cornan. Best wishes to you too!!

--Alex C.