Loaner: LSA “Discovery Warp One” Class D power amplifier

LSA “Discovery Warp One” Class D power amplifier

Many people have expressed interest in a well implemented class D power amplifier. This may be the ticket. Click below for more information.

• 150 watts per channel stereo power amplifier
• Class D

Spoiler: Click for specs and more details

Our new Discovery Warp One, 150wpc, stereo amp will be the sonic class leader at its price point. It outputs 250 watts at 4 ohms. Is is 2 ohm stable as well. It is the perfect mate to our DPH-1 preamp/DAC above.
The Design is finished and we will ship in late July 2021.
The Warp-1 amp utilizes the class-leading Texas Instruments TPA3255 "Purepath" Class D amp Reference Design as our initial inspiration, but with extreme care in the layout design and choice of high performance componentry to ensure that the amp operates at its true potential.
The state of the art layout was made using double planes stitched together with thousands of vias wherever an ultra-low impedance path was needed. We do this to ensure extraordinary signal transfer which gives you ALL The Music and Dynamic Contrasts.
Attention was paid to keep current loop areas as small as possible. Power input paths were kept as short as possible as well. The signal integrity is our primary focus here. Paying attention to these parameters yields phenomenal low noise for Blacker Blacks and Deep Soundstage that will amaze.

The ground paths were designed with a star hub topology (note that the power entry jack is in the middle of the board). Ultra-high current low distortion CoilCraft flat copper wire SER shielded inductors for the output filter provide unfettered current flow while ensuring the minimum in distortion. These are techniques found in Amplifiers at 5 x the price.
The PCB is an extra thick 2mm FR4 with 2oz (70um thick) copper traces and electroless nickel immersion gold (ENIG) finish. All of these finer points add up to a sum that is greater than its parts, thereby yielding a Class D amp that sounds dynamic, engaging, natural, and non-fatiguing… so you therefore get a product that performs at many times it’s price --- but most importantly honors the Musical Event in a very real way.

The Class D amplifier is just the core, and it must be supported by a state of the art low-noise power supply and buffer preamp, both of which are custom made for Warp-1. An oversized 600w switch mode power supply provides the amplifier with an abundance of power on-tap without a hint of hesitation. Bass Slam will delight you track after track.

The Warp-1 has a custom made signal input buffer that accepts either balanced (XLR/TRS) or single ended (RCA) sources and utilizes our choice for best results --- the superb sounding state of the art Texas Instruments OPA1656 operational amplifiers for signal conversion and amplification. The buffer has a DIP switch that allows selectable gains to match any source. The gain on the input buffer can be selected from 0dB, 6dB, 14dB, and 20dB. The TPA3255 amp has an intrinsic 22dB of gain so the setting from the factory is 6dB for an overall 28dB gain. For most systems this will be the perfect setting to ensure trouble free, low-noise operation.

Some applications may require lower gain so 0dB can be selected for overall 22dB of gain. The 14dB setting will give an overall 36dB of gain which might be useful when playing from a less powerful source – perhaps a Lower Gain Preamp. We would prefer that the 20dB setting not be used as this is just too much gain for most applications.

These components and techniques combine together to yield an amplifier that has a performance in the rarified air of 130dB signal to noise ratio. Even without a source playing, the Warp-1 will be absolutely silent with the ear pressed to the speaker cone - you cannot tell the amp is turned on unless the LEDs were glowing. This amp can be used in every type and sort of High Performance Audio System with spectacular results.

The Warp-1 amp redefines what an affordable Class D amp can sound like.


THD+N @ 1kHz at 50W
< 0.0027% into 10 Ohms
< 0.0057% into 5 Ohms
14" wide x 10" deep x 3" high

MAXIMUM AUDIO OUTPUT CURRENT: 17 A peak, per channel, both channels driven

INPUT SENSITIVITY
Low-Gain = 2.7 Vrms, Gain = 22 dB
Mid-Gain = 1.4 Vms, Gain = 28 dB
High-Gain = 0.55 Vrms, Gain = 36 dB
Gains Selectable via DIP Internal Dip Switches on Input Buffer
INPUT IMPEDANCE: 25 k Ohms (Single Ended or Balanced Inputs)
PROTECTION CIRCUITS
Fully Electronic, No Relays
Mute Sequencing
Distortion Detection (Clip Warning)
Short Circuit Protection
Over Current Protection
Over Temperature Detection and Protection
SOA Detection (Output device safe operating area)
PSU Fault Protection
OUTPUT VOLTAGE INTO VARIOUS LOAD IMPEDANCES
27.0 Vrms into 10 Ohms < 0.0052 % THD+N
27.0 Vrms into 5 Ohms < 0.0056 % THD+N
22.4 Vrms into 10 Ohms < 0.0038% THD+N
22.4 Vrms into 5 Ohms < 0.0064 % THD+N
15.8 Vrms into 10 Ohms < 0.0048% THD+N
15.8 Vrms into 5 Ohms < 0.0057 % THD+N
11.2 Vrms into 10 Ohms < 0.0058 % THD+N
11.2 Vrms into 5 Ohms < 0.0059 % THD+N

SNR & DYNAMIC RANGE
Rated output relative to output noise, inputs shorted: 115 dB
NOISE VOLTAGE
Output noise voltage, inputs shorted: -119dBV, 1.1 uVrms

Spoiler: Explanation about the amp from the designer

I contacted LSA audio about the AliExpress unit so they could comment. The designer of the amp wrote this about the Warp One amp.


“Hi Whitney,
I am the designer of the Warp-1 amp and hopefully can give you some more info here.

A while back, I needed a good Class D amp for some projects coming up. I also tried buying the 3E TPA3255 Class D amp from China - Inwould have used it if it sounded good enough. I listened to it and did not have the sound quality or features I was looking for to make it a higher end amplifier. I also designed mine to have high mechanical robustness and to be able couple the heat directly to the amp chassis without an internal finned heatsink.

The thread that discusses the core amp board that I developed is here (I am xrk971 on DIYA):

www.diyaudio.com/forums/group-buys/340880-tpa3255-reference-design-class-amp-gb.html

I set out to extract everything I could from this amp. We did the layout using state of the art techniques to reduce impedance of the large current paths, reduced loop area to reduce noise pickup, use 2oz copper traces and 2mm thick PCB. All the components are genuine name brand quality parts such as Nichicon, Wima, Elna Silmic etc sourced from Mouser. The output filter inductors are a key source of distortion and I spec’d ultra high current capable CoilCraft SER series which uses flat (rectangular cross section) thick copper wires and these alone probably cost more than the parts of the 3E TPA3255 amp (which retails for $75). The layout was designed by a veteran professional layout designer, JPS64 on DIY Audio with more than 35 years experience designing electronics for aerospace and audio industry.

There is a custom single ended / balanced input buffer on the Warp-1 that auto switches between RCA and XLR inputs with an internal relay. This buffer resides right on the input panel and uses state of the art best in class OPA1656 opamps and OPA1637 balanced line drivers. The buffer provides a powerful and transparent low impedance drive to the balanced inputs of the amp. There is switchable gain on the buffer (internal DIP switches). You can select 0dB/6dB/14dB/20dB. It’s set up for 6dB from the factory. Combined with 22dB gain of TPA3255 that gives a nice 28dB overall gain. The amp board has lost filter feedback (PFFB) capability built in bit is not enabled as that feature limits output power to 75w. The design of this buffer is so transparent and natural sounding - it’s one of the reasons why you won’t get as good of sound from a run of the mill TPA3255. This buffer is an improved custom version of the BTSB buffer on DIYA. More info in that here: www.diyaudio.com/forums/group-buys/358142-btsb-buffer-se-bal-se-bal-buffer-gb.html

All of this is powered by a custom 600w ultra quiet SMPS that also provides the 12v to power the dual rail DCDC converter to make the +/-12v for the buffer. The SMPS is oversized to allow maximum headroom and was developed using a special topology specifically meant for audio. It does not suffer from SMPS hiccup mode under large capacitive loading. And it’s ultra quiet. The measured noise floor of this amp is -125dB relative to 50w output at 0dB. That’s less than a 1uV rms noise. You cannot tell the amp is turned on with your ear pressed to the speaker.

The power/standby switch in the front activates the PSU enabled mode and has built in fine delays to prevent speaker pop.

Details such as double high strand count silicone jacketed wires connect the amp to the pure solid copper premium Viborg binding posts to ensure the lowest possible impedance path.

All of these details when combined in a heavy gauge CNC aluminum chassis with 6mm thick bottom and top plates that are powder coated make for a superb sounding and mechanically robust and beautiful amp.

This amp, although it uses a regular TPA3255 chip, its PCB layout and choice of superior components permits it to have an incredible harmonic profile that is dominant second order (vs third as most other Class D amps) at lower powers. This gives the amp an organic and non-fatiguing sound that you can enjoy endlessly. The low noise floor lets you hear small details not possible before. The low impedance layout and wires and copper binding posts give it incredible grip in the bass area.

I hope this helps answer why this amp is different than a $100 3E TPA3255 from AliExpress. Of course, I invite you to compare them side by side for a listen. For maximum impact try to use a source or preamp with balanced outputs.

Regards,
Viet Nguyen

Here are some photos of the details that set this amp apart. These are from the pre-production sample so wires are not perfectly neat.”


Closeup of the buffer board and front end of amp:



Closeup of the thick copper wire CoilCraft inductors. Not the TPA3255 chip is mounted on the bottom and is in thermal contact with the chassis through a heat transfer block.



This is the custom 600w SMPS that handles the power on sequence with a soft start front panel switch:



This is a closeup of the Viborg solid copper binding posts with enameled brass knobs:

Normal Rules

• Friends and contributors on case by case basis but please don’t be shy to ask
• UPS/FEDEX only
• Insure for 500$
• Impressions required here
• 5-10 day loaner period
• Please include this speaker amp switcher with the Warp 1 amp loaner
  
• Post your location if interested

List
@Inoculator WA
@fastfwd Bay Area CA
@StageOne OH
@philipmorgan NM
@dBel84 WI (keeping it until after Thanksgiving)
@spwath WI
@shotgunshane FL
@dasman66 WA (with Vanguard speakers)
@scblock CO (with Vanguard speakers)
@jlucas OH (with Vanguard speakers)

 

That seems really pricey for something based on a TPA3255. I have heard good things about the chipset, but I'd really like to know how different it would be from something like this: https://www.aliexpress.com/item/1005001849585611.html
3eaudio redid the reference boards as well (as opposed to the reference board clones all over ebay and Aliexpress) and got favorable reviews on DIY forums. I have my old Adcom so am not really interested in the loaner, but for $100 extra, it would be a really interesting shootout.

 

Oh man I don’t know. I reached out to LSA Audio about loaning their planar magnetic headphones and established a good relationship with him. He’s a good guy, definitely not a swindler. He was interested in multiple loaners and this is the product he was most excited about and wanted to start with.

illl look into the AliExpress unit but it would take a month or more to get here and I’ll have to clear the expense. It would also likely offend the LSA rep who is currently wanting to share gear with us.

I sure hope people sign up for this. LSA has more products they want to loan out and we shouldn’t be so spoiled to ignore this kind of generosity.

 

Count me in, located in WA.

I have always been curious about LSA offerings, and I think this would be a perfect device to compare to the NAD M33 which has slowly been winning me over despite being class D. Will use the NAD M33 as a preamp out to this when comparing so source is kept the same. No DIRAC, have not messed with it yet. Will be driving Graham Chartwell LS6F and/or Ohm Walsh Tall 4000 if they are here by the time my turn comes up on the loaner.

 

No worries, I don't discount any of the efforts LSA might have put into the product and certainly can't make judgements on the people behind the scenes. I am just a limited-means/cheap ass and like to know what what the extra $$ and effort can get out of inexpensive chips. Kind of how the original Gainclone was priced super high, but you can build clones for a couple hundred.

Thanks for the efforts on getting the community loaners.

 

I haven't listened to Class D anything in a few years, and am willing to check my biases. Comparisons would probably be to Vidar and Parasound HCA-750A driving Vandersteen 2C speakers.

Denver, CO, but I will be out of town until Sept 20, so could be later on the list.

 

I have a couple of digital amps from PS Audio. Both modified by Cullen, but I know there is a gentleman here who was doing swaps with another set of guts with 250wpc instead of 100wpc I believe.

The room I have it setup in is probably not dialed in well enough to do a proper review of this, but I'm always curious if digital amps are improving.

My setup is kind of weird and backwards now that I think about it. My Onix Strata Mini's use a digital amp (PS Audio C100 'Cullen' modded) for the 3-way and an a/b plate amp runs the built-in woofies. I'd need to get serious with my room treatment if I want to get any fancier with my amplifiers.

 

You don’t need to be set up to do a proper review to join. Should I add you to the list?

 

No, but that you very much. I've got too much on my personal plate as it is.

Weird pet peeve - those power buttons. I laughed at Lampizator and now I gotta do it here. I'm sorry. I've always associated that switch as a cheap DIY product. I know they've made better versions of it to handle more current, but still... glowy-rings of blue just don't do it for me

 

@fraggler

I contacted LSA audio about the AliExpress unit so they could comment. The designer of the amp wrote this about the Warp One amp.


“Hi Whitney,
I am the designer of the Warp-1 amp and hopefully can give you some more info here.

A while back, I needed a good Class D amp for some projects coming up. I also tried buying the 3E TPA3255 Class D amp from China - Inwould have used it if it sounded good enough. I listened to it and did not have the sound quality or features I was looking for to make it a higher end amplifier. I also designed mine to have high mechanical robustness and to be able couple the heat directly to the amp chassis without an internal finned heatsink.

The thread that discusses the core amp board that I developed is here (I am xrk971 on DIYA):

www.diyaudio.com/forums/group-buys/340880-tpa3255-reference-design-class-amp-gb.html

I set out to extract everything I could from this amp. We did the layout using state of the art techniques to reduce impedance of the large current paths, reduced loop area to reduce noise pickup, use 2oz copper traces and 2mm thick PCB. All the components are genuine name brand quality parts such as Nichicon, Wima, Elna Silmic etc sourced from Mouser. The output filter inductors are a key source of distortion and I spec’d ultra high current capable CoilCraft SER series which uses flat (rectangular cross section) thick copper wires and these alone probably cost more than the parts of the 3E TPA3255 amp (which retails for $75). The layout was designed by a veteran professional layout designer, JPS64 on DIY Audio with more than 35 years experience designing electronics for aerospace and audio industry.

There is a custom single ended / balanced input buffer on the Warp-1 that auto switches between RCA and XLR inputs with an internal relay. This buffer resides right on the input panel and uses state of the art best in class OPA1656 opamps and OPA1637 balanced line drivers. The buffer provides a powerful and transparent low impedance drive to the balanced inputs of the amp. There is switchable gain on the buffer (internal DIP switches). You can select 0dB/6dB/14dB/20dB. It’s set up for 6dB from the factory. Combined with 22dB gain of TPA3255 that gives a nice 28dB overall gain. The amp board has lost filter feedback (PFFB) capability built in bit is not enabled as that feature limits output power to 75w. The design of this buffer is so transparent and natural sounding - it’s one of the reasons why you won’t get as good of sound from a run of the mill TPA3255. This buffer is an improved custom version of the BTSB buffer on DIYA. More info in that here: www.diyaudio.com/forums/group-buys/358142-btsb-buffer-se-bal-se-bal-buffer-gb.html

All of this is powered by a custom 600w ultra quiet SMPS that also provides the 12v to power the dual rail DCDC converter to make the +/-12v for the buffer. The SMPS is oversized to allow maximum headroom and was developed using a special topology specifically meant for audio. It does not suffer from SMPS hiccup mode under large capacitive loading. And it’s ultra quiet. The measured noise floor of this amp is -125dB relative to 50w output at 0dB. That’s less than a 1uV rms noise. You cannot tell the amp is turned on with your ear pressed to the speaker.

The power/standby switch in the front activates the PSU enabled mode and has built in fine delays to prevent speaker pop.

Details such as double high strand count silicone jacketed wires connect the amp to the pure solid copper premium Viborg binding posts to ensure the lowest possible impedance path.

All of these details when combined in a heavy gauge CNC aluminum chassis with 6mm thick bottom and top plates that are powder coated make for a superb sounding and mechanically robust and beautiful amp.

This amp, although it uses a regular TPA3255 chip, its PCB layout and choice of superior components permits it to have an incredible harmonic profile that is dominant second order (vs third as most other Class D amps) at lower powers. This gives the amp an organic and non-fatiguing sound that you can enjoy endlessly. The low noise floor lets you hear small details not possible before. The low impedance layout and wires and copper binding posts give it incredible grip in the bass area.

I hope this helps answer why this amp is different than a $100 3E TPA3255 from AliExpress. Of course, I invite you to compare them side by side for a listen. For maximum impact try to use a source or preamp with balanced outputs.

Regards,
Viet Nguyen

Here are some photos of the details that set this amp apart. These are from the pre-production sample so wires are not perfectly neat.”


Closeup of the buffer board and front end of amp:



Closeup of the thick copper wire CoilCraft inductors. Not the TPA3255 chip is mounted on the bottom and is in thermal contact with the chassis through a heat transfer block.



This is the custom 600w SMPS that handles the power on sequence with a soft start front panel switch:



This is a closeup of the Viborg solid copper binding posts with enameled brass knobs:

 

Hi rythymdevils.
I'm interested in the loaner program. Will be my first personal encounter with class D.

I guess I should preface that I have Maggie's MG III with a 3 ohm load, so if it's not a match, pls let me know and you can feel free to omit me.

Vinyl only. Tube phono and tube line preamps. Cirrently Class A/AB mono amps.


In Honolulu.

 

I'd love to include you, but loaners are only open to friends and contributors. Unless someone here can vouch for you, we can't send expensive gear to people we don't know. I'm sorry.

 

I appreciate RD's awesome communication. Now things sound very interesting. Designer's non-sugar coated comments could be the best way to market in sbaf. At least I believe so.

Anyway, please count me in. Will compare this to Aegir (x1 and x2) and Accuphase Clone in driving Spatial OB speakers.

 

Tempting given the response from the designer!

 

Just as an aside Viet /X on DIYA is a stand up guy who gives an awful lot to the community. He designed 2 of the projects I have built and his ongoing forum support belies the fact that he has so much going on in his professional life.

He just designed a set of monitors for LSA which look absolutely fantastic and measure exceptionally well too.

I woukd vouch for him any day.
.. dB

 

I had no idea it was XRK behind LSA! Indeed, he has done a tremendous amount for the DIY crowd and has put out a ton of DIY boards on his Etsy shop. Very cool that he has commercial offerings even if they are beyond my means. I think it is some of his earliest experiments with the TPA3255 that got me interested in the chipset and put the 3e audio board on my radar - had no idea he had taken it this far. Very cool. I look forward to reading the loaner impressions.

 

I'm guessing it is only stable down to 4ohm stereo? I hope people find this similar to his Pocket Class A amplifier. I really enjoyed that little amp with my Andromeda.

 

The spec says 2 ohm stable.

 

I accidently only clicked the spoiler below it and read it and forgot about the top spoiler. 2ohm stable.. hmmmm LCD-R... how much power can you really take??? LOL J/K - I enjoy them very much with the JOT-A, but I'm keeping my eyes out for potential future options. After hearing the Pocket Class A, the dude actually knows what he is talking about with his harmonic profile.

 

Regarding the front button, from the designer:

“Btw, the front panel "power" button only switches a small low voltage logic signal to activate (enable) the PSU's high voltage output. The preamp/buffer is always on as long as the rocker switch in the back is on. The blue power button is not carrying full mains voltage and current from the back of the amp to the front. That would be silly (and prone to a lot of 60Hz noise inside the amp).”

Can more people sign up please? They want to send us a unit to hear but 4 people isn’t really fair to them.