SDRplay Release the RSP1A: A $99 14-bit 1 kHz to 2 GHz Revision of the RSP1

Today SDRplay have released the RSP1A, a revision of the popular $99 USD RSP1 with some significant improvements. The press release is pasted below: 

SDRplay Limited has today announced the launch of a new Software Defined Radio product – the RSP1A.

The SDR-play RSP1A is a major upgrade to the popular RSP1 and is a powerful wideband full featured 14-bit SDR which covers the RF spectrum from 1 kHz to 2 GHz.

Due to its exceptional combination of performance and price, the RSP1 has proved to be a very popular choice as an “entry level” SDR receiver. Since launching the RSP1, we have learned a great deal about what people are looking for in SDR receivers, and where possible, we have incorporated these improvements and new features into the RSP1A.

The RSP1A therefore delivers a significant number of additional features which result in benefits to amateur radio enthusiasts as well as significant benefits for the scientific, educational and industrial SDR community.

Here are the main additional features of the RSP1A compared to the original RSP1:

  • ADC resolution increased to 14-bit native for sample rates below 6 MHz, increasing to 16 bits with decimation.
  • Enhanced RF pre-selection (greater filter selectivity plus 4 additional sub-bands compared to the original RSP1) for reduced levels of spurious responses
  • Improved LNA architecture with variable gain. The RSP1 had just a single gain step.
  • Improved intermodulation performance
  • Performance extended to cover 1kHz to 2GHz with a single antenna port.
  • Bias-T facility
  • Improved frequency stability incorporating a 0.5ppm TCXO (software trimmable to 0.01ppm)
  • Selectable broadcast AM/FM/DAB notch filters
  • RF shielding within the robust plastic casing

When used together SDRplay’s own SDRuno software, the RSP1A becomes a high performance SDR platform. The
benefits of using the RSP1A with SDRuno include:

  • Highly integrated native support for the RSP1A
  • Calibrated RF Power Meter with more than 100 dB of usable range
  • Calibrated S-Meter including support for IARU S-Meter Standard
  • The ability to save power (dBm) and SNR (dB) measurements over time, to a CSV file for future analysis
  • The IQ output wav files can be accessed for 3rd party applications

SDRplay has also worked with developers of the popular HDSDR, SDR-Console and Cubic SDR software packages to ensure compatibility. As with the RSP1, SDRplay provides multiplatform driver and API support which includes Windows, Linux, Mac, Android and Raspberry Pi 3. There is even a downloadable SD card image available for Raspberry Pi3 which includes Cubic SDR.

The RSP1A is expected to retail at approximately £76 (excluding taxes) or $100 (excluding taxes) For more information visit our website on

About SDRplay:

SDRplay limited is a UK company and consists of a small group of engineers with strong connections to the UK Wireless semiconductor industry. SDRplay announced its first product, the RSP1 in August 2014

The datasheet is available here (pdf), and a the full technical information is available here (pdf).

We've had a RSP1A beta preproduction unit for a few weeks now and will be releasing a full review comparing it against the RSP1 in a day or so. For a quick review conclusion we note that we've noticed that the filters are significantly more effective on the RSP1A compared to the RSP1, and the inclusion of the MW/FM and DAB notch filters help a lot in certain situations. The increased ADC resolution is due to decimation on board the MSi2500 chip and is noticeable in some situations, but does not seem to cause a huge improvement. Overall compared to the RSP1 some overloading problems are still present with strong signals, but intermodulation and imaging is reduced significantly and in some cases the RSP1A even outperforms the RSP2.

Also, Mike Ladd KD2KOG a member of the SDRplay technical support team has uploaded a video announcing and demoing the RSP1A. 

Announcing the RSP1A



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I’m still looking for this elusive $99 RSP1a. Two years later, the price from the official U.S. reseller is currently $119. Was $99 was an introductory “loss-leader” retail price? Or was this a gradual price increase due to the change in pound-to-dollar exchange rate? Not good business practice, regardless.


Really? You’re moaning about a measly $20.00? For what you get its more than worth it. Best stick to your 8-bit sticks then.

Gus Mendel

I agree with them. nobody likes a bait n switch


Very improvable design. Minimum 16 bit in ADC. Filters and LNA incorrectly positioned. High noise level, having ultra low noise economic MMIC. The frequency cuts of the filters do not correspond at least with Region 1, and their quality can be improved. The notch filters can also be improved in quality and in frequency, a fourth filter is needed to avoid the annoying LTE of 700/800 Mhz. Cutting frequency in the ideal filters to preserve aeronautical, communications, satellites bands and avoid broadcasting:


Hopefully in a few years it will be improved even if it costs a little more.

Tech Guy


– OR –

Burn that pile of MSI*** tuners and jump to the new era of high performance tuners that do not need band-aids.


Can you please name us some commercial receivers with this new era of tuners?


1) LOL, you can’t be serious. We’re discussing shack SDR receivers and you offer this?? Show us any dev who has any intention of supporting any of that stuff.

2) None of those sites has any info on any specifics (such as ADC data bits, for starters). Show us specifics, or stuff a sock in it.

2) I bet you’re lots of fun at parties.

Tech Guy

#Idiot #Troll


You’re the idiot, posting links to nebulous automotive silicon in this thread.

Let me use smaller words, because you clearly didn’t understand my request the first time: Show us any specs — there are no specs to be found anywhere on any of those sites.

We continually ask you for specifics, and you repeatedly ignore our requests, and I’m the troll?? LOL!

You post, “Is there a way to combine two RSP1A to handle strong signals without overloading?”, and you call me a troll? LOL!

I’m done with you.

Stephen E

“(such as ADC data bits, for starters)”

Can you point at the official Mirics documentation for the “current” ADC. Not after the binary blob of DSP code running on the 8051 CPU, but the actual sample rate of the silicon. The only document I have seen is down below and new “upgraded” silicon chips usually take 3-5 years, unless there is a major flaws with the previous revision, that make it unfit for purpose.

Since you called the information in the only publicly published document by Mirics incorrect am I to assume you either currently or previously used to work for Mirics ?

Anyhow the real problem is that all the cheap tuners and associated chips used in the STB (Set Top Box) market are covered by NDA’s. And I don’t mean cheap as in junk, but in a mass marketed part whose market size should make it very cheap.


1) Wrong. I didn’t call the Mirics document incorrect, I pointed to a statement from the SDRPlay dev team that had later, more accurate information that conflicted with the undated, unmaintained “Confidential” Mirics document.

2) To assume that I’ve ever worked for Mirics would make you wrong, again.

Stephen E

The Mirics document can still be 100% correct and the information provided by sdrplay can also be 100% accurate (after it is processed by the binary blob of DSP code running on the 8051 CPU). I do not see it as being one is right, so the other must be wrong.


For Tech Guy: Oh yes, all the tuners mentioned are so modern (including the RSP1A) that they still need filters at the entrance to avoid intermodulation. What you say does not exist yet. The tuner with integrated tuneable filter does not exist either.

Tech Guy

> The tuner with integrated tuneable filter does not exist either.

I see you still didn’t do your homework. There’s at least 15 years between the release of Mirics and these other tuners. In these 15 years of RF innovation, things like N-Path filters were invented and integrated in virtually everything that has a radio receiver, from bluetooth, cell-phones, wifi to portable radios… but not in the Mirics tuners – which is unfortunate for the hobbyists.

PS: I was serious about the homework thing.


All I’ve seen up to this point in these comments is either pure conjecture or brand name bashing.

As I’ve stated elsewhere, what good is 100+ dB of dynamic range in the HF bands, when I’ve never seen an actual real-life HF signal that’s even 80 dB above the noise? If anyone has a picture of such an occurrence, please post it for everyone to see. Of course you can’t, because it doesn’t exist. So spending $200 simply to buy 100+ dB of dynamic range in an HF receiver actually buys me nothing at all.

But any of the SDRPlays can certainly deal with 80 dB or more of dynamic range. Here’s a picture of the 2 meter band last night on my RSP2 (my RSP1a is currently doing HF duties):

Look at the noise floor in the area of 146.600 and 146.800 MHz, it’s -115 dBm or so. Now look at the strength of the signal at 146.700 MHz, it’s showing -32 dBm. That’s over 80 dB of range, folks, and the SDRPlay is managing that just fine.

Btw, here’s a pic of my RSP1A doing duty on 20 meters last Sunday (running on Simon Brown’s superlative SDR Console V3 software…you guys should try it.):

As you can see, the band was very active that evening, with plenty of power in a number of those signals, but nothing approaching anywhere near 80 dB of dynamic range above the noise floor (and 20 meters has a relatively low noise floor, at least for HF). And I was feeding that RSP1A with an 80 meter dipole at 38 feet elevation, not some random length wire. So I was getting some great signals. But nothing approaching anywhere near 80 dB dynamic range.

So can someone please tell me why I should spend twice as much money for an Airspy HF+ when I’ll never realize any additional benefit from it that I’m not already getting from my RSP1A? Not to mention that the HF+ can’t see but a fraction as wide of a slice of spectrum at a time as any of the SDRPlays, and can’t see anything at all that’s UHF or higher, so it’s not nearly as all-around useful as any of the SDRPlays (btw, I have all 3 models).

I don’t buy any of my toys based on how great somebody else says they are, I buy them based on how well they actually perform in the real world. And I’m exceedingly happy with my SDRPlay RSP1A.

If anyone can tell me why I should now regret my purchase, please speak up now, as I’m all ears. 🙂


I don’t think you will get a proper reply until the hardware is out in the wild, from what I can see only a few people have the prototype hardware and they appear impressed:


My question wasn’t really what can the HF+ do that the RSP1A can’t, but rather why I should regret my purchase, because there’s nothing I need an HF SDR receiver to do that my RSP1A can’t do as well as any other receiver.

I’ve put the challenge out for anyone to post a screenshot of an 80 dB-over-noise signal, but crickets were all that abound. Well, here’s a screenshot of multiple 80+ dB BCAM signals in the same bandslice (a much bigger slice than an HF+ can grab, btw), and my RSP1A handles that just fine:

For the record, I waited patiently for a long time to capture that snapshot.

But wait, there’s more. Here’s a signal at a solid 85+ dB-over-noise:

I’m not even gonna tell you how much time I wasted looking for that one. 🙂

So this is my statement to all the trolls attacking the RSP1A: The radio does a damn fine job of MW/HF reception, as good a job as anything else that anyone else can offer. What good is an advertised 110+ dB of dynamic range when there’s no real life signal out there that even comes close to that level? Any SDR receiver that brags about that much DR as its main selling point (especially at the expense of receive bandwidth and spectrum coverage) is simply taking advantage of the ignorance of the buyer.


You don’t seem to have a clue. Are you, by any chance, confusing in-band and out-of-band DR? FYI. Any low cost radio will survive a single 80 dB signal, including RTL-SDR’s. Plug a real antenna with a lot of strong signals and you will see all your dreams fall apart, like it still happens with all the RSP based radios.

Of course, if you are happy with your toy, you should keep using it – just don’t make a fool of yourself by exposing your ignorance.

SDRPlay definitely succeeded in building a community of clueless idiots. But how bad can it be? There’s an infinite supply of them in the Internet.


And here’s a shot of BCAM feeding straight thru from my 80/40 dipole to the RSP1A, no attenuation at all (normally I go thru my legal limit tuner set for 80 meters which attenuates MW somewhere between 20-30 dB)):

The signal at 820 AM is extremely strong (-12 dBM) but still 80 dB over the noise. And notice the RF (MW/FM) Notch filter (top of screen) is “Off” so there’s no filtering either, just hell-for-stout signal feeding straight into the tuner front end.

And the RSP1A is handling it just fine. Just look at that screen. Beautiful. Not a hint of overload anywhere.

To say I’m pleased with my RSP1A would be an understatement.

Gonna go ride my mountain bike now (I do all my own stunts, look out!).


> (-12 dBM) but still 80 dB over the noise

That’s actually very poor. This means normal signals nearby at -100 dBm are wiped away?
Did I say infinite supply of idiots? HAHA!


Good grief, dude … you’re the biggest idiot in this thread, LOL. Any signal that’s at -100 dBm in that picture would be well below the atmospheric noise, and even your revered (and as-yet unavailable) HF+ would never see it.

Jeeze! The fact that you’re actually calling anyone an idiot is truly scary.

I’m done with you too, dude. I’ll not bother to respond to you or Tech Guy anymore (lol, what a presumptuous username … “Tech Guy”!), as you’re both obviously clueless, and clearly trolls.


> Any signal that’s at -100 dBm in that picture would be well below the atmospheric noise

I’m glad you’re also bad at math and physics. Keep on the good work. Entertain us!


You’re clueless. Goodbye.

Tech Guy

Is there a way to combine two RSP1A to handle strong signals without overloading?


You shouldn’t have to combine RSP1As to accommodate strong signals.

What specifically are you trying to do? I have my RSP1A connected straight to my 80/40 fan dipole and receive some hellaciously strong signals at times, but they’ve never overloaded my front end. Once I’ve got my gain settings adjusted for the particular band I’m in, I can receive everything from the strongest to the weakest signals on the same screen with no problem at all, and with no regard to how close together those signals are in the band.

Tech Guy

That was a joke. This whole thing looks more and more like a scam. I would rather get a real receiver.


Then your little joke was on you, because for some unfathomable reason you’ve convinced yourself that the RSP1A overloads at the drop of a hat, without ever having actually laid eyes on one in person, let alone actually having laid your hands on one. So you truly are clueless.

But I do own one, so I already know what it can do. And it can handle at least 80 dB of dynamic range just fine. I say that because I’ve never found an HF signal with over that much strength yet (and I’ve been looking really hard), but I did manage to find a solid 82 dB signal on broadcast AM and snapped this pic:

Look at the 820 kHZ signal strength (at -58 dBm), and compare that to the noise floor at lots of places in the picure below -140 dBm. That’s at least 82 dB dynamic range on the RSP1A.

VHF is a different story. Here’s a picture of over 85 dB dynamic range on broadcast FM on my RSP2 (and remember, the RSP1A has even better range than the RSP2):

So your joke’s only on you, big boy. Go ahead and get your “real receiver” if that’s what floats your boat, and when you do, do us all a favor and try to find a signal with over 80 dB of dynamic range anywhere below VHF, and then post up a pic of it when you do. Good luck with that, lol. And while you’re saving up for your “real receiver”, you might want to put aside another little pile of money for a second radio that’ll pick up 6 meters, because the HF+ can’t.


Nice touch.

The amount of ignorance and arrogance of these unofficial SDRPlay spokesmen is blatant. I own every single SDR that was produced including the RSP’s and by now, we all know how they work.
Overselling your favorite product/brand can only be harmful, especially that it’s easy to find evidence in the internet that shows.
The problem with the all the RSP’s is that the analog frontend falls apart way before the ADC has a chance to sample useful data. Fix that instead of “squeezing bits off the silicon”.
For < $100, the RSP's are very good, or rather excellent. Do we need yet another iteration of "avobe average" radios? Not sure. YMMV.


Show us some real-life evidence to support your allegation that the RSP’s front end “falls apart” (you can’t). I’ve shown you screenshots to the contrary.

Your snarky open attacks against me as “ignorant” and “arrogant” merely reveal the troll side of you. Try to rise above that, for once.

I’ve shown you multiple screenshot evidence of the real-world dynamic range of the RSPs (which is precisely what has been the subject of constant attack in this column).

Now it’s your turn. Show me evidence of the RSP’s front end “falling apart” before the ACD has a chance to sample the data. I’ve never seen it, at least not on a pre-filtered feed. And the RSP1A’s pre-filtering is plenty effective. I know. As I stated earlier, I live between two 50 KW transmission towers.

And your statement that “we all know how [the RSPs] work” is clearly BS, otherwise we wouldn’t even be having this discussion, and I wouldn’t have needed to post snapshots of how well they do in fact work in real life. If yours doesn’t work then you’re doing it wrong. Read up on proper gain settings.

Bendail Vam

Frogive me, but are we alls seriously debating a (or actually a lot of;) sub ~200$$ devices???? We almost starting a McD/BK thing here, they both have burgers – we dicing up devices that for what we paying for them are incredibly useFULL for the HOBBY they make them for. None of them are marketed as lab quality device nor have I ever seen any of this said to be for lab analysis – you looking for lab quality repeatable SDR RF receiving equipment expect to get pay 10x to 15x what they ask for these devices. WE should ALL be thankful to anyone who takes the time effort to bring us these cost effective gems for our hobbies. Becuase as I have stated in previous post; there seem to be a few who are already trying to pick the orchard clean.


Seriously guys? This has become more like a religious war rather than an engineering discussion. To quote from the movie “Ratatouille”:

“In many ways, the work of a critic is easy. We risk very little yet enjoy a position over those who offer up their work and their selves to our judgment. We thrive on negative criticism, which is fun to write and to read. But the bitter truth we critics must face, is that in the grand scheme of things, the average piece of junk is probably more meaningful than our criticism designating it so.”


It is true, but I would love to be a fly on the wall for their the next product development meeting. “OK, we have managed to ship the same core product four times (RSP1/RSP2/RSP2 Pro/RSP1A), with incremental improvements, now how do we do we knock the ball out of the park for a fifth time. The R&D department are already toying with a new name the RSP2A and possibly even the RSP2A Pro. I know it is not as sexy as new silicon but about this time we add more switches and filter banks ?”

Tech Guy

ADC resolution increased to 14-bit

The increased ADC resolution is due to decimation on board the MSi2500 chip and is noticeable in some situations, but does not seem to cause a huge improvement.



That’s a joke. Srsly.


What? The SDRPlay press release clearly states, “ADC resolution increased to 14-bit native for sample rates below 6 MHz, increasing to 16 bits with decimation”. So why does the author of the RTL-SDR article subsequently state, “The increased ADC resolution is due to decimation on board the MSi2500 chip”? That statement is clear evidence that the author didn’t actually read what he had just quoted a moment earlier.


Pre decimation in the MSi2500 it is ~10 bits according to Mirics ( ref: )


That document is undated, has never been updated (Revision 1 version 1.0), and is clearly marked “Mirics Confidential”.

OTOH, a much more recent statement from the SDRPlay Team says “As the original spec for the MSi2500 called for 12 bit resolution, the fact that the converter was capable of delivering 14 bits for final sample rates of less than 6.048 MHz was ignored. Working with the Mirics team, we have been able to unlock the extra two bits of resolution that the MSi2500 was always capable of delivering. Using sample rates above 6.048 MHz, the ADC defaults back to 12 bit resolution”.

That statement and more can be found here (click on the bold underscored “READ THE REPLY” link just before the PCB photos):


It is marked “Confidential”, but every search engine shows it up, so it is not like they are doing anything to actually keep it Confidential.


And it’s not like they’ve done anything to keep it current.

Point being, I wouldn’t depend on that document to be an authoritative source of any specific information, particularly when much more recent information is available. Ref the statement above from SDRPlay.

And tell me, exactly what does “~”
mean? Be specific..


Sorry for not answering you fast enough, boss people around much ?

Traditionally in that context I would assume that it would mean an approximation ( ) so mathematically I would assume it could be from 9.5 bits to 10.4 bits. So 2^9.5 (724) to 2^10.4 (1351) possible discrete states returned by the ADC. So I would also assume some from of flash ADC where space available on the silicon die dictated the number of states.


Wasn’t at all meaning to boss you around, I probably should have put a “please” after the “be specific” … tonal inflection doesn’t come across very well in text.


I couldn’t stop laughing HA HA HA! So, it went from 9.5 bit to “approximately” 14bit for marketing purposes?


These chips are no longer suitable for nowadays congested RF environment, but they can still work fine with some band-aids and a lot of marketing. Boring.


Squeezing the last two bits. Are those chips or oranges?

Useful Gain

Is it me or they just added more filters?


Does it work with Spy Server?


This will help to make the 50$ discount permanent for the Airspy HF+


Not likely. At least in the short term. The HF+ is a specialized receiver that is not directly competing with the SDRPlay offering. The RSP1A is a wide-band non specialized receiver and the other is focused solely on HF, with some VHF coverage. If you look at the figures and real world examples put forth so far the HF+ is likely still far and ahead of the RSP1A in performance in the HF region.


I agree. It looks like SDR-Play are producing the same radio design every year and only add more band-aid filters to attenuate the symptoms of urban overload. Thus RSP1A is reusing the same stockpile of failed TV chips from the defunct Mirics company. Shame.
I got rid of my RSP1 and RSP2 Pro on ebay two months ago in anticipation of this fail, and ordered a new HF+ with the discount offer. More cheap radios won’t make a better radio. Now counting down.


This is a replacement of the RSP1 to reach the same performance of the RSP2 but with entry level price. Hopefully the RSP2 will be replaced with a completly new project to (try to) go closer to the Airspy HF+.
Regarding my comment about the $50 discount on the HF+, i remember that the target price has always been $149, so i think that it has been increased to take adavantage from the many people waiting to get it as soon as released.


Why all the fuss about RSP’s? Didn’t they prove inefficient in the consumer market? So inefficient that SDRPlay they are still trying to fix it with more and more filters and attenuators and sell it to unsuspecting old men? I think Mirics/SDRPlay have a serious problem with innovation. It’s a company looking to the past, not to the future we aspire to.
I already have a ColibriNano, a KiwiSDR and an Airspy Mini and I don’t want another RSP based POS. I was waiting for Mirics/SDRPlay’s to offer a serious alternative but I’ll just eat my hat. I ordered an HF+ instead.

bernd lauert

same shitty tuner as rsp1?

DoaJC Blogger

What’s wrong with the RSP1’s tuner? I use it all the time and I don’t see any problems.




does this comes with one source driver or binary blob like the original RSP?


I clicked on the first link and all I ever get is a spinning white square in the middle of a blue background, guess it must be some java or flash thing on their website. My browser has both disabled for security.

No Pain No Gain

How does it compare to the AirSpyHF+?

More DR

It’s half the price for a start, but performance comparisons will be interesting for sure. I guess a better comparison would be with the Airspy R2, which is a more similar product

No Pain No Gain

After more reading, I think I don’t buy the “14bit” and “16bit” claims. Unless they change the DAC chip, nothing is going to magically improve the effective number of bits. I was expecting some new technology like the the competition is doing everywhere, but all we see now is just more notches and filters around the same old chips. A bit upset.


Enhancing ADC resolution by over sampling is the way most sdrs do it, why do think the airspy hf+ have so narrow bw for an example. Yeah that’s right… To get its 18bit…

No Pain No Gain

Then any one can rebrand any *existing* radio technology by adding decimation… BS.


It’s called “processing gain”. Oversampling and decimation have been used for decades to increase dynamic range. The theory has been known since at least the late 60s. And no, it’s not just for SDRs.

If you really want to understand, there are plenty of good DSP books out there authored by Stephen Smith, Rick Lyons, and of course Alan Oppenheim.

No Pain No Gain

So what changed in RSP chips to sell them as 14bit? Or are they making fools of us?


At the heart of the MSi2500 is an 8051 CPU, ~10bit ADC, DSP and USB functionality. So basically they updated the firmware blob to do extra decimation there, but it is still limited to a low maximum transfer rate because they are Isochronous USB Transfers (in this case less than 25MB/sec). But carrying out processing inside the device, and lowering the data transfer rate, instead of more processing on the computer is not a bad thing.

14bit: 2MSPS – 6.048MSPS (7MB/sec—21.168MB/sec)
12bit: 6.048MSPS – 8.064MSPS (18.144MB/sec—24.192MB/sec)
10bit: 8.064MSPS – 9.216MSPS (20.16MB/sec—23.04MB/sec)
8bit: 9.216MSPS – 10.66MSPS (18.432MB/sec—21.32MB/sec)

If it really is 14-bits at 2MSPS, that would imply that the 10bit ADC is sampling at 512MSPS
And 14-bits at 6.048MSPS, that would imply that the 10bit ADC is sampling at 1548.288MSPS
Those numbers sound far too high for a device clocked at 24MHz, my marketing BS meter is tingling.

Lets assume that it is 13.0000001 bits that they end up with after decimation inside the MSi2500, so lets round that down to 13 bits to keep the maths easier and for 2MSPS @ 13-bits, that would be 10-bits at 128MSPS which still look a little too high for a 24MHz clock.

Lets assume that it is 12.0000001 bits that they end up with after decimation inside the MSi2500, so lets round that down to 12 bits to keep the maths easier and for 2MSPS @ 12-bits, that would be 10-bits at 32MSPS which looks to be more in touch with reality. So maybe they are transferring 14-bits where one of those bits is always going to be zero.


So that thing only has 8bit at 10MSPS? Then the other numbers don’t add up. If you divide 10MSPS by 4 you only get one extra bit. So 2.xx MSPS should be only 9 bit. WTF????


See the link to the datasheet in the article, and look at the ADC Characteristics section.

The dual ADC’s in the MSi2500 are always sampling at ~10 bits, I don’t know the exact sample rate, it is not listed in any public information from Mirics (but from the above I’d guess somewhere between 32-48MSPS). But because of the USB bottleneck (by using Isochronous) they have to throw away bits to transfer data across at higher sample rates than 9.216MSPS to keep the data transfer rate under ~25MB/sec.


This may explain why they can’t get real 12bit performance like the AirSpy’s.


Any pictures of the back, or the PCB, basically does it supports an external reference ?


After some research I’ll answer my own question – no.

To be fair it is basically an tweaking (upgrade and downgrade) of the RSP2.

The RSP1 is no longer for sale, so this is a replacement for that, which is basically the same but with extra frontend filters, the option to bypass the LNA and a variable attenuator to reduce overloading caused by the positioning of the fixed gain LNA(/MMIC).

After comparing the block diagrams the RSP1A is a RSP2
The following was removed :
Port A
Hi-Z port
clock in and out (no 24MHz!?!? external referance)

And they added :
0-2MHz LPF
2-12MHz BPF
They added the LNA back in but with a bypass switch.
An extra notch filter to attenuate DAB

With all those switches in the RF path there will additional attenuation and some extra noise.

Is the tuner still a Mirics MSi001 – yes
Is the ADC/DSP/USB still provided by a binary blob running on the Mirics MSi2500 – yes