B2 questions


Please let me have any questions or feedback about B2 here and I'll put your question and my answer on the website - Martin Brennan.

Quick update 18th September

Thank you for all your recent questions - they are going to help me make the website more useful - I am currently working through the questions and adding to this page - Martin

Search the Brennan website using Google - JB7 and B2 



How will B2 perform with my 4 Ohm 10 watt speakers or will it destroy them?

I haven't tested this extensively - but B2 is was fine driving BSP50's in parallel to simulate a 4ohm speaker. The power amplifier has a thermal shutdown and this will kick if too much power is drawn because of the reduced load - but it will be fine for normal listening levels.

Beware though B2 is capable of destroying your 10 watt loudspeakers - so keep the volume down.

Does the B2 take Headphones?

Yes - plug them into the Line Out at the back - that will mute the main speakers.

As I understand it, I can use my iPhone or android phone to control the B2 and to select / search through my collection and play an album or track.  However, what is the dependence on these phones?  I am looking for longevity on my B2 and worry that it may not function as phone develop to a point where they are unrecognisable to today's models.

Good question - actually I sidestepped that problem because the B2 has a web interface - so when you control it with an iPhone or Android - its not an "App" but the handset web browser that you use. Future devices will work with B2 in the same way you can confidently expect them to display old websites.

Internet radio: will Radio Caroline be included in the "more coming" comment?

If you are prepared to do a bit of digging I can add your radio station to the next software release. Your radio station needs to stream mp3 and I'll need the URL of a playlist file - typically ends in something like .m3u or .pls. If you look on the Wikipedia entry for BBC Radio Two - you can see their URLs. Send in the URL of your favourite station and I'll add it. 

I found these Internet Stations that would be good, I did not know which URL to use so copied them all. Absolute Classic Rock stream URLs MP3 128k: http://network.absoluteradio.co.uk/core/audio/mp3/live.pls?service=vcbb

Thanks - thats perfect I
 just added all the Absolute Radio stations you sent me.

Hi Martin,
I have been looking for an intuitive easy to operate home juke box and your product looks like it may fulfil all my criteria. Will the B2 collect track listings from the internet when uploading my CD collection?

Yes - assuming you have an internet connection - B2 will go online and collect album, artist and track names from freedb.org - whenever you insert a new CD. These names are used when you copy the CD to the B2 hard disk or if you just play the CD. If you do not have an internet connection its not a problem - B2 will use an offline / internal database of 3.4 million CDs instead - thats the way JB7 worked. The internal database will not have CDs released after the database was created but we update the database monthly so its pretty up to date.

If your CD is not in the database or online - just copy to disk with the default name and rename albums and tracks later as necessary.

There are several mentions made of future applications. Is the B2 designed so that modifications in the future can be loaded into the B2? In short can the B2 be constantly modified in the future?

Yes - the easiest way is to do an internet upgrade - just go to Settings->Web Upgrade - takes a few seconds. I'll publish what the new versions do on the website. You can also upgrade using a USB memory stick if your B2 is not connected to the internet. Finally you could swap the SD card - so B2 could run third party software.

How many playlists can you create and can you name them rather than the colour system on the JB7?

At launch B2 will have the same seven playlists as JB7. The good news is that while JB7 had very little memory making new fautures or improvements difficult - B2 has tons of memory - and I have just scratched the surface of what is possible. I will be putting a wish list on the website showing what features are in the pipeline and to let you register what is important to you. 

Will the new B2 wireless compatable . I live in a four story house and would like to use wireless speakers if possible.

We cannot drive wireless speakers right now - I think thats something for the wish list - let me know if there is a particular wireless speaker that you favour and I will look into it.
Update Bose Soundlink has been suggested - I have one of those so I've added that to the wish list.

Will CDS which were originally transferred to the JB7 without any track information (because it wasn't in the database) be updated automatically once transferred to the B2?

Good question - when a CD is not in the database - its fingerprint is saved on the hard disk so that it can be looked up in a later version of the database. The re-index function on JB7 did this.  It has to be a manual process because there can be multiple matches in the database. B2 will have a similar mechanism that can be applied to music you copy from your JB7 to B2.

Does the B2 have an analogue line out as my HIFI does not have a digital line in?

Yes - B2 has analogue line out. Because B2 is so small there isn't a lot of room for connectors so we used a special combo connector for SPDIF/Line Out. You can plug in a standard 3.5mm stereo jack for analogue or plug in our optical cable that has a standard Toslink connector on the other end for digital. Optical is not susceptible to ground noise so is better - if you have kit that has it. 

Can I transfer my JB7 music collection onto a B2?

Yes - if you backup your JB7 onto a USB hard disk - then B2 can load this backup. What's more B2 will read the backup twenty times faster than the JB7 so its a relatively quick process. Also B2 will extract artist information - where available - from the backup and organise your JB7 music by artist... a feature not available on the JB7.


Can I purchase my own speakers for the B2?

B2 was designed for 8 ohm loudspeakers - like our BSP50s. The BSP50s are matched to the power and physical size of the B2. If you are looking for higher quality loudspeakers then you need to think about spending more than £200. 

Will B2 work in North America on 110V?

Yes - B2 has a universal laptop computer style AC adaptor that will work on 110V. The mains lead/cord is detacheable with a small figure eight style connector.


What is the size of the B2? - Thanks

Not sure if you wrote this before we wrote the B2 specifications page on the website - click on features above then B2 specification on the left - its 4.8cm high, 17cm deep and 15.3cm wide though.


Hello Martin
Your instruction manual says the B2 will play M4A files, does that include the Apple Lossless (ALAC) file format? They use the file extension m4a but are more like a FLAC file than an AAC file. I believe Apple have made the ALAC licence universally available now.

Sorry just WAV,FLAC,MP3 and AAC right now. Your request has been noted.


hi does the b2 have a radio built in if not would it be possible if you released a new jb unit?

B2 does not have a traditional radio receiver and I'm unlikely to add one. Part of the reason is that DAB reception is rubbish where I live and work. Internet Radio is great and if you need real radio you could feed the line out or headphone output of a traditional radio receiver into the B2 Aux In.


hi, good luck with this new product. Question. If i load CD discs and connect the device to an external high quality CD player which can be used as a DAC (Simaudio Moon CD 3.3) in my high end hi fi system, are the files compressed or will it sound the same as playing the CD? Thank you.

On B2 CDs are normally compressed to FLAC and FLAC files are reconstituted to exactly the same samples - so it will sound the same as the original CD - because it is the same.

Can you just plug in a portable USB hard drive and copy across the music in folders? Is this supported? Also, does it support USB 3.0?

Yes use the Import function in the USB menu. B2 will copy all compatible music files - using the parent folder as the album name - and the grandparent? folder as the artist. If the track name begins with a number eg 15-Jailhouse Rock then that number will be used for track ordering. This convention is used quite a bit.

Sorry no USB3 but 480Mbits USB 2 is a whole lot better than 12Mbits JB7.

does the B 2 have dab radio or bluetooth?

DAB no. Bluetooth yes - you need to buy the optional dongle. Bluetooth input only at the moment - play your phone or tablet through B2.

Can you deliver to Dominican Republic?

Yes - anywhere the big couriers go.

If my cd isn't a official cd, can i then program the track/artist info myself?

Yes you can rename the album and tracks any time. You cannot rename the artist at present. It will be filed under unknown artist.

Will I be able to transfer CD tracks to my iPhone?

Not directly - I recommend you use a PC or Mac. First backup your B2 to a USB hard disk then plug the backup disk into a PC or Mac. Copy the music to the PC/Mac then import to iTunes.

Will the B2 eventually be compatible with MP4?

I've no plans to support video but this is something that could come from the Raspberry Pi community.

Can you hook up speakers to the B2,,as did the JB7.I did not see any speaker wire connections on the back of the B2..Thanks

Yes - there's a small picture showing speaker wires on the Features page at the left.

Can I use B2 in conjunction with my wireless Sonos Speaker system?

Sorry no - I believe Sonos use their own proprietary wireless system.

Will it be able to store or play 24bit hi res files with the aid of an external DAC?

In theory yes - B2 could drive a 24bit USB DAC. The SPDIF output is restricted to 16 bits I think though. 24bit comes up from time to time but there has been no significant interest expressed in the thousands of comments received from customers. Maybe because there is no ready supply of 24 bit music. 


Will multiroom with several b2s be possible albeit with tweaks to the raspberry pi is I've seen several implentations on the pi that do?


Its clearly possible from a technical perspective but I want to keep B2 simple. So this may be something that the Raspberry Pi community will get into...

Hi Martin

I've had the JB7 for some time and regularly back it up but was wondering if by connecting the JB7 to the new B2 via a USB cable, can I cut out the middle man of my back up disc or do I have to load from my back up?

You have to use your back up disk - but B2 USB is twenty times faster than JB7 so importing the JB7 music will be much much faster.


...Having read about the ‘new improved’ B2 on the website (especially the inclusion on internet radio!) I ordered one sometime ago and hope to be able to use it during the Proms season starting 17 July 2015. I think the site mentions one of my queries (fast forward and rewind) but I would be very grateful if you could answer the following queries: 

a) I am assuming that I can record directly from the internal internet radio without using a lot of other ‘gear’? Definitely the most attractive new feature to me!
b) Have you managed to incorporate some kind of ‘pause during recording’ facility?
c) ‘Fast forward & rewind’ if not already implemented, can I add this in the near future via a download?
d) I’m assuming from reading the website that I will not lose-out by buying the B2 on its launch (rather than waiting 6 months) as any new features can be added later. Is this correct?
As classical music (and the collecting of it!) has been a major part of my life from school to retirement, I can honestly say the JB7 has been great fun and I look forward to using the B2.

Hi - thanks for the feedback and the longest question so far.

a) recording from internet radio is on the wish list
b) pause during recording - not heard this request before I've added to wish list.
c) Fast foward and rewind - this is in the pipeline I've already coded some of the inner workings of this.
d) Quite right - you will be able to upgrade and early adopters will get more of a voice in shaping how B2 works - I've talked to quite a few new B2 owners about what they want out of B2.

I cannot seem to play the line out from a VideoLogic DAB tuner through the Aux Input of the B2 without to sounding as if though it's being overdriven because the speaker output is distorted. This morning I swopped the JB7 and the B2 around and tried again - the DAB tuner plays through the JB7 without any distortion and yet it distorts through the B2. Any ideas what's causing this please?

Sounds like you have run into one of the limitations of the Raspberry Pi - you need to restrict the USB speed to get crackle free Aux In. Use Settings->USB Speed->Low Speed.

Secondly can a favourite Dutch Internet Only station I often listen to be added to the station line-up http://www.radio10.nl/players/stream.php?channel=6070s

You will need to do some digging around I need a URL that ends in something like m3u or pls. The url above is for a web page as opposed to the stream itself - sorry.

Hi Martin.
Can you please list which internet radio stations you already have in B2. Is Smooth radio included?

Smooth Radio not yet - I'm working on a significant increase in number of UK stations - and a way to find them. I'd appreciate any help Internet Radio outside UK. 

Update 25th August - Here is a list of 750+ UK stations about to be added to the software.

I have a Netgear ready NAS on my network which I use for remote backing up of my PC etc. Can the B2 backup to a remote NAS?

Hi B2 can't do that but given the question you may be able to set this up yourself by logging into the Raspberry Pi in the B2 (user root password brennan). Have a look around. You will find your music in /media/hdd1/music.

What software reads the catalogue of albums and tracks?

None - its meant for human consumption.

How does the latest High Court ruling on copying CD'S affect the Brennan?

I am not a lawyer but this doesn't really change anything. As I undestand it its a challenge against the government as opposed to a music publisher or artist going after CD owners. I take a great deal of comfort in the statement - I think it was the Britsh Phonographic Industry - made in the House of Lords that they would never pursue music owners making copies for their own use. I imagine it would be commercial suicide for a publisher or artist to do so - imagine the internet mediated backlash. 

HI Martin,
Great product. Glad to see yet another innovative use for a PI.
Obviously with this at it's core is there any chance of adding DNLA client software.With over 1000 CDs stored on a NAS drive, a compact all in-one unit would be great.
Similarly allowing the B2 to act as a DNLA server would be great.

Hi I have added this to the wish list - and I will investigate further - although I have to say DNLA did not come up a lot in the thousands of comments I received. Interoperability is a potential problem.

The back-up disc doesn't appear to work from Port C - only Port A - so we have to take the wireless key out of the port to back-up. Is this right? Could the wireless key go in any other port?

The two ports have slightly different power capabilities so if it works with your hard drive in A thats fine. 

The only thing to note is that the wireless dongle can interfere with the audio – very slightly – when it is in Port C. This can be remedied by using a short USB Extension cable like this from Amazon.

If I rename a CD or track on JB7 then backup and upload the backup disk to B2 - will B2 upload the manual changes?

Good question. The short answer is yes B2 will upload the new names. But...if you did a backup on JB7 then changed the name of a track (for instance) and then did another backup. JB7 would treat the track as a new track and you would have two copies of the track on the backup disk - with both names.

My suggestion is that - before you load the B2 - delete the old JB7 backup - use a PC and delete folder "hardfi" on the backup disk - and do a fresh backup from the JB7. That way you will get just one copy of everything - with the latest names.

Can the JB7 be connected directly to the B2 to copy music?

Sorry no. Need a backup disk as intermediary.

How do I get rid of unwanted artists? May seem a strange question, but I have three artists named:

Emerson, Lake & Palmer
Emerson Lake & Palmer
Emerson Lake and Palmer

Another good question - and I tried to show how to do it in my first Youtube - but I made the mistake of trying to show everything in one video so its a bit tedious - for me and for you.


The best way is to decide on the best version of the artist name - then rename the other two artists to match.

You can do it from the front panel by finding the artist - say Browse Artist (or Goto Artist from the Album) then in the Artist Menu select Rename Artist.

Its all a lot easier with the Web UI - just double click on the artist name and you get to rename it.

By the way its important not to turn off B2 immediately after a lot of renaming - press and hold the stop button to force B2 to save the changes to disk. If you turn it off by accident don't worry Settings->Scan Disk will sort it out.

PS I will do a few shorter Youtubes when time permits - let me know anything that needs explaining.

I have a few WAV files that do not compress!

Heard this from a couple of B2 owners I will investigate but Settings->Scan Disk fixes it.

What quality is the DA converter? For a top end, system ie SE OTL tube amp, full range horns, would I need a separate higher(?) end DA converter? If so, would you be planning an upgrade choice to a higher end chip in the B2, for extra few $$$?

We use a Burr Brown (Texas Instruments) PCM2902C DAC - you can look it up. The optical SPDIF output from B2 means you can spend as much as you can afford in pursuit of audio quality on a DAC, Amplifier and Speakers and the B2 will not compromise the sound. 

Could you be a little more explicit about how to log on to the Raspberry Pi? Something that would be useful to someone who hasn't done it before? 

You need to use SSH to login to the Raspberry Pi from a PC on the same network. I use a prgram called Putty. Select SSH as the Connection type. Type the IP address of the B2 and click Open. You should then see a terminal window with a login prompt. The user is root and the password is brennan. [I found that the connection is more reliable if I set Seconds between keepalives to 1 - on the connection tab of Putty at startup]


What Pi is inside? Could I upgrade to a Pi2 just by switching the Pi Board to get the performance increase.
Any plans for B2 Pi2?

We use the Raspberry Pi model B. The later Pi is not physically compatible. No plans.


Hello Martin,
Could the B2 be used as a hard drive? I am currently ripping some DVDs to .avi and wondered whether I could store them on the B2? I don't expect to play them via the B2 just use it as a repository.

B2 is a fully fledged linux computer so if you understand how to use the linux command line you can get access to the B2 hard disk and could use WinSCP for instance to store files on B2. If you are not familiar with Linux its not a consumer oriented system so a steep learning curve.

Will it be possible to edit Album details, as with the JB7, by saving the listings via the USB port, editing on a word processor and importing them ? This method is far easier than using the remote.

The Web UI is a far simpler and more direct way of editing Album details. So it is unlikely that I will develop an equivalent to the JB7 import-export mechanism.

Why do all hard disk models of B2 have a capacity of 5000 MP3 CDs - regardless of disk size?

There is a software limit of 5000 CDs even though the hard disks themselves have sufficient space for 7,500/15,000/30,000 CDs. The reason is that I am not aware of anybody with a music collection greater than 5000 CDs and it would be difficult and time consuming to test the software worked with 600,000 tracks!

The real benefit of the larger B2s is the number of FLAC albums they can hold.

If you do own more than 5,000 CDs let me know and I will consider increasing the software limit.

Troubleshooting B2 Tips

Get the latest software
Turn off and on
Settings->Scan Disk

CD not working?

Settings->USB Speed
(needs to be High Speed)

Problems with Radio Stations?

Make sure you have the latest radio station addresses. Use Settings->Radio Update to bring them up to date.

Our Radio Station links have been provided by www.radiofeeds.co.uk.

If any stations do not work Vincent is keen to hear from you here. Radiofeeds is a UK only directory.

Vinnie has written some tips here.

Can I have a copy of the B2 instruction booklet?

Quick Start Guide download



I am developing a comprehensive online user guide that will be change to reflect new software features. Current version here.

I am buying a 500G B2 can I upgrade to a bigger capacity hard drive in the future?

Yes - we intend to be hobbyist friendly so if you want to open up your B2 and replace the hard disk thats OK.

If the SD only version is ordered, can a HDD be retrofitted later? Is 64Gb the current SD limit, and is SSD an option for retrofit instead of HDD?

Good Questions - The SD only model lacks a PCB and mounting for a HDD you would need to buy these from us.
64G is not a limit - I anticipate providing an image file that you can copy to any SD and it will use all the available space. SSD is compatible with the hard disk but they are expensive if you don't need the speed and hard disk noise is not an issue with 2.5" drives.

Can one substitute a 256G SD card for the 64G one to increase capacity?

Yes - thats exactly what I want you to do - to take advantage of new technology. In fact B2 has new menu functions to transfer everything to the new bigger card.

I already have a Bluetooth dongle, but will add this to my order in case the b2 needs a specific one.

If your Bluetooth dongle says CSR4.0 on it then yours will work.

Can headphones be used with the b2?

Yes - plug them in the line out.

Can the B2 be used in the USA? ie 110V?

Yes - the power supply is international

Will the B2 allow me to store and play my dvd collection from UK USA France Hong Kong and Australia?

B2 is physically capable of playing DVDs - I was able to play DVDs using a Raspbmc SD card - its not something I will be supporting but Raspberry Pi enthusiasts should be able.

Do I need to keep separate back up drives for the two devices - one for my JB7 and one for my B2? or can I use the same one for both, assuming that both have the same content?

You only need one backup disk. In fact if you loaded new CD A to the JB7 and new CD B to B2 then backed up each to the one backup disk - then the backup would contain both CDs. If you then restore then only the absent CDs will be transferred.

However...JB7 cannot play FLAC files so if you need your music to be interchangeable with a JB7 either set compression to MP3 or turn off compression - on the B2. Thanks Jim.

What's the Standby Power Consumption?

B2 doesn't have a true low power standby mode - so I urge you to turn off at the mains when not in use - it will extend the life of the OLED display as well. The idle power consumption is just over 6 Watts.

How do I stop it cross-fading between tracks?

Settings->Segue->Segue Off

Does the B2 come with a remote control or do I have to buy one?

Yes B2 comes with a remote control.

Will I be able to use a USB keyboard on the B2?

Yes - latest software has USB keyboard support added.

The b2 looks like a great product.
I currently have the jb7 and looking to upgrade to the b2 in the near future.
Can you advise if it's capable of recording directly from the internet radio, or if this could be possibly be implemented in a future upgrade?

Thats a good idea - B2 doesn't allow do it at the moment but I have added it to the wish list and I'm steadily adding all worthy requested features. Yes you will be able to upgrade when its done - takes a few seconds.

Am I missing something? I can't believe the display only shows the name of track, not it's time or number within the album. JB7 did this so greater functionality.

Look again I added these features. In general the B2 will be able to to do anything the JB7 could do and better.

With the 64g SD version pre-ordered; Can you advise on the selection of appropriate larger SD cards?
I am looking into these (plan to buy a larger one) and costs vary as so their 'speeds'; is there a minimum specification (other than storage capacity) that I should look for to function well with the demands of the B2?

I've not encountered any SD cards that don't work. Some take a bit longer to boot just a second or two extra but after that no difference. The biggest I used so far was a very cheap 128G seems OK but let me know any experience good or bad (especially bad) and I will publish it.

Hello Martin,
Is it possible to put multi disc audio books as well as music albums on the B2 in such a way that they aren't included in the random play function, and would play in order.

Not possible at the moment but another good idea. I seem to remember a B&O product that grouped music into different members of the household. I've put your question in the wish list. I think some of these ideas will be a lot more feasible with the new web UI that I'm working on.

Dear Martin.
Can you tell me the 2TB external hard
drive which you would recommend. Is it your intention to offer this for sale through your shop? 

Hi JB7 had a bit of a problem with external USB drives because it needed something called FAT32. That was pretty common when JB7 was launched but became hard to get later so we sell a FAT32 500G USB drive. B2 uses FAT32 but B2 can format the external disk to FAT32 for you. Use Settings->Maintenance->Format USB. So you can buy any 2TB externalk disk for backup.

Hi Martin - a friend has recommended one of your players and I am very interested in the new B2 model. Some questions - I can make a one-off copy off a USB drive filled with 600Mb of FLAC files ? I can also out the output into a DAC as well as a standard audio output into my amplifier ? I know I don't need to do this but I have the DAC in place already for an Apple TV.

Yes you can load all your FLAC files onto the B2. Use USB Functions -> Import From C. If your DAC has an optical SPDIF input then yes you can drive the DAC from B2 - then the sound quality is limited only by the depth of your pockets because everything is digtal up to the DAC.

I've had a JB7 for a few years. I don't like the segue play mode but obviously I can switch this off. However where this doesn't work is one of these operas which are divided into about 40 tracks - the jerk between tracks is jarring but then this doesn't lend itself to segue either. It's not just opera, a live recording which has just been split into tracks without fades does the same.

I suspect there isn't an answer but maybe the B2 has leapt forward?

I'm surprised about this - I listened to a few live albums on JB7 uncompressed and could not hear any transition. Although audio artefacts will depend on the actual music - you will hear a small interruption in a sustained pioano note that you would not hear in an audience clapping. There is a reason why MP3 encoding would introduce a discontinuity - because it works on frames of data about 1/40 of a second and CD frames are 1/75 of a second. WAV and FLAC do not work with frames so no reason in principle for a discontnuity. I'll be happy to investigate and attempt to remove any discontinuity on B2 if possible.

Hi Martin,
It seems to me that the B2 would be capable of storing and playing DVDs as well as CDs with the correct programming - is that the case and if so, would it be on your list of future developments or would you leave it to hobbyists to create the program? 

Its certainly possible to play DVDs on B2 - I did it with a Raspbmc SD card - but I will leave video to hobbyists.

Does the B2 have base and treble adjustment?

Not yet - its on the wish list - JB7 had it - I just need to copy the code.

What is the audio level out of the line socket?

Its not a true line out - this output doubles up as headphone output so the level changes with the volume control - unlike a classical line out. The level goes up to about 1V pk-pk or 350mV RMS.

I have a JB7 500GB - with this I can load/rip cds with no compression ie perfect copy of the cd - on looking through your literature for B2 it states cds loaded with no compression are then converted to FLAC - is there any way I can have my cds loaded and playable with no compression on the B2 like the JB7 - many thanks

Hi at the moment B2 compresses either to FLAC or MP3. You can reconstitute the orginal WAV file from the FLAC because it is lossless. There is no way to turn it off. However if you have no space worries then I can see it might be useful to disable compression - I've added it to the wish list - won't be hard to add - as it involves doing nothing.

Update 8th September - can now turn off compression.

What lead do I need to connect B2 to my Yamaha RX3040 Receiver?

Hi - I just looked at a picture of the RX3040 - what a monster - its bigger than my first car! Seriously though - your amp has optical inputs which is ideal - uncompromised audio quality - so you should buy the SPDIF lead from our shop page - or similar elsewhere.

If your amplifier does not have optical you generally need a 3.5mm to RCA (aka Phono) lead. Like this from Amazon. 


Can you confirm that an up to date database will be included? If not please include a database CD with my order.

Yes your B2 will have the latest album database installed. You won't need it if you connect the B2 to the internet.

The B2 does not update its "offline" database with a CD like the JB7. You need to download this file. Copy it to a USB memory stick and plug it into B2 USB C. Then Select USB Functions -> Load Database.

A small fraction of my CDs give the message "rip incomplete". What does this mean and is there any way I can rectify it?"

This usually means there is a video track on the CD - sometimes not mentioned on the CD cover. In this case it is the last track that fails to load. Can also happen if the CD is damaged. Try washing gently with Fairy liquid, rinse and dab dry. Then retry. Sometimes you will find that a larger desktop CD mechanism will read a difficult CD - so try ripping on a PC as a last resort. Then transfer the music using a USB memory stick.

I have a 2TB NAS drive. Could I use the B2 SD only model with the NAS drive?

Sorry the B2 does not work with NAS storage and although the Raspberry Pi can do that sort of thing I am unlikely to develop that facility. My experience of NAS products has been - difficult to setup, unreliable and poor performance. Do you have a NAS that is simple and reliable?

If the web interface on my phone/tablet connects to the B2 via browser is it going to affect my phone data limit? I'm guessing not as no data directly going to the phone unless I'm streaming spotify, etc.

Good question – no it won't affect your data limit to simply control B2 – but yes if you stream from Spotify over 3G / 4G – but at home your phone would normally be setup to use the (free) household Wifi.