Raising HiFi (Optical Blog)

My BT2 arrived this last Friday.

I loaned the demo unit a few months ago to see if my current preamp (a modified Musical Paradise MP-701 mkII) could be improved upon.

Listening to the prototype BT2 I was surprised in most ways but at the same time also not.

I was surprised that something could reveal so much more information across the spectrum. In combination with the Soekris 1421 it was providing just the right level of detail without becoming too hard etched and certainly never fatiguing or shrill. It made drum hits finally sound like drum hits.

It's funny how accustomed you become to something and for years I've always advocated having valves somewhere in the chain, usually in the preamp so effectively it gives the same effect or 'flavour' of sound signature to what is going into the power amp and out through the speakers.

One thing I was a little hesitant regarding was losing that valve 'lushness' and warmth that they bring to the performance. The BT2 certainly cut down on this factor I have to say and with some stuff switching my valve preamp back in did yield an initially more pleasing listen, but then the inner detail and certain bits of information were given up for this effect.

With the above in mind as well as my conscious effort to move away from valves through out my system (this was just before the valve shortage thing actually!) as I didn't fancy the increased cost and difficulty of sourcing quality and matched valves for the next 40+ years, I decided to send a deposit to Oli to get one built for me.

Fast forward a little bit. There were some teething problems (nowt to do with Oli might I add) just manufacturing defects regarding the motor/frame housing the stepped attenuator with remote volume control. Basically it was 'skipping' the odd increment now and again. Oli was not happy to send it to me like this so endeavoured to rectify it. After some hours spent fine tuning and tweaking it was working properly and the build was finished.






BT2 arrives:

So it arrives and I can finally get to listen to the thing. It also pretty much matches the front of my 686, a lovely brushed aluminum facia.

Okay, this isn't the same preamp I commissioned. It's better, it's miles better.

Likely due to the higher quality power supply fitted along with the PC-Triple C wiring internally combined with the ultimate care and attention to detail Oli brings to each build, whatever the reason, it was even a few levels above the performance of the prototype which was a bit of a revelation in it's own right.

This, this was the component that made me hear what valves were doing in my system, masking the top and the bottom end with audible distortion, pleasant on a lot of material yes, but not what you want when attempting to get the most natural and faithful signal from source to speakers.

I am not saying that valves are a bad thing, I'm not saying everyone should drop them in favour of SS designs, just that I had not heard SS manage to do enough of what I like about the valve signature sound without the drawbacks, until now.

A lot of my system contains what I would call 'tweaks' in order to deal with things like room modes and reflections. For instance in my preamp, I use a slightly higher capacitance wire in one position which helps underpin the bottom end, possibly at the expense of a little bit of midrange and top end 'sparkle'. However, the valves are enough to help these a little bit thus 'balancing' out the sound coming from the speakers.

I've always found ways to draw the sound signature I like from my systems using cables/valves/sub woofer settings and positioning etc. Well, this has eliminated the need for this pretty much instantly. There is so much more information across the entire spectrum it really doesn't need any help from any 'tweak' or similar, in fact any links in the chain (DAC, TT, cartridge, interconnect, speaker cable etc etc) unless it is neutral and transparent is just going to sound bad and be highlighted when a preamp like this shows up.

I say 'a preamp like this' but what I should say is 'this preamp' because I actually find it hard to believe that anything quite like this exists elsewhere.

I won't get into comparisons with big manufacturers of expensive preamps because A) I haven't really heard any and B) I don't think I need to hear any now.

But I will say this, having done some research now on the importance of signal purity and circuit simplicity, the BT2 incorporates these factors without compromise. You can have preamps with displays, XLR balanced inputs, Rhodium plated what-nots but for amplifying an unbalanced signal from source to power amplifier, this is as good as it can be.


Back to the listening:


By now the BT2 has also corrected a small imbalance in image centring the system had been suffering from, I'd gone some way to correcting it with acoustic treatment but it didn't sound correct for all material at all frequencies, basically a kick drum could often be located a foot or so to the left of everything else in the soundstage (basically a mode between 70-120Hz). Well this is gone and now I can actually pin-point if a drumkit is slightly to the left or right of being dead centre (often they are actually) and with a synthesised bass sound (electronic stuff) a bass 'kick' usually comes from absolute dead centre now.

I've also been able to lower the frequency roll off of both my subwoofers. There is higher quality and indeed more bass coming from the drivers of the main speakers so the subs are now really only doing the sub Hz work where the speakers start to roll off (30Hz and below). The integration is now a lot more seamless with so many layers of the low end now being revealed.

Now for the best part . . . . . vinyl.

My vinyl setup is incredibly modest by most standards here (although I'm working on that which will be coming on another post).

It's 'just' an Audio Technics LP5 turntable with a Technics 270C cartridge and NOS stylus. Via an Arcam rPhono (with recently added cheap LPSU).

Vinyl through the BT2 is quite literally startling. There is no other way to describe it. My digital setup is a proper streamer reading files from an internally stored SSD drive using AES out into the Mutec MC3 USB+ re-clocker then high quality BNC cable into Soekris 1421 with LPSU, it sounds great.

THIS vinyl setup destroys it.

Talk about analogue sound, it is rich but never synthetic, atmospheric yet with pinpoint accuracy, textured without ever being bloated. It's very 3D, it's very immersive.

Makes me wonder what will happen when I do upgrade to a 'proper' vinyl setup.


A summery for the BT2:


It's a purist design, build by purists for people who want to hear everything in their hifi chain. It enables maximum performance from what goes before it while out of it flows a faithful signal into all components after it.

No other component has slotted in and corrected so many elements which I hadn't even considered needed correcting, and so seamlessly.

People say preamps should be 'gain with wire', while I can see why I think there is so much more to it than that. The BT2 has a knack of 'unfolding' or 'decrypting' the incoming signal in a way that only something designed with this level of attention to signal purity and quality can do. It is so finely attuned to the job and adept at doing what is supposed to.

I no longer sit there wondering if a speaker requires a bit more toe-in or if a sub could do with being a couple of notches lower. In a word it has brough clarity, complete clarity both audibly and in my own mind. It is just right for me.

As I've said I have no idea what a 20k+ preamp sounds like but if it sounds even a small magnitude better than this, I'd be surprised.



I make no secret of my current approach to hifi, to read and listen to what others currently treading this path have to say and what they do. I have no issue 'copying' certain aspects of people's findings and systems because their choices make a lot of sense to me. It's certainly a darn bit cheaper than having to find out for myself and come up short 90% of the time. Allowing people with the experience and knowledge to do the bulk of the R&D for me has resulted in the sound I'm now getting; I doubt I'd have been able to get there this quickly and indeed frugally had I wanted to go entirely my own way. Not that there's anything wrong with that approach at all by the way, it's just a question of efficiency almost in getting there for me.

Having said that I did take a massive punt on my current Martin Logan Prodigy's and that seems to be paying off so maybe it's a case of knowing when to listen and knowing when to act.

I also make no secret of my admiration and respect for many on this forum (as many have helped me on the journey) but putting any of that aside this is a truly incredible product.

I wouldn't say it's a 'giant killer', (it could be) because it hasn't dislodged any 'giant's' in my system, what it has done without question is improve my enjoyment of listening to music, immeasurably.

I've had a weekend with it now but I knew within 5 minutes, maybe 5 seconds.

Preamp - Done.

Thanks for sharing your feedback on the BT2, Chris.

Funnily enough, the other guy who recently bought one said very much the same about how much better it was than the prototype.

I am very happy with that statement, as I thought exactly the same.

It's always very pleasing to read that it's landed and has hit the ground running.

The issues with the stepped attenuator motor are ridiculous. They are not fit for purpose, as three out of three all exhibited the same issue.

In all likelihood, these three BT2's will be the only ones that have the motorized stepped attenuator in. We are looking at a different way of doing this. It involves a relay based attenuator that we can build ourselves, with the same quality channel matching and our preferred resistors etc.

Hence the recent attempt at PCB design.

Excellent review Chris.
Intelligent and considered.

Nice review, good to see the final product in action. 👍

Suprd stuff by the sound of it and good to see issues being ironed out before despatch too.

you just can't have zero IGD, it's one of those things that's totally unavoidable. I think what you mean is it doesn't bother you.

I've had people tell me before 'There's no IGD on my system' and then when I go for a listen there it is. They just aren't tuned into it, they don't listen that way.

I don't get what is wrong with your digital. This is one of those things where I suppose I would have to hear it for myself to get what you are saying.

yes it is to simplistic fortunately that's not what I was saying. 

however it is quite possible that if I came to have a listen I would come to the opposite conclusion that you have. That has happened to me before, more than once. The owner of the system prefers vinyl and is adamant that vinyl is clearly  his best-sounding source, but my verdict has been that his digital was considerably better. (On one occasion the reaction to that was close to outrage ).

What we class as 'better' is very much subjective and what we listen out for when listening critically is not the same for all of us. For example if I am listening critically I am listening to the technical reproduction (sorry but  I can't think of a better way to express that) whereas others may be listening for less objective criteria that are more important to them.

If not listening critically, just sat about with a few drinks having fun, then I'm not at all concerned with that, I'll happily listen to music on cassette tape on a cheapo Sony deck.

Apologies if this comes across as combative, it's not meant to. I enjoyed your write-up and I think you made a very good decision with the BT2. It's a superlative, end game pre-amp.

Just goes to show , each to their own (preference) I think as long as you know what it is then that's half the battle. It also doesn't matter why necessarily, it just is.

Obs if you want more/better of a particular type of sound knowing why it is that way is helpful for upgrades etc. 

Not at all Martin, I think we've had enough discourse to conclude that neither one of us writes anything to be intentionally combative, I welcome the debate of course.

It's always easy to go off at the deep end when you've paid for something and you start listening to it, but I know what's what in my setup and this humble vinyl setup knocks shades of most other systems I've heard (that number is growing but admittedly it's not as big a reference as most).

I know what you mean about the listening for different things element but overall the vinyl just sounds much more 'alive' than the digital. The dynamic swings are the most obvious aspect to highlight, they really jump out of the speakers and completely fill the room with the vinyl, the digital (although sounding great) does seem a little restrained in comparison. The digital is by no means 'constrained' it's just that when in direct comparison the vinyl has sheer massive presence.

It could indeed be that the digital is in fact more accurate and reproducing exactly what was recorded but the way the vinyl is presenting this information is so much more enjoyable. The IGD and background noise stuff really is a non issue now because it is absolutely dead silent at almost any volume. I don't really own any bad condition vinyl and it's all been through an ultrasonic RCM at least once. All helping to deliver maximum performance. As well as spending a lot of time and effort with cartridge setup and alignment of course. Hassle but worth it.

It could be that I've yet to unleash the digital completely, the Mutec should benefit from it's own LPSU (although I don't think that's what is holding it back) and some further experimentation with BNC/digital cables etc is warranted.


Don't read that I'm not happy with the digital, I'm over the moon with it, but listening to records is just a different level now.

Still non the wiser.
However thanks to the internet..
It’s definitely Insane Gangster Disciples… yeah, definitely

Yes I used to get it all the time on some records until I bought a cartridge that seemed to combat it the best - AT440mla (micro line) they've discontinued the later 'mlb' version now which is a bit of a shame. Yes things could get a little shrill sometimes until I tried a proper cartridge, it basically eliminated it, yes not entirely but it was better than nearly everything else at it. My other points were mainly in relation to the setup being very quiet helping the overall performance. I've had setups that would flap the subwoofers with just the stylus dragging through the groove, even with rumble filters etc, so it's an important aspect for the stylus to be setup correctly which should in turn help IGD also.

It could well be the case that I don't experience it perhaps as much as some as a lot of my vinyl is electronic music, a lot of which actually have very long run outs (sometimes 30% of the record surface) as they often only contain 1-2 tracks per side.

Although when I do play a more 'traditional' LP with tracks right to the middle, I can very rarely detect any at all.

Hahaha...I thought it was just me who didn't know what IGD was. TBH I thought it was an ingredient of Chinese takeaways 

Anyway Chris, great thread and an interesting read. They say you learn something something new every day 

Very entertaining write up Chris, you're heading in way, valves to SS, I'm moving the other  

Pleased you are enjoying the pre and a BIG well done to Oli and Angus.

Yup I second that.