Bigbottle Phonostage - MK3 Design, Pictures and More!

No idea but i like the look of the pink valve holders!🙂

It does look a tidier layout than the mk1 though.

Can you comment on any sound difference between the 2 yet ?

No worries just curious.

A bit more progress

Its starting to look a lot like the final version!!

Also, how cheeky is that little logo! lol

Except we know it's much better than that, don't take the sim as gospel.

A few developments:

The relays will no longer be energised when MC is selected.

A "mild to wild" amount of different sized output caps can be used on the Phonostage, thanks to Craig's creativity with the layout.

The FET will have a dual footprint allowing the use of surface mount BF861C or an equivalent leaded version. Unfortunately, we are yet to find a perfect suitor. I will endeavour to find one as this will help those who are new to soldering.

+ & - indicators are now on the Capacitors and what else is rather cool is..............you can now populate the PCB on either side (except the valves) which enables you to easily have the valves on show. How cool is that!

Electronumpty, this would have made life really easy for you. I am sorry lol

A pic of the new PCB mockup to follow

Neat little job that Bigman

We are very lucky at work our employers have 3D printing for circuit boards, re-flow and pick and place machines so we take it for granted all of the effort that goes into a project like this, full marks El capitaino

Ha! Now you change it! 


Seriously, looks really good and a very user friendly layout , not that I'm an expert about that sort of thing. 

I'm sure it'll be great!

You never know , I seem to have PCBitis at the moment! lol  

Thats looking great Oli. Silk screen on both sides is a great idea.

Just a thought or two - MC's mostly seem to work loaded by 100 ohms upwards and going further never seemed to make much of an effect, although Naim and NVA to mention two, seemed pretty universal at 470 ohm loading (as time went on, we used Naim 'K' boards for practically everything with no issues i seem to remember). MM's today are usually settled on required 47k and 50 - 100pF which combined with the tonearm exit cable, seems enough for all but the most old fashioned types ime.

Most important of all I think, is to ensure a good high overload margin plus clean behaviour when upset by record ticks and splats. Cheaper stages don't always have the headroom and can latch or let go momentarily when set off by a loud tick or pop. The best stages I ever heard, seemed to subjectively lessen the 'effects' of surface noise.

Many modern cartridges have an hf rise rather droop as was common in the pre-digital age and the performance of the phono stage at very high frequencies can help a lot here in terms of handling the excesses in my now ancient experiences..

Most mc carts have a sub ten ohm impedance, so any loading over 100 ohms has no further effect on electrical damping and taming the hf rise.

Theres relatively few, like higher end Benz and Lyra carts, that genuinely need over 100 ohms due to the combination of coil inductance and impedance.

I like a c300 ohm load on my Benz lp though it sounds good even into a 3k load.

Google parallel resistor calculator just put in 1000 ohm for the first number then adjust the second value until you get the required number.

So 111 ohms gives you a 100r loading with a 1k native impedance