Building the VTA, tubes4hifi PH16 Phono Stage
Just in case anyone is interested, i am planning to put on here the progress of my build of a Tubes4hifi PH16 Phono amp Vacuum Tube Audio PH16 phono preamp
Just a quick bit about me, I have not picked up a soldering iron for about 30 years so this will be a warts and all description, Hopefully to help anyone else who is thinking of starting a "kit Build" and is worried that it could be a bit daunting.
I will be placing at the end the itemised full cost in time and money to build
After quite a bit of research, I decided on the PH16 and as Roy was helpful with my initial questions.
As I am in the UK I have ordered just the parts kit so the transformer and enclosure will be sourced here, but am planning to make this look a bit different to usual diy valve amps.
The kit has arrived, and i have bought a new solder station from maplins, I have also ordered a toroidal transformer from Terry at Canterbury Windings Home
here are all the parts and where it will be built.
Would be grateful for any advice and will be happy to answer any questions as i go.
Good luck with the build which I will follow with interest.I built one of their SP14 linestages last year and must say it is an excellent sounding piece of kit.A friend borrowed it for a while and it was nearly as good as his Audio Note pre only the lack of a remote letting it down!
What is the gain of the PH16?
Hi Marra, this is the 45db version for MM only, there is a MC version and I am waiting to hear from Roy to see if there is a possibility of making this switchable between MM (45db) and MC (55db)
Roys Kits are delivered with the components in separate bags so the power supply resistors are in one bag, caps in another
amplifier stage resistors, caps and loading resistors all in separate bags.
the instructions/manual/schematics/circuit diagrams are clear and well written.
So once set up from a trip to Maplins with new solder station, Multimeter isopropyl alcohol (for cleaning the boards) a third hand (Magnifying glass, with crocodile clips to hold the work to allow two hands to do the soldering) A roll of Silver Solder, heat shunt, and wire (green, red,black and a length of low cap coax) I was ready to go.
I printed of a resistor colour code chart to identify the resistances and checked them with the multimeter,1. to check i was right and 2. to match resistors in pairs which was unneccessary as the majority of the resistors are quality dale resistors which were pretty spot on.
As it has been decades since i have picked up a soldering iron I decided to start with the Power supply first, after cleaning the boards with the isopropyl alcohol (to remove grease/fingerprints etc) putting on the standoffs I started.
all resistors first, then diodes and capacitors..
Just a tip for anyone wanting to use the silver lead free solder, make sure you have a powerful enough soldering Iron as the silver solder has a higher melting point than usual lead multicore solder ie savbit.
all went very smoothly and here is the finished power supply
Tomorrow: the amplifier
After researching all the phono preamp kits out there I also concluded that the PH16 should be the best sounding. I plan to build a phono preamp next summer and will be following this thread.
I am a believer in premium power supplies and high parts quality. I may throw in my 2 cents on these issues as this project moves along.
Stage 2 Amplifier section;
After seeing the bewildering choice of valves available priced from £6 a piece teslas to £100+ siemens, telefunken and amperex.
so I decided as this is my first build and getting it working was the first priority I plumped for the cheap teslas. I sourced a set of 4 from Langrex-Electronic Valves And ComponentsSpecialising In Original British, German And American Tubes. (very helpful and also supplied the 12x4 rectifier tube for the power supply.)
On Roys VTA instruction parts list i noticed there was an option to upgrade the signal path capacitors to sonicaps , so i decided to do a bit of research and again was stunned at the choice and price range of audio grade capacitors.
wanting to get the best sound i could but within a budget I have bought 8 polypropylene audio grade capacitors from maplins. Search audio capacitors | Maplin
obviously not the best but i think they will be an improvement on the supplied WIMA capacitors and like the valves there is an opportunity to upgrade these as and when required.
So, same as the power supply I started with the resistors, jumper leads, Dip switches then the normal and electrolytic capacitors and finished with the audio grade caps and valve bases.
Just a quick note on the dale resistors, they are not coded with the colour bands but with a 4 digit number whereas the first 3 numbers are the value and the last number is the multiplier, so;
10R0 = 10 Ω
2152 = 21.5 k Ω
2494 = 2.49 M Ω
once i got used to this it is a much quicker way of reading the values.
Anyway again everything went together well, and it is refreshing to find all the components listed to be there with nothing missing nor nothing extra well done Roy
Here is the stage build of the amplifier section:-
Tomorrow, enclosure choice, hardware and a bit of carpentry!
Stage 3 the enclosure!
first decision was enclosed valves, or exposed. Pros & cons:-
exposed valves make it obvious it is a valve phono stage but for whos benefit? I know it is a valve phono stage and want it for top sound quality not as a "look at me i have gone retro statement" (the rack of vinyl says that anyway!)
Don't get me wrong I want it to look good but the layout of the valves of the top fascia would mean extremely accurate machining and finishing to make it look professional.
the other problem with exposed valves is the dust/cleaning aspect of it.
So you can probably guess from above I have decided to go with the fully enclosed chassis/enclosure.
I have also decided to purchase the enclosure and this was my first choice High Quality Enclosures for Audio, DIY Hi-fi & Electrical projects
but at nearly £140 for the enclosure the cost was too prohibitive.
so after a lot of trawling the internet and sourcing the other items i needed (rca plugs, IEC inlet filter, Mains inlet plug, on off switch ) I found this Buy General Purpose Enclosures 3Ux279Dx305W Electronic Enclosure RS SAC3.0D2W2 online from RS for next day delivery.
£33+vat much more like it!
A boring box but with excellent ventilation.
So now to "tart" it up
Two lengths of oak plank offcuts blagged from my local Joiners and a few hours with a sander, router and some beeswax I have ended up with this(see if you can spot the not so deliberate mistake!):-
Tomorrow, Putting it all together
Keep going... I like the wood, it's a nice touch. As for your mistake, I'd say that the color coding was wrong on the RCA jacks.
Nice work. I have also built a SP14 and could not be happier. I am looking at the PH16 for quite some time now, but have not yet pulled the trigger. I am very interested in your journey.
spot on steven it was the channel colours!
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