DIY :Pass F5 Turbo V2 Joshua & Ali's Documented Build

[jls001]

Some pictures of the N56 heatsink from Perfect Metals, Bangalore. Those are two heatsinks placed side by side. Each is 215 mm wide, fins are 75 mm tall, and the height is exactly 9" (sorry for freely mixing up measurement systems, but I have a better mental grip of lengths when expressed in inches and feet, but agree that mm is easier to work with).





Below is a close up the fins. The cut is clean. Should not need further milling or polishing. Small blemishes will likely be covered up during anodising process.




A side view. The height is exactly 9". Perfect Metals has done a good job of cutting to the required height:





By my estimate, the weight of the 4 sinks must be 19.29 kg. After adding 6 mm base plate, 3 mm top plate, 3 mm back plate, and may be 10 mm face plate, it looks like the unloaded weight of the cabinet could add up to about 25 kgs. All the copper from the 1kVA toroidal transformer (expecting delivery tomorrow) could take the final weight to about 35 kgs. This will be a heavy weight in the literal sense!

 

[omishra]

Nice heatsinks, I dont think you need more efforts to attach these to front and back plates. Thanks to those grooves where you can slide square nut and bolt from outside.

 

[jls001]

Couple of items bought for the build:

1) fans - 80 mm, AC, 0.1Watt, quite silent (as far as I could make out at the shop), and much cheaper than the 92 mm Noctuas, which in any case were too big for my needs. Couldn't get Silverstone or Coolermaster in 80 mm size. Current thinking is to mount these two fans on the rear plate. Top plate will have lots of holes for air flow. Need to figure out how to punch/drill these holes without spending silly money on having it milled. Any pointers?




LP cover and CD for size reference.

2) Close-up of fan:




3) Toroidal transformer: I have not weighed it but it is stupidly heavy. It is definitely 15+ kgs by my best guesstimate.

 

[quad]

wow ..that's some transformer!
Hope your home has strong floors/foundations. This is a
real "heavy metal" amp

 

[magma]

just the trafo
heatsinks heatspreader and cab "framework" is 34kgs

still the parts will be put in
the heavy bottom plate and fromt plate full aluminium 10mm thk
will still be added

loking good for half century

My amp is planned to have Stainless steel "horns"

 

[jls001]

wow ..that's some transformer!
Hope your home has strong floors/foundations. This is a
real "heavy metal" amp

Yes, it is big. Diameter is 7-1/4" and height is exactly 4". The manufacturer gave us a ballpark figure of 8" dia and 5" height. Turned out the estimate was way off, so we have wiggle room of 3/4" along the width and 1" along the height.

I started populating the boards tonight, starting with the resistors in the power amp boards. Progress is slow.

 

[bijinmb]

Couple of items bought for the build:


3) Toroidal transformer: I have not weighed it but it is stupidly heavy. It is definitely 15+ kgs by my best guesstimate.

Do you have any idea about the dia and height of the trafo ?

 

[captrajesh]

@Bijinmb, dimensions are given in Jls001's post just preceding that of yours.

 

[bijinmb]

@Bijinmb, dimensions are given in Jls001's post just preceding that of yours.

Sorry that i didn't see it.

Trafo is really big!!

 

[jls001]

Small beginnings:

 

[jls001]

Amp boards nearly completed - all passives except TH1 and TH2 have been populated. Actives are pending.

@Om: quick question --- are the TH1 and TH2 on the power amp board temperature sensing thermistors?

A small suggestion for future board builds (if it happens again) -- the soldering points for the pots P1, P2 and P3 are really tiny. Once you plug in the pots and the pins are in place, there is barely enough copper on the soldered surface to hold the solder. I ended up scraping the contact points to make better contact.

 

[omishra]

@Om: quick question --- are the TH1 and TH2 on the power amp board temperature sensing thermistors?

Yes, see Sann's build. It has to be touched firmly to MOSFets body.

A small suggestion for future board builds (if it happens again) -- the soldering points for the pots P1, P2 and P3 are really tiny. Once you plug in the pots and the pins are in place, there is barely enough copper on the soldered surface to hold the solder. I ended up scraping the contact points to make better contact.

Make sure P3 is in center or omitted. It changes THD nature of amp.
The holes are PTH, though there is small pad on track, its flowed through hole, sticking its surface internally.

 

[jls001]

I forgot to update prices of recent parts purchases:

1) Rexnord make AC fans, 230V, 0.1W: Rs 350 each. Bought from a shop that sells only fans in Chunam Lane, off Lamington Road (the lane closest to the Police Station, west of Lamington Road)
2) Toroidal Transformer, 1 kVA, four 24-0V secondaries, M/S Toroidal Transformers, Goregaon East, near Film City: Rs 5300 plus tax.
3) Soft Start kit, from theaudiocrafts.com, with quad temperature sensors: Rs 1950 plus shipping from Delhi. Dispatched on Sat, received on Tuesday. Prompt response. Much appreciated. The kit comes with four temperature sensing thermostats (KSD-01F) that will cut the electrical supply once the temperature reaches 75 Deg C, and automatically give power back once temperature drops below 75 Deg C. Cables that will connect the soft start kit to the front panel impulse switch, the lead that will power the LED lamp built into the impulse switch, the leads that will connect the thermostats, four clips with transparent insulation jackets - are included.

 

[jls001]

PS Board populated:

Next up: to populate the Rectifier Board

 

[sachu888]

HI Joshua,
your build is looking nice.I am tempting to build one for myself

Regards,
Sachin

 

[jls001]

HI Joshua,
your build is looking nice.I am tempting to build one for myself

Regards,
Sachin

You should. I am quite sure this will be a sonic upgrade to whatever I have had.

 

[quad]

Looks great so far, Joshua.
It might be advantageous go for 105 degree rated caps.

 

[jls001]

The Rectifier Board has been populated:

I have used a 5 mm spacer below the board. The feet of the MUR3020WTs are bent in such a way that when the assembly is placed on a flat surface, the metallic back surface of all the MURs touch the flat surface. Bending at equal distance is critical so that all of them are of uniform height.


@Om & Sachin : need your kind help with some clarifications

1) In the Rectifier board, are IN AC1 & IN AC2 the inputs for the 24 V AC out of the transformer? Is IN AC1 live and IN AC2 neutral? Or are they interchangeable?

2) On the power amplifier board, I see three points marked as SPK OUT, see the areas circled in red. They look like the same point (at least by looking at the trace on the circuit board). Does this mean we have three points from where we can tap speaker out? From the PCB trace, the two holes inside each red circle are on the same PCB trace. Meaning all three circled points seem to be one and the same. Where do I tap the negative out for the speaker?

3) The Rectifier Board mentions 16 numbers of MUR3060WT and the power amp board mentions MUR3020WT (8 nos). But I got only MUR3020WTs (24 of them). Are these interchangeable? I looked closely after completing soldering the Rectifier Board and made this discovery. I hope they are interchangeable


4) Power Supply Wiring

Should the wiring be: IEC socket --> fuse --> soft start board --> transformer --> Rectifier Board --> PS board (the one with the capacitor bank) --> then to the power amp boards?


5) The kit includes two 3510 Bridge Rectifiers along with one 10A NTC thermistor. Where do I use the second 3510?


Edit - Adding one more question: on the power amp board, is it advisable to couple the MUR3020WTs to the main heatsink just like the power transistors? Or should we use a small independent heatsink for each MUR3020?

 

[jls001]

Looks great so far, Joshua.
It might be advantageous go for 105 degree rated caps.

This is what I got (or rather Sachin got for me) after a very long wait and search. The power supply capacitors almost derailed my build!

 

[magma]

mine is to be done likes this

Please note that it is best practice to ensure the fuse and the power switch are both in series with the Live terminal of the mains supply. The pcb is not marked correctly and you should connect the mains to the terminals marked "SW" and connect the on/off switch to the terminals marked "IN". The Live connection should go spade connector that is next to the switch. The external circuit being powered should be connected to the terminals marked "OUT". The board will have live mains voltages when plugged in and should be installed in a closed box, observing normal safety rules applied to mains powered devices. As follow

672A68079898-1_conew3_zps0d4a6ef7.jpg Photo by lishuangjian11 | Photobucket


note

i have two switches

one in the front of the cab and one in the rear

the switch in the front is connected to soft start terminals marked IN

the rear switch is connected to the terminals marked SW

the IEC is connected to the rear swtich