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

[magma]

Hi all,

Heres yet another probably repetitive Nelson Pass F5 Turbo V2 build

However i will try and document each step along the way with pics
and info pertaining to where we sourced our parts , other options one can consider , prices etc

The build belongs of FM Joshua who will add the electronic progress as i add the "other than electronics" progress

and is supported by Om,Sachu,Capt and Anilva
All whose support is and will be thoroughly appreciated

The build is planned to feature two different types of heatsinks
and solid Copper conduction

The entire cabinet including the chasis is an extension of the heatsink itself and hence is made from cross braced aluminum extrusion that is thermally coupled with the sink
The base and top plates are also aluminium

The plan is to run the devices as cool as possible and as mentioned earlier to use the chassis and part of the cab as a heatsink too

 

[magma]

First step

Procure PCBs



One rectifier PCB
Two PS PCBs
two mosfet PCBs

Where to buy : we got ours from om/sachu
Price paid : i think rs 3000
Options : DIY audio

 

[magma]

Next Step

Procure Kit

Where to buy : we got ours from om/sachu
Price paid : i think rs 8500 odd
Options : DIY audio

 

[magma]

Next

Procure Heatsinks

there are options here
Many members have used a variety of options

However our calculations show we should try and use close to 14 kgs of sinks to be safe in the indian summer

A variety of sinks can be used as shown here
You can think of the MG 36 , MG 75 or MG 98




The MG 36 is the easiest to use one piece , but the heatsink needs to be used wither vertically (like how OM did one of his builds ) or then it needs to be TOP mounted ( i.e on the top plate )
I would assume a 12inch length per channel would be sufficient

The MG98 is another poplular sink
however you will need to use 4 pcs of the sink
2nos per channel
minimum cut lenght ( i.e height 7-8 inches )

I have used the MG98 in one cab and the MG 75 in another
the MG 75 shows quickest dissipation due to its design
but is is slightly smaller than the 98
Also it is not easy to work with
a copper spreader is required which needs to be absolutely ground flat on a surface grinder
Hand polishing wont do
We want every part of the surface to be in contact with the sink


Where to buy : The flower design was procured from hindalco and the other one also is from Hindalco - perfect metals banglore is one source , the other is opposite CK switches in lamington road , yet another is Municilap Ind estate Byculla Mumbai , gala no 16 i think and i think there are a couple others whome Fms may add

Price paid : i think 4 nos 7 inch pieces of the MG 98 should cost you close to 6000-7000 rs
depending on whether the dealer has stock
Options : As shown in above pic

 

[magma]

More Heatsink Pics here





the MG 75 cut in 8 inch lengths

 

[ghatgepatil]

The fins look mighty thick. Could'nt they have been thinner? I do not think thicker fins would have any measurable difference in heat dissipation. Or, is it indeed difficult to manufacture the thinner variety?

 

[omishra]

For above plain finned HS - Please try to keep the cut length >8". I could prefer 10" without fan. for 6" cut length we could get 76W dissipation/ch without fan.

 

[jls001]

@Om: When you say >8", do you mean height?

To have a common understanding, please refer to the pic linked below (Imageshack has a new UI and I haven't figured out how to embed a pic, so I am giving a link instead), where W is width and H is height.

http://imagizer.imageshack.us/v2/800x600q90/713/egkl.jpg

So far, most of the heatsinks we have seen are limited to about 8" of W, or slightly larger than 8" (like the 215 mm = 8.46" wide N56 which magma has shown in a previous post). H is running length so it can be flexible (7, 8, 9, 10, inches.....).

I am also very interested to understand what will be the best size of sink to be able to bias the F5T/II to its full power. I will gladly overlook cosmetics and aesthetics

Another option is to use low-speed fan, low-noise fan to reinforce the cooling. I have not explored this in detail but I am very interested in this path.

 

[omishra]

Yes I am talking about running length H as >8". I am also exploring fan option. FM rohitmusic tried fan with high success.

 

[magma]

Misc fasteners



Misc fasteners

Aluminium L die cast connectors for chasis/ frame- 16 nos 800Rs
Aluminium Die cast T nuts M5 - 15nos 200 Rs
M6* 12 grub screws - 35 pcs 75Rs
M5*10 SS allen screws for top rear and bottom - 15nos 50Rs
M5*12 SS allen screws for affixing heat spreader to sink - 16nos 60Rs
M6 * 40 counter allen 16 nos coupling heatsink to frame 80Rs

total : 1265

Where to buy : your local hardware market - i got mine from the Zenith Stores
Price Paid : As above
Options :
Make chasis/frame locally using sqaure pipe from a metal worker
A 20mm sqaure pipe or 20mm Angle will do
This will save rs 1600

However take care while drilling the holes for fastners
Lining up holes takes care

 

[jls001]

Yes I am talking about running length H as >8". I am also exploring fan option. FM rohitmusic tried fan with high success.

Can FM rohitmusic please post photos of his implementation of fan? And some technicalities like which fan is good, how it powered? etc. Thanks in advance.

 

[darshanjoshi]

Great Thread Magma.

Thanks to all contributing to this build !!!

I will request you all for a small Demo at your place once this monster is up and singing.

 

[rohitmusic]

Can FM rohitmusic please post photos of his implementation of fan? And some technicalities like which fan is good, how it powered? etc. Thanks in advance.

I had tried this fan.

Implementation: The placement was experimental. I had opportunity to try this on Omji's F5 T V2 amp with the vertical fins design.

I had placed the fan under one of the fins as shown in the figure. I had kept one fin without fan purposely to observer the delta/difference between temperatures with and without external cooling. This is to allow the natural convectional flow of warm air upwards.
Supported the fan with legs using thick steel wire. The fan has mounting screw holes on all sides. Attached DIYed wire legs to these holes as I wanted flexibility in placement. The legs are placed on ground and provide easy adjustment of height and placement.

Which fan is good?
I tried searching for fans some were directly powered by AC current but they were noisy.
So went for cooler master silent fans as they are dead quiet. Could not hear them play.

Size: Chose the 120mm as it is bigger in size and wanted to over engineer the solution as it was a prototype implementation and wanted to see the efficiency that could be achieved with a fan solution. This works really well with no noise at all. I can't hear any fan noise and it cools well. I find this fan to be sufficient and its size to be manageable.

Powering the fan: I used a AC to DC adapter which was lying with me. These are available for around Rs. 250 or so. Since I was trying only one fan so I used only one. for dual fans need to power both of them accordingly.

Efficiency and measurements:
Goal of experiment: Identify efficiency of fan cooling.
Duration: 2 hours
Frequency of measurements: Measure in 10 minute intervals.
Measurement tool: Thermometer
Room temperature: 30 *C

Readings:
Starting temperature of fin without fan: 30 *C
Recorded high temperature: 56 *c


Starting temperature of fin with fan: 30 *C
Recorded high temperature: 44 *C

Temperature graph (curve):
The temperature of both fins showed a steady rising curve upto 42 *C. The fin with fan had a lagging slower curve reaching there. (Was lagging by around 2-3 *C lesser than fin without fan)

For fin with fan the curve peaked at 44 *C. This "palteau" was maintained and a flat curve was observed for the rest of the experiment.

While the fin without fan continued to show rise in temperature till it reached a peak saturation temperature of around 56 *C and it stayed around that peak for the rest of the time in this experiment.

So there was a difference of around 12 *C observed with the fan.
So without fan rise: 26 *C
With fan rise: 14 *C
So temperature difference (efficiency) of almost half was observed. Around 50% efficiency over the observation period.

Note: I did experiment with only one fin purposely to take reading with and without the fan cooling.
The amp was placed in one corner of the room where there is virtually no natural flow of air and the ceiling fan was turned off throughout the experiment.

With both fins on fan cooling the efficiency should rise further as both fins would be cooled and the entire "system" should be cooler.

Thanks,
Rohit

 

[magma]

hmm
thanks rohit

this is something i think i might be able to incororate in my build

external fans under the sink

i just need to figure a way how to hide the fan from the outside
i will need to make some kind of extensions to the sinks

ohh waitt...
i have an idea !!!

 

[spirovious]

Nice one magma,its real easy to follow the thread and make when you explain with pictures.
Congrats to you and Joshua.

 

[rohitmusic]

hmm
thanks rohit

this is something i think i might be able to incororate in my build

external fans under the sink

i just need to figure a way how to hide the fan from the outside
i will need to make some kind of extensions to the sinks

ohh waitt...
i have an idea !!!

Additionally a supplementary exhaust fan built into the enclosure should be helpful too. Possibly on the top. Two vents could be made in the bottom below the heating components, which will suck in fresh air creating a constant flow of air current passing over the hot components. This will help control the internal temperature of the cabinet.

 

[denom]

Hi rohit,

surprised to hear of your f5 build what happened to your AP amps??? sold them???

 

[rohitmusic]

Hi rohit,

surprised to hear of your f5 build what happened to your AP amps??? sold them???

Hi Dear,
I don't have them any more. Going though a financial situation.

 

[denom]

Hi Dear,
I don't have them any more. Going though a financial situation.

Sorry to hear of your bad times. What is paired with the f5 now???

 

[rohitmusic]

Sorry to hear of your bad times. What is paired with the f5 now???

Fortunately I had opted for the Pass B1 (thanks to the group by). Using that as the pre which seems ideal.

Speakers remaining same - Paradigms 7s. Thinking of downsizing the speakers as well - as our 1 year old toddler needs some playing space. Perhaps some really good bookshelves (exploring some good DIY options)