DIY: Pass F5 turbo v2 initiated

[omishra]

I'm ordering trafos today. Would there be any difference between a single 800 va vis a vis 2 x 400 va trafos?

What are the pros and cons (if any)

In 800VA you will get concentrated weight at one place (con), and save some space (pro). for 2 X 400VA reverse of that.

Also core will have more weight in 2X400VA so will heat lesser and due to more cross sectional area, should saturate at last. But mounting double transformer is taking much space.

 

[captrajesh]

Went to SV Troniks today. I got quotes of 2700 for 24-0 400va trafo & 4800 for 800 va trafo with 24-0 dual secondaries. I have to get one 400 va trafo from Miracle Electronics in place of the one I had earlier sourced for my Class D Amp but returned for being wrongly speced. I'm sure that it'll cost me a bomb if I source a 800va or another 400 va trafo from them.

 

[omishra]

Went to SV Troniks today. I got quotes of 2700 for 24-0 400va trafo & 4800 for 800 va trafo with 24-0 dual secondaries. I have to get one 400 va trafo from Miracle Electronics in place of the one I had earlier sourced for my Class D Amp but returned for being wrongly speced. I'm sure that it'll cost me a bomb if I source a 800va or another 400 va trafo from them.

I got 2x(24-0,24-0,300VA) for 1750 each. Sann got 4X24-0,1KVA for 3450 before taxes with personal pickup from torotrans.

 

[sann]

Torotrans also ship the trafos, lot of FM's have got them shipped. I met Mahesh, the owner of Torotrans when I went to collect my trafo, he is a gentleman and a very nice person to deal with.
regards,
Sann

 

[pdhanwada]

I got my two toroids from torotrans for Rs 3500 including shipping. They are 300VA each.

 

[captrajesh]

Thanks guys; So SV Tronicks is not cost effective after all. Having got a quote from Miracle, they sounded reasonable to me:indifferent14:

 

[omishra]

Thanks guys; So SV Tronicks is not cost effective after all. Having got a quote from Miracle, they sounded reasonable to me:indifferent14:

What did the quote, ofcourse if you don't mind to disclose?

 

[jls001]

I got 2x(24-0,24-0,300VA) for 1750 each. Sann got 4X24-0,1KVA for 3450 before taxes with personal pickup from torotrans.

I got quote of Rs 5250 for 24-0, 24-0, 24-0, 24-0 1.2 kVA from Toroidal Transformers Mumbai. Dia about 8", height about 4". 1.2kVA is probably overkill for the v2, so may be 1kVA or even 800VA will bring down the price quite a bit. I had bought a 340VA from him in the past for my MyRef C. Build quality is quite good.

Usable internal dimensions are 11" (W)X 12"(D) X 6" (H) with +-1mm tolerance.

I saw this heatsink today and need opinion of experts if they will suffice for F5 v2:



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Dimensions mentioned in red are added by me. The seller was not clear how much is the weight per meter.

Max cabinet depth that can be obtained with this heatsink is 205 mm ( = 8 inch) as shown in the picture.

Height is flexible.

For example, 8" deep x 8" high piece is quoted at Rs 3000.

 

[cmsajith]

Is there anyone from bangalore has started v2 build? Any plan for a GB for the transformers or heatsinks?

 

[captrajesh]

What did the quote, ofcourse if you don't mind to disclose?

Mishraji I've already given the info in my previous post (No. 653)

I got quotes of 2700 for 24-0 400va trafo & 4800 for 800 va trafo with 24-0 dual secondaries.

I saw this heatsink today and need opinion of experts if they will suffice for F5 v2:



Max cabinet depth that can be obtained with this heatsink is 205 mm ( = 8 inch) as shown in the picture.

You can use 4 of them, two per side.

8" deep x 8" high piece is quoted at Rs 3000.

This appears to be very much on the higher side. My heat sinks are 215 mm wide. I've bought 4 each each of which is 7" high. The bugger goofed up while cutting and there is a variation of height to the tune of 4mm. I need to get them precision cut probably using a laser. They cost me 7.4 k. I have also bought heat sinks for MUR diodes. The 2 x 2 feet long heatsinks would be cut equally to act as individual heat sinks of 24 of these diodes.

I've placed the CDs for reference.

Edit: The smaller heat sinks measuring a total of 4' (for MUR diodes) cost me Rs. 240/-

 

[jls001]

You can use 4 of them, two per side.
-

First, some quick clarifications about the dimensions of your sinks:




Uploaded with ImageShack.us


1) Is it two heatsinks placed side by side - marked as A and B in the picture?
2) What is the height? 7 inch?
3) Is greater height possible?
4) With two 7-inch high (assuming it is 7") heatsinks placed side by side, does it mean each heatsink will be responsible for dissipating the heat from two power transistors each? Is that enough "heatsinkage" for the F5 v2? My biggest worry is to get adequate heatsink to be able to operate the F5 in summer in Mumbai.
5) I am assuming the heatsinks will be - mechanically - load bearing members in the construction of the cabinet. How do you plan to join the two heatsinks? Or are you planning some sort of "wireframe" like omishra did?
6) how much is the combined length marked "How long?" in the picture?

Thanks in advance for bearing with me for all the inane questions

If I am to use two heatsinks side by side, effective depth will be 2 x 8" + combined thicknesses of the front and rear panels - which is within 16 and half inch. Come to think of it, one would not call that too deep, would we?

 

[omishra]

Mishraji I've already given the info in my previous post (No. 653)

Captain, is that 800VA is dual secondary or quad secondaries - 24-0 X4? By using four secondaries, I feel better separation could be achieved from separate floating ground for each channel. Also it will share current among diodes of rectifier boards. You already have all parts, and this 4 secondaries will make it possible. Otherwise two secondaries will work but both channels will share common ground and only two bridges will be utilised from rectifier bridge. Also they will conduct relatively double current making them hot.

 

[captrajesh]

First, some quick clarifications about the dimensions of your sinks

1) Is it two heatsinks placed side by side - marked as A and B in the picture?

Yes, each of which is 215 mm long.

2) What is the height? 7 inch?

A little over 7". I have to get them trimmed so that each of them is of uniform height which would be roughly about 7" (About 4U)

3) Is greater height possible?

Sure. Each heat sink is about 4 metres I guess (and 215 mm wide). So you can cut any length.

4) With two 7-inch high (assuming it is 7") heat sinks placed side by side, does it mean each heat sink will be responsible for dissipating the heat from two power transistors each? Is that enough "heat sinkage" for the F5 v2?

That's correct and that should be enough according to my discussions with Omishra in the context of his cabinets and that of Sann's.

5) I am assuming the heat sinks will be - mechanically - load bearing members in the construction of the cabinet. How do you plan to join the two heat sinks? Or are you planning some sort of "wire frame" like omishra did?

Yes, the heat sinks will form the side walls of the cabinet and the joints will be reinforced like the way in Sann's cabinet. I'm planning a single SS sheet about 12" wide and 18" deep which would be bent about 1/2 to 1" in the front onto which, the Face plate would be fixed and 7" at the back to form the back plate.

6) how much is the combined length marked "How long?" in the picture?

215 + 215 mm = 430 mm.

If I am to use two heat sinks side by side, effective depth will be 2 x 8" + combined thicknesses of the front and rear panels - which is within 16 and half inch. Come to think of it, one would not call that too deep, would we?

I don't think it would be called too wide. For example, take a look at Anilva's cabinet in his build thread.

 

[captrajesh]

Captain, is that 800VA is dual secondary or quad secondaries - 24-0 X4? By using four secondaries, I feel better separation could be achieved from separate floating ground for each channel.

I'm assuming that dual secondaries means 24-0 24-0. So four wires would be there on the secondary side, one pair for each channel.

If I were to order quad secondaries, 24-0 x 4, 8 wires would be there on the secondary side. How would these be connected to the bridge rectifier?

Sorry for the noob queries, I wish there is some pictorial explanation.

 

[omishra]

I'm assuming that dual secondaries means 24-0 24-0. So four wires would be there on the secondary side, one pair for each channel.

If I were to order quad secondaries, 24-0 x 4, 8 wires would be there on the secondary side. How would these be connected to the bridge rectifier?

Sorry for the noob queries, I wish there is some pictorial explanation.

Captain, I already posted pics of four secondaries from 2 transformer, here. In place of two transformers you can expect one transformer giving out 4 secondaries. Further connection remains same. On the same page 'sann' has posted pics his transformer with 4 secondaries, yellow, blue, white and brown coloured pairs of wire here.

 

[kroyin]

I have one channel (monoblock) up and running. Bias at 360mV offset of 8mV.
Soundwise definite improvement on F5 (speciallly in bass)

Crappy photo (will try to post innards soon)

 

[omishra]

I have one channel (monoblock) up and running. Bias at 360mV offset of 8mV.
Soundwise definite improvement on F5 (speciallly in bass)

Crappy photo (will try to post innards soon)

Great going man, keep it going. We are near by. Yesterday IEC socket holes are done and cabs are going for anodising. This weekend I will populate all boards.

 

[kroyin]

Inside. If the cab was aluminum i'd have bolted the rectifier diodes directly to the base plates.
I cut the rectifier board in half, drilled an additional hole.

Both PSU & Rectifier PCB are lifted 10mm from base using nylon spacers and mounted with nylon screws.
Each diode has its small heatsink

Many thanks to Om & Sachin for making this happen

 

[omishra]

Inside. If the cab was aluminum i'd have bolted the rectifier diodes directly to the base plates.
I cut the rectifier board in half, drilled an additional hole.

Both PSU & Rectifier PCB are lifted 10mm from base using nylon spacers and mounted with nylon screws.
Each diode has its small heatsink

Many thanks to Om & Sachin for making this happen

Kroyin, how hot those fairchild devices are on heat-sink?

Another question how much those MUR rectifier diodes on PS board are dissipating in heat? I plan to use small Aluminum strip or smaller black heatsink.

Btw these rectifier board has taken idea from Nelson Pass's comment. One of them is recently here.

 

[sachu888]

Kroyin, how hot those fairchild devices are on heat-sink?

Another question how much those MUR rectifier diodes on PS board are dissipating in heat? I plan to use small Aluminum strip or smaller black heatsink.

Btw these rectifier board has taken idea from Nelson Pass's comment. One of them is recently here.

Hi Om,
I have read that Diodes doesn't even get warm.I don't know how true is this.

Regards,
Sachin