DIY Sony VFET pt 2 (N-Channel Build)

[Signal lost]

Looks much better Vunce.

I found what looks like a K-type thermocouple for my DMM and touching the V-fet gives me 160F or 71C. The non contact infrared device was off by over 20C. Only a few degrees difference from the T-bar to the heatsink so I think there is good contact. Need to see what temps others are getting.

 

[drjbf1]

I had some buddies over to help with stereo…..

Series or parallel???🙂

 

[Monk55]

Grateful Dead roadies?

Seattle 74

 

[Vunce]

Thanks SL.
I also have a probe for my Fluke DMM, when I'm powered up I will check temps. Shiny metal gives inaccurate IR thermometer readings. If you put a piece of Kapton tape on the device your readings would improve. But, I wouldn't do that with the precious SIT's, you could remove the labelling when the tape is removed😱

 

[zman01]

Vunce, Rewind,

Nice work with getting the heat-sinks flattened and now the fit with the T sections looks much better.

Monk55,

Is the Greatful Dead pic somehow related to the discussion, or I am missing something? Sorry if I come across obtuse. 🙂

 

[woofertester]

Just received the chassis box yesterday. Parts kit is already in hand. Time to start organizing the build. I have to source some BNCs as my friend who I am building it for uses BNCs.

 

[Gianluca]

It has to do whith which tolerances the manufacturer chooses to operate with. I think it is a shame that Modushop sends out heatsinks with scratches and uneven surfaces. They could have impressed 300 future customers, instead many are left with "meh". At least it has a nice front and rear, but all other surfaces have scratches and needle-like shavings sticking out. I managed to place all of the faults inside or under the amp, so I guess that's nice. I won't have to think about it after I am finished with the amp

The problem is that is something out of our control.

Our supplier which anodizes all our panels usually use special hooks to pick up them and put them in large anodization tanks. When they do this, the part where they use the hooks can have some scratches and may be a little uneven but since this part is covered and remains on the inside it will not be visibile

 

[Rewind]

Thank you for replying, not every manufacturer would.

There were also scratches on the lids as well. The lid with scratches on both sides I used as a bottom lid.

 

[RafaPolit]

Looks much better Vunce.

I found what looks like a K-type thermocouple for my DMM and touching the V-fet gives me 160F or 71C. The non contact infrared device was off by over 20C. Only a few degrees difference from the T-bar to the heatsink so I think there is good contact. Need to see what temps others are getting.

This follows my AMP’s performance, almost to a 1 degree C. I get 69C or 70C on the FETs with the thermocouple.

Rafa.

 

[Gianluca]

Thank you for replying, not every manufacturer would.

There were also scratches on the lids as well. The lid with scratches on both sides I used as a bottom lid.

More than happy to send you a replacement, feel free to send me a PM so we don't go off topic here

 

[Signal lost]

Thanks Rafa, now my V-fet temps will not make me worry.

Vunce all other times I have used the IR device the heat sinks were anodized black and it agreed with the thermocouple, Thank you for pointing out the shiny surface problem.

 

[xrk971]

Almost any tape over shiny surface works better for IR thermometer. White liquid paper correction fluid is excellent, as is black vinyl PVC tape, even white paper masking tape, blue tape etc. the Kapton is the only one that will take heat and not leave nasty tape residue. The emissivity of most plastics and paper is close to 1 whereas shiny aluminum is like 0.2.

 

[Monk55]

Darn tight in there….time for a break & go over everything prior to power.

 

[Rewind]

Thanks, my switch worries are over. 🙂

 

[Signal lost]

Anyone else measure the temp of the power supply brick? 54C was what I measured after two hours of playing music. Seemed quite warm to me.

 

[RafaPolit]

I can do that tomorrow. My brick is buried behind our living room “console” with books and other 3 or 4 bricks (the ACP+ one, the Qutest one, the Magni 3 one, the RPi one), so I’d need to fetch it out.

It did feel warm to the touch, but I doubt it was 55°.

 

[astouffer]

Did some people get a DPST switch in their kits? Mine is SPST but jumpering the relay should do the same thing as you're still switching the incoming power.

Also how are people securing the LED? There are tapped holes on either side but no hardware. A dab of epoxy should do the trick.

 

[Zen Mod]

or neoprene glue

 

[Signal lost]

To secure the led I did it like the ACA amp with a bit of heatshrink over the back edge of the led and just squeezed it into the opening. For the switch I ordered these from amazon.

 

[Rewind]

The front gets really hot. If you don't want to breath hot glue fumes I suggest something else.

Here is last nights Digikey shopping list:

image GRSV-4021-0006
CWI494-ND
SWITCH ROCKER DPST 16A 125V

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antall Restordreantall Enhetspris Utvidet
pris

2 0 15,31000 30,62 kr

image UKA1H102MHD
493-4612-ND
CAP ALUM 1000UF 20% 50V RADIAL

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antall Restordreantall Enhetspris Utvidet
pris

14 0 19,45700 272,40 kr

image RFS-50V100MG3#5
604-1119-ND
CAP ALUM 10UF 20% 50V RADIAL

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antall Restordreantall Enhetspris Utvidet
pris

2 0 6,60000 13,20 kr

image RFS-50V221MJ6#5
604-1123-ND
CAP ALUM 220UF 20% 50V RADIAL

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antall Restordreantall Enhetspris Utvidet
pris

4 0 22,70000 90,80 kr

image 4900-18G
473-4900-18G-ND
SAC305, 96.3% TIN, 0.7% COPPER A

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antall Restordreantall Enhetspris Utvidet
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1 0 159,28000 159,28 kr

image CMF501K0000FHEB
CMF1.00KQFCT-ND
RES 1.00K OHM 1/4W 1% AXIAL

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antall Restordreantall Enhetspris Utvidet
pris

6 0 5,98000 35,88 kr

image CMF50100R00FHEB
CMF100QFCT-ND
RES 100 OHM 1/4W 1% AXIAL

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antall Restordreantall Enhetspris Utvidet
pris

2 0 5,98000 11,96 kr

image CMF5010K000FKEB
541-CMF5010K000FKEBCT-ND
RES 10K OHM 1/4W 1% AXIAL

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antall Restordreantall Enhetspris Utvidet
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5 0 5,37000 26,85 kr

image CMF5027K400FHEB
CMF27.4KQFCT-ND
RES 27.4K OHM 1/4W 1% AXIAL

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2 0 5,98000 11,96 kr

image CMF601M0000FKEB
CMF1.00MFGCT-ND
RES 1.00M OHM 1W 1% AXIAL

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6 0 4,93000 29,58 kr

image RN60D8252FB14
RN60D8252FB14-ND
RES 82.5K OHM 1/4W 1% AXIAL

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2 0 18,04000 36,08 kr

image RN60D47R0FB14
RN60D47R0FB14-ND
RES 47 OHM 1/4W 1% AXIAL

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2 0 4,93000 9,86 kr

image RN60D1250FB14
RN60D1250FB14-ND
RES 125 OHM 1/4W 1% AXIAL

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pris

2 0 4,93000 9,86 kr

image CMF50100K00FHEB
CMF100KQFCT-ND
RES 100K OHM 1/4W 1% AXIAL

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antall Restordreantall Enhetspris Utvidet
pris

2 0 5,98000 11,96