Juma's Head Amp

[prasi]

Thanks for your comments Fred.
I will get a chance to work on layout only during next week. I think I can make a 'lm317 only' layout for you once I finalize the complete layout.
Reg
Prasi

 

[pchw]

Thanks, Prasi.
There are always more important things than the hobby which is just to occupy the leisure time. Layout can always come later

Take care,

 

[saheb11123]

Any chance of a group buy of pcb?

 

[prasi]

Any chance of a group buy of pcb?

Hi,
There are many guys who have ordered PCB's may be one of them have extra set spares.
May be someone will communicate to you through pm .
Reg
Prasi

 

[saheb11123]

Hi,
There are many guys who have ordered PCB's may be one of them have extra set spares.
May be someone will communicate to you through pm .
Reg
Prasi

Yes that would be nice, what would be more nicer if that person lives in India then the hassle of international shipping is gone.

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[pchw]

I will post the Dirty PCB link once I receive and verify the board. You can use the link to purchase 10 (usually there are 11) for USD $14.shipped. Shipping a couple from US probably will cost half of this price. With 10 boards, you can give some to your buddies as Christmas gift or do some experiment

 

[saheb11123]

I will post the Dirty PCB link once I receive and verify the board. You can use the link to purchase 10 (usually there are 11) for USD $14.shipped. Shipping a couple from US probably will cost half of this price. With 10 boards, you can give some to your buddies as Christmas gift or do some experiment

Thanks mate.

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[gannaji]

Dear Saheb,
I am interested in a pair when you get them.
--gannaji

 

[saheb11123]

Dear Saheb,
I am interested in a pair when you get them.
--gannaji

Done.

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[pchw]

My hacked up +ve rail Nazar CM built from the universal 3-pin adjustable reg board from forum member mravlca

The board is 5cm x 5cm, so the final footprint is little bigger than that. This board is very handy. I just wish it could accommodate the TO-220 rectifiers. It is not quite complete yet. I am still hunting for the 0.33uF cap to solder to the D44H11. I probably will put in a Wima 1uF for proof of concept if I don't find any.

 

[saheb11123]

My hacked up +ve rail Nazar CM built from the universal 3-pin adjustable reg board from forum member mravlca

The board is 5cm x 5cm, so the final footprint is little bigger than that. This board is very handy. I just wish it could accommodate the TO-220 rectifiers. It is not quite complete yet. I am still hunting for the 0.33uF cap to solder to the D44H11. I probably will put in a Wima 1uF for proof of concept if I don't find any.

You could use a crossover cap.

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[pchw]

I have some nice 0.33 film caps, but they are too big. I want to fit that to the CE pins of the D44H11. Take a look at Nazar's 2 transistor stabilizer which is essentially the Nazar CM that I referred to. So, the 1uF should work just fine. I found some Wima MKP 0.15uF caps, so I can parallel 2 for this use too.

 

[prasi]

Here is what I could come up with for the reg PSU, like Fred said, one could use D4XH11 or try with TIP4XX or TIP3XX.
For LM and TIP, One could use either a heatsink or mount on the bottom on case or use an aluminium plate as a heatsink. Mounting hole options as per heatsink choice.
reg
Prasi

 

[saheb11123]

Did anyone do any measurements with either just a lm317/337 based supply vs nazar's vs a shunt?

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[Hikari1]

I compared the 317/337 vs 317/337 followed by a cap multiplier (similar to the nazar but not the same) in the F5 headamp which is this same as this amp but with a jfet input, not bjt.

The cap multiplier sounded better. No measurements. Fuller sounding, a little more drive.

 

[saheb11123]

I compared the 317/337 vs 317/337 followed by a cap multiplier (similar to the nazar but not the same) in the F5 headamp which is this same as this amp but with a jfet input, not bjt.

The cap multiplier sounded better. No measurements. Fuller sounding, a little more drive.

Understandable, its because of the capacitance, and what you hear is a bit of rounding off at the edges.

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[pchw]

Finished my hacked up Nazar reg and tested a load of 230mA at 11.5VDC.
The AC input was a 12.6VAC/1.2A filament transformer. The LM 317 was at 50C with such
small heatsink, but the D44H11 was only slightly warm. When running with a 15VAC transformer and to supply 15VDC to the HA circuit, I will need a bigger HS for the. LM. Or, mount it to the bottom plate.

I will build another one for the -ve rail to test the board's when they arrive.

 

[xrk971]

Looks real nice Prasi. I am confused why 8 diodes and dual secondaries are needed for a supply with one set of +15/-15v outputs.

I would use a 4 diodes and one split (half) secondary from the trafo per PSU for two monoblock PSU's (common ground).

 

[prasi]

Looks real nice Prasi. I am confused why 8 diodes and dual secondaries are needed for a supply with one set of +15/-15v outputs.

I would use a 4 diodes and one split (half) secondary from the trafo per PSU for two monoblock PSU's (common ground).

thanks x, its what the design called for, see http://www.diyaudio.com/forums/pass-labs/271926-f5-headamp-85.html#post4848402

 

[xrk971]

Hmm... I guess this is for use with two little 10w trafos, one for each channel like how many people are doing it. Not sure if all that monoblock practice for max channel isolation makes sense when a crossfeed (aka crosstalk) filter will be used anyway.