BOZ preamp project

[likeDIY]

Hi all,
I'm going to build a Bride of Zen pre-amp but I have some difficulties finding some parts.
Can someone tell me the equivalent of IRF610 and TIP29GCE ?

Is IRF610 = IRF9610?

These IRF and TIP will be solded on the same side with other parts or on the other side?

I have finished the PCB as in the passdiy.com.

Thanks heap.

Cheers!

 

[senee]

LikeDIY,

I thinks, The IRF610 is not equivalent with TIP29GCH.
And IRF610 = N channel Mosfet
IRF9610 = P channel Mosfet
You can buy the IRF610 and IRF9610 at MOUSER and DIGIKEY

 

[likeDIY]

Thanks Seene, but I didnt mean the IRF610 = TIP29, What i meant is "What are the equivalent to IRF610 and TIP29".

 

[Babowana]

TIP29:

The operating voltage between C and E is about 25V and current is less than 0.5A. I however would apply my "don't worry be happy" factor 2. If so, any NPN TR rated at max. VCE of 50V and 1A or bigger will be okay.

IRF610:

Buy all IRF510/ IRF520/ IRF620/ IRF630 /IRF140 /IRF240/ IRFP250N . . .
And take experiment of sound differences from them . . .
Lot of fun . . . !!!
You will love diy, Likediy . . . 😀

 

[Babowana]

at max. VCE of 50V and 1A or bigger

My problem is I can not distinguish max and min . . .
I that I should have said "min" . . .

 

[likeDIY]

On the PCB, i have seen there is a hole for the drain of the IRF, I'm a bit confused how we actually connect the drain pin and this hole, is this through a screw nut?

 

[Babowana]

On the PCB, i have seen there is a hole for the drain of the IRF, I'm a bit confused how we actually connect the drain pin and this hole, is this through a screw nut?

Put whatever . . . tight size into the hole . . .
As you know, as long as the drains are "electrically" connected with R104/204 . . . fine . . .

 

[Mad_K]

Did you see my revised schematic? It saves you the trouble with the TIP29 part anyways..

 

[Zen Mod]

http://choky.on.neobee.net/My_BOZ.html

 

[lohk]

sorry off topic - but I really like your (and Oly's) "fuse killer" 😀

 

[likeDIY]

Thanks guys,
I made the PCB followed the image from passdiy.com, so it's better to find the components as guided.

I'll try to find in local markets if these TIP, IRF are available.

Cheers.

 

[lineup]

IRF610:
Buy all IRF510/ IRF520/ IRF620/ IRF630 /IRF140 /IRF240/ IRFP250N . . .
And take experiment of sound differences from them . . .

Even if these IRF510, IRF520, IRF610, IRF620 all can be used in lower power stages
IRF610 is popular among builders & designers. Including Nelson.
All these 4 MOSFET have slightly different data.

What I think is, the relatively low input capacitance of IRF610 is a little in favour.
In the Datasheet you will see this value called Ciss and is measured in pF.

In short, the input of a transistor with lower input capacitance
is easier to drive for the circuit attached to its input.
Very big MOSFET with higher Ciss ( >2000pF ) needs more bias current
from predrivers or voltage amp stage, in order to keep performance good.

lineup - thinks IRF610 is a good choice for preamps and headphone amps.

 

[likeDIY]

hi guys,
What type of transformer should I get for this? 30-0-30 VAC ,??VA?

cheers.

 

[vdi_nenna]

I rebuild mine 2 weeks ago. I've got a 30+30 250va (4.35 amps) on mine. Sounds better with a higher current transformer.
250va is a lot. Whatever it calls for double it.

Avel-Linberg- $46 from PartsExpress.com.

They are hard to find. Do a search on Avel-Linberg.

 

[likeDIY]

Would it be too much for it with the transformer of 30-0-30 300VA?

 

[Babowana]

300VA?

30VA is big enough . . .
50VA is okay . . .
300VA is also okay . . .

 

[lineup]

30 - 30 will give something like
45 - 45 VDC

Transformer VA can never be 'too large' and powerful.
But certainly be too small and weak.

But there are some few drawbacks with overdimensioned trafos.

1. Cost you extra money, even if you maybe get no noticable result, at the output, from it.
this is a waste of money.

2. Bigger trafos gives more electromagnetical radiation around them.
Not the optimal, especially if housed in same case as your amp circuit.

3. Makes amplifier or power supply very heavy to carry, move and transport.

4. Bigger trafos may have more inrush current spikes.
This is when you swtch on amplifier. This one I am not so sure of.
some one may correct me, if I am wrong.


When building a Nelson Pass amplfier, you can 100% count on
his recommendation for transformer is already a bit 'more than normal'.
So there is no real need or significant improvement going beyond this.
But if you do, nothing bad will happen.
If something will change, it probably some very small improvements
in some measurable data.
But hardly something you notice with your 2 sound sensors at both sides of your head.


lineup 🙂 cant hear you ... but read you

 

[likeDIY]

Thanks a lot Lineup!
The reason why I ask that because I already got one transformer with that ratings. So it's good that I can reuse.

 

[likeDIY]

I couldnt find the TIP29 and IRF610 in local markets, can I use TIP31 and IRF620 as replacement?

 

[Mad_K]

Those transistors will do 😉