PCB for Aleph P 1.7 preamplifier

[strobo]

Thanks GRollins,

Will there be some other changes, except lower output power, when drive the Aleph 5 with lover power supply voltage (32 V instead 35) ?

 

[GRollins]

The difference between 32 and 35V won't be enough to upset the Aleph. You'll get slightly lower output wattage, but that's about it.

Grey

 

[strobo]

Thanks GRollins,


I will try to use 2x23 V / 1000 VA transformer for Aleph 5, just to have one less think to worry about - transformer heat.

I will use one 35 A diode bridge and one 1000 VA transformer for two Aleph 5 channels.

Can diode bridge be mounted on the same heatsink as the FETs or it must have it's own heatsink ?

 

[UrSv]

Maybe for BrianGT...

How did you decide which one to build of BoSoZ and P1.7? I like the simplicity of the BoSoZ but have not been able to find out (although searching thorugh threads) what people think about the BoSoZ compared to P1.7. Either one would suit me. Which one is "better" or are they not that different at all?

/UrSv

 

[Peter Daniel]

Can diode bridge be mounted on the same heatsink as the FETs or it must have it's own heatsink ? [/B]

Yes, it can, no separate heatsink required.

 

[strobo]

Thanks,


What about electric isolation, does the diode bridge must be electric isolated from the heatsinks, like the mosfets ?

 

[Dornier]

Hello,


I just come back from the PCB-DESIGN website
( http://web.vip.hr/pcb-design.vip ), and I must
say that I never seen the better layouts of the PCB's.

I tried to design some by myself, but I couldn't get them even close to the PCB-DESIGN state.
The person who designed them was probably survived a couple of lightning strikes to the head ! (joke)


However, I am very interested in the Aleph P 1.7 and Aleph 2 PCB's.
On the PCB-DESIGN website I saw that the prices for the more PCB's will be quite lower, so I would like to ask here before I order;

Does somebody plan to organize the bulk purchase for the
Aleph P 1.7 or for the Aleph 2 PCB's from the PCB-DESIGN ?

 

[Peter Daniel]

Thanks,


What about electric isolation, does the diode bridge must be electric isolated from the heatsinks, like the mosfets ?

It doesn't have to be isolated.

 

[Peter Daniel]

I would think twice before using PCB for Aleph P1.7. Comparing circuit that simple on PCB and done point to point is probably like comparing IC to a discreet circuit. It doesn't take much to do it p2p, and by saving money on PCB, you could buy better capacitors. It's not complete yet, but another 4 resistors and that's it.

 

[strobo]

hi Dornier,


In the previous thread you wrote:

"The person who designed them was probably survived a couple of lightning strikes to the head !"

Well, I agree with you 100 % !!!

The PCBs really look very nice.
I am also interested in some PCBs from the PCB-DESIGN.
Also, I will be interested in bulk purchase of the PCBs, if someone will organize it in the very near future.


--------
Strobo

 

[Gabster]

What is the answer to the good old "what transformer is required to supply the Aleph P1.7 (voltage and VA)" question? Since there is a regulator, I guess the range is not crittical. Plitron sells 60V transformers. Using two individual windings, one transformer could supply two channels... btw, is it required to use two regulators to drive the two channels or one single regulator will do the job as well?

If I want to add a VU-meter, can I simply pick up the signal thru a buffer (say AD's BUF03) and feed it to my VU-meter display? I want to be absolutely sure that the sound (signal path) will not be affected by that addition...

best regards,
Gabriel

 

[Gabster]

No one has the answer?

 

[Peter Daniel]

One regulator will do the job but since they are so simple I strongly suggest separate for ea. channel. 60V is OK, the power of the transformer should be as reasonably high as possible for better sound. I would suggest at least 200W. While less power would do the job, bigger transformer will sound better.
Buffer for the meter sounds like a good idea.

 

[kristijan-k]

Hello,


I agree with HPotter for the buffer use.

Also, the buffer for the meter should be placed at the output of the preamplifier.

If done with the care, there will be no significant loss in the sound quality.




Regards,
Kristijan Kljucaric

 

[Gabster]

Is it 200VA per channel or for both?

thanks,
Gabriel

 

[Peter Daniel]

Both, but if you have enough space and resources I might be tempted per channel.

 

[Super_BQ]

Dual Split Bobbins

The link to my website below shows the dual split bobbin transformers I used in my BLS pre-amp.

Furthermore we did a sound off with the Naim 72 pre-amp WITH the "SuperCap" external power supply. To say the least, my friend is convinced on building the same pre-amp as mine but going external power supply.

 

[kristijan-k]

Hello Super_BQ,


Nice website.
I like the heatsinks that you used for the SOZ .
Are they comercially available, and do you know who produced them ?



Regards,
Kristijan Kljucaric

 

[Super_BQ]

SoZ Heatsinks (O/T)

Kristijan,

I've found those heatsinks about 18 months ago from one of the local scrap metal yards where I live. I'm still kicking myself for not taking the whole drum barrel full of them. Nevertheless, I continue to build up my own collection of heatsinks seeing how valuable they are for DIY audio.

If you take a closer look, they are IDENTICAL to the Plinius heatsinks. I suspect there is a local foundry in Christchurch that casts them for the Plinius factory way up north in Palmerston North.

BQ

 

[kristijan-k]

Thanks Super_BQ,

Are the heatsinks of the SOZ clear anodized, or they are bare aluminium ?


Also, does anyone know where the dual split bobbin transformers
can be found (around 1000 VA) ?



Regards,
Kristijan Kljucaric