BZLS work in progress

[till]

not ready, but allready playing music:

[till]

backside:

[till]

inside:

[mdlover]

great work and nice looking!

did you make the case yourself?

cheers

[moe29]

very nice Till!

have you detailed your input selector and volume control
elsewhere? If not could you give us some details of what
you came up with? Looks very promising


moe29

[till]

Hi, of corse hardcore diy, case is the easyest part to make.

input selector board isn´t build yet, needs some time. Also remote corntrol and more advanced firmware.

The gain stage is Nelsons BZLS as descibed on passdiy, but double sided PCB, upper layer shielding. Rectifier is made with MBR10100.

Everything will be as simple as possible, only XLR, no RCA, only 2 sources.

For the MC and volume section i started to write documentation, but it also is work in progress.

http://home.arcor.de/dddddd-/relais/relais.html

[lgreen]

I notice you don't have dual mono supplies, but what's this? Have you added a couple of slabs of metal next to the PS heat sinks and behind the diodes? Interesting! I am making one very close to yours (without the pic) but you are far ahead of me. Have you thought of using quad relays? I am using NAIS D4 series, I figure one per input.

[till]

lgreen,
I have only one power supply for for the BZLS, i don´t think wit a class a design preamp and a 160VA powers supply a dual one would make difference, and it would be much more expensive. I try to build without spending more money as necessary.

There was no quad signal switching relay offered at the companys i buy from. The Takamishawa is i´m sure a good one and about 2€ each. I did see it in audio equipment for this purpose.

Also the design is versatile for balanced and unbalanced, i made a BOZ with ADC0804 volume control and these relais. But the ADC0804 has the disadvantage of holding a volume setting not so stable as a counter/pic. You can´t use 8 bit, and you cant make such things like startup volume level programming, remote control, if you need( i don´t) LCD and menu stucture for volumue and source control with one rotary encoder etc.
And a Pic is for some reasons the cheapest solution.

At regulator heatsinks i glued a second heatsink because 100°C was too much. The rectifier diodes are mounted on half an old 80486 heatsink each side, not because they need in this applikation, but beause i build them first for testing a schottky rectifier. They would also work in an alephx i think...

[lgreen]

Ahhh, nice work. I'm jealous! Looks like you took an economical approach, I'm finding out that the cost of all these parts adds up. Anyway, good luck finishing that, it sure looks nice on the outside and the inside.

[till]

Looks like you took an economical approach

i spent less than 140€ on parts,
Neutrik connectors, Wima caps, Takamishawa relays, alps encoder. I´m happy some parts are for free like the shown shilded Lap Ölflex mains cable, all diodes, etc...