Current source for BOZ

Couple questions on building Aleph P 1.7

Jam or anybody .......
1. Is building Aleph P 1.7 a lot more involved than building BOSOZ?
2. If it is, what are some of the tricky areas?
3. Isn't it true that they have a patented volume control?
4. Is the volume (controller?) easily built too?
5. Does anybody know approximately what it would cost to built this pre-amp?
6. Is all the parts shown on the schematics easily obtainable?
 
The disadvantage of he P circuit is that you need input coupling capacitors. I have not tried a current sourced balanced BOZ against an Aleph P (1.7). The current sourcing will surely elevate the performance of the BOZ coupled the with the elimination of the input capacitor may give the P a run for it's money.

Jam
 
fcel I just love your questions. You are able to cover every angle.

1. From looking at both schematics I'd say that Aleph P is 3 times more complicated but requires only positive supply so I'd say it's almost the same complexity.
2. The tricky areas here would be more circuitry you have to deal with. So if you decide to do PCBs - more complicated artwork, if you wire p2p - more work. But nothing serious really.
3. I don't know if the volume is patented but I woudn't touch it. From what I see it's more complicated than a preamp. I would just use switched attenuator, something like the volume in Pass Labs Dac. Very simply and it works great.
4. I guess I answered it previously.
5. The cost greatly depends on the componets, power supply and chassis. If you want to do it really cheap it might cost you $50, on the other hand doing it the way I like you might have to spend $500 (still it's only rough calculation)
6.If you not talking about original volume cotrol no problem with parts.
 
Peter,

Looks like a good design I believe it is different from the P(1.7) in that it uses cascodeing and the P uses an active load on the drains of the differential. Should make an interesting comparison.
I have been working on cascoded version of the BOZ (low current) with outputs hooked to current sourced buffers.

Jam
 

BrianGT

diyAudio Moderator Emeritus
2002-01-21 2:42 pm
near Atlanta, GA
www.chipamp.com
fcel,

I am also interested in making an Aleph P 1.7, and I am planning on laying out some pcbs next fall, and possibly getting together another bulk order in august/september if there is enough interest.

I think that you should build the BOSOZ for now, since there are good quality boards available for a reasonable price from audioXpress.com. I am almost done building mine. The parts were quite easy to get. I used all of the components listed in the article, except for I used Vishay Dale RN55 resistors instead.

It should work great with your aleph, and you can later on use the same chassis for an Aleph P, should boards be made.

--
Brian
[email protected]
 
Brian,

For your information, I have built the BOSOZ already and I'm very happy with it. I spent 80% of the time building the chassis because I don't have the right tools and that's why I decided to invest a little bit on the tools for building the Aleph 2 and possibly many other projects in the future. When I said building the chassis, I actually meant modifying a case that I bought from swap meet - took out all the internal parts, drill holes and so on.

As for the BOSOZ itself, I have asked a couple times (including you) about getting a 4 gang 10K pot for the volume control (at a reasonable price) but so far no luck. I'm currently using two 2 gang pot for the left and right volume control. I have built it with balanced input and output.

Then the subject came up about building a Aleph P - it's probably you or Dale that brought it up. I want to let you know that I would be interested to join again for another bulk order.