It's working 
Hi folks, first picture of my working MiniA
It sounds very nice right now, no hum, no buzz, only music !!!
Ok, I need a good enclosure
I let it burn in this configuration.
You know what ? I feel good !
Many thanks to all of you, Mr Nelson PASS, BrianGT and to other guys who make it real
Hi folks, first picture of my working MiniA
It sounds very nice right now, no hum, no buzz, only music !!!
Ok, I need a good enclosure
I let it burn in this configuration.
You know what ? I feel good !
Many thanks to all of you, Mr Nelson PASS, BrianGT and to other guys who make it real
Attachments
Heatsinks
Glad you got it working. Could you tell me the size of those heatsinks, and approximately how warm they are getting. (Finger test is accurate enough).
Could you describe the sound in two or three sentences?
Hi folks, first picture of my working MiniA
It sounds very nice right now, no hum, no buzz, only music !!!
Ok, I need a good enclosure
I let it burn in this configuration.
You know what ? I feel good !
Many thanks to all of you, Mr Nelson PASS, BrianGT and to other guys who make it real
Glad you got it working. Could you tell me the size of those heatsinks, and approximately how warm they are getting. (Finger test is accurate enough).
Could you describe the sound in two or three sentences?
Thanks Anchan
The heatsinks are oversized 20x10x8cm (L/H/W), just a little bit hot.
I can let my fingers on without hurt, very low temp.
About the sound, very detailed, deep bass, everything is much more "clear".
Running config : UGS preamp / MiniA / Opus DAC and USB, balanced inputs except USB. Previously I was using only a UCD180ST.
As I've got a DCX2496, I'll bi-amp my system, UcD will be dedicated for bass only.
Very rich sound, much more "life" in the speakers, more details in the sound, yes "rich" sensations.
Sorry for my bad English.
Cheers
All components are stock values, but all of them are matched...
The heatsinks are oversized 20x10x8cm (L/H/W), just a little bit hot.
I can let my fingers on without hurt, very low temp.
About the sound, very detailed, deep bass, everything is much more "clear".
Running config : UGS preamp / MiniA / Opus DAC and USB, balanced inputs except USB. Previously I was using only a UCD180ST.
As I've got a DCX2496, I'll bi-amp my system, UcD will be dedicated for bass only.
Very rich sound, much more "life" in the speakers, more details in the sound, yes "rich" sensations.
Sorry for my bad English.
Cheers
All components are stock values, but all of them are matched...
Last edited:
Pierre,
if You have briangt boards, see the partslist from attachment below.
However 680pF (c6 in original) not be used, it´s the same as orig. NP aleph5 scheme.
Regards denis
(sorry for my bad english here)
denis thank you very much for helping me out on that one and by the way don't be sorry about your english i am french from quebec and ihave the same difficulty,but we were able to communicate and understand each other in something we both love it is absolutly fantastic so thanks again pierre
BOM for Aleph Power Supply (from chipamp.com)
I purchased the Aleph boards (amplifier and power supply boards) at chipamp.com but the BOM for the power supply board (AMP-PS-PCB) does not seem to exist. I emailed chipamp.com but have yet to get a reply. By any chance does anyone have the BOM for the Aleph power supply board? If so, it would be great if they could post it.
I purchased the Aleph boards (amplifier and power supply boards) at chipamp.com but the BOM for the power supply board (AMP-PS-PCB) does not seem to exist. I emailed chipamp.com but have yet to get a reply. By any chance does anyone have the BOM for the Aleph power supply board? If so, it would be great if they could post it.
Mini Aleph
Just a couple of questions to this very interessting amp:
- On the schematic of the A30... All i need for the Mini-A is the part on the left side? Including Q6 and Q7?
- The Parts on the right are for upgrading to an A30, right?
- As i can see, the neg input must be grounded for unbalaced input... Think i read this anywhere here... P-grounded or S-grounded?
- In the schematic are some resistors called "TBD" as value. What do they mean?
That´s it so far... Just began to route the layout...
Just a couple of questions to this very interessting amp:
- On the schematic of the A30... All i need for the Mini-A is the part on the left side? Including Q6 and Q7?
- The Parts on the right are for upgrading to an A30, right?
- As i can see, the neg input must be grounded for unbalaced input... Think i read this anywhere here... P-grounded or S-grounded?
- In the schematic are some resistors called "TBD" as value. What do they mean?
That´s it so far... Just began to route the layout...
Last edited:
Xandrell, to what schematic are you referring? For a mini all you need is the front end (P channel differential pair and CCS) and a pair of output devices (One for the active current source the other for the gain device and maybe the current limit circuit (two resistors and an npn bipolar.)
Yes, That's Brian's schematic. The mini is the main body of the schematic, located on his main board. The other parts are on the output boards he supplies. At the sale price of $7.20 it's hardly worth the effort to design your own boards unless you want to learn how.
TBD stands for To Be Determined.
R6 may be used to help correct offset if there is a mismatch in Q1 and Q2. You don't need it if you get a good match.
R12 sets the AC current gain. You'd be at 50% with 1K
R13 fine tunes the bias in the output stage. The higher the value the greater the bias.
R17 is a protection circuit part that sets the Q6 current when the protection kicks in. 392R has been used before. I used 1K and 1k2 for R21.
Connect the negative input to the signal ground for single ended operation.
TBD stands for To Be Determined.
R6 may be used to help correct offset if there is a mismatch in Q1 and Q2. You don't need it if you get a good match.
R12 sets the AC current gain. You'd be at 50% with 1K
R13 fine tunes the bias in the output stage. The higher the value the greater the bias.
R17 is a protection circuit part that sets the Q6 current when the protection kicks in. 392R has been used before. I used 1K and 1k2 for R21.
Connect the negative input to the signal ground for single ended operation.
Thanks to this point man... Wishing german posters would try to help like the people here ^^
One part is to learn how (designing and which function every part has ^^). On the other hand i´m living in germany and 15 bucks for shippment is far more expensive than having fun designing and etching the layout at work for free
So, back to the initial question My "part of work" is to design and route the schematic as shown above until R23-R26 for a Mini-Aleph?
Just hoping it will work from a 2x12V/100VA toroid per channel
One part is to learn how (designing and which function every part has ^^). On the other hand i´m living in germany and 15 bucks for shippment is far more expensive than having fun designing and etching the layout at work for free
So, back to the initial question
My "part of work" is to design and route the schematic as shown above until R23-R26 for a Mini-Aleph?Just hoping it will work from a 2x12V/100VA toroid per channel
Last edited:
Yes, just the left side of the schematic will be a mini-Aleph. The two sub-circuits to the right of R23 are the output boards used in a larger Aleph.
That transformer won't give you much room for anything but a big capacitive filter (a CLC or CRC might eat up a lot of rail voltage) but otherwise will work and give you ~16V rails.
Try around 30K for R13 (using an MPSA-18 for Q4,5) to give you ~25W total dissipation to keep your transformer operating at roughly half its rated VA. When ordering, pick a few values between 20K and 47K to try.
That transformer won't give you much room for anything but a big capacitive filter (a CLC or CRC might eat up a lot of rail voltage) but otherwise will work and give you ~16V rails.
Try around 30K for R13 (using an MPSA-18 for Q4,5) to give you ~25W total dissipation to keep your transformer operating at roughly half its rated VA. When ordering, pick a few values between 20K and 47K to try.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.