Banned
Joined 2002
Mark A. Gulbrandsen said:
Troy,
Here is what Mark posted a while back regarding the rail voltages.. 20v.
Regarding the webpage, Vikash made the chipamp.com webpage for me, and I took the source and modified it (with a couple new graphics) to make the aleph order page.
--
Brian
Mini Aleph PCB order page:
http://www.chipamp.com/aleph
Hey Brian-
I saw that, but that is using the Mini-A to drive loudspeakers.
I will most likely run the Mini-A regulated @ 15 volts but have higher unregulated rails for the output boards. I guess I should have been more specific the first time.
Is there a know maximum for the output boards other than the semi conductors max voltage rating? I was planning 24VAC secondaries with +/- 35 VDC on the output boards..
I saw that, but that is using the Mini-A to drive loudspeakers.
I will most likely run the Mini-A regulated @ 15 volts but have higher unregulated rails for the output boards. I guess I should have been more specific the first time.
Is there a know maximum for the output boards other than the semi conductors max voltage rating? I was planning 24VAC secondaries with +/- 35 VDC on the output boards..
rabstg said:
Aleph 5 uses 3 output devices per bank to make 60w per channel on +/- 34v rails.
I bought a 4x25vac 1kva transformer that I was looking to use to make a stereo Aleph 5 amp with.
I will try eventually try building it with these boards. Have a look at the Aleph 5 service manual:
http://www.passlabs.com/downloads/old product/a4serv0.pdf
--
Brian
Mini Aleph PCB order page:
http://www.chipamp.com/aleph
Boards look great as always. I have a question about R3 and R4 on the PSU board. This gives an option for CRC wiring, but am I correct to assume that it would have to be wired externally since it will probably get too hot even if a to220 is mounted in there ?
Great job btw, i'll be ordering soon
Great job btw, i'll be ordering soon
Jean said:Boards look great as always. I have a question about R3 and R4 on the PSU board. This gives an option for CRC wiring, but am I correct to assume that it would have to be wired externally since it will probably get too hot even if a to220 is mounted in there ?
Great job btw, i'll be ordering soon
For the power supply, the default configuration would be to just put a short circuit jumper, instead of using a resistor, as that is the way that the original Aleph amps were built. Since the current draw from the supply is constant, there really isn't a need for a CRC supply.
The pads should accomidate larger resistors, which could also be wired off board.
--
Brian
Mini Aleph PCB order page:
http://www.chipamp.com/aleph
BrianGT said:
Hey Brian-
Your URL points to the Aleph 4 manual. But I used it to get to the A5..
http://www.passlabs.com/downloads/old product/a5serv0.pdf
rabstg said:
You are correct. I pointed to the wrong one. Thanks for correcting me.
--
Brian
Mini Aleph PCB order page:
http://www.chipamp.com/aleph
For the PCB order, please be sure to submit your order on the webpage by March 31st (thursday night), so that I can order enough pcbs.
--
Brian
Mini Aleph PCB order page:
http://www.chipamp.com/aleph
--
Brian
Mini Aleph PCB order page:
http://www.chipamp.com/aleph
Banned
Joined 2002
Hi all
I’m new to amp building, so can someone confirm with all the info buried in the number of pages, if I’ve got this all straight please:
To build stereo (not monoblock) amps: two*each of:
a 30 watt Aleph 30
*and a 10 watt miniAleph, for all pieces needed, is it:
Amplifier (from BGT) & PS boards (- *four sets at $32 + shipping) from BGT *plus register at the Wiki (??)
Parts kits from JL not yet for sale, but registration of interest on the miniALEPH PCB Component Kits Wiki by the coming Friday.
(And I will need to source chassis and PS - transformers, caps, rectifiers and fuse(s)).
Thanks
I’m new to amp building, so can someone confirm with all the info buried in the number of pages, if I’ve got this all straight please:
To build stereo (not monoblock) amps: two*each of:
a 30 watt Aleph 30
*and a 10 watt miniAleph, for all pieces needed, is it:
Amplifier (from BGT) & PS boards (- *four sets at $32 + shipping) from BGT *plus register at the Wiki (??)
Parts kits from JL not yet for sale, but registration of interest on the miniALEPH PCB Component Kits Wiki by the coming Friday.
(And I will need to source chassis and PS - transformers, caps, rectifiers and fuse(s)).
Thanks
transformer question
Hello,
This is my second project so please correct me if I'm incorrect. Still learning...
I have a 300 va 12-0-12 transformer that sounds like it would be suitable for an aleph-mini. From what I understand, it should be more then sufficient but I was wondering if adjusting the bias allow the circuit to produce more then 10wpc? It seems that increasing the output for class A can be achieved either by increasing the bias or the voltage?
Planning on ordering a set of boards from Brain and parts from Jason so I'd like to figure out which parts to order.
regards
Dave
Hello,
This is my second project so please correct me if I'm incorrect. Still learning...
I have a 300 va 12-0-12 transformer that sounds like it would be suitable for an aleph-mini. From what I understand, it should be more then sufficient but I was wondering if adjusting the bias allow the circuit to produce more then 10wpc? It seems that increasing the output for class A can be achieved either by increasing the bias or the voltage?
Planning on ordering a set of boards from Brain and parts from Jason so I'd like to figure out which parts to order.
regards
Dave
rick57 said:
Hello,
1 mini Aleph pcb set can build either 1 mini-A or 1 A30, so if you wanted to build 2 stereo A30 amps, and 1 stereo mini-A, you would need 3 mini Aleph PCB sets and 3 power supply pcbs.
--
Brian
Mini Aleph PCB order page:
http://www.chipamp.com/aleph
Re: transformer question
Rick-
Australia is the BEST place to get heat sinks. Conrad is right there and have excellent heat sinks reasonably priced.
http://www.conradheatsinks.com/products/
Dave-
If you use the output boards 12-0-12 x 300va will get you around 20-25 wpc.
Jason-
I'm signed up on the Wiki for some parts kits but I would like to pay for them if the price is now stable .
Will you be accepting Paypal or first borns only? I'm JOKING. 7:51 AM here... Maybe it's too early to start having fun.. Sorry.
Anyway, I do thank you for doing the parts kits. Really helpful.
rick57 said:
phoneisbusy said:
Rick-
Australia is the BEST place to get heat sinks. Conrad is right there and have excellent heat sinks reasonably priced.
http://www.conradheatsinks.com/products/
Dave-
If you use the output boards 12-0-12 x 300va will get you around 20-25 wpc.
Jason-
I'm signed up on the Wiki for some parts kits but I would like to pay for them if the price is now stable
.Will you be accepting Paypal or first borns only? I'm JOKING. 7:51 AM here... Maybe it's too early to start having fun.. Sorry.
Anyway, I do thank you for doing the parts kits. Really helpful.
Re: transformer question
Dave,
Your transformer will give limit the power output to around
12 W or so into 8 ohms. This is just a function of the limited
voltage swing.
The bias in the original mini-A is about 1A per rail. This is
just enough to give the 10W at 8 ohms. Below 8 ohms,
the output drops because you're now limited by the bias
current. Increasing the bias will help will lower impedence
load. Besides, distortion on these devices drop with
higher current.
In your case, you may consider running the bias up
closer to 2A. Your transformer will be fine. With
adequate heatsinking, the output devices will also be ok.
Cheers,
Dennis
phoneisbusy said:
Dave,
Your transformer will give limit the power output to around
12 W or so into 8 ohms. This is just a function of the limited
voltage swing.
The bias in the original mini-A is about 1A per rail. This is
just enough to give the 10W at 8 ohms. Below 8 ohms,
the output drops because you're now limited by the bias
current. Increasing the bias will help will lower impedence
load. Besides, distortion on these devices drop with
higher current.
In your case, you may consider running the bias up
closer to 2A. Your transformer will be fine. With
adequate heatsinking, the output devices will also be ok.
Cheers,
Dennis
OK... Now I'm confused. I intend to build a 4 channel, 30w/c amp. I ordered 2 Mini-Aleph kits and 2 PS board kits. From what I read above, this is not correct. Do I need to order 2 more mini-Aleph kits?
Brian, have you identified an Avel that's just right for a 30w/c amp?
It would seem that where there's enough VA in their product line, there may be too much voltage.
Thank you in advance for your patience with this nuub stuff.
Brian, have you identified an Avel that's just right for a 30w/c amp?
It would seem that where there's enough VA in their product line, there may be too much voltage.
Thank you in advance for your patience with this nuub stuff.
chipco3434 said:
Sorry for the confusion. 1 amplifier pcb set = 2 channels, which can be used with or without the outboards.
With regards to the transformer, the A30 uses +/- 25vdc rails, so a 2x18 vac transformer should work well. I haven't decided what VA to use for this. The A30 manual states a power consumption of 200w for 2 channels.
--
Brian
Coulomb said:
Correct. I will clarify this on the webpage.
--
Brian
Mini Aleph PCB order page:
http://www.chipamp.com/aleph
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