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Old 15th April 2008, 04:48 PM   #1
stighe is offline stighe  Norway
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Default Help with Aleph 5

Hi all

I'm building an Aleph 5 with Mini-A PCBs. I got all the parts as a kit, and the enclosed parts list is taken from Brian's website (http://www.diyamps.com/aleph/aleph.shtml).

To test, I've connected one of the amplifier boards (hooked up to 2 output boards) to the power supply. I get no voltage across R4 or D1 and no sound at all

The power supply is fine.

Could it be something missing on the boards? I have two 3ohm 1W resistors I don't know where to put. The only 3ohm in the parts-list is R0 (3W).

Thanks,

Stig
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Old 15th April 2008, 05:04 PM   #2
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Assuming R4 is the suppressor gate resistor for Q3 and provided all solder joints are good, there is apparently no current through the zener for some reason.BAD zener?? Zener in backwards?? Anyway NO current source ,NO sound.Find out why that circuit is not active.
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Old 15th April 2008, 11:08 PM   #3
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Apparently you are operating off a different schematic than what
I have. Can somebody post a copy?
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Old 16th April 2008, 12:37 AM   #4
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Quote:
Originally posted by Nelson Pass
Apparently you are operating off a different schematic than what
I have. Can somebody post a copy?

The MINI-A boards are the blue variety I believe , which were based basically on the A3-30. I do not have a schematic for the 5. Apparently an Aleph 5 was built on these boards with higher rails and more devices in the output.
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Old 16th April 2008, 12:42 AM   #5
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Quote:
Originally posted by Nelson Pass
Apparently you are operating off a different schematic than what
I have. Can somebody post a copy?

Don't feel bad. I've been running into the same thing recently with the Mini-A. People start talking about part numbers that don't make any sense, even though they're using the same circuit name.

Grey
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Old 16th April 2008, 01:02 AM   #6
Stones is offline Stones  United States
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Default Re: Help with Aleph 5

Quote:
Originally posted by stighe
Hi all

I'm building an Aleph 5 with Mini-A PCBs. I got all the parts as a kit, and the enclosed parts list is taken from Brian's website (http://www.diyamps.com/aleph/aleph.shtml).

To test, I've connected one of the amplifier boards (hooked up to 2 output boards) to the power supply. I get no voltage across R4 or D1 and no sound at all

The power supply is fine.

Could it be something missing on the boards? I have two 3ohm 1W resistors I don't know where to put. The only 3ohm in the parts-list is R0 (3W).

Thanks,

Stig
sandstorm33 has it coverd. I have no idea where or what D1 is and for those "spare 3ohm resistors" assuming you have a short or some other 3ohm resistors in R0 you can keep these in your parts draw.




http://www.diyamps.com/aleph/docs/miniAleph-sch.pdf
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Old 16th April 2008, 10:50 AM   #7
folkeb is offline folkeb  Norway
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Stig and I tried to compare the schematics of the original aleph 5 design to the schematics of the aleph mini. To state the obvious: They are not identical.

Has anyone on the forum built a aleph 5 with these boards? The person who sold the kit has apparently gone underground so we can't turn to him for help.

I remember from when I built the aleph 1.2s I forgot the led light and I experienced the same issues as we do now. However, by soldering in the led everything worked fine. Incidently, I notice that there is no led in the aleph mini schematic. Can it be that history is repeating itself, the infamous missing led again?
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Old 16th April 2008, 12:37 PM   #8
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You must have gotten a parts list with the kit. How does it describe D1??

It is possible that a LED was in the design . If so it would be connected at the positive rail through a 10K? resistor (anode) to the collector of the CCS BJT(cathode). I believe that is the way it was done on the 1.2.
wortha try!!!
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Old 16th April 2008, 05:03 PM   #9
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It was done that way on the 1.2 for layout convenience.
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Old 16th April 2008, 05:09 PM   #10
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Quote:
Originally posted by sandstorm33
You must have gotten a parts list with the kit. How does it describe D1??

It is possible that a LED was in the design . If so it would be connected at the positive rail through a 10K? resistor (anode) to the collector of the CCS BJT(cathode). I believe that is the way it was done on the 1.2.
wortha try!!!

Correction;anode of led to Emitter!
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