New Aleph Mini PCB GB

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Mini/A30 ?

Measurement question

Sorry, don't mean to hijack thread but.....
I bought 4 sets of the Mini/A30 boards from BrianGT. I stuffed one set as Mini's and three sets as Aleph 30's. I finished an A5 about a year ago where I learned (courtesy BDP) how to make the voltage measurements prior to installing the output boards/devices.

On all eight boards I see the ~9V drop across Z5, ~4.1Vgs on Q3, ~3.9Vgs on Q1,Q2. On seven boards I see ~4V drop across the 392R resistor (R18), the last board (an A30) I measure a drop of ~2.7V. Seven of the boards would seem to be good to go. Is this 2.7 V too low (ie, do I need to chase down the offending part(s))?

This resistor "sits" between the -V supply and the drain of Q2 and would seem to define the voltage drop across that resistor (I measured 2.7 volts between these points as well). What would cause the drain to be 1.3-2.3V too negative (Is Q2 the problem?)?

Thanks,
SteveA
 
Progress...

This is the bottom of chassis for my Mini/30 4 channel

Ya baby!
 

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chipco3434 said:
Almost ready for the light bulb trick turn on...

need a bottle of courage.



Please don't connect a speaker or a input to the amp :) it will help :) Trust me :) if you need any other help just post or email me..

Jason

To be honest i didn't even use a lightbuld bor variac :) i just plugged it in with no load or input :)
 
HOLY COW!

It all came together tonight and it sounds GREAT.

Had a little speaker with Dayton Neo and four NSB's. I had been listening to it for a few days on the Aleph. Sounded like poo in full range no tweet and even worse with a cross.

I broke out the MOX active project I completed a year ago, all the time with the 4 channel Aleph in mind. 10 watt side to the tweet and the 40 on the midwoofs.

The results were UNBELIEVABLE. Fantastic clarity and control.

GO ACTIVE
GO "A"

Thanks for the help!
 
chipco3434 said:
HOLY COW!

It all came together tonight and it sounds GREAT.

Had a little speaker with Dayton Neo and four NSB's. I had been listening to it for a few days on the Aleph. Sounded like poo in full range no tweet and even worse with a cross.

I broke out the MOX active project I completed a year ago, all the time with the 4 channel Aleph in mind. 10 watt side to the tweet and the 40 on the midwoofs.

The results were UNBELIEVABLE. Fantastic clarity and control.

GO ACTIVE
GO "A"

Thanks for the help!

I told you these amps are good :) now im excited to get my pre-amp built and my new speakers im working.
 
steenoe said:
Hi Chipco, that is realy neat work on that amp. Looks cool.



Could anyone point to a thread where the "lightbulb trick" is explained? I did some searching, but didnt find anything usefull.
A short instruction here would be just fine too:)

Steen:)

Hi steenoe, it seems like a good idea to me, looks pretty cheap as well.

http://antiqueradio.org/dimbulb.htm

Stan
 
Roger that...

In series with the hot on the AC supply. Learned about it here. Evidently it greatly reduces the volume of smoke on funky startups.

You don't really need the light bulb Trick but if you want to use it any ways.

Jason's right about that. There's usually something between the new amp and the light pole outside that will give up!

I'm sure a lot of people get just a little gunshy when they first flick the switch on their new baby. It "takes the worry out of being close".
 
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