Aleph 3 standby mode, possible turn off

[mercc]

Hi,

I noticed that turned off Aleph 3 has charged capacitors, only on one side in this case of propably not properly functioning one (about half power consumption, bit of distorted sound when turned on), so I think it is maybe active somewhat. I want to ask if its possible to turn it off and if it can be in the turned off state.

Thank you for your response.

 

[Zen Mod]

which , what , how

pics , please , and more info

 

[mercc]

What more info?

 

[Zen Mod]

pictures , so you don't need to put efforts in explaining is your Aleph DIY or original,does it have bleeders on caps , how much capacitance etc.

 

[mercc]

It is original Aleph, capacitors are changed to Vishay 12000 hours, 85 C, some of the originals were a bit bulged. Capacitance is the same 8x22000uf. Read something somewere about the bleeders but dont know what it is. When i was changing capacitors, the IRF 9610 stopped working, now i found out that one was changed, i measured the previous one and seemed ok so now the IRF 9610 are original. The four IRFD 9110 were changed too. Tried to measure only with diode tester but the values of the originals varied a bit so i didnt changed them.

 

[Zen Mod]

put 2K2/3W resistors across each cap bank (both positive and negative) ; those are bleeders

regarding rest of your first post , I'm not getting what and when/how long is distorted

 

[mercc]

I posted 2 posts so i tried to reference it to second post. Aleph has about half power consuption as normal, when music is played the sound is a bit distorted. Also found out that one of the 3W resistors on the bottom of one pcb was a bit released so i soldered it.

 

[Zen Mod]

both channels distorted ?

any hum or buzz ?

are you able to open it and do some strategic measurements ?

best way is , if I post schematic here , that you write measured values directly on schematic

in MS Paint or any similar prog

 

[mercc]

Yes, I think both. I think the hum is a little, as was previously. One of the reasons i tried to change capacitors, but i think later the hum remained still. I have it opened now, schematic is in the service manual, but some simplified or better to understand schematic would be maybe good.

 

[Zen Mod]

there is no simpler schematic than in SM

download this , print and study few days ;it's best if you can understand what's what .

for start - check PSU voltages

 

[mercc]

DC voltages are 18 and 17 volts. Also noticed AC voltages on the wires to the four heatsinks.

 

[Zen Mod]

DC voltages are too low

I don't understand what you mean with "AC voltages on the wires to the four heatsinks"

 

[AudioSan]

i quess the AC voltage from transformer to diodes

 

[mercc]

PSU DC voltages i measured on pins two grounds and plus, minus before capacitors. Then on ground before capacitors and on pins v plus, minus, and src, out, based on schematics. Also measured AC voltages on DC ground and mentioned pins and there appears to be AC. Dont know what exactly AC voltage should be on the colored wires to the transformer in the manual schematics i didnt found it. I think the transformer could be the problem. Sorry, Im a bit tired or something.

 

[AudioSan]

meassure DC AFTER the caps.

 

[Zen Mod]

considering that you have lack of electronic experience ,only way to finish this is - post exact schematic (from SM)ofr your amp , and post pictures

then we can communicate making marks on schematic and pics

either that , or send amp to someone with adequate knowledge

 

[mercc]

Where to measure DC after the caps?
Also i noticed that the chasis is grounded right to the caps outside earth ground and that caps in the turned off state had voltage near 12 volts. When I opened it, discharged caps, after a while it gradually charged again.
It is standard amp or original, only capacitors and irf9610 and irfd9110 were changed.
Dont know if someone has adequate knowledge about aleph or amps in as such.
If i can ask, why is the resistor called bleeder?

 

[AudioSan]

between PSU and amp board.
the resistor is caled bleeder becouse it bleed out the voltage from the caps when the power is turned off.

 

[RS232]

Where to measure DC after the caps?
Also i noticed that the chasis is grounded right to the caps outside earth ground and that caps in the turned off state had voltage near 12 volts.

You measure DC on the same points where you measured the AC...
The thing is like this
220/240V inlet goes to transformer to the rectifiers (before the rectifiers you have AC)
From the rectifiers to the capacitors to the boards you have DC...
The only thing you have to do is switch the voltmeter/multimeter from AC to DC and check on the capacitor (positive(red lead) to ground (black lead) and from ground (red lead) to negative (black lead)).
The leads are from the voltmeter and not the wires on the amp.
I'm no expert on the Aleph 3 but you should have around 26VDC on each side of the capacitor bank.

Ric

 

[mercc]

One amp board is horizontal in the middle with capacitors and two thermistors and four boards are vertical with transistors, resistors, smaller capacitors and heatsinks. Voltage before capacitors i think should be similar to voltage after capacitors. Side amp boards are connected to caps board with white square hard wires, two of the boards havent them straight because it was a bit difficult to put it upside down with the bigger heatsinks removed. I measured the voltages in the point where transformer connects to PSU horizontal board and on PSU horizontal board where are attached white square hard wires.