Re: My Aleph30 Starting Problems
Do not worry, very normal. I just finished my A30 as well, 2 days ago - same problem. The current jump is due to Inrush current, which is from the transformer. (I measured this inrush current with a peak crest meter and it was as much as +33A and -17A on the 1st few cycles. This is for onle a split second then it starts dropping.) Best solution are to fit a slowblow fuse AND add a thermistor inline just after the primaryside fuse. (As in Aleph3) This method works perfect. More about this here:
http://www.meritekusa.com/meritek_pdf/O.01_09_NTCpowerThermistor.pdf
http://www.kristronic.com/softstart/tech.htm
http://www.tortech.com.au/article.html
Post some pic's if you got and good luck with your project.
Algar_emi said:
Do not worry, very normal. I just finished my A30 as well, 2 days ago - same problem. The current jump is due to Inrush current, which is from the transformer. (I measured this inrush current with a peak crest meter and it was as much as +33A and -17A on the 1st few cycles. This is for onle a split second then it starts dropping.) Best solution are to fit a slowblow fuse AND add a thermistor inline just after the primaryside fuse. (As in Aleph3) This method works perfect. More about this here:
http://www.meritekusa.com/meritek_pdf/O.01_09_NTCpowerThermistor.pdf
http://www.kristronic.com/softstart/tech.htm
http://www.tortech.com.au/article.html
Post some pic's if you got and good luck with your project.
R21
Hi,
I have not yet have had the time to fiddle around with R21. Though I've changed R19 on one channel, to get it to dissipate as much heat/biasing it as the other one.
Though I will have a look on R19 some time after christmas, just to get the grip on it.
//magnus
Hi,
I have not yet have had the time to fiddle around with R21. Though I've changed R19 on one channel, to get it to dissipate as much heat/biasing it as the other one.
Though I will have a look on R19 some time after christmas, just to get the grip on it.
//magnus
Re: R21
You mean R21 ???
If I may quote Peter Daniel:
"Say what you mean-mean what you think-think anything
Why not"
😉
swede said:
You mean R21 ???
If I may quote Peter Daniel:
"Say what you mean-mean what you think-think anything
Why not"
😉
Just BTW
Why do I see this where Swede's signature is suppose to be?
"__________________
perl -ne'chomp;$a.=pack"b*",$_;END{print"\n$a\n\n"}'<<RM
10000010001101101010011000001110000101100000010001001110
101011100011011010100110110011101000010001010000
RM"
Just out of curiosity.
Why do I see this where Swede's signature is suppose to be?
"__________________
perl -ne'chomp;$a.=pack"b*",$_;END{print"\n$a\n\n"}'<<RM
10000010001101101010011000001110000101100000010001001110
101011100011011010100110110011101000010001010000
RM"
Just out of curiosity.
My sig...
Run the perl command in any UNIX like terminal window. ;=) It is not harmful.
//magnus
Run the perl command in any UNIX like terminal window. ;=) It is not harmful.
//magnus
HUM
Just got my aleph 30 going. I am using it single ended. There is hum that I can just hear from the listen position about 10 feet(3 meters) away. My speakers are not supper efficent. So this seems a bit much. Is this normal or to much hum? My power supply is an exact copy of the original aleph 30. My other impression is that this is a pretty dark sounding amp. Pleasant sounding and smooth but covering up detail.
Thanks in advance.
Just got my aleph 30 going. I am using it single ended. There is hum that I can just hear from the listen position about 10 feet(3 meters) away. My speakers are not supper efficent. So this seems a bit much. Is this normal or to much hum? My power supply is an exact copy of the original aleph 30. My other impression is that this is a pretty dark sounding amp. Pleasant sounding and smooth but covering up detail.
Thanks in advance.
R19 Biais values
Here a small table listings the value that I found in my Aleph30:
R19 I-FET PWR
47.5K 0.8A 20.0W
33.2K 0.6A 15.0W
30.2K 0.5A 12.5W
26.7K 0.4A 10.0W
Power dissipation is for 25V Rail...
Bye.
SB
Here a small table listings the value that I found in my Aleph30:
R19 I-FET PWR
47.5K 0.8A 20.0W
33.2K 0.6A 15.0W
30.2K 0.5A 12.5W
26.7K 0.4A 10.0W
Power dissipation is for 25V Rail...
Bye.
SB
Paul,
hum should be inaudible at more than a few cm from your speakers so if you hear it at 3 meters something is not quite right.
Dark sounding? I can imagine what you mean but can´t really find this in my Aleph5 (wich should sound more or less the same). Of course it depends on where you´re coming from (amp wise) but I must say that one of the things the Aleph does really good is revealing small details in the music that go by unnoticed with lesser amps. It does this without sounding aggressive or bright.
How have you set your bias and ac-current gain?
william
hum should be inaudible at more than a few cm from your speakers so if you hear it at 3 meters something is not quite right.
Dark sounding? I can imagine what you mean but can´t really find this in my Aleph5 (wich should sound more or less the same). Of course it depends on where you´re coming from (amp wise) but I must say that one of the things the Aleph does really good is revealing small details in the music that go by unnoticed with lesser amps. It does this without sounding aggressive or bright.
How have you set your bias and ac-current gain?
william
Gnomus: Thanks. I have the same feeling of the loss of details. I believed ( according to furore of other diyers and rewievs) it could be something wrong on my side. In all probabillity not. Thank you for you oppinion once more. By the way it seems to me that the older Aleph 3 sound better than A30 in this point of view. So I rebuild A30 to A3, rised bias (to 0.9A per case and I am experimenting with BJT input differential - I gaves lower THD, sonically I dont know now what happens.. I can only anticipate).
With out regulation is the Aleph 30 hum free? Or, is there normally some low level hum that can be heard at the speaker? Because, I remember reading some place that they work well with horn type speakers.
Still find the amp sweat, rich and full sounding. Very musical. And that works with music. Detail is lost. But, maybe over time the amp will break in and sound more open. I am not one that is in the camp that believes that electronics changes a lot after it does the "break in thing" . After an hour or so I feel that is the sound of the electronics and do not expect any big changes.
Still find the amp sweat, rich and full sounding. Very musical. And that works with music. Detail is lost. But, maybe over time the amp will break in and sound more open. I am not one that is in the camp that believes that electronics changes a lot after it does the "break in thing" . After an hour or so I feel that is the sound of the electronics and do not expect any big changes.
Without supply regulation, but with selection of transistors,
we have been able to get the typical Aleph 30 down to
about 200 uV noise (20-20K unweighted).
we have been able to get the typical Aleph 30 down to
about 200 uV noise (20-20K unweighted).
Thanks!
200uV noise is hard to comprehend. I need an analogy. Like it would be as loud as the sound of an ant waliking on leaves if you could hear it. Maybe very faint hiss heard with your ear at the tweater is on target? Or a range. A high figuar that would be considered noisy and a low figuar that would be nearly impossible to hear.
200uV noise is hard to comprehend. I need an analogy. Like it would be as loud as the sound of an ant waliking on leaves if you could hear it. Maybe very faint hiss heard with your ear at the tweater is on target? Or a range. A high figuar that would be considered noisy and a low figuar that would be nearly impossible to hear.
Hi,
This is a little off topic but can anyone tell me what the heat dissipation of an aleph 60 is?
On page 4 in the manual it says 240Watts.
Later in the manual it says 200Watts.
On the specs page it says 220Watts of power consumption
What to believe??🙁
Thank you,
Remco
This is a little off topic but can anyone tell me what the heat dissipation of an aleph 60 is?
On page 4 in the manual it says 240Watts.
Later in the manual it says 200Watts.
On the specs page it says 220Watts of power consumption
What to believe??🙁
Thank you,
Remco
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