Hi All
I have an Aleph P (remote model) that have noise issue from one of the channel.
I’d sent it to a Pass Labs authorized distributor for servicing and was told the had done what the could and I am left to my own devices due to short availability with parts.
I really do not want to part with this lovely Preamp and hope that I can some how fix the issue.
I’ve recorded a short clip of the noise . A pair dummy load were inserted to the inputs to prevent and self noise from the input stages, the output was recorded through a AD/DA with a DAW. I’ve checked the tape out, there is no noise issue.
Hope to have someone here to point me to where I should start with the fault finding. I am not a tech but hopefully with the guidance here I may be able to somehow fix this wonderful Preamp.
Thanks all
Jason
I have an Aleph P (remote model) that have noise issue from one of the channel.
I’d sent it to a Pass Labs authorized distributor for servicing and was told the had done what the could and I am left to my own devices due to short availability with parts.
I really do not want to part with this lovely Preamp and hope that I can some how fix the issue.
I’ve recorded a short clip of the noise . A pair dummy load were inserted to the inputs to prevent and self noise from the input stages, the output was recorded through a AD/DA with a DAW. I’ve checked the tape out, there is no noise issue.
Hope to have someone here to point me to where I should start with the fault finding. I am not a tech but hopefully with the guidance here I may be able to somehow fix this wonderful Preamp.
Thanks all
Jason
fact that you have crackling noise in one channel only - says that culprit is not common for both channels, so you can exclude both PSU (common to both channels) and also digital side of things (if it leaks it can leak only in main PSU somehow )
now - if you can - try testing ( simple test with active small speaker for PC is good enough ) do you have crackling sound in both phases on output - positive and negative
that could help for narrowing what to change
btw.
that's bad distributor .......... obviously being in business just for initial part of business - take most of the cream
now - if you can - try testing ( simple test with active small speaker for PC is good enough ) do you have crackling sound in both phases on output - positive and negative
that could help for narrowing what to change
btw.
that's bad distributor .......... obviously being in business just for initial part of business - take most of the cream
Hello Zen Mod, Hello Dennis Hui
I will do the phase switch noise test when I get a chance tomorrow. I’ll let you know the out come. Really appreciate your help and guidance Zen Mod.
On things with the distributor. The Aleph P was not purchased though them, it was from another company. The Pass Labs distributorship here may had switched a few times through the years. The guy did try to help me but he was a sales guy and the company definitely out source repairs and servicing. These things are rather common with most of the Hifi shops here in my country.
Thanks guys for lending your ear and helping out.
Fully appreciate all the help. Cheers
I will do the phase switch noise test when I get a chance tomorrow. I’ll let you know the out come. Really appreciate your help and guidance Zen Mod.
On things with the distributor. The Aleph P was not purchased though them, it was from another company. The Pass Labs distributorship here may had switched a few times through the years. The guy did try to help me but he was a sales guy and the company definitely out source repairs and servicing. These things are rather common with most of the Hifi shops here in my country.
Thanks guys for lending your ear and helping out.
Fully appreciate all the help. Cheers
Hello Nelson Pass
Wow thanks for checking this post, Mr. Pass
Sending the Aleph P to Pass labs would be the most ideal.
Unfortunately, I would have to get the unit sent from Singapore to USA and back, on top of parts and servicing. The sum may be somewhat higher than I would hope. I'll check the with available courier services for shipping cost before I commit to have the unit be service in the States.
Thank you very much for your kind attention and all those wonderful gear and design you share with the world.
Jason
Wow thanks for checking this post, Mr. Pass
Sending the Aleph P to Pass labs would be the most ideal.
Unfortunately, I would have to get the unit sent from Singapore to USA and back, on top of parts and servicing. The sum may be somewhat higher than I would hope. I'll check the with available courier services for shipping cost before I commit to have the unit be service in the States.
Thank you very much for your kind attention and all those wonderful gear and design you share with the world.
Jason
Hi Zen Mod
Good Day!!
Finally found myself some time to steal myself away from the daily need-dos.
What I did may be a little different to want you had asked. I've recorded the audio instead.
Here I have the recorded audio from Pin 2 of the XLR and Pin 3 of the XLR
I've also included a spectrograph of them. This is Pin 2's and this is for Pin 3's
Do feel free to download them and let me know does the file helps and what you think.
The audio are record at 24bit 96kHz (mono) wav.
Noise are detached on both the Positive and Negative of the channel output. One can clearly see the noise of pin 3 (-ve) much higher than on pin 2 (+ve).
Besides the noise burst, the spectrograph shows there are a few constant HF noise on 8khz, 16kHz, 24khz, 32khz. I am rather puzzled by this harmonic noise content.
Would love to hear what you think they are and what step I should take next. Thank you so much for the help and hope you have a great weekend
Cheers
Jason
Hi Zen Mod
Thank you very much for the advice.
I’ve downloaded the 1.7 version service manual, which I was told the one I need for the remote model of the Aleph P.
As mentioned on my early post i have little experience with trouble shooting electronics. I’ve use a soldering iron on cables, jacks and patchbays, but not beyond.
Any kind of guidance would be greatly appreciated and will be super helpful for me.
Thank you very much.
Jason
Thank you very much for the advice.
I’ve downloaded the 1.7 version service manual, which I was told the one I need for the remote model of the Aleph P.
As mentioned on my early post i have little experience with trouble shooting electronics. I’ve use a soldering iron on cables, jacks and patchbays, but not beyond.
Any kind of guidance would be greatly appreciated and will be super helpful for me.
Thank you very much.
Jason
I think it would certainly be worthwhile recapping it, replacing any internal wiring with new stuff, and cleaning electrical contacting parts (switches, rcas, volume pots, ground etc) or replacing them.
I got this kind of sound on my bass guitar when one of the volume pots got some kind of contamination in them.
I got this kind of sound on my bass guitar when one of the volume pots got some kind of contamination in them.
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Just to chime in here: I have owned something like a dozen different Pass products, and have had many of them serviced by Pass. It is absolutely ridiculous how good their service is, how well they treat their customers, even when we have bought stuff used.
To give an example: I once had some noise issues with an Aleph 5 and sent it back to Pass. They replaced all the power supply caps, at no charge,even though it was long since out of warranty. I've had other experiences that were similar.
I have also known other people who've had their Pass products serviced by local techs, usually due to shipping-cost issues. All of them have told me that the Pass people were in touch with their local techs with information about how to perform the service, what parts to use, etc.
Conclusion: You can't go wrong, either way you choose to proceed. The Pass folks will find a way to make things right for you.
PS At this stage, recapping make a whole lot of sense, no matter what your other issues might be. Papa says in the manual that, after 25 years or so, the power caps will start to dry out (and, eventually, the sun will go supernova). The parts cost is not that bad.
To give an example: I once had some noise issues with an Aleph 5 and sent it back to Pass. They replaced all the power supply caps, at no charge,even though it was long since out of warranty. I've had other experiences that were similar.
I have also known other people who've had their Pass products serviced by local techs, usually due to shipping-cost issues. All of them have told me that the Pass people were in touch with their local techs with information about how to perform the service, what parts to use, etc.
Conclusion: You can't go wrong, either way you choose to proceed. The Pass folks will find a way to make things right for you.
PS At this stage, recapping make a whole lot of sense, no matter what your other issues might be. Papa says in the manual that, after 25 years or so, the power caps will start to dry out (and, eventually, the sun will go supernova). The parts cost is not that bad.
Hello All
It’s been 2 years since I first posted this.
I have taken the decision to get the unit send to Pass Labs to get it service. I have a kind friend that will be flying back to SF and he will helping me out with the arrangements.
@Nelson Pass, I look forward to getting this unit back to shape,getting it back to how you’d designed it to be.
It’s been 2 years since I first posted this.
I have taken the decision to get the unit send to Pass Labs to get it service. I have a kind friend that will be flying back to SF and he will helping me out with the arrangements.
@Nelson Pass, I look forward to getting this unit back to shape,getting it back to how you’d designed it to be.