Hi French fellow, still no service manuals... that's sad.
As for my VA100 it does soooooo good!:
As you can't see there is a LME49720HA instead of the LM4562NA and a pair of LME49710HA on the phono stage wich can be powered off via the former Tape switch.
It's all better and clearly noticable, as expected. Won't do much on this now, I need good sources as the phono is not mine and the DVP5500 SACD player just want to detroy my ears in highs.
For later is planned a dedicated PSU for the LME as it works better with higher and regulated voltage (13.6V unregulated here from the main 50V).
After havin the best sources of the world (that means at wallet & speakers scale), then, if I'm in the mood, discrete op amp as Audio GD. Or not.
I have some noises come in when touch the knob, I think as they are not the painted ones and I've no earth on the wall plug that's quite normal...
As for my VA100 it does soooooo good!:
An externally hosted image should be here but it was not working when we last tested it.
As you can't see there is a LME49720HA instead of the LM4562NA and a pair of LME49710HA on the phono stage wich can be powered off via the former Tape switch.
It's all better and clearly noticable, as expected. Won't do much on this now, I need good sources as the phono is not mine and the DVP5500 SACD player just want to detroy my ears in highs.
For later is planned a dedicated PSU for the LME as it works better with higher and regulated voltage (13.6V unregulated here from the main 50V).
After havin the best sources of the world (that means at wallet & speakers scale), then, if I'm in the mood, discrete op amp as Audio GD. Or not.
I have some noises come in when touch the knob, I think as they are not the painted ones and I've no earth on the wall plug that's quite normal...
Enough for this right now, more problem having the speakers in the right setup 
Sounds defo good, ask myself if my former chinese tank was that foot tapping...
Anyway, time for a CDP, spikes under the stands to cancel the soft floor bad effect. And records!
Last but not least, when just start to play a record (not cold, really just start to play or after a long time no play) the phono stage does not play the low level right chanel, if it's a loud sound it will "krsshhgrzzziii" only, then music appears on the chanel under one minute of play, like one part needs to be "duty" for one minute of music before it sings. Few parts there, any idea? I have only borrowed discs, own only two and just damaged one...
Sounds defo good, ask myself if my former chinese tank was that foot tapping...
Anyway, time for a CDP, spikes under the stands to cancel the soft floor bad effect. And records!
Last but not least, when just start to play a record (not cold, really just start to play or after a long time no play) the phono stage does not play the low level right chanel, if it's a loud sound it will "krsshhgrzzziii" only, then music appears on the chanel under one minute of play, like one part needs to be "duty" for one minute of music before it sings. Few parts there, any idea? I have only borrowed discs, own only two and just damaged one...
Another VA100 fan
Hi everyone, just read through this fascinating thread. I have a VA100 which I bought new in 1993 and am still enjoying today. It is only recently that I have started to give it some attention. I have replaced the bias resistors and reset the bias currents according to the service manual that B&W very kindly forwarded to me. Perhaps you can point me in the right direction of what I need to replace to reduce the mains hum. From new this amp always had a very slight hum (zero volume & no inputs connected) but now after 16 years the hum is audible from a few feet away. The hum is from the speakers, whereas I have experienced the amp humming (vibration) over the years with certain other appliances switched on.
Any advice greatly appreciated, at the moment I just want to reduce the noise, maybe later I will get more adventurous like some of you guys.
Cheers
Hi everyone, just read through this fascinating thread. I have a VA100 which I bought new in 1993 and am still enjoying today. It is only recently that I have started to give it some attention. I have replaced the bias resistors and reset the bias currents according to the service manual that B&W very kindly forwarded to me. Perhaps you can point me in the right direction of what I need to replace to reduce the mains hum. From new this amp always had a very slight hum (zero volume & no inputs connected) but now after 16 years the hum is audible from a few feet away. The hum is from the speakers, whereas I have experienced the amp humming (vibration) over the years with certain other appliances switched on.
Any advice greatly appreciated, at the moment I just want to reduce the noise, maybe later I will get more adventurous like some of you guys.
Cheers
Re: Another VA100 fan
Hi Veri,
If you mind may you send me the service manual?
I'm also concerned by the bias even if untuched since now for my amp is good sounding and DC offset low.
Anyway, mine also does hum quite a lot, too much for the phones outlet (as for me that's not a prob as when I'll go for headphones I'll look at Grado and dedicated amp).
All my stuff hums when whasing machine is on or such, my main is noisy and unstable.
I've managed to keep it very low (need to ear at less than 40cm to hear anythng with my B&W DM4 so not a real concern) by moving the internal flat cable wich lead the signal from inputs to pot then coax from pot to input caps on PCB. The first one is floating there and the coax goes as low as possible.
Tell us if that helps.
Regards, Matthieu
(as a later upgrade maybe will do, as for my cdp, also later, some super-regulators with a dedicated tx for the op amp in both preamp/buffer and phono stage).
Veri said:
Hi Veri,
If you mind may you send me the service manual?
I'm also concerned by the bias even if untuched since now for my amp is good sounding and DC offset low.
Anyway, mine also does hum quite a lot, too much for the phones outlet (as for me that's not a prob as when I'll go for headphones I'll look at Grado and dedicated amp).
All my stuff hums when whasing machine is on or such, my main is noisy and unstable.
I've managed to keep it very low (need to ear at less than 40cm to hear anythng with my B&W DM4 so not a real concern) by moving the internal flat cable wich lead the signal from inputs to pot then coax from pot to input caps on PCB. The first one is floating there and the coax goes as low as possible.
Tell us if that helps.
Regards, Matthieu
(as a later upgrade maybe will do, as for my cdp, also later, some super-regulators with a dedicated tx for the op amp in both preamp/buffer and phono stage).
Thanks for reply, I have the black coax cables as low as possible, I was wondering if with the amp so old there were a couple of important caps that could be changed to improve mains noise. I have read on other forums that these components deteriorate with time.
Because I am new here I am still under moderation so it is not possible for me to send emails, as soon as I can I will email you the service manual.
Until then I can tell you that the bias currents listed are:
240v, 24mA +48mA per channel (120mA)
220v, 24mA +50mA per channel (124mA)
The service manual gives detailed instructions how to set this.
DC offset should be less than 15mV
Because I am new here I am still under moderation so it is not possible for me to send emails, as soon as I can I will email you the service manual.
Until then I can tell you that the bias currents listed are:
240v, 24mA +48mA per channel (120mA)
220v, 24mA +50mA per channel (124mA)
The service manual gives detailed instructions how to set this.
DC offset should be less than 15mV
About the caps I don't think they can bring noise or they should be in short and this is worst than old
Anyway you'll be wise to change the main big caps (go for 6800µF instead of 4700 as far as they're "audio" and fit the slim case) and the 4 around op amps supplies, they are defo old now. Rubycon ZA/ZL works fine and I stick to these.
I'll be happy to see the service manual as soon as you can send it to me. Let's see if you can get my mail.
edit: no, you have no "PM" button...
Anyway you'll be wise to change the main big caps (go for 6800µF instead of 4700 as far as they're "audio" and fit the slim case) and the 4 around op amps supplies, they are defo old now. Rubycon ZA/ZL works fine and I stick to these.
I'll be happy to see the service manual as soon as you can send it to me. Let's see if you can get my mail.
edit: no, you have no "PM" button...
Well I've read some and redone the radiator like it should: it's defo warmer, good sign.
Final pic, the way the source ribbon cable routes is the one with no humming. Some noise floor is still here, always been and unfamous on these amps. It's just working like a charm, the best on the low power amp I ever owned!
Final pic, the way the source ribbon cable routes is the one with no humming. Some noise floor is still here, always been and unfamous on these amps. It's just working like a charm, the best on the low power amp I ever owned!
An externally hosted image should be here but it was not working when we last tested it.
Hoping this image hotlink issue will be solved soon...
Back to questions:
I want to use the headphones socket in order to listen to my main source.
Unfortunately it's humming a lot (and not at all at speakers...) and my question is;
does it make sens to fit a resistor in the path to lower volume and herein lower the flow to nothing?
Thanks,
Matthieu
http://img216.imageshack.us/img216/7581/aurava100evomod.jpg
Back to questions:
I want to use the headphones socket in order to listen to my main source.
Unfortunately it's humming a lot (and not at all at speakers...) and my question is;
does it make sens to fit a resistor in the path to lower volume and herein lower the flow to nothing?
Thanks,
Matthieu
http://img216.imageshack.us/img216/7581/aurava100evomod.jpg
Last edited:
Hi all,
I've read the whole thread trying to understand, but unfortunately I am not technically skilled enough...
I own an VA-100 evolution II that hums quite a lot. Since I am not an expert, I'm going to take it to a repair shop. However, I would really appreciate if any of you guys could tell me what the fix is in simple words, in order to be able to explain to the service men.
Grateful in advance,
JINT (Spain)
I've read the whole thread trying to understand, but unfortunately I am not technically skilled enough...
I own an VA-100 evolution II that hums quite a lot. Since I am not an expert, I'm going to take it to a repair shop. However, I would really appreciate if any of you guys could tell me what the fix is in simple words, in order to be able to explain to the service men.
Grateful in advance,
JINT (Spain)
The end of the game!
Hi Jint, sorry I haven't seen this!
Mine humms like hell when some devices like washing machine in on, you may try it in someone else house, maybe not the neighboor in case some nasty things are shared. A good excuse to go to grand'ma's house
But once it also started to hum by itslef, maybe a case of ringing or such? I'm not an expert either... then turned it off for a while and it was gone.
Unscred the transformer and put under some soft or rubber like stuff can be a good idea to at least make it not too loud until it's solved.
Good luck guy in saving this little wonder!
As for me as I really enjoy my TT I've regreted not to have changed the elcaps at pre-phono, wich I've just done, removed main opamp ones to pre-phono (Rubycon ZA 220/35) and hardly replaced them with Black Gate 330/50. Now it's definitive! Sound report in a while, these BG bugs need time... last pic was factory setup.
Matthieu
Hi Jint, sorry I haven't seen this!
Mine humms like hell when some devices like washing machine in on, you may try it in someone else house, maybe not the neighboor in case some nasty things are shared. A good excuse to go to grand'ma's house
But once it also started to hum by itslef, maybe a case of ringing or such? I'm not an expert either... then turned it off for a while and it was gone.
Unscred the transformer and put under some soft or rubber like stuff can be a good idea to at least make it not too loud until it's solved.
Good luck guy in saving this little wonder!
As for me as I really enjoy my TT I've regreted not to have changed the elcaps at pre-phono, wich I've just done, removed main opamp ones to pre-phono (Rubycon ZA 220/35) and hardly replaced them with Black Gate 330/50. Now it's definitive! Sound report in a while, these BG bugs need time... last pic was factory setup.
Matthieu
Attachments
Hello everybody, sorry if this is not the right place to post, but this is my very first "contribution", hope I´ll soon be able to start my own threats
I own an AURA VA100 evolution, wich I bought new in 1998. After having listened to my ARCAM AVR300 for a while, I switched back to the old stereo and am loving it again! The only thing I regret is that I cannot feed my AR sw30 active subwoofer (my speakers are B&W dm 604, reaching quite low though...). I don't want to use the high-level connections, maybe I wont' be using the subwoofer everytime...
I wonder if it's possible to turn the REC-OUT of the AURA (fixed volume) into a PRE-OUT (post-volume) so I can connect the subwoofer via line-level connections (and use its own crossover).
Thank you for your expert advice, greetings,
Andres
I own an AURA VA100 evolution, wich I bought new in 1998. After having listened to my ARCAM AVR300 for a while, I switched back to the old stereo and am loving it again! The only thing I regret is that I cannot feed my AR sw30 active subwoofer (my speakers are B&W dm 604, reaching quite low though...). I don't want to use the high-level connections, maybe I wont' be using the subwoofer everytime...
I wonder if it's possible to turn the REC-OUT of the AURA (fixed volume) into a PRE-OUT (post-volume) so I can connect the subwoofer via line-level connections (and use its own crossover).
Thank you for your expert advice, greetings,
Andres
Aura Phono stage problem
Hi, I am new to this forum and I am not particularly knowledgable on electronics but trying hard to get a grasp. I have owned an Aura VA100 and the TU*) for many years and had a lot of satisfaction from them. I am reasonably happy with the VA100 but have recently started to use the phono with a new Systemdek turntable I have acquired. The phono when first used sounded good but after approximately 3 minutes the right channel died. I have swapped the stylus feeds around and I am happy the problem lies in the amp which either refuses to run on the right channel or if it does it lasts only for approximately 2 to3 minutes. Can anyone point me in the right direction for identifying the possible problem? Jak
Hi, I am new to this forum and I am not particularly knowledgable on electronics but trying hard to get a grasp. I have owned an Aura VA100 and the TU*) for many years and had a lot of satisfaction from them. I am reasonably happy with the VA100 but have recently started to use the phono with a new Systemdek turntable I have acquired. The phono when first used sounded good but after approximately 3 minutes the right channel died. I have swapped the stylus feeds around and I am happy the problem lies in the amp which either refuses to run on the right channel or if it does it lasts only for approximately 2 to3 minutes. Can anyone point me in the right direction for identifying the possible problem? Jak
Aura VA100 Upgrade
Hi Matthieu,
I'm about to do similar work to my Aura as you have done.
A couple of questions if that's ok.
In your final pictures, you seem to have removed the C1, R1 components into the op-amp, are these removed, or just out of view on the other side of the board?. If removed, where do you now connect the coax lead from the volume pot?, straight into the input resistor, (possibly R2), on your photo.
Did you ever manage to get a service manual or other documentation, if so I would very much appreciate a copy.
Regards,
Kevin Moore.
Hi Matthieu,
I'm about to do similar work to my Aura as you have done.
A couple of questions if that's ok.
In your final pictures, you seem to have removed the C1, R1 components into the op-amp, are these removed, or just out of view on the other side of the board?. If removed, where do you now connect the coax lead from the volume pot?, straight into the input resistor, (possibly R2), on your photo.
Did you ever manage to get a service manual or other documentation, if so I would very much appreciate a copy.
Regards,
Kevin Moore.
Hi Kevin,
well I don't remeber well, caps are removed, my sources had no DC or protected, reisistors... under maybe, when I had big inpuit caps and needed room there.
Please give me your mail in pm and I'll send you the service manual
You can flavor the sound best at the main opamp and its decoupling caps.
Have fun!
Matthieu
well I don't remeber well, caps are removed, my sources had no DC or protected, reisistors... under maybe, when I had big inpuit caps and needed room there.
Please give me your mail in pm and I'll send you the service manual
You can flavor the sound best at the main opamp and its decoupling caps.
Have fun!
Matthieu