Author Topic: Troubleshooting help required - New Bryston B135 cubed integrated amplifier buzz  (Read 1651 times)

Offline ivanlyf_2011

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Dear all,

I'm hearing a buzz from my speakers after I replaced my Roksan Kandy K3 integrated amplifier with a new Bryston B135 cubed integrated amplifier. The B135 was bought and installed into my setup on wednesday but I only noticed the buzz today.

Description of issue:
A hum / buzz from my B&W 705S2 speakers even when there is no music playing. The hum/buzz can only be heard when I go near the speaker, at my usual sitting position, I have to really concentrate to hear the buzz. It doesn't get louder than the music.

Recent change:
Replaced my Roksan Kandy K3 Integrated Amplifier with Bryston B135-cubed Integrated Amplifier. No other changes.

Setup:
Roksan Kandy K2 CD Player -> S/PDIF -> Bryston BDA-2 -> VDH RCA -> Bryston B135 cubed -> VDH Spkr -> B&W 705 S2 speakers

All equipment are connected to an Isotek Evo 3 Sirius

Tests performed

1. Tested Roksan & Bryston as a standalone equipment.
All RCA cables from upstream sources unplugged, only power cable and speaker cables plugged in. Amplifier connected to wall socket alone.
Outcome: Buzz persists once amp is turned on for Bryston. No buzz for Roksan.

2. Tested Bryston back in the setup as described above.
No music playing but adjust the volume up and down.
Outcome: Buzz persists.

3. Tested Bryston back in the setup as described above.
Connect BDA-2 to a different amp input port, no music playing and adjust the volume up and down.
Outcome: Buzz persists.

4. Tested Bryston back in the setup as described above.
Bypassed BDA-2; connect CD player direct to amp input port, no music playing and adjust the volume up and down.
Outcome: Buzz persists.

Any idea what else to do?

AFA audio says it's my system problem because there was no buzz at the store and maybe because the original fuse blew so the replacement fuse might cause the buzz.

Thank you for your help.
Ivan
« Last Edit: November 03, 2018, 21:29 by ivanlyf_2011 »
Bowers and Wilkin 705S2, Sennheiser HD800, Bryston B135 Cubed Integrated Amplifier, Bryston BHA-1 Headphone Amplifier, Bryston BDA-2 DAC, Roksan Kandy K2 CD Player, Isotek Evo 3 Polaris, Isotek Evo 3 Sirius.

Offline Boxerfan88

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Disconnect all sources at amp side. Just amp & speakers, still buzz?


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Offline ivanlyf_2011

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Disconnect all sources at amp side. Just amp & speakers, still buzz?


Sent from my iPhone using Tapatalk

Yes still buzz. Test condition 1 as described was that test scenario of amp and speaker alone without source connections.

I’ve even repeated it with the Roksan, Roksan amp is ok, no buzz.
Bowers and Wilkin 705S2, Sennheiser HD800, Bryston B135 Cubed Integrated Amplifier, Bryston BHA-1 Headphone Amplifier, Bryston BDA-2 DAC, Roksan Kandy K2 CD Player, Isotek Evo 3 Polaris, Isotek Evo 3 Sirius.

Offline jaffrie

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Why did the fuse blow ? Might have to open up to check

Offline ivanlyf_2011

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Why did the fuse blow ? Might have to open up to check

Good point - I'm not sure either. At AFA (SG's authorised Bryston distributor), the sales person said probably because the unit too long never turn on since it was shipped from the factory. As far as I can see, the B135 cubed was brand new in box so I don't think it has been tested since it left the factory.

AFA's defence was that there was no humming during the short functional test that was done so there's probably nothing wrong with the B135. However, they are okay if I bring the unit back to test.
Bowers and Wilkin 705S2, Sennheiser HD800, Bryston B135 Cubed Integrated Amplifier, Bryston BHA-1 Headphone Amplifier, Bryston BDA-2 DAC, Roksan Kandy K2 CD Player, Isotek Evo 3 Polaris, Isotek Evo 3 Sirius.

Offline jaffrie

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You should bring it back. At times when speakers at show room are low sensitivity you'll not hear hum or buzz issues. In general such issues can be traced to cold soldering or grounding.

Offline nfnc

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AFA audio says it's my system problem because there was no buzz at the store and maybe because the original fuse blew so the replacement fuse might cause the buzz.

Thank you for your help.
Ivan

Good point - I'm not sure either. At AFA (SG's authorised Bryston distributor), the sales person said probably because the unit too long never turn on since it was shipped from the factory.
...

AFA's defence was that there was no humming during the short functional test that was done so there's probably nothing wrong with the B135. However, they are okay if I bring the unit back to test.

Honestly ..... Replacement fuse causing buzz?!  Unit too long never turn on => fuse blows and buzz develops?

Wow

If a fuse blows, it is more likely that there is a fault somewhere - your AC supply, the fuse or the amp (possibly transformer, power supply board, etc)

Would suggest that you bring the amp back to AFA for them to open up and insist that the check & test properly.

James Tanner from Bryston is on XP (search for James from Bryston). You can PM him - I am sure that he will at your dealer’s responses.

Alternatively, message him on facebook https://m.facebook.com/pg/BrystonLtd/about/#!/BrystonLtd/
« Last Edit: November 04, 2018, 02:08 by nfnc »

Offline Boxerfan88

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Yes still buzz. Test condition 1 as described was that test scenario of amp and speaker alone without source connections.

I’ve even repeated it with the Roksan, Roksan amp is ok, no buzz.

Apologies, my oversight.
Having a quick scan of your product manual, there is a pair of switch that you can separate the preamp section. Try switching to “separate” with no sources.

If the buzz stays, then your amp section is generating the buzz. If the buzz goes away, it implies the preamp section is contributing the buzz.

If you’ve a headphone, try to checkout the headphone output for buzz.


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« Last Edit: November 04, 2018, 06:42 by Boxerfan88 »
Soekris dac1541 | DA&T A38  | Usher MD2+X616 | Orisun DD12 | Samsung PS50B850 |
Yammy RXA3030 | RPi3+Kodi | BDP-S5100 | PC+foobar2000 | Chromecast

Offline ivanlyf_2011

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Honestly ..... Replacement fuse causing buzz?!  Unit too long never turn on => fuse blows and buzz develops?

Wow

If a fuse blows, it is more likely that there is a fault somewhere - your AC supply, the fuse or the amp (possibly transformer, power supply board, etc)

Would suggest that you bring the amp back to AFA for them to open up and insist that the check & test properly.

James Tanner from Bryston is on XP (search for James from Bryston). You can PM him - I am sure that he will at your dealer’s responses.

Alternatively, message him on facebook https://m.facebook.com/pg/BrystonLtd/about/#!/BrystonLtd/

Yeah I know...I felt as if I was treated like a fool in their response. I've done my due diligence to try some test cases and it all failed, at least tell the user to bring it back for check up instead of being so defensive and saying the unit didn't hum at the store.

Yes - I've also emailed Bryston directly on their website via the technical support and made a complain on AFA. I will see Bryston's response - corresponded with Brian Russell 2 days ago so I can email him directly too if I need.

Thanks - will be more insistent that AFA Audio check it for me.
Bowers and Wilkin 705S2, Sennheiser HD800, Bryston B135 Cubed Integrated Amplifier, Bryston BHA-1 Headphone Amplifier, Bryston BDA-2 DAC, Roksan Kandy K2 CD Player, Isotek Evo 3 Polaris, Isotek Evo 3 Sirius.

Offline ivanlyf_2011

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Apologies, my oversight.
Having a quick scan of your product manual, there is a pair of switch that you can separate the preamp section. Try switching to “separate” with no sources.

If the buzz stays, then your amp section is generating the buzz. If the buzz goes away, it implies the preamp section is contributing the buzz.

If you’ve a headphone, try to checkout the headphone output for buzz.


Sent from my iPhone using Tapatalk

Good idea. I have a headphone (Senn HD800) too so I will go try out these suggestions in the afternoon.

Thank you,
Ivan
Bowers and Wilkin 705S2, Sennheiser HD800, Bryston B135 Cubed Integrated Amplifier, Bryston BHA-1 Headphone Amplifier, Bryston BDA-2 DAC, Roksan Kandy K2 CD Player, Isotek Evo 3 Polaris, Isotek Evo 3 Sirius.

Offline AndrewC

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...All equipment are connected to an Isotek Evo 3 Sirius

...

Ivan, before you go poking around inside the Amp, have you tried connecting the Amp directly into the Wall AC socket and nothing connect to it except the speakers? Or a different AC power point altogether?

Especially, disconnect your Isotek Evo3, it appears to have some inductive coupling between sockets, which I can’t imagine would be any good for a highly transparent Amp like the Bryston ;)

http://www.isoteksystems.com/products/performance/evo3-sirius
Quote

Unique Inductive Resistance Gate© optimises the isolation between each of the six outlets.


Good luck!  :)
You'll never get to heaven with a smile on your face from me.

Offline ivanlyf_2011

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Hi to all who've helped - I did the additional tests as requested and no the buzz doesn't go away:

Apologies, my oversight.
Having a quick scan of your product manual, there is a pair of switch that you can separate the preamp section. Try switching to “separate” with no sources.

If the buzz stays, then your amp section is generating the buzz. If the buzz goes away, it implies the preamp section is contributing the buzz.


I have done that, switched to separate the pre-amp (i.e. disconnect pre-amp from amp) and also disconnect the RCA cables so the amp is not connected to source. Still buzzing

If you’ve a headphone, try to checkout the headphone output for buzz.

I have done that, switched to separate and also connected, with my Sennheiser HD800, no buzz at all. Headphone output works as upon connecting it in, the speakers are mute as described in the manual.

I think with the 2 test cases above, we can further isolate the problem to the power amplifier section.




Ivan, before you go poking around inside the Amp, have you tried connecting the Amp directly into the Wall AC socket and nothing connect to it except the speakers? Or a different AC power point altogether?

Especially, disconnect your Isotek Evo3, it appears to have some inductive coupling between sockets, which I can’t imagine would be any good for a highly transparent Amp like the Bryston ;)


Hi Andrew, yes I have tested the amp in a standalone test (See Test 1 in opening post):
- Amp is connected directly to a wall socket by itself (no conditioners or another device sharing that socket)
- Only cables connected are speaker cables and power cable (no connection to upstream source or downstream component)
- Buzzing sound is still heard.
- Repeated standalone test with Roksan amp -> no buzzing sound heard.
Bowers and Wilkin 705S2, Sennheiser HD800, Bryston B135 Cubed Integrated Amplifier, Bryston BHA-1 Headphone Amplifier, Bryston BDA-2 DAC, Roksan Kandy K2 CD Player, Isotek Evo 3 Polaris, Isotek Evo 3 Sirius.

Offline kaydee6

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Is it a buzz or hiss? Some amps have the hiss like Naim amps.
If it is buzzing, I would ask for replacement. If after replacement, still the same and it could be caused by your home grounding issue. Again, ask for a refund as the amp design and specification did not meet your expectation like the Roksan did.

Offline ivanlyf_2011

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Is it a buzz or hiss? Some amps have the hiss like Naim amps.
If it is buzzing, I would ask for replacement. If after replacement, still the same and it could be caused by your home grounding issue. Again, ask for a refund as the amp design and specification did not meet your expectation like the Roksan did.

I think I would call it a hiss.

Another thing I observe is when I disconnect the pre-amp from the amp in my B135, the hiss is still present but it's softer.

Don't think can refund -> just hoping that AFA Audio is willing to have a look at it and if it needs to be returned to Bryston, to do so speedily instead of taking their own sweet time to ship
Bowers and Wilkin 705S2, Sennheiser HD800, Bryston B135 Cubed Integrated Amplifier, Bryston BHA-1 Headphone Amplifier, Bryston BDA-2 DAC, Roksan Kandy K2 CD Player, Isotek Evo 3 Polaris, Isotek Evo 3 Sirius.

Offline nfnc

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Would you mind sharing:

- when did the fuse blow?
- what happened just before the fuse blew?
- did it happen at the dealer or at your place?
- who replaced the fuse and was it with the same type and value?