S.E.X 2.1 - Help me

[quy lam nguyen]

Recently, my S.E.X 2.1 has been making noises, which sounds like electrical interferences). That noise randomly appeared, and lasted for about 15-30 secs. That noise seems to not coming from the volume component. I also tightened all the screws, changed the tube, checked the power supply, wired from top plate to the ground, disconnected all connections from the DAC, etc. - but no luck
(My O2 head- amp works normally on the same power supply)
After cleaning with 90% alcohol the noise has reduced a bit, but still it's very clear.
Please help me. Any help will be appriciated.

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I have an original S.E.X 2.1 purchased from ebay, but unfortunately the seller did not send the Manual CD as commited. Every attempt to contact the seller was unsuccessful.
The lack of the manual makes DIY (upgrading, re-building, etc.) more challenging and difficult to me.
Without the manual CD, I can not upgrade and/or find a solution to the problems encountered while using the amp, so I really need the manual (either in CD or PDF).
It looks like if you register and purchase products at Bottlehead.com, you can be able to download the PDF version of the manual.
If so, I will ask my friend in the US to buy some spare parts for the amp to have the manual. Where I live can not access Bottlehead.com. Orders can not be accepted when using VPN
The Manual will help me fully enjoy the fun of DIY Bottlehead
I hope to receive help from everyone. I'm most grateful
Best regards
Quy Lam Nguyen

[fullheadofnothing]

The most common causes of interference are cell phones and WiFi devices.

[Paul Birkeland]

If you live in one of our blacklisted countries (just due to spam), we are happy to whitelist your IP address.  You can e-mail your IP address to docb(at)Bottlehead(dot)com and we'll get that taken care of for you.

Josh is quite correct, the interference you're describing sounds like a noisy cell phone that's nearby.

[quy lam nguyen]

fullheadofnoth: Thanks for replying
I am willing to throw my iphone into the river and live the rest of my life without it if that can help overcome the problem for my beloved S.E.X 2.1
Unfortunately, it seems not to be the reason. In a desperate attempt to find the cause, I tried turning off all electrical and electronic equipment nearby (including cellphone), leaving the only S.E.X amp connected to power and the headphone. And still there is noise.
(Now I'm thinking about the mass or lead solder after a period of use has caused problems, which need to re-build. But that couldn't be done without a manual. When it comes to reassembly, I might run out of control if there isn't a manual to help me around this.
Again appreciate your comments. Thank you

*****
Paul Birkeland: Thank you, DocB's email also says like that. Unfortunately in where I live, individual internet subscribers are usually only provided with Dynamic IP. Static IP are usually very expensive, so only companies subscribe them. That's why I can't provide my fixed IP address for the whitelist. Thank you very much.
I hope to order some replacement parts (like the SEX 2.1 C4S Upgrade Kit for example). Although I do not need it right now, but maybe someday I will need it to replace my old components. If through ordering those parts I am allowed to download the PDF Manual, so I can upgrade my own S.E.X 2.1 amp by experiences shared in the forum. It is a happiness for me
Once again, I would like to thank everyone who helped me find a solution to my problem.

[Paul Birkeland]

(Now I'm thinking about the mass or lead solder after a period of use has caused problems, which need to re-build. But that couldn't be done without a manual. When it comes to reassembly, I might run out of control if there isn't a manual to help me around this.

Solder joints don't go bad over time. 

Did you try also turning off the light fixtures in your room?  Are you in a home or perhaps an apartment that shares power with many other units?

[quy lam nguyen]

Paul Birkeland: Thank you
I still leave it on the desk in my own room (which uses home power supply). The noise has only recently appeared (after about a year and a half S.E.X had been working very well). Electrical equipments in my room weren't changed during that time.
Electrical-interference-like noises often appear randomly without any pattern.
I tried to turn off all electrical appliances nearby (including light bulbs), but the noise was still there.
I think it may be because the solder, capacitor connections, electric wire,etc. were physically impacted during use which cause it to leak, but I'm not sure about that.
So I want to have a Manual CD or PDF file for safer rebuilding.
And I also want to try upgrading such components like the volume potentiometer, the Russian teflon caps or the Mundorf SGO, according to experiences shared on Bottlehead Forum and Loquah (from Head-fi) ... for a better audio experience as well as the fun of DIY that Botthead can bring.
I'm really interested in this, and that was the reason that brought me to Bottlehead, instead of choosing a fully assembled head-amp.
But the lack of Manual CD made my dream impossible.
So, if by ordering spare components at Bottlehead.com that I can get my Manual CD or PDF file, or if anyone has a way to get the Manual then please help me.
Thank you very much
P/s: The image is taken without any other light from electrical appliances and with the S.E.X being disconnected. (I took the image with flash light from the camera.) In that state, the S.E.X 2.1 still generate noises, while the O2 amp (connected to the same power) doesn't.
I'm sorry for not being able to post any comments sooner because the VPN and errors like ERROR 500 (which I do not understand) did not allow me to post.

[Paul Birkeland]

I think it may be because the solder, capacitor connections, electric wire,etc. were physically impacted during use which cause it to leak, but I'm not sure about that.

Has the amp been dropped?  I do not see any evidence of anything leaking in any of the photos you've posted.  I would strongly advise against completely rebuilding the amp, as this is a legacy kit with some parts that are going to be very hard to find or are potentially discontinued. 

And I also want to try upgrading such components like the volume potentiometer, the Russian teflon caps or the Mundorf SGO, according to experiences shared on Bottlehead Forum and Loquah (from Head-fi) ... for a better audio experience as well as the fun of DIY that Botthead can bring.

The manual is not helpful for this.  The volume control is a 100K stereo logarithmic carbon potentiometer.  The values of the coupling capacitors are written on the caps themselves. 

I'm really interested in this, and that was the reason that brought me to Bottlehead, instead of choosing a fully assembled head-amp.
But the lack of Manual CD made my dream impossible.

You bought an assembled amp...
When the manual wasn't delivered with the kit, then the appropriate course of action would be to open a case against the seller for not fulfilling your purchase. 
We tend to avoid providing manuals because of negative experiences in the past (specifically with the SEX kit actually). 

Are the terminals numbered on your amp?  I can provide some basic voltage checks to ensure that your amp is operating properly if you'd like.

-PB

[quy lam nguyen]

I apologize for not noticing the troubles of providing the Manual.
I am very esteemed and careful when using the S.E.X head-amp. The mentioned physical impacts are moving, displacing, disassembling to change impedance switch. (mostly on my desk).
MY S.E.X AMP HAS NEVER BEEN DROPPED. Never, never and never!
The account who sold this amp to me seems to be active on ebay, though they won't answer any questions about the lack of the manual. I'm not thinking about sueing him for the troubles it may bring.

"You bought an assembled amp ..." Yes. Although I really like the DIY Bottlehead, but I do not have much experience in building one, so the safe option was to buy a Bottlehead SEX 2.1 assembled amp in the hope of having a fun experience in the process of upgrading it, according to experiences shared in the forum. But the upgrading didn't go as planned, and I'm afraid that I can not go back to its original state if I do something wrong due to the lack of the manual.

"Are the terminals numbered on your amp" - Did you mean the handwritten digits written by the builmers behind the top plate? Those numbers are still there, but some digits are not clear. I tried a lot of different ways to try to identify the cause of electrical noise, and I realized the noise only ends when I remove the tube
(Setting the impedance switch to 4ohms mode makes the noise smallest, but it's still enough to be annoying.)
Should I reheat the solder joint? Is it possible that the wires of the mass or foot of the tube are loose, causing the leakage of electricity?
If there is no other way, can I use the Repair Service to my problems? Does it include missing parts, and the Manual? Please tell me
If that is necessary I will try to persuade my friend to bring the amp back to the US to use that service (Because of my huge love to Bottlehead
Thank you very much for the good advice
I really believe that everyone will find many useful tips from the famous Bottlehead Forum community. Thank you

P/s: Sorry for my long comments (which are quite different from most of them in the forum). Due to the instability of my VPN, I usually pack a lot of information in one comment. Hope that everyone doesn't mind and thanks for reading it

[Paul Birkeland]

Just out of curiosity, what headphones are you using with your SEX amp?

You would have to talk to the boss about a flat rate repair.  I can see some hardware used to mount the power transformer that's absolutely not supposed to be there, but otherwise the kit looks stock.  It may be that this hardware is part of the issue. 

[quy lam nguyen]

Thanks for your curiosity It helps me feel less lonely in my attempt to solve the problem..

I have some headphones (Sennheiser HD600, HD650, Foster, Beyer DT770, AKG K240). But I often use my AKG K501, because I feel it is suitable for my favourite classical type of music)

*****
I have used my S.E.X 2.1 with a lot of different headphones. In a year and a half after purchasing the amp, it has worked just fine with almost any type of headphone. Noises just appeared recently
When the noise appears, I have tried with different headphones.
I also tried with other head-amps (on the same electric source) that I could borrow (O2, Shitt Valhalla 2, etc) but there is no noise.

*****
The transformer has been changed to Bottlehead's 240VAC to match where I live. This was done by the seller in the US, before handling it over to my friend (who lived in the US) who brought it to me. Is there a possibility of electrical noises coming from that?
If that can happen, how do I test it? (I have a power meter which I'm not good at using, a welding torch, Cardas lead solder ...). How does someone guide me? (I have no Manual - for those who did not read the topic from the beginning). I am most grateful

My S.E.X amp in the image has disconnected from the DAC. I also turned off the electrical equipments around. Even so, there's still noise in the headphone
The O2 head-amp located nearby, connected to the same power supply plug, has absolutely no noise.
Thank you for taking the trouble to help me. I do appreciate it.

[Paul Birkeland]

Terminal numbers.

[Paul Birkeland]

Voltages.  (Terminal 3 is a good one to use as ground)

[quy lam nguyen]

Thanks Paul Birkeland.
You've been very patient in helping me and I'm very appreciated about that.
I've sent an email to Doc.B and he replied me about the steps on ordering on Bottlehead.com. I will order some spare components (like a C45 for e.g.) and hope that I can be able to download the PDF Manual. Then I would be able to understand and follow the instructions in the Forum to resolve the issue
That's my last hope
_____
I'm sorry. Although I love the Bottlehead amp so much....., but I'm just a newbie in DIY:(