Help me Diagnose a Problem with my BC

[julius]

Hello. Been using my bottlehead crack for months without any issues, a few days ago my 6080 blew out, make a loud cracking and popping sound through my headphones, a bright flash in the tube and some small sparks by the looks of it were produced inside.  Over the last few days I put new tubes in without any problems until today, odd fluttering sound was produced on the low end.  I swapped all my tubes and interconnects and each combination is producing the same fluttering low end. 

Though other sources, including my Aune dac or portable sources, the headphones sound stellar, no problems what so ever, when the bottlehead is put into the combo that problem is immediately present.  What could be causing this?  I don't want to resell it, but I might have to resell as defective but potentially fixable.  Could a blow tube cause damage to the amplifier itself?  When that event happened, I powered off the amplifier within seconds.  Any advice is appreciated.

[julius]

The headphones were damaged.  I only just recently confirmed.  At the time I was using the JVC DX1000, my favorite headphone, I just wrote a review for it on Headfonia that will be posted soon.  It immediately went dim on the right side and sounded hallow and cave-like.  A few hours later, I went back and things were seemingly fine but there was that looming feeling some quality was lost and that it could be very damaged, but I was just not noticing it. I assumed they were fine, I only listened to one track and it seemed ok. I took a long drive out to another friends house out of state today, due to him being the only other person I know who owns a DX1000.  I a/b'ed them and his sounded much more clear, spacious and solid.  Mine was hazy, a little warped on the low end and slightly dimming as the seconds passed on during the tracks.  Volume would return to the right cup, but then dim a little over a short period of time.

I came back home a few hours ago and my Hifiman HE500s arrived in the mail, i plugged them into my Bottlehead and immediately noticed the distorted low end.  I was terrified it was the headphones, but I switched all the tubes I have and cables, tested it with known-working headphones and each produced the same fluttering sound.  I just purchased a great 5998 tube and some Epiphany Acoustics Atratus / Kimber interconnects, as well as this HE-500.  Lol...ouch.  I feel microwaved at the moment.  Happy I got nice gear today, but sad that the amplifier is faulty now.  Ugh...I need some alcohol

*salutes the best amplifier I've ever had

[Doc B.]

First things first - stop plugging brand new headphones into an OTL amp that isn't working right. A fluttering low end sounds like it could be motorboating, which is related to bad caps. Check to see if all of the electrolytic capacitors are properly oriented on the terminals with respect to the negative stripe. Then recheck your voltages.

[Paul Joppa]

As Doc says, voltages are the first thing. When you post them, tell us whether the Speedball upgrade is installed or not - that will help the de-bugging.

If the fluttering is equal in both channels, it's probably in the power supply. While you're under the hood checking voltages, first look at the ends of the electrolytic caps to see if any are bulged (indicating damage).

[julius]

I have almost no experience with circuitry.  I have no clue what any of that means, what to look for or how to test it.  Best I can do is list it for sale on Ebay.  I do not have the time or experience, nor do I know anyone who can deal with this type of a problem.  Was great while it lasted, I guess.

[galyons]

Julius,
Where are you located?  I am in the San Francisco area and would be willing to help you diagnose the problem.  If you are not close to me, then there may be someone close to your area, if you post location.
These are pretty simple amps.  It was obviously working, so something "took a crapper", just need to figure out what.

Cheers,
Geary

[julius]

I live in Ohio, pretty far away.  

I am fully capable of learning how to fix whatever problem is going on in there.  I'll just have to go buy the tools needed to preform the checks that were suggested here.  Despite that tube going bad a few days ago, it was working just fine late last night.  It wasn't until I returned from a short trip today and plugged in the new headphones that I discovered this issue.  It was off and unused for about 10 hours or so, once I got home I discovered that flutter.  I have a ton of headphones, cheap and expensive.  I was using a specific set of earbuds before I left earlier today with no problem, fast forward 10 hours or so and the same earbuds produced that flutter ( as did everything else I tested with it )

im sure its fixable, it will take time.  I'm just super lazy and a bit disabled at the moment to get things done.

[Paul Joppa]

Am I correct in guessing that you did not build this amp yourself?

Almost all Bottlehead products are built by the owner, and the advice you've received has assumed that you have the familiarity with the parts, circuit, and nomenclature that comes with building it in the first place. Of course, if you did not build it yourself, you won't have nearly as much familiarity with the insides as we have been assuming - but everyone here is still going to be as helpful as possible.

The forum has a very high success rate in helping builders succeed, and if necessary diagnose and fix the products, or find someone who can if necessary. Hang in there!

For what it's worth this is not a common problem - I can't recall seeing the same one before, and Bottlehead has sold a LOT of Cracks!

[julius]

Mine was built by a friend and then given to me as a gift.  Support so far has been absolutely great and I am doing my best to balance work and trying to learn how to repair my BC.  I looked at all the solder joints and didn't see anything lacking, nor did I see any bulges in any components, any warping or out of place pieces. 

Since the problem likely started with the 6080 tube going bad, is it safe to assume the most likely thing to go bad after that would be the platform the tube goes into ? 

[Grainger49]

Julius,
Where are you located?  I am in the San Francisco area and would be willing to help you diagnose the problem.  If you are not close to me, then there may be someone close to your area, if you post location.
These are pretty simple amps.  It was obviously working, so something "took a crapper", just need to figure out what.

Cheers,
Geary

There is another benefit of the Forum.  There are Bottleheads in Ohio, but I'm not sure where.  Hasafracker is one Ohio Bottlehead.  Milosz might be another.  Start a new thread in the General folder asking for help on a Crack in Ohio. 

[ironbut]

Hi Julius,

I suggest you contact the friend who built the Crack (especially if he's located nearby).
I don't mean to suggest that you complain. But since he built it, he's more familiar with that particular unit.
Most folks that build Bottlehead kits are keen on learning audio electronics and troubleshooting something that you've built can be a source of a great deal of knowledge.
I think I've learned more from troubleshooting that I have from building any kit that works perfectly the first time.
Because of this, I consider repairs to be an very important part of learning.
In other words, if I were your buddy, I wouldn't feel like you were "looking a gift horse in the mouth". On the contrary, I'd wonder why you didn't consult me in the first place.

[Paul Birkeland]

We do also offer repair services here if you  are unable to source this locally.

-PB

[Grainger49]

I had misread the post from Doc, it is only the assembly service that was discontinued, not repair services.  

Who better to find the problems with a Crack than Bottlehead?

[Doc B.]

Specifically it was the fixed price assembly service that has been discontinued as it was falling very far short of covering our expenses. We do still offer the service, but it is charged by the hour at our regular shop rate. For assembled kits the thing to do is call us to discuss an estimated price and estimated timing of completion. And yes, we do also offer repair service at our hourly rate of $65.

[julius]

Thats great, Doc.  If I can't find someone else near by who can diagnose and repair it,  or if I am unable to do so myself, I'll give you guys a call and send it on over to you for repair service.  

Also, the person who purchased it for me past away a few months ago.  For anyone interested, here is a high res photo of the entire board. These are the only snaps that I have of it at the moment, but I can snap more soon for anyone who wants to see.

http://djangophile.deviantart.com/art/Bottlehead-3-335931249
http://djangophile.deviantart.com/gallery/#/d5k05vi