Blown fuse after PC swap?

HPower · « **on:** 30 Apr 2007, 11:01 pm »

Hey guys,

I got home from work today to find 3 new Blacksand PCs had been delivered.
John sent me 2 violets and 1 Silver that I planned to mix and match to my amp, CDP, and SWL.

I swapped out the OEM cables for the Blacksand and then powered up the SWL...
much to my surprise the fuse blew inside the preamp.

I replaced the fuse twice and each time it blew again, once with the Blacksand and once with the
OEM cable.
I tried the Blacksand cable that was used during the initial blown fuse and it powered up
my CDP without any problem.

Yesterday everything was working fine, I actually played a fair bit of music on Sunday.

I left Dan a phone message and have yet to hear back from him so I thought I would
see if you guys had any ideas.

Thanks

SCompRacer · « **Reply #1 on:** 1 May 2007, 02:19 am »

IIRC your SWL has the tube rectified PS. I had a rectifier tube (Sovtek) go bad in the tube rectified PS for my 9100ES and it did the same thing. I was demoing it at a friends place and it was working fine. After we had lunch, we found the fuse had blown. I had a spare tube to put in and Dan sent me a replacement tube.

When I had replaced the fuse after it blew, I had the cover off when I turned it back on. At first things were normal, then it looked like a lightning storm inside the tube and the fuse blew.

TheChairGuy · « **Reply #2 on:** 1 May 2007, 03:52 am »

The Rusky rectifier tubes have a (deserved) bad wrap for consistency. I've had issues with 5U4 and 5AR4's (EH, I think, on both).

I don't think it was a big surprise to Triode Electronics that I had to return them....they accepted without a fuss. Something told me in their tone that I wasn't the only one returning them after they blew (I have another that developed a bad buzz, but the 6 months was just barely over to return it...so it's actually 3 gone bad of 4 purchased)

Buy some cheap NOS ones if they exist for your preamp. Not for sound purposes, just for the long-lasting durability they tend to have. over the Russky ones these days.

HPower · « **Reply #3 on:** 1 May 2007, 07:48 am »

Thanks guys,

I did not even think of a possible tube problem...

I also had the cover off for the 2nd and 3rd fuse blows but did not notice anything obvious happening
with the rectifier tube.
I will try to find a cheap replacement 5AR4 tomorrow and see if that is the source of the problem.

I had planned on trying a "better" PS tube after things got broken in a little more... as of right now
I am hearing a too much sibilance sounds and was hoping something like the NOS Mullard might
help with that.

As far as the new AC cables go, I also noticed that of my 3 components, the SWL seemed to make the loosest
connection when plugging the cable into the back of the preamp.
My amp and CDP accept the Blacksands with a much firmer, tighter grip on the IEC inlet.
Has this been a concern for anybody else?

Thanks

AB · « **Reply #4 on:** 1 May 2007, 03:15 pm »

Hi HPower,
How many hours are on your SWLP now?
Just an FYI from my experience - I thought my SWLP was done settling in at around 250 hours but this turns out not to be the case. After about 250-300 hours it had gone through a definite change but now at around 400 hours it is changing again.
I have been traveling quite a bit this Spring and the unit has had a few weeks of rest between the usual marathon work at home/listening sessions it normally goes through. This last trip has it back to being somewhat sibilant. This was quite a surprise. It even seemed to get worse as the unit warmed up and played for about 8 hours yesterday.
It did this early on in it's break in too so I am not worried. If I remember correctly it needed about 15 hours or so before it came back to sweet again but after each time this happened I had a few tube mongers phone numbers in my hand ready to go for a NOS 5AR4. But after giving the unit some time to come back around I choose not to change a thing.

I can't help you with your fuse problem but I would hesitate a bit longer before jumping into a new NOS 5AR4 until the unit has really settled in. How long for that? You got me...I am still waiting. I guess the long rests are adding to the break in of the caps. Before the last trip the SWLP was just perfect to my ears.

HPower · « **Reply #5 on:** 1 May 2007, 03:46 pm »

Hi AB,

You are correct about the sound moving around a little bit.
I do not have as many hours on my SWL as you do on your SWLP, I have had it for about a month now,
maybe a little over 100 hours.
Right out of the box it sounded ok but lately (right up 'til everything stopped with the blown fuse) the sibilance
has been very concerning.
Dan also recommended holding off on the tube rolling until the loooong break-in is completed.
I was just figuring if I do have a bad rectifier tube that has caused the fuse problem , I might look
at something like a NOS Mullard, now.
You may be right about waiting but it is hard to be patient and now I'm a little more frustrated with this fuse problem.

AB · « **Reply #6 on:** 1 May 2007, 04:25 pm »

Funny thing is that after listening yesterday I was all set to make a few calls today looking to see who had a NOS Mullard available. Then I read these last few posts about bad 5AR4s and they had me doubly set to make the calls.
So I get where you're coming from.

The issue for me is spending $130+ on a tube I may not like. There might be a few good used ones around for half that though. And then there's always the standard $20 new production pieces too.

I just would hate to have one go BZZZ and leave me stranded without a replacement.

If I call Andy today I'll ask how many calls he's gotten about 5AR4s

HPower · « **Reply #7 on:** 1 May 2007, 06:49 pm »

Well Guys,

I just spoke with Dan on the phone and he seems to think it is probably a bad rectifier tube.
He is going to sent me a replacement out as soon as he can but I am sure it will be at least a week or
so for it to make it's way to me up here in Toronto.

If I thought that I could find something locally I might pick up one, I now see the importance to have a back-up tube.

AB,

Even if I get a cheapy tube locally I think I still will try to find a NOS Mullard.
If you do get the urge to go looking and do come accross a stash, please pass the info on to me.

Thanks

jqp · « **Reply #8 on:** 1 May 2007, 06:55 pm »

Just a thought, when testing for faulty tubes, etc. with the cover off, wear glasses/goggles.

HPower · « **Reply #9 on:** 1 May 2007, 07:10 pm »

jqp,

That sounds like some smart advise, thanks.

Guys,

I just got a responce on an inquiry about finding Mullard tubes from Jim McShane at:

http://pages.prodigy.net/jimmcshane

Jim says he has:

(2) 5AR4/GZ34 Mullard black base NOS/NIB, branded
Knight/Mullard, scalloped plate tubes, print intact, very nice!
The boxes are beat but the tubes are great! $104.50 ea.

They appear to be 60s vintage.

I also have these:

(19) 5AR4 Philips/ECG (Sylvania) NOS/NIB. These tubes
are labeled "5V4GA", but are actually large bottle 5AR4/GZ34s.
These were built in the '80s, and they are fully capable 5AR4s -
they just were sold as 5V4GA. They're great USA made
5AR4s at a great price, $64.50 ea.

Those are terrific too.

Any thoughts on these?

AB · « **Reply #10 on:** 1 May 2007, 07:37 pm »

The $104.50 for the 60's Mullards sounds right. I have seen them for $105 to $140. The steel base ones from the 50's are the craziest priciest.

Are these the tubes the guys here have all loved? Someone needs to chime in with that.

As for the 80's vintage Sylvanias, I have seen them for $50 to $75. Does the large bottle fit in the PSU?

What's Dan sending you?

HPower · « **Reply #11 on:** 1 May 2007, 08:13 pm »

Ya, I would like to hear what some of the more seasoned tube guys have to say on these tubes as well.

Dan is sending me just a new OEM Sovtek, he said that is all he stocks.

For NOS tubes he suggested searching some of the online outlets.

rlmacklin · « **Reply #12 on:** 1 May 2007, 08:24 pm »

I spoke with Andy Bowman (Vintage Tube Services) yesterday afternoon.

He said he has some Mullard 5AR4s coming in next week.

I have been talking with him re getting one or two of these for a month or more
(when he didn't have any)...so there may be other buyers already in line for the ones coming in...

AB · « **Reply #13 on:** 1 May 2007, 08:55 pm »

Quote from: rlmacklin on 1 May 2007, 08:24 pm

I spoke with Andy Bowman (Vintage Tube Services) yesterday afternoon.

He said he has some Mullard 5AR4s coming in next week.
I have been talking with him re getting one or two of these for a month or more
(when he didn't have any)...so there may be other buyers already in line for the ones coming in...

Ok. Andy gets another call from me too then.

I have a Ruby 5AR4 that's pretty damn good. $14.95

Anyone else try it?

TONEPUB · « **Reply #14 on:** 1 May 2007, 10:08 pm »

No one is fearing "powered by Honda" in Formula One...

But I would love to see that change! Jenson Button
is a great guy!

AB · « **Reply #15 on:** 1 May 2007, 10:19 pm »

Quote from: TONEPUB on 1 May 2007, 10:08 pm

No one is fearing "powered by Honda" in Formula One...

But I would love to see that change! Jenson Button
is a great guy!

Ok. You win this non sequitur contest.

HPower · « **Reply #16 on:** 1 May 2007, 11:50 pm »

Thanks for the heads up rlmacklin, I may give him a ring tomorrow as well.

TONEPUB, you are correct... lately the Formula One Honda motors have been wanting
to make like my fuse, and blow up.

I am a big fan of Nicky Haden, "Honda's current Moto GP Champion" but so far this year it
has not been all that great either.

modwright · « **Reply #17 on:** 2 May 2007, 08:42 am »

Hi guys, yes there have been a small percentage of the Sovtek rectifier tubes fail. They seem to either fail immediately upon testing or a week or two later. Of course we will gladly send out a replacment tube in the event that this happens. We can't afford to ship all of our units with NOS rectifiers and I don't know that the current production Chinese tubes would be more reliable.

Thanks,

Dan

HPower · « **Reply #18 on:** 4 May 2007, 11:52 am »

D'oh,

I picked up a tube on Wednesday and tried it in the SWL but unfortunately it did not solve my
fuse blowing problem.
The tube was a JJ GZ34... $20 at The Tube Store.
I don't think this tube is anything special, I just wanted something to get me up and running and then
it could serve as a back-up tube once I find something else.
As it turns out this tube is about 15mm taller than the Sovtek and will not allow the cover to go back on.
The Tube Store did say that they would exchange it for a new Sovtek, so it is not a total lose.

I sent an email out to Dan to tell him my findings, but have not heard back from him yet, which is a little
strange, as he usually fairly quick to respond.

It has been pretty frustrating this week not having the system working and I am really not looking forward
to the down time if I have to send the SWL back to Dan for repairs.

A week or so to go from Toronto to Dan, then the repair time, then another week or so for the return shipping...

So it looks like my SWL is going to take at least a month longer to break-in than anybody else's... Double D'oh

AB · « **Reply #19 on:** 4 May 2007, 04:16 pm »

So the new tube still blew the fuse?
Just to be clear.