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Headamp Blue Hawaii Special Edition - Page 299

post #4471 of 4975

my understanding is the problem is much worse recently as the high V parts for CRT drive are discontinued, official distributor stock depleted

 

so for a build with parts bought 2-3 years ago the parts are more likely to be correct than if bought today

post #4472 of 4975

there are 2 transistor device testers you can buy on ebay that can verify

these devices. one measures beta and high voltage breakdown and the

other measures gate capacitance.  So for about $80 total, you are good

to go. Justin, and I have real curve tracers in addition because telling

real input jfets from fake switching input jfets is a lot tougher.

post #4473 of 4975
Quote:
Originally Posted by jcx View Post
 

my understanding is the problem is much worse recently as the high V parts for CRT drive are discontinued, official distributor stock depleted

 

so for a build with parts bought 2-3 years ago the parts are more likely to be correct than if bought today

 

dont forget all the low noise jfets 

HeadAmp Audio Electronics - home of the Pico and Gilmore amps.  Now with Audeze, Fostex, HiFiMAN, Sennheiser, and STAX.
Find us at www.HeadAmp.com

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post #4474 of 4975
Quote:
Originally Posted by magiccabbage View Post
 

that is such ******** - how can they get away with that. Do you know straight away if the parts are fake? Is there a way of testing. Could they potentially ruin a build if it went unnoticed?

 

several ways.

 

1) appearance, if you know what a real part looks like, the fake parts are usually different. however often the photos will show real parts.

2) basic tests with a transistor tester for max voltage, and gain, and of course assuming the pin-out is the same.

 

if you get this far and the part tests good, it will probably work in the circuit, just not to the same specifications which could mean higher noise or frequency response issues. there are probably many working amps out there with fake parts. 

 

as an example this is a fake 2SK216, a part used in the BHSE: http://www.ebay.com/itm/1pcs-2SK216-TO-220-Silicon-N-Channel-MOS-FET-/181048422761?pt=LH_DefaultDomain_0&hash=item2a2753b169

 

i have notified ebay about it and also asked the seller to remove their listing, but it has not has happened. you will see these have been sold and the buyers have left positive feedback, but they are very fake parts.


Edited by justin w. - 12/19/13 at 11:28am

HeadAmp Audio Electronics - home of the Pico and Gilmore amps.  Now with Audeze, Fostex, HiFiMAN, Sennheiser, and STAX.
Find us at www.HeadAmp.com

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post #4475 of 4975
Quote:
Originally Posted by justin w. View Post
 

 

several ways.

 

1) appearance, if you know what a real part looks like, the fake parts are usually different. however often the photos will show real parts.

2) basic tests with a transistor tester for max voltage, and gain, and of course assuming the pin-out is the same.

 

if you get this far and the part tests good, it will probably work in the circuit, just not to the same specifications which could mean higher noise or frequency response issues. there are probably many working amps out there with fake parts. 

 

as an example this is a fake 2SK216, a part used in the BHSE: http://www.ebay.com/itm/1pcs-2SK216-TO-220-Silicon-N-Channel-MOS-FET-/181048422761?pt=LH_DefaultDomain_0&hash=item2a2753b169

 

i have notified ebay about it and also asked the seller to remove their listing, but it has not has happened. you will see these have been sold and the buyers have left positive feedback, but they are very fake parts.

incredible, what goes on under your nose. 

post #4476 of 4975
Quote:
Originally Posted by magiccabbage View Post
 

that is such ******** - how can they get away with that. Do you know straight away if the parts are fake? Is there a way of testing. Could they potentially ruin a build if it went unnoticed?

 

When I got the parts I just put them into storage without giving them a second glance.  I had enough 2SA1968's at hand for the time being so it was a few months until I dug out the stash and realized they were all fake.  Dalbani spun some BS that I should have tested them on arrival but a quick reply stating that when dealing with reputable suppliers that isn't needed.  I've never had to test any part I've gotten from Mouser to see if it was real or not. 

post #4477 of 4975
Justin, can you comment on how components have changed (eg, using one brand of cap vs another), over the build lots?
Is this current lot using the same component brands that you used for the previous runs?
post #4478 of 4975
Quote:
Originally Posted by Surge74 View Post

Justin, can you comment on how components have changed (eg, using one brand of cap vs another), over the build lots?
Is this current lot using the same component brands that you used for the previous runs?

 

yes

HeadAmp Audio Electronics - home of the Pico and Gilmore amps.  Now with Audeze, Fostex, HiFiMAN, Sennheiser, and STAX.
Find us at www.HeadAmp.com

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post #4479 of 4975

I like it when Justin says the "yes" word.

post #4480 of 4975

After months of simply enjoying my system, with  no changes or tweaks, my tranquillity has been shattered by the most unnerving thing: Yep, it's the dreaded...…UNEXPLAINED NOISE :eek:.  In around 2 decades of Stax ownership, I've never had an Unexplained Noise before (discounting the Stax fart, obviously), so I'm quite worried about it.

 

It sounds like a sharp click, like a static discharge or pulse on the line, always in one channel. Hours may go before it happens, but when it does it's most likely to repeat within seconds. It's not the source and it doesn't appear to be affected by volume control, but it hasn't happened often enough for me to be sure. There is no channel imbalance and the SQ is fantastic. There was nothing unusual about heat or humidity when this problem started.

 

So suggestions please Sherlock on the most likely culprit?

 

To my mind it must be one of: the tubes, the BHSE or the headset. As my 007 Mk1 is the only electrostatic headset I have, my swapping options are limited. Removing and shorting the 007's pins made no difference.

 

I'm hoping it's the tubes because they are the easiest to replace. And these are the Psvane PH's after all, with their suspect quality control. So last night I pulled out the PH's (very carefully) and pushed in the Treasures. Result was no clicks that evening. But to be conclusive, I should swap the PH's back in to see if the noise returns. My question is: would it be very, very unwise to put the PH's back in? I.e. is the Unexplained Noise a warning of imminent tube failure?

post #4481 of 4975

swap the tubes to the other channel and see if the noise moves with it

HeadAmp Audio Electronics - home of the Pico and Gilmore amps.  Now with Audeze, Fostex, HiFiMAN, Sennheiser, and STAX.
Find us at www.HeadAmp.com

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post #4482 of 4975

Doh! Good point Justin. I'll give it a try tomorrow.

 

One thing I should point out when going back to the Treasures after a long gap: It's confirmed that the PH's are still on a higher plain on the SQ front.


Edited by TheAttorney - 12/22/13 at 4:54am
post #4483 of 4975

well please let us know how Rachel responds to your questions about quality control.  I believe she sent a 32 page instruction manual to the boys in Hong Kong detailing how to test those tubes. Be careful of asking how she monitors compliance from Canada if she never actually touches the tubes that she sent to you. 

post #4484 of 4975

I finally gave up on waiting for the BHSE and now am the happy owner of a Cavalli Liquid Lightening 2.

 

Even if the BHSE is better it is great actually being able to listen to music through my SR009s. So far I'm loving the combination.

 

I have no regrets.

 

regards Macrog

post #4485 of 4975
Quote:
Originally Posted by macrog View Post
 

I finally gave up on waiting for the BHSE and now am the happy owner of a Cavalli Liquid Lightening 2.

 

Even if the BHSE is better it is great actually being able to listen to music through my SR009s. So far I'm loving the combination.

 

I have no regrets.

 

regards Macrog

 

I don't mean to brag, but reading posts like this make me realize what a lucky person I am. Up until a month ago, I wasn't really interested in a BHSE, and I had no idea that its lead time is around 1-2 years. Here's what happened, and it began last month.

 

1. Back then I owned the SR-009 and SRM-007tII. To be honest, I wasn't really impressed by this combo, and I read many posts from fellow Head-Fi'ers whose opinions I trust that the discontinued SR-007 mk1 is better sounding than the SR-009, and a few have even stated that the SR-007 mk1 is not only the best Stax headphone up to date but also the best sounding headphone of all time. At any rate, this piqued my interest so I decided to see if I can buy a secondhand unit.

 

2. I looked at the Head-Fi classified section, and there were a couple sellers who had put up their SR-007 mk1 for sale. However I thought the price was too expensive, so I went to this Korean-based headphone online community where I frequently visit and put up a WTB post for a SR-007 mk1 there.

 

3. About a week later, a guy (in Korea, of course) contacted me. He was an owner of SR-007 mk1. However he did not call me to sell his SR-007 mk1, but to ask me several questions. We had a friendly discussion regarding headphones over the phone for about 30 minutes, but in the end he wasn't willing to let go of his SR-007 mk1, as he too considers it superior to SR-009. I was bummed, but oh well.

 

4. Then a few days later, while I was taking a nap, the same guy (I'll refer to him as Mr. A) called me. He told me that another headphile whom he know (I'll refer to him as Mr. B) is selling his SR-007 mk1, along with other associated gears including the WEE. Since Mr. A already owns the SR-007 mk1, he is interested in Mr. B's WEE only, but I could buy the SR-007 mk1. So I contacted Mr. B, and I was able to purchase Mr. B's SR-007 mk1 at a less expensive price (around $1,500) than here at Head-Fi. It was also in a very good condition, and I didn't have to pay for any shipping/PayPal fees, so I was quite satisfied. When Mr. B asked me which amp I'm going to drive the SR-007 mk1 with, I said I currently own the SRM-007tII. He said that I should look for a better amp, ideally the BHSE, to get the best performance out of it.

 

But my stroke of luck didn't end there...

 

5. Knowing that there has to be a better amp than the SRM-007tII for the SR-007 mk1, since SR-007 is harder to drive than SR-009, I did some quick research and indeed, the general consensus was that the BHSE is the best amp for it in the market. But I was naive... I had no idea that I would have to wait 1-2 years for a BHSE upon initial 1/4 down payment. When I realized this, I said to myself, "Screw it."

 

6. Then about a week later, Mr. B contacted me. He told me that he is personally acquainted with another guy (Mr. C) who owns a BHSE. Its unit number was #51, silver front panel, and had both Stax pro and Sennheiser outputs. Mr. C was selling all his electrostatic headphone system, including the BHSE, and he asked me if I was interested in buying a secondhand BHSE for a relatively inexpensive price, along with fully upgraded Psvane EL34PH tubes. He just wanted to let me know of this deal before Mr. C puts it up on the Internet, and someone else snatches it away first. What a coincidence, since I too had considered the EL34PH tubes when I had thought of ordering the BSHE! Apparently it was in very good condition, but the best of all, I didn't have to wait for f***ing 2 years. With tearful eyes, I said... "Yes!"

 

And well, here I am.


Edited by songmic - 12/22/13 at 6:18am
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