Dusty Chalk Posted May 4, 2016 Report Share Posted May 4, 2016 On 4/14/2016 at 6:08 AM, jpelg said: Would strategically placed silica gel packets help? That's actually brilliant. Quote Link to comment Share on other sites More sharing options...
johnwmclean Posted May 4, 2016 Report Share Posted May 4, 2016 (edited) Although the KGSSHV in question is one of Geoff’s beautiful builds I doubt there is any stupidity in there. 5 hours ago, spritzer said: If you do something stupid then the KGSSHV has more than enough potential to fry any Pro bias headphones. Edited May 4, 2016 by johnwmclean Quote Link to comment Share on other sites More sharing options...
spritzer Posted May 4, 2016 Report Share Posted May 4, 2016 It has nothing to do with the build, it's built in into the circuit. Any peaks that are double the bias voltage will run a high risk of damaging the drivers. That's why the old transformers were fitted with clamp circuits. Run an active preamp into the KGSSHV and you can have enough gain for this to happen... Quote Link to comment Share on other sites More sharing options...
sorenb Posted May 4, 2016 Report Share Posted May 4, 2016 13 hours ago, spritzer said: If you do something stupid then the KGSSHV has more than enough potential to fry any Pro bias headphones. What kind of "stupid" are you talking about here? 1 hour ago, spritzer said: It has nothing to do with the build, it's built in into the circuit. Any peaks that are double the bias voltage will run a high risk of damaging the drivers. That's why the old transformers were fitted with clamp circuits. Run an active preamp into the KGSSHV and you can have enough gain for this to happen... How would a clamp circuit help? Quote Link to comment Share on other sites More sharing options...
spritzer Posted May 4, 2016 Report Share Posted May 4, 2016 Both of those are very obvious... Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted May 4, 2016 Report Share Posted May 4, 2016 so with any fully dc coupled circuit, if you put a balanced signal on both inputs say -1 volt, the output of both drivers will go to -VCC (400,450...) resulting in a dc bias on the headphones of 1kv early srm717's had a protect circuit for this, but it did not work as the relays ended up arcing thru. Quote Link to comment Share on other sites More sharing options...
sorenb Posted May 4, 2016 Report Share Posted May 4, 2016 What about having a simple circuit that loads down the BIAS voltage if excessive DC is present on the output? Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted May 4, 2016 Report Share Posted May 4, 2016 not a good idea to do that to the diaphram Quote Link to comment Share on other sites More sharing options...
sorenb Posted May 4, 2016 Report Share Posted May 4, 2016 19 minutes ago, kevin gilmore said: not a good idea to do that to the diaphram also if the "load" is placed before the 4.7M balast resistor? Quote Link to comment Share on other sites More sharing options...
astrostar59 Posted May 4, 2016 Report Share Posted May 4, 2016 23 hours ago, spritzer said: If you do something stupid then the KGSSHV has more than enough potential to fry any Pro bias headphones. No idea what caused the failure in my 009s. It was the left driver that started fading output. No distortion and the right driver was ok. I don't think it was the amp, but I will measure the bias value anyway from the pad on the PS board, and the DC offsets at the socket.Most probably it is the dreaded 009 imbalance thing again. The only thing in my car is it took 23 months to appear, most cases I have heard about happen inside 3 months. My input is actually an RCA line out of 2V standard into a convertor plug RCA/XLR so actually is less than the expected 5/6v of an XLR input. I ran the pot at around 12 o'clock for loud listening, 11oclock for normal. Quote Link to comment Share on other sites More sharing options...
Laowei Posted March 31, 2017 Report Share Posted March 31, 2017 Visiting Osaka, and it seems they take thier audio very seriously here. Running a Blue Hawaii is not simply a choice, but a Lifestyle! 5 Quote Link to comment Share on other sites More sharing options...
Ali-Pacha Posted April 19, 2017 Report Share Posted April 19, 2017 Any hint about what Justin is cooking ? Ali Quote Link to comment Share on other sites More sharing options...
swt61 Posted April 19, 2017 Report Share Posted April 19, 2017 Knowing Justin, probably burgers. Quote Link to comment Share on other sites More sharing options...
spritzer Posted April 19, 2017 Report Share Posted April 19, 2017 So he's sending me something... He'll get that joke... Quote Link to comment Share on other sites More sharing options...
Dave R Posted May 12, 2017 Report Share Posted May 12, 2017 On the other site's BHSE thread, a head-fier I know " Bonesy Jonesy " wrote a post saying he once heard someone's BHSE and the SQ was terrible, he also said the tubes used were NOS's. So my guess is that someone is me because he did hear my BHSE with the 009's around 4 years ago, and at that time the SQ from the 009's was very uncomfortable, however the tubes being used then weren't NOS's, they were either stock mullard's or Svetlana's winged C's, because when Bonesy Jonesy visited my place in 2012 or 2013 they were the only tubes I had, and still do. Now I did try and write a post on that site correcting Bonesy Jonesy, because I didn't want others to think NOS tubes are bad, [ well at least the Mullard xf4's I use aren't ] but because that site has been changed somewhat, I got mixed up writing a post so decided to delete it. [ And this time I won't be writing anymore posts there ] On that sites BHSE thread good things have been written about Svetlana winged C's, but I haven't used mine for sometime, so thought I'd give them another try but this time the Yggy was being used. And I'm very impressed with the SQ I heard, not as good as the xf4's and there was/is still a slight edginess, but not uncomfortable as they were when using the K-01 I had. What this means is John [ johnwmclean ] was right when he suggested it could be the K-01 that was causing the uncomfortable SQ I had from the 009/BHSE/K-01. So John, I should've listened to you when you made that suggestion, sorry. Quote Link to comment Share on other sites More sharing options...
mwl168 Posted May 12, 2017 Report Share Posted May 12, 2017 I have used Winged C SED EL34 on my latest version of Blue Hawaii and with both 007 and 009 of the later versions. My DAC is a dual-mono Twisted Pear Buffalo II. I also like the sound. Never tried the re-issue Mullard. I should mention my BH has a few differences compared to the BHSE. It has the 10m90/DN2540 cascoded CCS and is powered by GRHV and GRLV. Quote Link to comment Share on other sites More sharing options...
Dave R Posted May 12, 2017 Report Share Posted May 12, 2017 Because listening to my 009's while using the stock Mullard's that came with the BHSE, and also using the K-01, made the SQ so uncomfortable and at times painful, I haven't used those tubes for at least 4 years, however because I'm happy with how the svetlana's/BHSE and Yggy now make the 009's sound I'll give those stock Mullard's another go. Now those NOS Mullard xf4's I have were got from watfordvalves, and Derek there told me he got them from a reliable source that bought them directly from the Mullard Blackburn factory in Lancashire England in the early 70's. Derek also told me Mullard never gave any of their secrets away, which is probably why they're still regarded as the holy grail of EL34's. Quote Link to comment Share on other sites More sharing options...
Dave R Posted May 13, 2017 Report Share Posted May 13, 2017 (edited) Swapped those Svetlana Winged C's for the stock Mullard's yesterday, had a listen then and today, and I'm very surprised and impressed with how the 009/BHSE/Yggy sound using those tubes. Like with the Winged C's there's still a slight edginess to the SQ, but I believe that's because of the 009's, now with the 007's both those tubes would be very good. ( imo ) I still favour the Mullard xf4's, but if I'd had the Yggy before getting those NOS Mullard's, then with how much they cost me I'm not sure I'd have got them. ? Edited May 13, 2017 by Dave R Quote Link to comment Share on other sites More sharing options...
Whitigir Posted May 13, 2017 Report Share Posted May 13, 2017 20 hours ago, mwl168 said: I have used Winged C SED EL34 on my latest version of Blue Hawaii and with both 007 and 009 of the later versions. My DAC is a dual-mono Twisted Pear Buffalo II. I also like the sound. Never tried the re-issue Mullard. I should mention my BH has a few differences compared to the BHSE. It has the 10m90/DN2540 cascoded CCS and is powered by GRHV and GRLV. That is closer to grounded grid ? Quote Link to comment Share on other sites More sharing options...
mwl168 Posted May 13, 2017 Report Share Posted May 13, 2017 The BH has one additional stage than the GG. Also my BH uses FET (2SK216/2SJ79) not the BJT. I have not finished my Grounded Grid build yet but will be interesting to see how they compares. Quote Link to comment Share on other sites More sharing options...
Rossliew Posted May 13, 2017 Report Share Posted May 13, 2017 10 minutes ago, mwl168 said: The BH has one additional stage than the GG. Also my BH uses FET (2SK216/2SJ79) not the BJT. I have not finished my Grounded Grid build yet but will be interesting to see how they compares. Would you know how your BH compares to HeadAmp's BHSE in terms of sound sig? Quote Link to comment Share on other sites More sharing options...
mwl168 Posted May 13, 2017 Report Share Posted May 13, 2017 No, I have never listened to Justin's BHSE. I know it looks a lot better than mine 2 Quote Link to comment Share on other sites More sharing options...
Ekstatikon Posted June 1, 2017 Report Share Posted June 1, 2017 Please Help Yesterday I turned the BHSE on, but it didn't work. The PSU blue light is on, just as well as the left blue light of the device. After two minutes, the right blue light of the amp also turns on (normal), but the red lights that can be seen from above remain off. Both the PSU and the amp won't heat, even though the four valves are lit. Do you have any idea of what may be causing this?thanks Quote Link to comment Share on other sites More sharing options...
johnwmclean Posted June 2, 2017 Report Share Posted June 2, 2017 Fuse? Quote Link to comment Share on other sites More sharing options...
mwl168 Posted June 2, 2017 Report Share Posted June 2, 2017 (edited) If the valves are lit but do not heat up, I wonder if the filament supply is on but not the high voltage supply? I am not familiar with the BHSE, does it have separate fuse for the high voltage supply? Edited June 2, 2017 by mwl168 Quote Link to comment Share on other sites More sharing options...
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