[kevin gilmore]

I forgot about the current source drivers, so yes there are a total of 7 x 2sa1968 per tube
 
and 2 more in the power supply

 

[Earspeakers]

  it's about 25W per heatsink. heatsink temperature reaches about 40C, not very hot. the original BH used the 1968. those were discontinued years ago and not available in large enough quantity to use for production. i think each BH used 24 of them.

Thanks, interesting. Could you tell us how the BHSE differs from the original BH? I've been operating on the premise that they were essentially the same. 

 

[justin w.]

Hi Justin ,
Have you sent the remain payment email for every one yet? I haven't got it. And as last question I ask, if any way that I could pay by credit card? Because I have no idea how much shipping fee I need pay if I did it at headamp.com.

Thanks,
Meng

 
Meng,
 
No, not yet. I will do that when the amps are fully assembled and I am testing them. You can pay by credit card, that will be an option when I send the email. The email will include shipping costs

 

[Meng-609]

Meng,

No, not yet. I will do that when the amps are fully assembled and I am testing them. You can pay by credit card, that will be an option when I send the email. The email will include shipping costs

Justin:

I got it. Thank you very much.

 

[justin w.]

 
 
Purple has arrived
 
I have some unanswered PMs regarding BHSEs and i will get to that tonight or tomorrow

 

[blackads]

Is there a risk of damage to the amp if power to the power supply is turned on and off at the wall (ie the switch on the power supply itself is left on but the wall outlet does the switching)?

Reason I ask is that I have accidently left my bhse on a couple of times (thankfully for only a few hours each time) and I am considering a smart power outlet which would allow me to turn off the supply remotely or by timer.

 

[NoPants]

BHSE uses some in-production parts where they are appropriate, shouldn't be hard to divine from the pictures

 

[justin w.]

Is there a risk of damage to the amp if power to the power supply is turned on and off at the wall (ie the switch on the power supply itself is left on but the wall outlet does the switching)?

Reason I ask is that I have accidently left my bhse on a couple of times (thankfully for only a few hours each time) and I am considering a smart power outlet which would allow me to turn off the supply remotely or by timer.

 
if the BHSE is unplugged from the wall power, it doesnt matter if the BHSE's power switch is on or off

 

[blackads]

if the BHSE is unplugged from the wall power, it doesnt matter if the BHSE's power switch is on or off

Thanks Justin, appreciate the prompt response. I have #137, picked it up last week from A2A – couldn’t be happier.
cheers

 

[The Monkey]

   
if the BHSE is unplugged from the wall power, it doesnt matter if the BHSE's power switch is on or off

 
I want mine to work even when it isn't plugged in.

 

[Earspeakers]

microwave beamed power. Might mess with your frequency response though.

 

[wink]

Tesla technology could do the trick.

 

[JamesBr]

  microwave beamed power. Might mess with your frequency response though.

 
+1

 

[arnaud]

oh well, looks like the BHSE died on me the other day .
 
Was working fine the whole day before. Switched it on again next morning, it shut off after the high voltage goes into the tubes (~1min on).
 
Switched the tubes today, tried to power it on, the left led did not light up, I quickly aborted.
 
Have not heard from Justin since it happened, I guess I am out of amp with weeks / months ahead ( …

 

[Earspeakers]

  oh well, looks like the BHSE died on me the other day .
 
Was working fine the whole day before. Switched it on again next morning, it shut off after the high voltage goes into the tubes (~1min on).
 
Switched the tubes today, tried to power it on, the left led did not light up, I quickly aborted.
 
Have not heard from Justin since it happened, I guess I am out of amp with weeks / months ahead ( …

Not good! Really sorry to hear that. If you put in new tubes and still bad then yeah you've debugged as much as you can. Maybe one of the tubes failed, which then pulled too much current and blew one of the transistors. Do tubes fail that way? I've always had them just gracefully die from the heater wearing out, this scenario would have to be a arc over or something.