Headamp Blue Hawaii Special Edition
Jul 22, 2014 at 3:51 PM Post #5,657 of 9,919

 
So if these are the BHSE from this batch being "burned in" and are running continuously, it must be getting hot in that room!
 
I see some silver ones, so my expectations are going up :wink:
 
Jul 22, 2014 at 8:45 PM Post #5,660 of 9,919
All:  Where is the queue at currently?  Anyone that ordered in July 2013 get a notice yet?  I saw a few posts about a May order and wanted to follow up.  I check this thread once every three months or so for order updates and to make sure that I didn't snooze by mistake and lose my spot (because of an email going to my spam folder or something) :)   Kind of interesting crowd-sourcing way to figure out when the order might ship.
 
Anil
 
Jul 22, 2014 at 10:46 PM Post #5,662 of 9,919
Which one is it ?
k701smile.gif


That one right there.
 
Jul 23, 2014 at 12:29 AM Post #5,663 of 9,919
Question: for tube rolling, how matched we need the quad EL34 to be? Any specs?

 
I see no compelling reason to match any tubes in this amp. DC offsets can be trimmed out, and there is global feedback setting the overall gain. I have unmatched tubes in my Blue Hawaii currently because I don't have a full quad available. DC trim was only off by a few volts when I lost half my quad and replaced with unmatched.
 
Jul 23, 2014 at 3:18 AM Post #5,665 of 9,919
Can you guys imagine the heat by generated by those amps?  I'm listening to my BHSE right now and it is splendid!  
 
Jul 23, 2014 at 7:40 AM Post #5,666 of 9,919
Can you guys imagine the heat by generated by those amps?  I'm listening to my BHSE right now and it is splendid!  


Yes, I guess with all those BHSE's in one room might be like a sauna, however I think one BHSE alone doesn't get as hot as some might think, in fact to me it only gets above warm. I have a 50" plasma TV that gets warmer than the BHSE.
I don't think I have to remind anyone how impressive the BHSE sounds.
 
Jul 23, 2014 at 12:49 PM Post #5,668 of 9,919
I recall this being asked before and somewhat being answered before -- I wish we had more details as well.

From memory, something along the lines of the left side tubes should be matched closely and the right side matched closely and the L + R sides (all 4) not necessarily needing to be as close.

The challenge is for the laypeople without tube testers or tons of experience with tubes in understanding the terminology of what the heck matched tubes really are.  I know that on ebay most of the times you just see sellers posting "matched pair" = tested for tube life and the two are somewhat close to each other.  Whether this is what is really needed in matching or not I doubt that it is enough information to be really useful.  Then you run into the date codes of tubes and buying disparate pairs and it gets way more challenging.

At any rate my ebay-fu is awful so if anyone happens to have a set of Mullard XF's available or knows where I can get them for not inflated prices please keep me in mind!


Thanks for the reply, really appreciate that.

"what the heck matched tubes really are!" That's exactly what I have in mind... only the old gentleman who built my current amp for 009 knows, but he's too old to look for a matched quad or me.
 
Jul 23, 2014 at 3:27 PM Post #5,669 of 9,919
Yes, I guess with all those BHSE's in one room might be like a sauna, however I think one BHSE alone doesn't get as hot as some might think, in fact to me it only gets above warm. I have a 50" plasma TV that gets warmer than the BHSE.
I don't think I have to remind anyone how impressive the BHSE sounds.

 
Is it true that most electrostatic amps run pretty warm/hot? At a meet-up last week I was able to listen to a KGSSHV and it did seem to get pretty warm (warmer than the dynamic amps). My Liquid Lightning amp also gets quite warm. Both of those amps are solid-state though. Maybe solid state amps are generally hotter than tube amps (besides the tubes of course)? Besides the tubes, does the top of amp/power supply get pretty hot on the BHSE? I imagine that as long as you give it enough space to breathe it should be fine.
 
Jul 23, 2014 at 3:47 PM Post #5,670 of 9,919
I think this comes down to an amplifier running in Class A mode. With Class A the transformer is supplying it's maximum rated output
on the grid at all times. This current pool is why Class A amps sound so good, the transistors are not switching on and off as in Class A/B.

All that excess current has to be dissipated as heat. The BHSE is part solid state, and the final gain stage is tubes which provide the final gain
and also produce their own heat doing that. As David says, the BHSE (in normal room temperature) is fine, warm to touch but certainly
not much over 20°C more than ambient on the heat sinks. Obviously the tube are too hot to touch but that applies top all tubes.
I live in South Spain and my house gets to 31°C in summer.

The key to good amplifier design is to vent the case and dissipate the heat by heat sinks. Some big Class A power amps use fans, though
that is only partially successful due to noise.

If I owned a BHSE I would mount it on a solid shelf with nothing above it at all.

Actually my KGSShv (off-board) gets quite warm, about the same case temperature as the BHSE actually.
 

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