I am in deep trouble thanks to Dr. Lloyd!
Oct 11, 2006 at 9:50 AM Post #46 of 111
I actually reckon that looks pretty cool, and no doubt it will sound awesome, if the standard EAR+ is anything to go by...
 
Oct 18, 2006 at 2:19 AM Post #47 of 111
just got an email from lloyd saying that pre-production models are being tested and he's now taking pre-orders for the HD150. the following pdf was also attached...i'd like to hear some discussion about the technical aspects of this amp:

also got this reply:

Quote:

The price is $750 including four tubes (ECC99, 6N6P, 12AX7, 5751). I have two HD amps to build then I will be starting the HD150 orders. So the first unit could ship the first week of November.


HD150.jpg
 
Oct 18, 2006 at 8:46 AM Post #48 of 111
I can't afford it and my wife would kill me if I did (having just bought the EAR+ HD) but I sure want one! Looking forward to reading some impressions of this amp when people have them in their possession...
 
Oct 19, 2006 at 5:19 PM Post #54 of 111
Can someone explain this part of the description: "The HD150 comes with two spare sockets and both a JJ ECC99 and Russian 6N6P as well as a new Tung-Sol 12AX7 and a Sovtek 5751—lots of combinations for tube rolling connoisseurs." I'm confused by this and I'm not sure how many tubes the amp uses. There are 4 tubes in the pictures, but are all needed to run the amp? I don't understand the spare socket part. I might have to send the Dr. an email to clear this up.
 
Oct 19, 2006 at 8:16 PM Post #55 of 111
The tubes supplied with the HD150 permit experimentation with different tube combinations (“tube rolling”). The active tubes are on the right side of the chassis. The input tube is a 5751,
12AX7, ECC83, or equivalent and the output tube is either an ECC99 or 6N6P. The extra tubes not in use can be inserted in the sockets on the left side of the chassis.
 
Oct 19, 2006 at 10:38 PM Post #57 of 111
Now I'm confused ... the regular ear+ uses 3 tubes but the special edition uses only 2?
confused.gif
 
Oct 20, 2006 at 1:57 AM Post #58 of 111
The following excerpts are from emails I have exchanged with Dr Lloyd:

Quote:

The outputs are handled by the two triodes of the ECC99. The extra tube sockets hold alternate tubes which are supplied. The ECC99 triodes have higher transconductance than the 12B4As and can handle the same power so the output resistance driving the headphones has been reduced from 7 Ohms to less than 3 Ohms. The power transformers are in the rear box and the output transformers in the front box. Everything is a tight fit in the 1" chassis which is why the mammoth Solens protrude through the bottom (not visible in normal position).


Quote:

The ECC99 has two triodes in one envelope which are not the same as the 12B4A (the ECC99 has a higher mu and transconductance so is easier to drive and yields a lower output impedance) but work very well in this circuit. They are also easier to obtain as they are currently manufactured by JJ Electronics.


Quote:

The HD150 has a 40% increase in available power output and a lower output impedance which makes it capable of driving an even wider variety of headphones.


Hope that this answers a couple of questions.

The big question remains: How does it sound?
 
Oct 20, 2006 at 4:13 AM Post #59 of 111
Oh what the heck, why not ... order placed. It's not like there's any major holiday coming up that I need to save for anyway.
biggrin.gif
 
Oct 20, 2006 at 10:59 AM Post #60 of 111
Quote:

Originally Posted by dslknight
Now I'm confused ... the regular ear+ uses 3 tubes but the special edition uses only 2?
confused.gif



The ECC99 is a dual triode, like the 5751 or 12AX7, albeit more powerful. The typical 12B4A is a single triode. He could have used two ECC99s, utilizing half of each (or paralleling them), but the best matching is often within the single envelope, and the separation is very good.

I think it makes for a tighter layout by a good margin. It would have been nice to have the two active tubes in the forward two sockets, but then you'd have a tall tube on one side, and the short tube on the other, with notably different levels of illumination, too. The tubes are somewhat hidden from forward view by the transformer covers, too.

It's possible that you could wire up the heaters of the storage sockets, it would total about 1.5A... but it seems wasteful. Alternatively, you could illuminate the two storage sockets from beneath with orange LEDs.

I'm glad that Lloyd favored signal path over appearance, in the end. It would have been nice to have it more balanced in appearance, but also having a tall tube on one side and a shorter, dimmer tube on the other would have been at least as strange.
 
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