the NEW Zana Deux, ZDT and Balancing Act thread

[atothex]

I hope you don't let the drunks within 20' of the Moth gear!!

But what if they were sexeh ladiez?

[Aura]

I hope you don't let the drunks within 20' of the Moth gear!!

Nah I move all the shit to my bedroom before we bust out anything alcoholic. It's a pain, but it's what I gotta do.

[recstar24]

Make sure there is room for Ryan. He'll probably be waiting on the porch when it is delivered.

Look outside:p

[morphsci]

Look outside:p

[Icarium]

Rant a bit about EML AD1 tubes and AD1s in general.

So some of this should come as to no shock to those familiar with EML as some of this is apparently common knowledge for EML vets.

So.. as you can see on the amp there is literally no base showing on the amp. This is not Craig's fault as due to how the AD1 tube is set up and how the socketing works there really is not much base available to grab.

What little there is (Craig estimated 1/8" if I'm not misremembering is obscured by the top plate of the BA).

So when Craig was disassembling it... the glass part came loose a bit from the base. This is a production issue with the EML tubes.. upon communication with Jac Craig discovered that they apparently used to use a resin to glue the tube/base together and have now switched to a rubber cement... though they claim that its never been an issue before. However, Craig notices signs that at least one glue repair has been done to one of the tubes...

Now, EML is willing to repair/exchange these tubes so I have that avenue, but then I'd have no tubes to use with the BA while that happens

Craig and EML suggest using super glue and non ceramic epoxy to fix the tube. So I may do that.. but I was thinking heavily about picking up a NOS pair to use while waiting on the RMA.

I've heard that EML have been know to die early (Under a year and sometimes several months when the owner is unlucky) compared to the more reliable NOS tubes. However, the EMLs come extremely well matched and have various tweaks (Mesh plates and other things.. it's talked about more on the website) that should make them sound better.

However.. in the course of figuring out this tube thing... Craig uncovered some more unexpected news and I quote:

If you read Jac's latest reply there is a new wrinkle in the AD1 dilemma. The original AD1 had a 4V 0.9A heater. The Emisssion Labs tubes can be 1.6A, and in a separate email can vary as much as 0.3A between tubes. He also indicates the the heater voltage has to be close to 4V for optimum operation. I mean how can this be anything like an AD1 if the parameters are that far off. Anyway the point being if you swap out what is in there for NOS AD1's the heater voltage will jump up because the oscillator is not regulated. The heater supply has an adjustment, and can be changed by the user, but you need a high frequency meter to accurately measure the voltage. The standard digital meter will not work.

Jac's reply:

I leave it up to you to design the oscillator, but note that Historical AD1 uses only 0.9Amps. Ours is around 1.5 or so. But this number can very a lot with other charges. So I would say it must work within 5% good from 0.9 to 1.6 Amps, with the nornal mains variation of 5% included. So you need also good line regualtion. So ar 115V +5% and 0,9Amps you need max 4V+ 5%. The other is at 115V -5% and 1.6Amps you need mininum 4V -5%. When like this, you're ok.

Anyway the takeaway here is that NOS tubes are NOT going to be like the AD1 and will not work without some adjustments for the BA. In fact they are almost like different tube that is similar to the AD1. This can be done by the end user, but it is a hassle. Craig will either figure out how to deal with this in the next batch or will not offer the AD1 tube as an option. Also there is no guarantee the NOS will really be all that more durable when pulled by the glass than the EML. Shrug.

Lastly.. the sockets. So.. Craig bought some of the NOS original sockets from EML. These are hard to come by as they got them off NOS tubes. He also sourced some cheaper Chinese ones off ebay. They are indistinguishable from the supposedly NOS ones. Craig is fairly certain they are the same...

Now while Craig was trying to figure out a full proof way to pull out the tubes.. one of the sockets cracked in half. This is pretty unexpected since the things are supposed to be like best sockets ever:

Quote from Jac:

Actually the pull out force with those is as gentle as can be, they're the finest sockets ever designed. If they pull out heavily, there is something wrong.

Anyway.. Craig's theory is that it's possibly Jac's people might have messed up and sent the Chinese sockets (Which they also have) instead of the good sockets.

Ahwell.. Yamamoto makes some outstanding sockets for the AD1 and I'm going to buy those and I feel as good as the NOS sockets are.. if the Yamamoto sockets do not have an overstrong grip they will be ideal. They aren't cheap though at about 26 euros a pop at one of the places I found that stocks them (Btw anyone know a cheaper place to buy them in the US?)... so if you end up still going with the AD1 then I suggest sourcing those for your amp.

Lastly... the story is not all grim. The BA with the AD1 sounds the best Craig says. It's extremely musical without giving up detail... I don't know if its THAT much better than the 307A.. I didn't do side by sides and didn't spend much time with the 307A except while it was in prototype form and it was damned good, but who am I to doubt the creator ;p and Craig has no love for dealing with the damn thing after all this. Anyway.. the AD1 sounds good driven with a Kenrad 6FG8 and rocking Electraprint partial silver output transformers. That's all I know

I hope this information is useful to those considering the AD1s. I'd let Craig make the decision for you unless you absolutely am willing to deal with the hassle for the last 0.00001%. If Craig comes up with an appropriate solution though.. life will be good for you guys I hope it trickles down to me.

And really shout out to Craig for really going all out to make sure that foo_me and I are taken care of... these issues were discovered in the course of the last 72 hrs and he went into overdrive mode to make sure that bases were covered prior to handing the amps off to foo_me yesterday afternoon. Since then he has worked long hours to get the straight dope from Jack and research how to make this a non-issue for batch 1 and future batches.

[jinp6301]

Nah I move all the shit to my bedroom before we bust out anything alcoholic. It's a pain, but it's what I gotta do.

respect dude. Thats a lot of work to get drunk

[deepak]

Bummer about the EML issue. Sounds like you're getting sorted out nicely though.

[morphsci]

Wow that is just really fucked up, but that is why you have to love Craig. He goes the extra 100 miles for his customers.

[zippy2001]

I hope you get all these AD1 issues sorted out. Those are definitely not cheap tubes to replace. I am sure Craig will help get all of these issues dealt with.

Enjoy your amp, it is as sweet to look at as it is to listen to.

[Icarium]

Oh yeah... I was freaking out pretty hard when Craig told me about it, but now having the thing in my possession I really don't mind thing doesn't feel loose to me at all. And I can't even be bothered to switch out the input tube ;p

I'm not a compulsive tube roller by nature so I think I'm in good shape.

[morphsci]

Woo Hoo. Just got the FedEx notification. The BA will be here Friday and it goes to 11!

[Icarium]

Woo hoo jealous of your beastly rotary fader!

[n_maher]

Woo Hoo. Just got the FedEx notification. The BA will be here Friday and it goes to 11!

Which tube compliment did you go with?

[Icarium]

6sn7/307a i believe

[recstar24]

Woo Hoo. Just got the FedEx notification. The BA will be here Friday and it goes to 11!

On Friday Jim, please leave the backdoor open so that its easier for me to come by and listen:p

Perfect timing too, with Monday being Labor Day weekend, and Friday the wife is going to be out...should be a great day to wait outside your door:)

[morphsci]

Which tube compliment did you go with?

6sn7/307a i believe

Damn I hate it when I have to go away and teach. But Dan has it right.

On Friday Jim, please leave the backdoor open so that its easier for me to come by and listen:p

Perfect timing too, with Monday being Labor Day weekend, and Friday the wife is going to be out...should be a great day to wait outside your door:)

No problem as long as you like dogs.

[morphsci]

Ahh... a wee box from California. I wonder what Schwarzenegger is trying to sell now?

Well I hope it is more than foam....

Now that is a little better.

Look Ma, no wall warts!

Now that is a rear end that is easy to appreciate.

You can never have enough tubez.

Seems to be settling into its new home quite nicely.

[Icarium]

Telling you.. need 6F8G + an adapter

Glad you have a suitable rack slot for it ;p Enjoying it man?

Just heard back from Craig's little shoot out:

Here is my two cents worth. Built two adapters, 7N7, 6F8G. The 7N7 is identical to it's 6SN7 brother, except for the loctal socket. I have 6SN7's here that look identical to the 7N7's, and they sound the same. Almost all the NOS tubes 6SN7, 7N7 sound better than the Russian made Tungsol 6SN7 the amp ships with. To exaggerate the point the Tung Sol sounds congested, and flat. The 7N7, 6SN7 GE are better, more enjoyable to listen to. I think this boils down to tube structure, the only one being radically different is the 6F8G. Now that tube is amazing, the 7N7 is somewhere in between the openness, and transparency of the 6F8G, I would say closer to the Tung Sol, but why fake it, 6SN7's don't make it. The Raytheon 6F8G, And Ken Rad were my favorite until the Arcturus burned in. Now that tube is precisely right, even the re-worked Grado RS-1's that I can't stand sound good. More open, space, the sense of being transported to another place, and time, wonderful, sign me up, I am buying a BA.

After building a small horde I have to say I agree

[jp11801]

Hot damn I want one! Nice amp, can't wait to hear Dan C's at the next mini meet

[Icarium]

Throwing something this Saturday ;p Shooting out some details tomorrow. Gonna have Min's here and do a proper input tube shootout... though ugh I think he has no adapter still.

[shellylh]

Ahh... a wee box from California. I wonder what Schwarzenegger is trying to sell now?

Looks great, how does it sound?

[penger]

Hot damn I want one! Nice amp, can't wait to hear Dan C's at the next mini meet

Does that mean it's time to organize another one? =P

[morphsci]

Telling you.. need 6F8G + an adapter

Already bought an adapter (actually a pair) and have a line on some Raytheon 6F8G.

Glad you have a suitable rack slot for it ;p Enjoying it man?

Yeah, that was lucky but expensive.

Just heard back from Craig's little shoot out:

Here is my two cents worth. Built two adapters, 7N7, 6F8G. The 7N7 is identical to it's 6SN7 brother, except for the loctal socket. I have 6SN7's here that look identical to the 7N7's, and they sound the same. Almost all the NOS tubes 6SN7, 7N7 sound better than the Russian made Tungsol 6SN7 the amp ships with. To exaggerate the point the Tung Sol sounds congested, and flat. The 7N7, 6SN7 GE are better, more enjoyable to listen to. I think this boils down to tube structure, the only one being radically different is the 6F8G. Now that tube is amazing, the 7N7 is somewhere in between the openness, and transparency of the 6F8G, I would say closer to the Tung Sol, but why fake it, 6SN7's don't make it. The Raytheon 6F8G, And Ken Rad were my favorite until the Arcturus burned in. Now that tube is precisely right, even the re-worked Grado RS-1's that I can't stand sound good. More open, space, the sense of being transported to another place, and time, wonderful, sign me up, I am buying a BA.

After building a small horde I have to say I agree

Working on my stash of 6F8G and 307A even as I type.

[Icarium]

Edit: Moved discussion about spare adapter to PM

Edited September 8, 2009 by Icarium

[morphsci]

Looks great, how does it sound?

I've only listened to the balanced K340 so far. Hearing them single-ended out of the Zana Deux convinced me to buy the BA. So far it has not disappointed, the BA has no problem driving the K340. In fact I have never heard them sound this effortless. Could be new poppa syndrome, but I don't really care right now.