[m2man]

I think it's just speaker out added on the 2A3, single ended only, different transformers. I assume the Mk IV actually has 4 2a3's. Not sure on that one though. BA can use 2a3's if you want. Otherwise very similar.

 

[Stapsy]

The new 2A3 uses an interstage transformer and has a solid state power supply.  The BA uses coupling caps and has a tube rectifier. I don't believe that the BA with 2A3 is an option anymore, there were very few of them made in that configuration. .  The high-frequency heater that was used in the BA has now been implemented in the newest version of the 2A3.  This is one of the reasons the BA has such a remarkable soundstage.   Between the two the main differences are in tubes, power supply, and transformer/caps
 
The 2A3 mkIV uses paralelled 2A3s and produces 6 watts of power compared with the mkII which produces 3 watts.  Either version can be used for speakers depending on requirements.

 

[SleepyOne]

Warning to fellow audio travellers, this is my experience with JJTUBES.eu when I bought a pair faulty JJ 2A3-40W. 
 
http://www.head-fi.org/t/700641/beware-of-jjtubes-eu-defective-jj-2a3-40w-is-your-amps-fault-even-if-it-works-fine-with-other-2a3-tubes

 

[Audio Jester]

sub'd

 

[Audioclyde]

I read the references to using different rectifier and driver tubes with the latest version of this amp (some with appropriate adapters); what are the possible substitutes in these locations?

Thanks in advance!

Randy

 

[purrin]

I read the references to using different rectifier and driver tubes with the latest version of this amp (some with appropriate adapters); what are the possible substitutes in these locations?

Thanks in advance!

Randy

 
In terms of the rectifier tube, Svetlana 6D22S, you can get old stock from ebay, but the vintage (say 1970s) ones have the same plate structure as the new ones. Maybe the used old ones sound better, but I don't know. Similar situation with the Sovtek 6C45pi drivers. I guess you can get them gold pinned a la EH or cryo'd, upon which they may or may not obtain majickal powers.
 
In short, there are no substitutes (unless you are willing to do funky stuff which will probably void your warranty). I actually think that's a good thing. Only need to roll the 2A3 and prevents OCTRD.

 

[SleepyOne]

Not sure what is best tubes combo for the latest version of EC 2A3 as they use different drivers and rectifiers to older version. You could email Craig and see what he thinks.

 

[Audioclyde]

Thanks; I've sent Craig an email this weekend, but haven't heard back yet (I assume the email link on the EC site is still valid?).  If I'm reading this thread correctly, the current version of the 2A3 uses SS rectification rather than tubed?  I suspect maybe the Eddie Current site just hasn't been updated.  I'm fine with limited or no tuberolling options re the driver tube (and rectifier, if my assumption that the current version uses SS rectification is incorrect), as I have plenty of 2A3 tuberolling options to keep me busy.
 
For those of you with the 2A3 amp, do you have any hum or noise issues with high sensitivity headphones?  I use ATH-W3000ANV's, which have high efficiency/sensitivity, and one thing I really like about the DNA Stratus is the hum pots which allow me to eliminate any trace of hum, even with these headphones....I don't see any hum pots on the pics I find of the EC 2A3 amp, so I'm very interested in getting feedback from current 2A3 owners.
 
I'm considering moving to the EC 2A3 as I'd like to also use my 2A3 amp to power my high efficiency loudspeakers from time to time, but I'm struggling to get a feel for the EC 2A3 in its current version, so any thoughts/input are most welcome!
 
Thanks,
 
Randy
 
p.s. if any current EC 2A3 owners are considering moving to a newer version or different amp such that they might consider letting their EC 2A3 amp go, please p.m. me.  Especially if it is quiet with high sensitivity headphones

!

 

[SleepyOne]

No hum issue when I used JVC DX1000 with EML 45 tubes, very quiet. Haven't tried the JVC with 2A3 as I sold the phone before I got the 2A3 tubes. With 2A3 and T1, same, no noise again.
 
Not idea what type of power supply is used in the new version (SS or valve based), all I know is that it uses 2 rectifiers tubes (different tube type to old version). Also there is now a choice of 2 power tubes & 4 power tubes, the 4 being better for speakers as it has more power. Best check with Craig for detail. 

 

[ValentinHogea]

  Thanks; I've sent Craig an email this weekend, but haven't heard back yet (I assume the email link on the EC site is still valid?).  If I'm reading this thread correctly, the current version of the 2A3 uses SS rectification rather than tubed?  I suspect maybe the Eddie Current site just hasn't been updated.  I'm fine with limited or no tuberolling options re the driver tube (and rectifier, if my assumption that the current version uses SS rectification is incorrect), as I have plenty of 2A3 tuberolling options to keep me busy.
 
For those of you with the 2A3 amp, do you have any hum or noise issues with high sensitivity headphones?  I use ATH-W3000ANV's, which have high efficiency/sensitivity, and one thing I really like about the DNA Stratus is the hum pots which allow me to eliminate any trace of hum, even with these headphones....I don't see any hum pots on the pics I find of the EC 2A3 amp, so I'm very interested in getting feedback from current 2A3 owners.
 
I'm considering moving to the EC 2A3 as I'd like to also use my 2A3 amp to power my high efficiency loudspeakers from time to time, but I'm struggling to get a feel for the EC 2A3 in its current version, so any thoughts/input are most welcome!
 
Thanks,
 
Randy
 
p.s. if any current EC 2A3 owners are considering moving to a newer version or different amp such that they might consider letting their EC 2A3 amp go, please p.m. me.  Especially if it is quiet with high sensitivity headphones

!

 
No hum issues at all... I've even used my CIEMs with it... Some microphonics yes, noticeable hum, nahh... not exactly!

 

[Audioclyde]

Thanks all for the input. I haven't heard back from Craig, but will give him a call this afternoon.

 

[SleepyOne]

Do. It is odd because normally I hear back from him on the next day.

 

[Audioclyde]

Glad to learn that actually; I was afraid that something was wrong. I know and understand that sometimes small business owners don't have time to get to all the email inquiries as quickly as one might like.

 

[Audioclyde]

I heard from Craig this morning and thought I'd share the following info to help clear up any confusion (certainly any that my posts may have contributed to); per his message, the 2A3MK II uses 6D22s rectifier tubes (and that EY500 also works), and driver tubes are ECC99.
 
He is backlogged right now and things are on hold, so again if anyone is interested in selling their EC 2A3 amp (not particular as to version/vintage, so long as it has speaker outputs as well as headphone outs), please shoot me a pm.
 
Thanks,
 
Randy

 

[SleepyOne]

Did he say is the power supply SS (with rectifiers mounted on the amp) or valve based (rectifiers mounted on the PS)?