[CJG888]

Having just pulled the trigger on a Tube Amp BL-2, I felt it might be a good time to set up a dedicated forum here for the discussion of portable tube amps. At present, no such thread appears to exist.

The thread has been created for the discussion of all portable tube and tube/solid state hybrid amps, with the proviso that they must be genuinely portable (i.e. battery powered and small). The upper limit is something like the ASP TU-05. The Pan-Am is, IMO, more of a transportable...

I will share some impressions of the BL-2 when it gets here from Shenzhen (in about 2-3 days). Until then, anyone else with a relevant device (Continental, PortaTube, Elekit, Miu or whatever) is welcome to contribute...

 

[DrSheep]

I don't know a lot about tubes and you mentioned the Continental V3 already, but please add the VentureCraft Go-DAP TT to your list.

 

[IceClass]

Continental V2 owner. Fan. Subscribed.

 

[CJG888]

By popular demand, here is a list of "qualifying" devices. Please feel free to add any I have missed out:

ALO Continental (v1-3)
ASP TU-05
ASP TUR-06
C&C TU
Elekit TU-HP01
Fostex HP-V1
GoVibe PortaTube
Little Bear
Millett Portable Hybrid
Miu Audio iH
Muse TU10
Tube Amp BL-1
Tube Amp BL-2
Venturecraft GoDAP TT

Any others?

 

[IceClass]

Does the HP-V1 actually exist yet or does it remain vapourware?

 

[CJG888]

AFAIK it exists as a prototype (but hasn't been launched yet).

 

[CJG888]

Last seen here:

http://www.head-fi.org/t/673292/tokyo-headphone-festival-presented-by-fujiya-avic-may-11-2013-pictorial

 

[CJG888]

May have to wait a while with those impressions....

My amp appears to be stuck in Shenzhen due to the typhoon :mad:

 

[papahommer]

I know we can get a battery for the Pan Am, but do I really want to listen to it on a train or bus or plane? Sorry, I am not sure if the Pan Am can be consider as portable???

 

[CJG888]

The BL-2 has arrived. First impressions with SE425 are very positive (but it gets seriously hot!).

More to follow...

 

[CJG888]

I have tried a number of cans with the BL-2 now: HD25, DT-48e, ATH-A900X (with A1000 pads), HD600 and FA-002w. Of these, I am (surprisingly) finding the 32 Ohm Fischer FA-002w to be the mont enjoyable match...

Also, the stock 3.5mm cable which is supplied with the BL-2 is actually rather good.

More (and a proper review) to follow!

 

[papahommer]

The BL-2 has arrived. First impressions with SE425 are very positive (but it gets seriously hot!).

More to follow...

Is the hot, very hot? I read somewhere it can get up to 45degC and above...

 

[CJG888]

The tube cage gets too hot to touch, the rest remains cool.

The tube in this amp is being run at or near its optimal operating point (no cool-running "powersave" mode). Hence the bright tube glow, intense heat and short run-time!

 

[ClieOS]

It really isn't a 'power-save' mode, to be precise.
 
Besides some sub-miniature tubes (*those tiny one, like those in the TU-HP01) that are designed to run on room temperature, most tubes need to run on fairly high temperature to avoid 'cathode poisoning'. It is actually easy to make an tube run colder, as it is just a matter of lowering the voltage. But doing so will cause the cathode to run in sub-optimum condition, causing faster degradation and eventually lead to early failure of the tube. Of course it might take sometime to reach that point of failure so some manufacturers might choose to compromise and make their portable tube amp run colder, knowing that by the time the tube fails, the warranty will likely have expired or the amp is no longer in use and they should come out clean. While this is not exactly a good practice, it does give a more portable design. The designer of BL-2 however chooses to run the tube in its recommended voltage, thus it is hotter than most portable tube amp out there.

 

[CJG888]

Is this then the reason for the 3.5 hour run-time between charges, or is the MOSFET output stage the culprit (or is the battery just too small)?