[1800yolk]

Nice... Price? What's the best pairing?

https://www.massdrop.com/buy/appj-1502a-tube-headphone-amplifier
 
you've got 50 minutes!
 
also, people say it pairs well with lower impedance headphones, and a few on here are fans of using it with the 400i, which is what i'm going to do :V

 

[BenWaB3]

The mass drop is over & they reached the amount of commitments they needed (actually I think they had reached it a while ago). So those who participated (myself included) should be enjoying this amp in about a month!

 

[canthearyou]

I was thinking about a 2nd one at that price. You know, just in case.

 

[canthearyou]

Received my Genalex Gold Lion power tubes today. Very much worth the $50. First thing that becomes apparent is an even quieter background. Next I noticed greater separation and clarity of instruments. This is with only 10 mins on the new tubes. I will update after a few days.

*Didn't even make it a few days. After the tubes got some heat to them the combo became to warm and soft for my taste. I swapped the pre-amp tube to Mullard 12AX7. Now I have that sparkle and crispness back with a black background.

If you have rather bright, detailed power tubes ie: Electro Harmonix, the Gold Lion pre-amp makes a nice combo. On the other hand, if you have warm power tubes, the bright, detailed Mullard makes a nice combo.

I know these are my opinions. But one thing I can say for sure is the Gold Lion power tubes have a much quieter background.

 

[CZ4A]

I have a very interesting vacuum tube to test that's currently in shipping:
 

 
This is an Amperex 8416. It's a rare, premium-quality tube originally intended for use in oscilloscopes. Electrically it's a 12v 6DJ8 (12DJ8). The Amperex (Holland-made) orange globe 6DJ8 is one of my favorite 9-pin tubes but isn't compatible with the 1502A. I'm interested to see if this lives up to the "premium-quality" billing.

 

[canthearyou]

Cool. Waiting for your impressions.

 

[braaam]

Interesting, didn't know these types could be used as well.

I went all French today: RT 6189 with the Visseaux 6F6. The RT is a military 12au7 screened for low noise. Very transparant and resolving with tight bass. A bit rolled off in the highs and a bit of sweetness in the mids. A great tube that fits a lot of styles.

Edit: update on the RT 6189

Listened to Bach's Concerto in E Major for Violin, Radiohead, Daft Punk, Patricia Barber. The RT 6189 is doing a lot (read: everything) right. Dynamic and alive with Daft Punk, intimate and never harsh with Patricia Barber and always in control with Radioheads "15 step". With Bach you can pick up every note from the different instruments but it all sounds coherent at the same time.

It may be resolving too much for things like black metal but that's not really a fault of the tube itself and could be fixed by using warmer power tubes I'm sure

It is close to perfection for what I'm looking for.

 

[CZ4A]

Interesting, didn't know these types could be used as well.

I went all French today: RT 6189 with the Visseaux 6F6. The RT is a military 12au7 screened for low noise. Very transparant and resolving with tight bass. A bit rolled off in the highs and a bit of sweetness in the mids. A great tube that fits a lot of styles.

The heater requirements (12.6V, 0.15A) and pinouts of the 12AX7 and 8416 are identical except for the #9 pin- on the 12AX7 its the center tap for 6.3V operation and for the 8416 (and 6DJ8, 6922, Cca, etc.) it connects to the internal shield. Since the #9 pin is not used in 12V operation, the 8416 should work (biasing notwithstanding).
 
That RT looks interesting. Never heard of that company. Nice to hear some positive impressions of it.

 

[braaam]

The heater requirements (12.6V, 0.15A) and pinouts of the 12AX7 and 8416 are identical except for the #9 pin- on the 12AX7 its the center tap for 6.3V operation and for the 8416 (and 6DJ8, 6922, Cca, etc.) it connects to the internal shield. Since the #9 pin is not used in 12V operation, the 8416 should work (biasing notwithstanding).

That RT looks interesting. Never heard of that company. Nice to hear some positive impressions of it.

Thanks for the explanation. What would the internal shield be used for?

The full name is La Radiotechnique. They were a subsidiairy of Philips but had their own production line. The sound has similarities to miniwatt tubes (great soundstage and smoothness) but it's more revealing, towards the Valvo's (which are probably a bit dryer overall). Comparisons are from memory, I'll do direct comparisons later.

In the meantime I'm also waiting for delivery of some rebranded Telefunken 5965 tubes to see how they compare.

 

[CZ4A]

Thanks for the explanation. What would the internal shield be used for?

To keep the electrons on their sides of the playground, of course! It's situated between the triodes. I don't think the shield is necessary for audio use- for example from what I've read there isn't any sonic difference between the 6CG7 and 6FQ7, which are identical aside from the 6CG7 having a shield between the triodes and the 6FQ7 lacking that shield. For more sensitive equipment like oscilloscopes. the shield might have been more essential.
 

The full name is La Radiotechnique. They were a subsidiairy of Philips but had their own production line. The sound has similarities to miniwatt tubes (great soundstage and smoothness) but it's more revealing, towards the Valvo's (which are probably a bit dryer overall). Comparisons are from memory, I'll do direct comparisons later.

Radiotechnique rings a bell. Thanks for the clarification.

 

[braaam]

To keep the electrons on their sides of the playground, of course! It's situated between the triodes. I don't think the shield is necessary for audio use- for example from what I've read there isn't any sonic difference between the 6CG7 and 6FQ7, which are identical aside from the 6CG7 having a shield between the triodes and the 6FQ7 lacking that shield. For more sensitive equipment like oscilloscopes. the shield might have been more essential.

Radiotechnique rings a bell. Thanks for the clarification.

That makes good sense

I was wondering: do you have experience with 6G6 power tubes? Seems they are similar in spec but accept only max around 190v on the plates. Would that be ok with the APPJ?

 

[CZ4A]

I was wondering: do you have experience with 6G6 power tubes? Seems they are similar in spec but accept only max around 190v on the plates. Would that be ok with the APPJ?

I don't know. It depends on the amp's plate voltage - if it's too high the 6G6s won't last very long.
 
I have a similar dilemma with a matched pair of 6W6GTs that I found- the max screen voltage is only 150v. Without those stats from APPJ all I can say is cross your fingers!

 

[braaam]

I don't know. It depends on the amp's plate voltage - if it's too high the 6G6s won't last very long.

I have a similar dilemma with a matched pair of 6W6GTs that I found- the max screen voltage is only 150v. Without those stats from APPJ all I can say is cross your fingers!

The question is out to APPJ, lets hope we'll get our answer before we start burning some fine tubes

 

[chellity]

     I've been using this amp for a few weeks now, and it still blows me away everytime I turn it on.  it truly is an experience...I love showing my set up to people and watching their reactions.   here are my impressions as a newbie with my first headphone/amp set up, period.  a set up like this made me devote so much time just to critical listening, because now I have to relisten to all my old favorites.  this amp and the 400i really did breathe new life into old music, for me.
 

 
 
     I tried out the vali 2 like others, and found it a little lacking.  I eventually found this amp and was surprised I could even get a full tube amp that would work with my 400i in this price range.  I bought a miniwatt ecc83, but the seller broke it so he sent me two equivalent quality tubes for the price of one I got pretty lucky..ended up with a fisher/amperex ecc83 and a dyanco/telefunken that I haven't even tried yet.  the amperex sounds so amazing that I don't even feel the need to pop in the telefunken yet.   I do find some microphonics on a few extreme songs, but i'm guessing its mostly because amperex ecc83s can be prone to ringing at times?  (neon indian, im looking at you)  I also tried some rca power tubes, but I'm not sure if they had a positive effect on the bass.  I might be interested in trying some newer power tubes, later.  
 

 
 
     keep in mind i'm a newbie, but i'm loving this mid-fi sound.  the soundstage on my 400i feels more than acceptable,even coming from a modi2/lsr 305.  the sound is rich, and compelling.  distorted vocals sound amazing, sometimes syrupy, and even ethereal at times.  electric guitars, chimes, metallic noises, seem to sound glittering (passion pit, beach house) I swear fender guitars seem to have that same bell-like quality that they have in real life, now. things just seem to sound more organic and a bit warmer, and maybe even less forced on some tones (obvs- jamie xx).  all those positives combined with the very low tube noises, surprisingly good build quality, and more than enough headroom for me makes this a really good beginner tube amp for me.  also...somehow I feel like I can notice the difference between flacs and high quality mp3s with this set up compared to my speakers (mostly just clarity).  any downsides I notice are probably more due to the nature of tube amps (since they might affect instrument separation, right?)  I couldn't really ask for more for a first time tube amp in this price range.
 


 
 
thanks to everyone that seemed to fight so passionately trying to get people to notice this amp!  and to those that helped with their input earlier.   I'm very happy with my first set up. 

 

[braaam]

Hi, @chellity, great post! Glad you like the Amperex, taking from your photo it's the same tube as the Holland-style miniwatt's. They are still among my favourites after trying many others. 

To me the RCA 6V6's can get a bit too hot in the treble department (slightly harsh) together with the European pre-tubes. They may sound better with different headsets (the 400i is a bit aggressive sounding).
 
And you didn't even try the Telefunken yet - that should be one of the top 12ax7 tubes! I suspect (from research) it will be less smooth and more analytical than the Amperex.