ALO Pan Am desktop/portable headphone amp/DAC: Impressions and Reviews - Page 7

Quote:

Originally Posted by dmcs414 


Same here! Mine comes in Monday morning, and the LCD2 rev2s are ready and waiting. Also ordered the Russian tubes and a pair of Mallard M8100s that the headfonia guys liked so much. Trying to decide on some additional tubes to roll also. Considering Raytheon, Motorola and RCA 6AK5s. Suggestions?

I've also ordered a pair of Mullard CV4010. However, they were from a random-ish ebay seller, so I'm hoping they are the real deal, and well stored/quality.

Quote:

Originally Posted by GarySaville 

I've also ordered a pair of Mullard CV4010. However, they were from a random-ish ebay seller, so I'm hoping they are the real deal, and well stored/quality.

The sweet-sweet Mullards. You guys are in for a treat!

Quote:

Originally Posted by dmcs414 

Well, so my Pan Am came in yesterday and I got it all nice and settled in on my desk with the Voshkod tubes warming up.. and I'm listening to it brand new, immediately out of the box - never had that experience before, I realized after. Every desktop headphone amp I've owned up till now I purchased used, from here. Add to that the fact that I'm also listening to my LCD-2s for the first time! (although I have heard others before and mine are burned in already)
So, long story short, I am now a believer - - nay! a devout believer - that an amp has simply GOT to burn in before it will sound right. Because mine did not at all sound right. It's amazing to experience that phenomenon first hand finally. Took me a while of listening before I was finally ready to conclude that must be the problem. It seemed so strange to me that parts of the frequency would sound normal, good even, and others just seemed odd in the extreme. Sterile, brittle, lacking body, and some parts of a song drastically over emphasized above others.
So anyway, my dear comrades, my rig is now happily burning away while I toil at the office and count the minutes until it will be ready to sing.
The vital question for me then, is how long does that burn-in process take, assuming I care not a fig for the last 10%?
Thanks for indulging my rather sleep-deprived and whimsical mood Head-fi.
Best,
Dave

New tubes tend to settle in after about 30-40 hours. Just don't leave them on forever after a 40-hour break in, I would turn the amp off when not in use. Tubes last about 5,500 hours, so if left on 7x24 they will fail in less than 1-year.

It could be the Voshkod tubes sound signature that you are not used to. The Voshkods have a bit of a forward dynamic sound to my ears.  Its not a bad sound, but its a bit different sort of vibrant to my ears. I personally like the 1950 era Raytheon 6AK5W a lot in my amp. The GE 5-star white label are nice too.  The RCA Radiotrons have a warm, tubey sound if you are into that and the Telefunkens from ALO sound very neutral to me.  I should also qualify that I am using AKG K702 cans, so your results may be different from mine.  The point being if you don't like the sound you might want to try a different set of tubes.

I listened to my PanAms with the Gateway thru' my JH16s with its USB input.

Absolutely amazing. As silent as the graveyard when no music is playing.

With music thru the USB, it is really very transparent.

The rest of the inputs are average. Even paired with AMR CD77 thru Audioquest Diamonds interconnect, the sound from the direct USB input is alot better. I don't think this is a fault of the CD or interconnect, but more of the way the RCA inputs are implemented.

But this only goes to show just how good is the USB input.

ALO doesn't say much about the Wolfson 24/94 DAC used.

No Asynchronous USB. No 24/192. No ASIO drivers.

But all these doesn't matter. It just sounds better than the Dragonfly even with the iFi Audio iUSB connected.

Worth every single penny.

Quote:

Originally Posted by bsn 

New tubes tend to settle in after about 30-40 hours. Just don't leave them on forever after a 40-hour break in, I would turn the amp off when not in use. Tubes last about 5,500 hours, so if left on 7x24 they will fail in less than 1-year.

 

I was under the impression the burn-in the amp needed was about more than just the tubes...was I wrong in that?  

Put the headphones back on my head for a few moments this morning before work.  Still doesn't sound as amazing as I'd expected.  Bass is light, highs are harsh, grating.  I'm starting to get nervous.  Little did I suspect when I went from a EF5/HE-500 rig to a ALO PanAm/LCD-2.2 rig I would be disappointed, but I am so far.  I really hope it's the burn-in thing.  The previous owner of these headphones said they had about 150 hours on them - perhaps they too are still burning in?  I just don't know...reassure me folks?  

So for clarity my source is a PC running J River, (no DSPs enabled or any EQ) using the Pan Am's DAC, and the amp is connected to the Passport.  I'm on the high gain setting, and have been playing around with adjusting amp volume vs J River volume, but that's the only tweaking I'm doing.  Have been burning in for perhaps 10 hours, give or take. 

I installed a pair of the Mullard 4010 into the PanAm a few days ago and find the sound better than with the either the stock or Telefunken tubes. The bass is more substantial than the Telefunken, and there is more clarity than the stock tubes offered.

While I find it quite hard to compare, I lean towards using the dragonfly into the 1/8 inch input over the PanAm's internal DAC. 

While the Bass with the Mullard tubes improves over the Telefunken and stock tubes, it is still heavily rolled off in comparison to listening directly out of the dragonfly. 

Quote:

Originally Posted by dmcs414 

 

I was under the impression the burn-in the amp needed was about more than just the tubes...was I wrong in that?  

 

 

To date, this has not been demonstrated objectively. Tubes yes. Wires and internal solid state components, no.