This amp is like the Bravo v-2 except it has a switch for 6 or 12 series tubes so it should have a greater choice in tube rolling. Mine has a GE 5814 tube but I don't know how good(or bad) this tube is vs other options out there for a reasonable price. The new mosfets fix the rolled off highs problem, now I'm wondering if a better tube would make as big a difference. Has anyone tried another tube(or other mod) that has made as big a difference?
Little Bear p-2 chinese tube amp with new IRF510 mosfets sounds good but...
Gear mentioned in this thread:
This is my first amp and decent headphones, so I wasn't sure if I would even be able to hear any differences. But after about two months now I have 4 sets of headphones and a pair of senngrados I put together, and can easily tell the differences the tubes can make.
For tubes I have:
A Amperex bugle Boy, it gives a a richer fuller sound with better base
A RCA clear top which is very clean and clear, low bass
A RCA long black plate ( organ pull ) a lot like the bugle boy but slightly cleaner
A tung-sol black glass with the black plates, the bass is heavy and cuts back on the highs
I also have about a dozen others now but the above have become my goto tubes.
The 6 volt tubes have a little more buzz to them whereas the 12 volt tubes seem to run a bit cleaner, but at volume you really can't tell. You will find that certain tubes will fit better with certain headphones and types of music.
The little bear may not be the best, but it's been a lot of fun to start out with. And if your up for some tube rolling I think you'll really enjoy the experience. Beware though, it's like a gate way drug, or lays chips, once you start it's hard to stop.
Edited by TroyS - 7/18/14 at 4:14pm
Awesome man! I've also got the Schiit Vali with HE-400 cans so the p-1 is an experiment in progress. What exactly is a lm317a? The HE-400's are a bit bright sounding so something thats a bit softer would balance those. I've ordered a Mullard 12ax7 from Amazon so we'll see how that sounds. I'll also check out the tubes you've mentioned. It is a bit of a drug but hey, there are a lot worse addictions. Happy listening.
I have a Mullard 12au7, it is a lot like the bugle boy, a fuller bassier sound. That should work well for you.
I've been looking at the schiit modi with the optical input as my next step. I just picked up a 2009 Mac mini for my music player, so it has been a busy couple of days learning how to set it up headless and remote control it.
I'm gonna need a second job at the rate I'm going.
One of the things I've noticed vs the Vali is a reduction in channel separation. It's not huge but noticeable on some material. The Vali still wins but it's not by much. I'm using a Fiio x-3 as my source which sounds pretty good on it's own. When I plug in the tube amp, I use the line out not the headphone out because it sounds better...you're essentially bypassing the amp in the x-3 and just using it as a DAC. I'll post something when I get the Mullard 12ax7 on it's sound signature. thanks for your input.
Well the Mullard 12ax7 was a bust...didn't work at all. I think it's just not compatible with the p-1(too much gain I think). I've also got some vintage Sylvania 12au7's that sound GREAT! In fact I now prefer it to the Vali! The original GE 5814 tube would start to distort on musical peaks as it heated up. The 12au7's sound just right with a minor bias adjustment. Just listening to some great music now!
Amazing what a cheap amp with a good tube and a little upgrading can sound like.
Did you put the irf510 in your amp or the irl530? I put in the irf510 and I just read the irl530 gives more power and headroom so I ordered 5(it was cheaper to buy 5 than 2!) and will put them in when they arrive. I'll let you know how the experiment goes...
I know, I've burned a finger or two especially on the lm317. I use the amp with the plastic top off and have a little fan going to help keep it cool. I also unplug the power supply when not in use as it stays warm and seems to draw current when the amp is off. My Vali is the same way, the wall wart stays hot when it's plugged in whether the amp is on or not. Saves a little energy too...
I think we're using the same source for the modifications:
http://www.mediafire.com/view/?648rn66jncce788 is where I got my info.