justin_tx_16 Posted July 24, 2003 Share Posted July 24, 2003 Got my new tube amp. I was kind of nervous about buying a brand I had never heard of, but upon opening it, it has Headroom.com stampings and whatnot. Here is a scan of the inside It came with two sets of DuMont 6922 E88CC tubes and one set of GH23n-EB 3707 tubes. (i could be wrong on how you write that all out, it is very hard to read on the glass. I also came with a MonsterCable PowerLine 300 power cord, 3 feet long. That is just a nice addon I suppose. I have not turned it on, going to do that as soon as I hit submit. Lets hope for the best! Quote Link to comment Share on other sites More sharing options...
mike stehr Posted July 24, 2003 Share Posted July 24, 2003 Must be a hybrid. 'cause all I see are transistors. Isn't this a headphone amp you posted about in the past? Quote Link to comment Share on other sites More sharing options...
justin_tx_16 Posted July 24, 2003 Author Share Posted July 24, 2003 Yes it is a hybrid and yes I posted about it earlier last week asking for advice before buying it. I am loving it! Sounds great. I would like a slighly warmer sound to it, but I can change out tubes to cater to my tastes... right? What tubes would you recommend for this application? Quote Link to comment Share on other sites More sharing options...
mike stehr Posted July 24, 2003 Share Posted July 24, 2003 6922 is basically a 6DJ8 varient. So you could possibly try some Amperex bugle boy 6DJ8's. They may be a improvment,never know until you try it. there is another varient, starts with a seven, I think it's 7308? Other should chime in with info as well, but your best bet is to do a search on the 6922/6DJ8. Doing that should give you plenty of information. Now have you bookmarked your favorite tube websites? Like Uncle Ned, or Duncan Amps? This will get you started: http://www.worldtubeaudio.com/directory/directory.htm Glad you like the amp! Personally, I think the Bugle Boy 6DJ8 is just a Amperex 6DJ8 with the fancy silk-screened label of a tube playing a Bugle. Other than that, they are probably the same tube. I've never compared a Bugle Boy 6DJ8 to a regular Amperex 6DJ8, so I can't say. JMHO. Quote Link to comment Share on other sites More sharing options...
justin_tx_16 Posted July 24, 2003 Author Share Posted July 24, 2003 this is cool... when you first turn it on the light is red, as soon as it is ready for use, say 10 minutes later(?), it turns blue. Just like the TriVista hehe. Now on for a good while it sounds even better. Quote Link to comment Share on other sites More sharing options...
AnalOg Posted July 24, 2003 Share Posted July 24, 2003 Justin, Try Mullards, there known for there laid back warm characteristics, of course this is a generalization an can give different results with different equipment. 7308, 6922, are the variants to the 6dj8. For what its worth, Amperex U.S.A, I believe is hailed the "king" of the family. Tom Quote Link to comment Share on other sites More sharing options...
tpg Posted July 24, 2003 Share Posted July 24, 2003 Very nice. Congrats! If only I was les lazy... I need to work on building mine... but who knows when I'll get to it (also a hybrid). I still need to do all of my summer assignments (4 of them). And with so little time left... I hate summer assignments. When I hear about folks swapping 6DJ8 variants, Amperex Bugle Boys and Mullards seem to be the most recommended... Quote Link to comment Share on other sites More sharing options...
sunnysal Posted July 24, 2003 Share Posted July 24, 2003 It does look nice Justin, congrats! glad you like it and you are right, you can roll tubes until you get the warmth you want. tony Quote Link to comment Share on other sites More sharing options...
NOSValves Posted July 25, 2003 Share Posted July 25, 2003 So Justin how does it sound ?? Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted July 25, 2003 Share Posted July 25, 2003 Justin, Congrats! You are one generous guy to post a pic even before you listen to the new amp. What does the top of that bad boy look like? Would be interested to see a pic there, too. Regards, Dee Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted July 25, 2003 Share Posted July 25, 2003 Justin, Congrats! You are one generous guy to post a pic even before you listen to the new amp. What does the top of that bad boy look like? Would be interested to see a pic there, too. Regards, Dee Quote Link to comment Share on other sites More sharing options...
justin_tx_16 Posted July 25, 2003 Author Share Posted July 25, 2003 Here is a picture of the front and top Here are a few other pictures... It sounds just great! After being on for like 14 hours, it sounds about the same as when it was on 2 hours. It sounds great. Still, looking for something warmer so I will look at Mullards. I think I am going to put a small granite slab right under it to prevent it from drying out the wood on my night stand. The entire outer body is like a heat sink, as you can see from the top picture, that seems to keep it pretty arn cool, but you can still feel heat. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted July 25, 2003 Share Posted July 25, 2003 So Justin how much better is this then the Knight amps Headphone jack ?? Quote Link to comment Share on other sites More sharing options...
AnalOg Posted July 25, 2003 Share Posted July 25, 2003 Justin, Check this out, might give you some insight on tube rolling. http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html#12AX7 Tom Quote Link to comment Share on other sites More sharing options...
justin_tx_16 Posted July 25, 2003 Author Share Posted July 25, 2003 compared to the knight? better detail, louder (without hiss/distortion in lower frequencies), and there are no pops when you plug the headphone into the Knight. It weighs about the same as the Knight though! The night seems warmer, but at the same time, it seems more dry than this one. Not sure if that makes sense, sound is ever so hard to describe. Quote Link to comment Share on other sites More sharing options...
Deang Posted July 26, 2003 Share Posted July 26, 2003 Just a couple of things here: Justin, It will be 50 to 100 hours before that unit is completely burned in. The small changes in the sound happen so slowly during break-in that you might not even notice. However, if you took a new unit, and compared it to one that had been used for a month or two -- you would definitely be able to tell. Give this thing a few more weeks and there will be a considerable smoothing to the sound. I would contact the manufacturer to see if you can use 6DJ8's in the amp. Typically, though it is circuit dependant -- it is not always the best idea to put 6DJ8's into a circuit designed around the 6922. The tubes are not exactly the same. It is common to use 6922's in place of 6DJ8's -- but not 6DJ8's in place of 6922's. Some Old Timers never interchange them. The 7308 is the premium version of the 6922. http://www.nj7p.org/cgi-bin/tube?index=1 My suggestion is to use what you have for now and start saving for a matched pair of Amperex 6922's or 7308s. If I had that amp that is what I would do. You really need matched pairs for that amp. Quote Link to comment Share on other sites More sharing options...
justin_tx_16 Posted July 28, 2003 Author Share Posted July 28, 2003 I almost put this thing on eBay the other night! I use my iPod primarily to source this amp. If you have the iPod connected to the base station you can bypass the internal volume control and use a line out on the base station. Supposed to get the sound to you with the shortest amount of hops and turns, therefor should sound best this way. YUCK! The amp was picking up the power going into the iPod, you could hear a squiiisshhhhmeeennnneeiiissshhh noise constantly. Took it off the base station. Ahh, the noise is gone. But what is this? No bass? No depth? No feeling? What is this?! So I plug directly my headphones into the iPod. Wow, hear comes depth and bass and extension and the sound stage these headphones are so famous for. Am I bypassing my $310 headphone amp for my $500 iPod? Dare say no! After debating on how I would write about this extreme disappointment, and how I would market it on eBay to make my money back, maybe profit(?) I begin thinking... (that can be dangerous). I think to myself... how long did I let the amp warm up? The light was blue so 20 minutes? But the first time it had at least and hour before I gave it a good listen... I decide then that I just need to give it one more try, letting it warm up at least an hour before listening. And Bingo Was His Namo~ Back to the wonderful sound I had from the beginning. It is amazing how you really do have to let these tube amps, even hybrids, warm/heat up. As of now it has been on for probably 10 hours and I am anxious to give it a listen! HHScott, did you get my email? Quote Link to comment Share on other sites More sharing options...
NOSValves Posted July 28, 2003 Share Posted July 28, 2003 I would wonder if there is a problem with the headphone amp. It should never have the drastic difference your describing from being on even 5 minutes to a hour. There will be a difference but this extreme makes me wonder ! Craig Quote Link to comment Share on other sites More sharing options...
justin_tx_16 Posted July 28, 2003 Author Share Posted July 28, 2003 If anything I have understated the difference from 20 minutes to 1 hour. This is what the previous owner had to say "it has a warm up period (like all tube audio equipment), the LED will change from red to blue when its ready although the sound will continue to get better until its completely warm which is around 2 hours. Depending on your listening habits turning it on and off once a day should be fine (rather than several times a day). -Michael" By the time it had gone through Sarah Brightman - La Luna to track 3 on Faith Hill - Cry, it was at its peak, just as I began to fall into the land of "zzzzzzzzzzzz". Why does it need to warm up? Does this not seem like a little long a time to warm up? Does it hurt tubes to stay on all day? Quote Link to comment Share on other sites More sharing options...
sunnysal Posted July 28, 2003 Share Posted July 28, 2003 that does seem like an unusually long warm up time and an usually big difference in sound for warming up, but that is what is it so you have to live with it. re: leaving it on, small signal tubes last a long, long time. but anytime electricity is being applied to a tube in your amp it is being "used up". I think given the huge tone difference for warming up I would leave it on most of the time, you can always replace the tubes once every year or two. regards, tony Quote Link to comment Share on other sites More sharing options...
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