Solder station is in celcius. The lead free solder on the board wanted around 430* before the components could be removed. Granted, it's a cheaper solder/hot air station and the readout may not be the most accurate. Components went in with different solder around 350*.
Celcius... can't get it to display in *F. Apples to apples, it seemed the smaller the tip, the higher the temp to do the job while the larger tips could get away with generally less heat. Spent a lot of time keeping the tip tinned at the higher temps and if you touched the board, it gone.
750-800 degrees is standard for lead free, 700 for leaded..Instant melt and dwell time of only a second or two is needed to avoid component damage and PCB laminate damage from heat stress. At 400 degrees you should not have been able to melt anything, lead free solder melts at 423 deg F (leaded at 361). You must be talking 400 degrees Canadian
I was working in electronics manufacturing when the Pb-free thing started up, the increased iron temp also came with the metal dry sponge instead of damp sponge for tip cleaning, so the iron wouldn't loose any heat when you cleaned it. The whole process made all manual assembly a bit more difficult, the irons oxidize much faster at 800 degrees, and the dry cleaning isn't nearly as good when working with the smallest of surface mount components available.
Notes in no logical order.
IMHO, $.02, YMMV ...
modded - more mid/top, not bright but now present. Not over the top or highlighted, just more linear than oem. Something to keep in mind if you are using this amp to make unlistenable mixes listenable. Haven't listened to any 80's hair bands yet. Voices still have that charm, not as creamy as oem, but they are so much cleaner/clearer now. Like a clean window vs a dirty one. At first listen bass seems to have taken a back seat to the rest of the spectrum but give it a little time, the bass is there and stronger than oem in the bottom/very bottom end. Modded bass is more controlled everywhere, especially the bass/mid bass? region the oem emphasis. Listening to EDM, yeah, more enjoyable. Modded is way tighter where oem is loosey goosey. Bjork _Hunter _ excites that wooly part of the bass and it can override the rest of the performance. It's still there modded but cleans up nice and tight.
Oem more closed-in, smaller space, where modded opens up the space. More dynamic.
I'd say order the irl530 mosfets, 35v caps, and do crosstalk mod. If it's not for you, pop the oem mosfets back in. Want the wash n wax, order the good resistors and wima caps.
It continues with boy's headamp. So much more resolving than before. First light and the sound was hashier' and lite on bass compared to the other modded Bravo. Much better than before modding but not as an involving sound as the other modded Bravo. Listened for a while making mental notes. Turned it off, let the music die, and did a quick and dirty tube swap. No bias adjust. Big difference between the oem Shino tube and a cheap $9 JJ. Bottom much improved and highs much smoother, mids less glassy ... and dang this thing can pull hidden stuff out of the mix and still please the ear. Time to get serious about this tube rolling and bias setting.
Rolling tubes, letting everything warm up, and setting bias.
TungSol, Electro Harmonics, JJ, Mullard reissue, Shino. At <$30, all of these tubes are run of the mill affordable.
Get rid of the oem Shino tube. Compared to the others, the highs are splashy, the bass is weak, and the middle lacks that tube magic.
Surprise, IMO, the best sounding tubes are ... you can make up your own mind.
The JJ is good in the middle, rolled off on the very top and very bottom. I prefer how the midrange is presented with the jj over any of the other tubes, even the Mullard, with exception of maybe the Electro Harmonics, which, for lack of a better term, is the same view under more vivid lighting. Oddly, you would think the decision between a cheap $9 tube and one redesigned after the famous $Mullard$ name would be a no-brainer. Nope. Due to its lack of extension, the JJ didn't strike my fancy in the 4sUniversal preamp but the midrange is pretty sweet in the Bravo.
The Mullard reissue has extension on top and bottom the other tubes lack, and a more 'analogue like' sound in the middle. The treble is there and extended, not harsh as the TungSol can be in the lower treble. Bass sounds lighter than the TS and EH tubes but at the very bottom, where those two roll off, the Mullard keeps going. Subtle but there. This tube wins in extension at the extremes but there's something about the middle that gives the JJ, with a nod to the EH, the upper hand. In the midrange, things feel more crowded with the Mullard than either the JJ or EH. Although this tube first comes across as soft, give it time, the highs are detailed without being harsh.
The Tung Sol attacks everything. Emphasis is placed on the initial attack of a note, the term 'digital sound' comes to mind. The initial whack is there in spades but the rest of the note drops away. The treble is not as extended as the Mullard but on par with the others. Some emphasis in the lower treble that makes it a little too hot for my taste. Good tight defined bass. If you want a dynamic and exciting tube, this may be your cup of tea.
The Electro Harmonics is somewhere in the middle. It does not have the Mullard's extension at either end but better than the JJ. All the tubes seemed to extend higher into the treble than the JJ. If it were not for the rolled off highs and lows, the JJ would have been my overall choice. The EH has some of the TSs' attack and slight forwardness in the lower treble but not overdone like the TS. Unlike the TS, with the EH the notes attack and decay. Tight bass and the midrange is comparable to the JJ but just a bit more 'clean'.?. The middle is good. I like this tube in the Bravo.
Could the 'heft' or 'bite' of the EH and TS in the 4s preamp be the way these tubes attack the initial part of the note?
And the middle is where things get fuzzy and hard to describe. The Mullard sounds busy, or crowded in the midrange while the JJ, and with a slightly different take on things, the EH, present a more revealing yet relaxed midrange presentation.
If imaging or spaciousness can be a thing with headphones, the EH and TS are hands down winners here.
Just my unscientific $.02 musings backed up with IMO tin ear YMMV observations.
Been listening to the modded Bravo with the Focal Elex cans. The Bravo now has a rushing sound most prominent on quieter passages. For some reason, it makes me think of current rush on a mosfet. Needed to order some stuff from Mouser anyway, so irl530&510, lm317at, and a few 2n3906 bipolars just in case.
I ended up with a solid state class A Bravo amp. There is a turn on thump I'd like to get rid of. Op amps are rollable, but I don't know that it'll help.
Comments
Solder station is in celcius. The lead free solder on the board wanted around 430* before the components could be removed. Granted, it's a cheaper solder/hot air station and the readout may not be the most accurate. Components went in with different solder around 350*.
Ahhh, makes a bit more sense. Celsius...ha.
Celcius... can't get it to display in *F. Apples to apples, it seemed the smaller the tip, the higher the temp to do the job while the larger tips could get away with generally less heat. Spent a lot of time keeping the tip tinned at the higher temps and if you touched the board, it gone.
750-800 degrees is standard for lead free, 700 for leaded..Instant melt and dwell time of only a second or two is needed to avoid component damage and PCB laminate damage from heat stress. At 400 degrees you should not have been able to melt anything, lead free solder melts at 423 deg F (leaded at 361). You must be talking 400 degrees Canadian
I was working in electronics manufacturing when the Pb-free thing started up, the increased iron temp also came with the metal dry sponge instead of damp sponge for tip cleaning, so the iron wouldn't loose any heat when you cleaned it. The whole process made all manual assembly a bit more difficult, the irons oxidize much faster at 800 degrees, and the dry cleaning isn't nearly as good when working with the smallest of surface mount components available.
The high temps, cheesy board, and my soldering skills kept it interesting.
@Wolf you mentioned a ss version. These are a step up from the ebay counterparts. garage1217.com/garage1217_diy_tube_headphone_amplifiers_006.htm
Notes in no logical order.
IMHO, $.02, YMMV ...
modded - more mid/top, not bright but now present. Not over the top or highlighted, just more linear than oem. Something to keep in mind if you are using this amp to make unlistenable mixes listenable. Haven't listened to any 80's hair bands yet. Voices still have that charm, not as creamy as oem, but they are so much cleaner/clearer now. Like a clean window vs a dirty one. At first listen bass seems to have taken a back seat to the rest of the spectrum but give it a little time, the bass is there and stronger than oem in the bottom/very bottom end. Modded bass is more controlled everywhere, especially the bass/mid bass? region the oem emphasis. Listening to EDM, yeah, more enjoyable. Modded is way tighter where oem is loosey goosey. Bjork _Hunter _ excites that wooly part of the bass and it can override the rest of the performance. It's still there modded but cleans up nice and tight.
Oem more closed-in, smaller space, where modded opens up the space. More dynamic.
I'd say order the irl530 mosfets, 35v caps, and do crosstalk mod. If it's not for you, pop the oem mosfets back in. Want the wash n wax, order the good resistors and wima caps.
I'm McLovin it. Listening non-stop for the past ~2hrs. If it were harsh the phones would have came off 30 minutes in.
@kenrhodes and @ScottS What up? Mod it. I think you'll really like it.
It continues with boy's headamp. So much more resolving than before. First light and the sound was hashier' and lite on bass compared to the other modded Bravo. Much better than before modding but not as an involving sound as the other modded Bravo. Listened for a while making mental notes. Turned it off, let the music die, and did a quick and dirty tube swap. No bias adjust. Big difference between the oem Shino tube and a cheap $9 JJ. Bottom much improved and highs much smoother, mids less glassy ... and dang this thing can pull hidden stuff out of the mix and still please the ear. Time to get serious about this tube rolling and bias setting.
Rolling tubes, letting everything warm up, and setting bias.
TungSol, Electro Harmonics, JJ, Mullard reissue, Shino. At <$30, all of these tubes are run of the mill affordable.
Get rid of the oem Shino tube. Compared to the others, the highs are splashy, the bass is weak, and the middle lacks that tube magic.
Surprise, IMO, the best sounding tubes are ... you can make up your own mind.
The JJ is good in the middle, rolled off on the very top and very bottom. I prefer how the midrange is presented with the jj over any of the other tubes, even the Mullard, with exception of maybe the Electro Harmonics, which, for lack of a better term, is the same view under more vivid lighting. Oddly, you would think the decision between a cheap $9 tube and one redesigned after the famous $Mullard$ name would be a no-brainer. Nope. Due to its lack of extension, the JJ didn't strike my fancy in the 4sUniversal preamp but the midrange is pretty sweet in the Bravo.
The Mullard reissue has extension on top and bottom the other tubes lack, and a more 'analogue like' sound in the middle. The treble is there and extended, not harsh as the TungSol can be in the lower treble. Bass sounds lighter than the TS and EH tubes but at the very bottom, where those two roll off, the Mullard keeps going. Subtle but there. This tube wins in extension at the extremes but there's something about the middle that gives the JJ, with a nod to the EH, the upper hand. In the midrange, things feel more crowded with the Mullard than either the JJ or EH. Although this tube first comes across as soft, give it time, the highs are detailed without being harsh.
The Tung Sol attacks everything. Emphasis is placed on the initial attack of a note, the term 'digital sound' comes to mind. The initial whack is there in spades but the rest of the note drops away. The treble is not as extended as the Mullard but on par with the others. Some emphasis in the lower treble that makes it a little too hot for my taste. Good tight defined bass. If you want a dynamic and exciting tube, this may be your cup of tea.
The Electro Harmonics is somewhere in the middle. It does not have the Mullard's extension at either end but better than the JJ. All the tubes seemed to extend higher into the treble than the JJ. If it were not for the rolled off highs and lows, the JJ would have been my overall choice. The EH has some of the TSs' attack and slight forwardness in the lower treble but not overdone like the TS. Unlike the TS, with the EH the notes attack and decay. Tight bass and the midrange is comparable to the JJ but just a bit more 'clean'.?. The middle is good. I like this tube in the Bravo.
Could the 'heft' or 'bite' of the EH and TS in the 4s preamp be the way these tubes attack the initial part of the note?
And the middle is where things get fuzzy and hard to describe. The Mullard sounds busy, or crowded in the midrange while the JJ, and with a slightly different take on things, the EH, present a more revealing yet relaxed midrange presentation.
If imaging or spaciousness can be a thing with headphones, the EH and TS are hands down winners here.
Just my unscientific $.02 musings backed up with IMO tin ear YMMV observations.
Revisiting an old thread.
Been listening to the modded Bravo with the Focal Elex cans. The Bravo now has a rushing sound most prominent on quieter passages. For some reason, it makes me think of current rush on a mosfet. Needed to order some stuff from Mouser anyway, so irl530&510, lm317at, and a few 2n3906 bipolars just in case.
Anyone else try the Bravo mod?
I ended up with a solid state class A Bravo amp. There is a turn on thump I'd like to get rid of. Op amps are rollable, but I don't know that it'll help.
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