[blazingazn]

   
Hmm. This has not happened to me. Have you tried swapping another tube? Use a cheap one, just to test.
 
How comfortable are you with repairing electronic devices? If you think you can handle it, try posting your question here:
 
http://rockgrotto.proboards.com/thread/5297/bravo-12au7-mods-appreciation-thread

 
I tube swap often. It's the same across the board.
 
I heard that Red LED is a weak link and may need to be replaced? 
Any opinions?
 
I'm out of that terribly short 6 month warranty period

 

[UmustBKidn]

  So I'm tempted to get a V3 to use as an output stage for my Aune T1 (uses the same tube, and can upgrade them later).
 
I've been told that these bravo amps suffer from crackling/noise floor/quality control issues.
 
Can any of you owners clear this up for me? 
 
Thanks!
 
(I know the answer probably lies in this thread, but it's 145 pages long..)

 
The "search this thread" feature (near the top) comes in handy.
 
I remember reading somewhere that the V3's had some sort of issue with the equalizer sliders being noisy. The issue didn't exist with the other models (that don't have those sliders). I had originally wanted a V3, but after reading some negative comments, decided on a V2 instead. The usual arguments against equalization being against the Audiophile Religion apply. I can't imagine how effective a 3-band equalizer could be anyhow.
 
I now own two of the V2's. I kind of wish I'd known about the Schiit Vali before buying the second one, but that's life. On the other hand, the Vali's aren't built for tube rolling. After owning this amp, I can't imagine myself ever buying a tube amp (hybrid or otherwise) that I couldn't replace the tube(s) on.
 
The V1's use a 6922 tube, that seems awfully expensive to replace. Tube rolling would be way too expensive. So the V2 was my choice.
 
Lots of folks on this thread have them (as well as the similar Indeed G3), and lots of those folks are rather passionate about their Bravo's (especially after performing the modifications to them). Call me silly, but I've done some extensive tube rolling with this amp (in unmodified form). I'm planning on modifying one of my V2's soon, and I plan on doing a comparison of the two amps once I'm done. I am really sold on tube-type amplifiers, mainly because of the positive experience I've had so far with my Bravo amps.

 

[UmustBKidn]

   
I tube swap often. It's the same across the board.
 
I heard that Red LED is a weak link and may need to be replaced? 
Any opinions?
 
I'm out of that terribly short 6 month warranty period

 
I don't think the LED is the problem. I would sooner believe there is something it's hooked up to, that's going bad. However, I wouldn't know what to suggest, beyond exploring the boards I linked above. I would bet that if you replaced the LED, it would still glow dimly. But I could be wrong.
 
I will say that I kind of knew when I bought my Bravo's that I was taking a risk. Something this inexpensive that's sold via eBay and made in China isn't going to be an item with great customer service. Even if it does take a dump in the warranty period, you're going to spend $20 bucks for shipping each direction. If it took a dump outside the warranty period, I'd try to fix it or ask advice online, and if that didn't work, I'd throw it away.
 
The Bravo amps are someone's idea of commercializing a common DIY design that's existed for years. Do some searching and you will see this is true. They are great if you're not an electrical engineer and don't want to attempt building one yourself. But there are issues with the construction and the design (hence the plethora of mods for the amp and tons of folks discussing the design issues). They are cheap, and they are great, assuming you have one that works.
 
If great customer service is something you want, buy a Schiit Magni or Vali. Schiit has some of the best customer service on the planet, not to mention some of the best audio gear. And soon you can spend $120 and buy a hybrid tube/ss amp from them (the Vali should be available soon). Or spend $99 on a Magni (I have one of those too, and honestly it rocks too). My Schiit gear is built like a tank. I drive one of my V2's with a Schiit Modi. Honestly, I know my kids will inherit my Schiit gear. The Bravo's, probably not.
 
If you want to step up from the Bravo's, the next step would be either a Schiit Valhalla or a Bottlehead Crack. One of those will be my next amp.

 

[dwayniac]

I received my Ocean in the mail today and right off the bat,I think the stock tube is lean on bass. It's not a deal breaker but I would only use my SR80i with the stock tube. Never the less,I do have three NOS tubes coming,Amperex,Philips and RCA,to try different sound signatures.

 

[richard51]

I am very anxious to read your impression.. i want to buy the ocean .....If others have this amp with the hifiman he 400 i am curious to know  if the synergy is good between them ......

 

[UmustBKidn]

I received my Ocean in the mail today and right off the bat,I think the stock tube is lean on bass. It's not a deal breaker but I would only use my SR80i with the stock tube. Never the less,I do have three NOS tubes coming,Amperex,Philips and RCA,to try different sound signatures.

 
The stock tube sucks. Period. As many have observed, almost any old American tube will be an improvement.
 
I recently picked up an old Raytheon long black plate tube, and it has a lovely crunchy sound on my metal music, and isn't too shrill even using my Pure i-20 DAC. Yes, I've put my i-20 back in line at work. I have decided to futz with tubes until I find some that tone down the brightness. Mullards do a nice job of that, but I am just not ready to leave an expensive tube at work.
 
I am slowly working through my selection of old American tubes again. So far, a Tung-Sol 5963, the Raytheon long black plate 12AU7, and an HP long black plate 12AU7 tube are my top choices. I have some oddball tubes with weird names that also sound good, often these are 5963 tubes that people overlook.
 
Keep your eyes open for the alternate tube types (5963, 5814, 6189, seem to be the most common) on eBay. People put such an importance on the 12AU7 and ECC82 types, that the price of those is now way too high (and the others are a bargain). As I mentioned in another thread, I've purchased 5963 tubes for as little as $2.50 each, which is an insane bargain. I play them all the time in my Bravo's with no issues, and they sound just as good as the more familiar types.

 

[UmustBKidn]

  I am very anxious to read your impression.. i want to buy the ocean .....If others have this amp with the hifiman he 400 i am curious to know  if the synergy is good between them ......

 
The Ocean is a V2 with a fancier case. Unless you've just got to have that case, skip the Ocean and get a V2, and spend the extra money on tubes

 

[dwayniac]

   
The stock tube sucks. Period. As many have observed, almost any old American tube will be an improvement.
 
I recently picked up an old Raytheon long black plate tube, and it has a lovely crunchy sound on my metal music, and isn't too shrill even using my Pure i-20 DAC. Yes, I've put my i-20 back in line at work. I have decided to futz with tubes until I find some that tone down the brightness. Mullards do a nice job of that, but I am just not ready to leave an expensive tube at work.
 
I am slowly working through my selection of old American tubes again. So far, a Tung-Sol 5963, the Raytheon long black plate 12AU7, and an HP long black plate 12AU7 tube are my top choices. I have some oddball tubes with weird names that also sound good, often these are 5963 tubes that people overlook.
 
Keep your eyes open for the alternate tube types (5963, 5814, 6189, seem to be the most common) on eBay. People put such an importance on the 12AU7 and ECC82 types, that the price of those is now way too high (and the others are a bargain). As I mentioned in another thread, I've purchased 5963 tubes for as little as $2.50 each, which is an insane bargain. I play them all the time in my Bravo's with no issues, and they sound just as good as the more familiar types.

As a matter of fact,I "rolled the dice" and bought a long plate RCA 5963,JAN Philips 6189W and a US made Amperex. My impressions of these tubes will determine if I buy more old tubes.

 

[dwayniac]

I received the Amperex and RCA tubes and are indeed a vast improvement over the stock tube. Of the two I received,I currently prefer the Amperex. I like the warmth it gives my SR80i.

 

[White Lotus]

I'm using an EH6922 in my Aune T1, like a lot of people are. My Bravo V3 (to be used as an output stage when it arrives) also has the same tube. Should I roll both to the Amperex? Much perceivable difference? 

 

[HOWIE13]

No noise from my V3 sliders which are very effective with most headphones I use. They are passive filters anyway and when  'off' don't affect the sound in any way that I can detect and using the filters could save the cost of tube rolling.

 

[UmustBKidn]

  I'm using an EH6922 in my Aune T1, like a lot of people are. My Bravo V3 (to be used as an output stage when it arrives) also has the same tube. Should I roll both to the Amperex? Much perceivable difference? 

 
The Electro Harmonix 6922 tubes are new issue, made in Russia tubes. I have not personally listened to that particular tube.
 
I have listened to the Chinese Shu Guang 12AU7 tubes that come stock in the Bravo V2. I have auditioned the JJ Electronics 12AU7 (brand new, bought it from Amazon), as well as a new issue Electro Harmonix 12AU7 (came with a batch of much better tubes in a lot from ebay). Frankly, they all suck. I consider those purchases a waste of money. I keep all those tubes in a cup labeled "Crappy Tubes". Because I spent good money on them, I haven't quite been able to bring myself to throw them away. Someday I may put them up for auction on ebay. Maybe someone else will need convincing, and be willing to give me a few bucks for them, LOL.
 
Many others besides myself, have stated that the brand new Chinese and Russian tubes simply are horrible, compared to any of the old* (1970's and prior) tubes (the older, the better). The Amperex tubes are very nice, but as anyone who's done any tube rolling will tell you, I can't guarantee what sounds good to you. There are simply too many variables. For example, would you be referring to the Amperex made in Holland, or the Amperex Mullards made in Britain? Amperex Bugle Boy tubes are bright, clean tubes, that probably sound best with cans and gear that are naturally dark, and need some uplifting.
 
The combination of your headphones, your DAC, your amp, and your ears, is unique. What I find good sounding may not be what you like. All I can tell you for sure is, the old vintage tubes will always sound better. Whether you should use an Amperex, a Telefunken, a Mullard, a Raytheon black plate, an RCA clear top, is a matter of opinion. But they'll all sound better than the newly made EH junk.
 
-------
 
*Note: the term NOS (new old stock) is overloaded, and frequently used improperly. Most sellers label anything old as NOS, because it brings more money to claim that some 40-50 year old tube has never been used, sitting in a box for years. I suppose a few of them are, but most are not. The more honest sellers will state that they "test NOS", which means that the tube was tested and exhibits readings equivalent to a new tube on a given tester. Regardless of what a seller labels a tube, you want to buy something that's been tested, and tests in the "good" range, preferably with "balanced sides" (meaning in the case of a 12AU7 that both triodes test equally good - or close to it).
 
On the other hand, bargains can be found with tubes that have not been tested, tubes that test below the "good" range, or tubes that do not have balanced sides. Be careful. There are a few good deals, but a lot more that aren't.
 
Over this last summer and fall, I have become something of an oddball tube collector. Well ok, I was already an oddball. So I guess I'm becoming a tube collector. I surely don't need this plethora of preamp tubes I'm accumulating. I just like comparing the sound that different tubes produce, with different music. My musical taste is pretty broad (or at least I like to think so), and as it turns out, there are tubes better suited to certain types of music than others. So much so, that one could probably create a catalog of ideal tubes to use for different recordings or genres.
 
And I'm doing all this with a Bravo V2.

 
I went to build a shopping list for modifying my V2 the other night, and much to my dismay have discovered that Mouser is out of IRL510's. I'm wary of buying some from ebay, but unless I want to wait until February, I'm out of luck. I am really, really wanting to mod one of my V2's to see what it sounds like. I may have to wait. So if I don't have to work overtime over the holidays, I may finally buy a Bottlehead Crack and have some fun building my own amp. At which point I'll have to start the whole tube buying exercise with power tubes. Yowza.

 

[HOWIE13]

Is it inevitably the case then that if a company makes a poor 12AU7 then all the other types of tubes it makes will also be poor?
I only ask this because I think the gold pin EH 6922 sounds quite good in the V3 and even the standard  EH6922 isn't all that bad either.

 

[White Lotus]

Thank you, perfectly written response. 
 
I have some research to do. 

 

[UmustBKidn]

  Is it inevitably the case then that if a company makes a poor 12AU7 then all the other types of tubes it makes will also be poor?
I only ask this because I think the gold pin EH 6922 sounds quite good in the V3 and even the standard  EH6922 isn't all that bad either.

 
Well, let me just say that they sound good until you hear something better. I thought the same thing, until I started my adventure with tube rolling.
 
Things have changed. Once the Transistor and Integrated Circuit were invented, the days of tubes were numbered. So was manufacturing in America.
 
Tung Sol tubes you find made new today are made by a company in Russia. The original company was in New Jersey (check the wikipedia article). The original American companies are mostly gone (I spent 15 yrs of my life working for one of the last companies to make specialized vacuum tubes in America - but those are not audio tubes). The art of making good tubes has been lost to time and technology, and sadly to economics. Manufacturing in the USA has been farmed out to many other countries that make things more cheaply. And when you make things more cheaply, the quality goes away too. They don't make em like they used to because they simply can't.
 
When people value low price over quality, this is what you get. It's taken a while, but America got what it asked for. We don't take things that break to repair shops any more ... when something breaks, we throw it away and buy a new one (unless its very expensive). My daughter dropped her laptop about a year ago. It cost $300 bucks to repair, which is about the same cost as a brand new laptop (not quite the same quality, but close). I only repaired it because she really loved it, and it was a $500 dollar model. But it took 3 months to get it fixed right (the morons who repair these things are pretty incompetent). Should have just bought a new one.
 
So, the question is not whether one poor product made by a manufacturer implies that all the stuff they make is bad. In the case of tubes, none of the manufacturers that really made them well, exist any longer. The folks who made good tubes are long retired or passed away. What they knew was clearly not passed on to others. That, or the technique needed to make tubes well, is just too expensive to reproduce.
 
Some day, all that we will have left will be the Chinese and Russian crap. Or we'll all just use solid state amps. Some tubes are already darn near impossible to find, and when you can find them, they are horribly expensive. That situation will only get worse, until they're just gone.