Bravo Audio - funny looking little tube amps
Feb 1, 2014 at 2:46 AM Post #2,401 of 2,720
  That's your system and your findings that is fine but peoples findings on Mullards are as I've described, I had a possession of over 30 Mullards various kinds for the 12AU7's integrated/headphone and preamp's I have they all sound distinctively close to each other. 
 
Baldwin organ tubes 12AU7 are made by Sylvania.
 
The best Mullards are Holland and Blackburn plant, same two plants Amperexes come from.
 
LOL, Telefunken's are not rolled off period that award goes to the English plant make Amperex's dark and laid back sounding, you must have a rebrand from another manufacturer, there is a reason they are the best amongst the dual triode family with a strong following out there, best 12AU7 based tube money can buy for sound is the ECC802S, made in West Germany. There lower "generic" range that go for $40-100 fitting the usual description of smooth ribbed plates and a D getter blow Genalex ECC82's out of the water (which are also good tubes) that go alot more. 


People ? which people ? Not the ones I know. I have a ton of 12AU7's and 12AX7's (every type, 5751, WA, JG, A's) and have tried on a variety of systems. Even self built. Black plates, triple MICA. So that's YOUR system and YOUR findings and YOUR preference.
 
One thing I have found out about tubes. You can't label a set or type of tubes as "the tubes". You also cannot discount tubes or assume (as WAY too many people do here) that they must be fakes. All tube preferences are system specific, application specific. They also have to be matched to the links in the chain. So if you have a tube phono stage, tube pre and tube amp, it is much harder to balance than just one of those having tubes.
 
In my power amp, I tried every 12AX7 pair from $10 to over $125 a tube. The final one ? A very rare and hard to find pair of Sylvania 5751 Triple Mica Blackplates Yellow print. why ? detail. My system is very detailed with forward mids, nice tight strong base, wide soundstage. GE and RCA's had the detail, didn't have the forward mids. On my systems, Tele's are DULL. Mullards are sweet (#2). Amperex. yuck ptooy.
 
Bottom line, don't disparage. encourage. If they want to try a Mullard it may be the most incredible tube they one...or ..they may hate it...only their system and their ears will know.
 
Feb 1, 2014 at 3:10 AM Post #2,402 of 2,720
I've had my V3 for 2 weeks now and like it except for the 3 band EQ. I had reservations about having an EQ but, at the time, the V1 was $30 more and the V2 was back-ordered at Parts Express. Since the V1 and V3 seemed (except for the EQ) to be the exact same amp so I ordered the V3. Well my reservations were well founded, I can't stand the way it sounds in stock form. The EQ has no markings to indicate were FLAT is or even what the center frequencies are with no instructions or anything to give me starting point. It does have center detents on the sliders so I started there. Well using my Yamaha HP-2s to start, there wasn't enough gain to get them louder than plugging them directly into my iPod touch, which BTW sounded much better. The only way the V3 sounded acceptable and had enough gain was with the sliders all the way UP! Makes sense since being a passive circuit they are attenuators. I still didn't like the sound.
 
I decided I would figure out how to bypass the EQ circuit and hear how it sounds before deciding to send it back. 
Well, after finding a couple of circuit diagrams of the V1, I located the 1K input resistors at the input of the main amp section. I soldered a stereo mini plug to them and ground and now I'm a very happy camper! The EQ just kills the sound quality especially in the low end and midrange. Bass dynamics are also crushed. 
 
The V3 came with a few assembly defects including sloppily placed resistors and loose transistor heat sink screws. One was so loose it was about to fall out. I would recommend anyone getting this amp to check the screws immediately to avoid overheating problems! 
I also replaced the IRF630 mosfets with IRL530s and it sounds even better! The warm tube sound I was searching for is now all there.
 
Feb 1, 2014 at 7:00 AM Post #2,403 of 2,720
  Very subjective..LOL
 
The Mullard short or long plate , Fisher branded Blackburn plant are amazing...I do agree though the 17mm long plates are a tad nicer (I have both)

 
Yay! Other people besides me talking about tube rolling Bravo amps! Yay! I'm no longer alone in the wilderness lol
biggrin.gif

 
Of course it's subjective. That's why I said it was subjective. Lol. Everyone's ears are different. As I've said in the sound science forum, our ears and brains are the least studied links in the audio chain, and as such the most mysterious.
 
At any rate, a subjective opinion doesn't make it any less a valid observation on the part of the person making the observation. I tend to keep a box of half a dozen different tubes at work (in a locked place of course), where I can choose to roll a variety of different tubes. In the box, I keep a vintage Telefunken, a late 50's round getter Mullard, a Raytheon black plate, a Tung Sol, a Hewlett Packard black plate, and a 5963 of some sort. When I get tired of listening to one, I swap in another, and listen to my collection all over again, until it strikes me to change the tube lol. Each and every one of those tubes has a slightly different audio signature, which just fascinates me no end.
 
Feb 1, 2014 at 7:03 AM Post #2,404 of 2,720
So, my V2 works fine with a US to UK mains adapter, no smoke. Out of the box it sounds good, bass seems a little less prevalent on my DT990 Pros and that's without any tube rolling or significant burn in. I did leave it to warm up though.

 
Good! Glad to hear it's working. Now for the fun part: tube rolling
L3000.gif
Muhahahaha.
 
Feb 1, 2014 at 7:06 AM Post #2,405 of 2,720
Feb 1, 2014 at 7:07 AM Post #2,406 of 2,720
Feb 1, 2014 at 7:10 AM Post #2,407 of 2,720
...  
And or if you can find a Blackburn Mullard / fisher branded...OMG ..sweet...

 
I have a couple Heath rebranded late 50's vintage round getter Mullards, a couple actual late 50's vintage round getter Mullards that I got really cheap from ebay when no one was paying attention, and a couple d-getter '56 vintage Mullards that I paid way too much money for, that sound spectacular, even on a stock Bravo V2. Yowza. Lol.
 
Feb 1, 2014 at 7:12 AM Post #2,408 of 2,720
...  
Bottom line, don't disparage. encourage. If they want to try a Mullard it may be the most incredible tube they one...or ..they may hate it...only their system and their ears will know.

 
^ This.
 
I have the parts. I just haven't had the time. I am ready to mod one of my V2's. I need to be brave, take everything out to the garage, and sit down...
 
Feb 1, 2014 at 7:32 AM Post #2,409 of 2,720
 
People ? which people ? Not the ones I know. I have a ton of 12AU7's and 12AX7's (every type, 5751, WA, JG, A's) and have tried on a variety of systems. Even self built. Black plates, triple MICA. So that's YOUR system and YOUR findings and YOUR preference.
 
One thing I have found out about tubes. You can't label a set or type of tubes as "the tubes". You also cannot discount tubes or assume (as WAY too many people do here) that they must be fakes. All tube preferences are system specific, application specific. They also have to be matched to the links in the chain. So if you have a tube phono stage, tube pre and tube amp, it is much harder to balance than just one of those having tubes.
 
In my power amp, I tried every 12AX7 pair from $10 to over $125 a tube. The final one ? A very rare and hard to find pair of Sylvania 5751 Triple Mica Blackplates Yellow print. why ? detail. My system is very detailed with forward mids, nice tight strong base, wide soundstage. GE and RCA's had the detail, didn't have the forward mids. On my systems, Tele's are DULL. Mullards are sweet (#2). Amperex. yuck ptooy.
 
Bottom line, don't disparage. encourage. If they want to try a Mullard it may be the most incredible tube they one...or ..they may hate it...only their system and their ears will know.

And so I have I, look on forums such as AA, AK, online tube sellers, the Telefunken ECC802S are regarded as one of the best easily, some classify it as the best and these are people are walking tube encyclopedia's and have the experience to know what they are talking about, of course if you're talking about multiple tubes used for different gain stages in a pre-amp especially it is much different, but I'm talking in the sense of one amp, one tube there is too many variables to count in if you're talking about some Conrad Johnson pre-amp for example that takes 5 12AU7's, 5 12AX7's and various other pentode family tubes. The Telefunken's are the GEC brown base of the 12AU7 family, the ECC802S don't go $450-500 a single tube for nothing if they were bad. Literally the holy grail of the 12AU7 family.
 
Unfortunately as it is they are quite a few fakes floating around especially on ebay, one will not be able to distinguish between the genuine article and a fake unless you know what the sound traits are and the structure of the tube, the plates, grid, getter, etched codes and bottom base structure to the pin's give it away. 
 
I don't know why you're taking this all personal and getting defensive about it because somebody else doesn't favour Mullard's as much as you do. Different strokes for different fokes, different application and different amps. To finally remind you this is a Bravo Audio thread on $50 tube amp's.
 
Feb 1, 2014 at 8:16 AM Post #2,411 of 2,720
My wallet is already cowering in the corner.

 
Well, what I recommend is a gentle stroll through the 12AU7, 5963, 5814, and maybe 6189 sections of the vintage tubes on eBay. Don't pay more than $10-15 per tube. Really, if you look and are patient, you can get them really cheap. I have purchased 5963 tubes for as little as $2.50 each, and they sound great compared to the stock tube. I recently bought a 50's vintage Raytheon black plate for $8 bucks. You can' t beat that kind of deal anywhere.
 
Save the Mullard, Amperex, and Telefunken adventure for another day when you win the lotto. Think Frugal, and be patient.
 
Feb 1, 2014 at 9:51 AM Post #2,412 of 2,720
  Doesn't take 12AT7 and 12AX7's. Yes they can work but the 12AU7 has the lowest gain of the triode family, then followed by the 12AT7 and then 12AX7 has the highest gain of all 3. It will overdrive the circuit and lead to distortion so it not a drop in replacement for this amp's circuitry. 12AU7 = ECC82 (European Prem's equivs) and a lot more, plenty of 12AU7's to be found. If you want you can buy an adaptor off ebay that will allow you to roll in 6SN7's.
 
As with distinguishing Mullards, the first thing that gives away a Mullard tube, be it a proper re-issue or rebrand is a big O getter that flashes on startup, 4 pinched groves on top of the tube glass surface and a very nice, deep low end and natural sounding treble, mids can be a bit distant and Mullards tend to have a good low-end but laid back neutral mid, treble and non sibilant highs. Detail is there but not as good as the Holland factory Amperex's which also can have a flashing O getter and pinched groves on the top tube glass surface.
 
If you want detail and awesome sauce soundstage, genuine and not cheap Telefunken's, Valvo, Philips and genuine Tesla's are what you should aim for.
 
But I'd think it'd be absurd rolling $150+ tubes in a $50 amp. 

Thanks for the info! I've been trying to figure that out for days and for the life of me I couldn't find anything on this. Besides Mullard's, what other brand of tubes would you recommend? I've heard Sylvania's are nice, but I'll admit it, I'm a total noob to tubes haha
 
Feb 1, 2014 at 11:08 AM Post #2,413 of 2,720
Well, what I recommend is a gentle stroll through the 12AU7, 5963, 5814, and maybe 6189 sections of the vintage tubes on eBay. Don't pay more than $10-15 per tube. Really, if you look and are patient, you can get them really cheap. I have purchased 5963 tubes for as little as $2.50 each, and they sound great compared to the stock tube. I recently bought a 50's vintage Raytheon black plate for $8 bucks. You can' t beat that kind of deal anywhere.

Save the Mullard, Amperex, and Telefunken adventure for another day when you win the lotto. Think Frugal, and be patient.


Thanks for the advice. Its not the fact that the tubes themselves are expensive, but I'll have to stop myself buying so many different ones to try. But I'll stick to you suggestions and try and get some for cheap.
 
Feb 1, 2014 at 1:10 PM Post #2,414 of 2,720
Thanks for the advice. Its not the fact that the tubes themselves are expensive, but I'll have to stop myself buying so many different ones to try. But I'll stick to you suggestions and try and get some for cheap.


RAZOR...I feel your pain,,,,LOL
 
My 12AU7/12AX7 and 6L6GC journey was like that as well as EL84's...
 
NOW...I just recently went overboard with the 6922/6DJ8/6GM8/6AQ8/7308 's for my AUNE T1 tube DAC. I have 3 I settled on...and 14 I don't need !!! LOL
 
My very particular Velleman amp...Takes 1 - 12AU7  2 - 12AX7's and 8 (yes eight) 6L6GC's

 
 
 
And this is an amp I built for my office...The preamp (solid state) was a kit, VU meters from China and the power amp portions is an EL84 power am I restored. The box was scrap wood...
 

 
A Baldwin tube amp - was an organ pull customized ( I cant take credit for the build...just the improvements) - output trannies underneath

 
Feb 1, 2014 at 1:14 PM Post #2,415 of 2,720
I just need to pace myself, I can probably survive for now on the stock tube, as I haven't heard anything better. 
 

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