[Didhefocus]

  About the defect: The defect is not because the "burn-in". I related the "burn-in" to sound quality. Believe me, the sound changed after some days. I had been comparing (plugging and unppluging the headphone in either gears!) both gears. I was disapointed with the V3 but yestarday I felt the changing! Exciting!
 
The defect happens only when I make tube rolling. I tested 3 differents tubes. My tubes are in good conditions.I used them on my phono preamp, because it used 12AU7 tubes alsol.
 
About the supposed crosstalkig: The distortion is very high in a channel only! Quite possible any person to feel it! One of the tubes (RCA) simply won't work, no sound at all! Electro Harmonix works with very high distortion on the left channel.
 
About mods: And yes, I will try saome mods and I would like so much to try the mosfet mod. Nice your suggestions about power supply mod! I liked it!
By the way, IRL510 is veru diffucult to find here in Brazil. IRF510 is easier. What about this (IRF510)?
 
Thank you! Your message was helpful!

The IRL510 is the best replacement for this amp. NOT IRF!
Make sure you are using only compatible tubes such as 6922/6DJ8 or equivalent. You mentioned 12AU7 in your post...this is NOT a compatible tube for the Bravo V3!

 

[mateusfig]

Sorry for not checking in for a while! I'll have to check the MOSFET part numbers later. I usually get my parts at Newark.com. Don't the online electronic suppliers ship to Brazil?

Hi. No problem. I bought the parts from e-Bay some days ago. I'm waiting receive them. 

 

[mateusfig]

  The IRL510 is the best replacement for this amp. NOT IRF!
Make sure you are using only compatible tubes such as 6922/6DJ8 or equivalent. You mentioned 12AU7 in your post...this is NOT a compatible tube for the Bravo V3!

 
Oh okay! I tried 12AU7 because my model says "12AU7" on the stock tube and I thought 12AU7 was compatible to 6922. Anyway, I have 12AU7 and not 6922. What about that? I'm confused! Lol!

 

[Didhefocus]

From what I remember, the "6xxx" in the tube number stands for 6 volt heater voltage and "12xxx" is 12 volts.  That would definitely explain your problem! I have another similar amp (Little Bear P-1) that can use 6xxx and 12xxx tubes but it has a 6/12 volt switch.

 

[mateusfig]

 
From what I remember, the "6xxx" in the tube number stands for 6 volt heater voltage and "12xxx" is 12 volts.  That would definitely explain your problem! I have another similar amp (Little Bear P-1) that can use 6xxx and 12xxx tubes but it has a 6/12 volt switch.

You are right, but why my amp has a stock 12AU7 tube and it works? See the picture:
 

 

[Didhefocus]

  You are right, but why my amp has a stock 12AU7 tube and it works? See the picture:
 

Well since you are having problems I can only assume this is the reason! If the heater in that tube gets only 6 volts, it will never transfer elections properly for good sound 'cause it never warms up!

 

[HOWIE13]

  You are right, but why my amp has a stock 12AU7 tube and it works? See the picture:
 

Just because the blue LED lights up doesn't mean it's working.
As Didhefocus has explained the Bravo V3 is not designed for 12V tubes.
The wrong tube type was in it and that has misled you into thinking the amp was defective. You could contact the seller again and ask for an explanation. Maybe the seller confused the V3 with a different amp which uses 12V tubes and put the wrong tube in your V3
Of course the amp may have been defective too but you would never know that unless you used a 6V tube: 6922, ECC88 etc.
Good luck.

 

[Didhefocus]

I previously had an issue with my amp powering off after warming up and found it was the blue LED shutting down and taking the power supply with it. I replaced it with a large red LED from a mouse that became flakey and I've been using it that way ever since. Well another mouse bit the dust and it had a small blue LED, a perfect replacement for the original one! My V3 now looks normal again!

 

[mateusfig]

  Just because the blue LED lights up doesn't mean it's working.
As Didhefocus has explained the Bravo V3 is not designed for 12V tubes.
The wrong tube type was in it and that has misled you into thinking the amp was defective. You could contact the seller again and ask for an explanation. Maybe the seller confused the V3 with a different amp which uses 12V tubes and put the wrong tube in your V3
Of course the amp may have been defective too but you would never know that unless you used a 6V tube: 6922, ECC88 etc.
Good luck.

 
 
I'm really confused.

 My amp works nice after technician fix. I keep on using the (as labeled in the tube) stock 12AU7 tube and only it works very nice. How it could not work with 12AU7?
 
About 6922, I will receive a couple (Tesla) as soon, but I'm afraid to check this and damage my new tubes. 
 
How can I make sure what kind of tube my amp use? Whether  6v or 12v tube and what exact tube model...

 

[HOWIE13]

   
 
I'm really confused.

 My amp works nice after technician fix. I keep on using the (as labeled in the tube) stock 12AU7 tube and only it works very nice. How it could not work with 12AU7?
 
About 6922, I will receive a couple (Tesla) as soon, but I'm afraid to check this and damage my new tubes. 
 
How can I make sure what kind of tube my amp use? Whether  6v or 12v tube and what exact tube model...

I don't know what your technician has done to your amp.
Easiest and safest thing would be to ask him whether you can use 6V as well as 12V tubes.

 

[mateusfig]

  I don't know what your technician has done to your amp.
Easiest and safest thing would be to ask him whether you can use 6V as well as 12V tubes.

Alright. My technician told me there were mounting errors. He only unmount some parts and re-mounted. Else, there was 1 bad capacitor (the big ones) and he changes (both).
 
I will ask him some helping to identify the right tube for my amp. But, anybody here could help me? What it would necessary (parts values? resistors, capacitors e and CI?) to identify? 

 

[Didhefocus]

  Alright. My technician told me there were mounting errors. He only unmount some parts and re-mounted. Else, there was 1 bad capacitor (the big ones) and he changes (both).
 
I will ask him some helping to identify the right tube for my amp. But, anybody here could help me? What it would necessary (parts values? resistors, capacitors e and CI?) to identify? 

Why not just look at the schematic and previous posts in this thread?

 

[mateusfig]

 
Why not just look at the schematic and previous posts in this thread?

You're right but I need check my unit itself. Pehaps my unit has different build. The bulding is very simple and I think was not hard to find the right tube specification looking for a few components and meansuring the voltage. I will return with this data. 
 
Anyway, I will check the topic, as you suggest.

 

[mateusfig]

I just put the 6922 on my Bravo V3 and made sure the 12au7 it was a big mistake. Never existed this version of V3. The seller sold me it used with the wrong tube and caused all this mess. Thanks for all help and for clear this up.
 
It's working lovely with a Tesla 6922 gold pins.
 
Now it's time to adjusting bias right. 15,5v on both?? Actually I checked and its in 10 to 11,5v on the left and 12,5 on the right. I don't want damage the tube (it was a little expensive) and the amp.

 

[Didhefocus]

I'm glad you finally got your V3 working properly!
The Voltages, 13.5-15.5, are just a guideline and you should adjust them for the least amount of crosstalk and distortion by ear.