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Bravo Audio - funny looking little tube amps - Page 126

post #1876 of 2599

I'm going to say this again. Replace IRF5/6XX with IRL510/N's or 530's.

post #1877 of 2599
Quote:
Originally Posted by viveksaikia22 View Post

I bought a Bravo Audio Ocean amplifier and did some heavy overhauling of the components.
I did the following mods -

1. Replaced the stock mosfet transister (IRF630) with the IRF510. This has opened up the highs considerably and have widened the soundstage.
2. Replaced the 25v rated capacitors with 3300uF 35v panasonic capacitors. This has tightened the bass significantly. The flipside is that the top of the case doesn't closes anymore now due to the size of the capacitors. I prefer to keep them open as the amp runs quite cooler this way.
3. I bought some NOS tubes from eBay. RCA and Sylvania tubes. They sound good with very well defined high end and a bit forward mids, but guess what!! I like the sound of the stock Chinese tubes more than these as they introduce a very sweet sounding distortion. Call me crazy.

I am quite happy with my desktop set up paired up with my Sennheiser HD600s. Pure honey to the ears.

You're crazy. You couldn't POSSIBLY have a taste for something different than me. No way, no how!
On another note, I haven't actually heard the Electro Harmonix. LoL!
post #1878 of 2599
Quote:
Originally Posted by Mshenay View Post

I got my new tube with RCA tubes, clear tops and 5963s. And it does sound very nice. The bass is slighty more detailed than on my crappy Haromix Eh6992 [or waht ever cheapo brand it is] but the mids r a little smoother as well as more treble extension. So I'm a happy camper [and technically I could swap one of my RCA clear tops into my indeed G3] but I'd rather stick with the 6992 tube 

 

Okay, consider this a Public Service Announcement. You truly owe it to yourself to demo at least one of the clear tops (if not all of them) for an extended period. On the 12V side of the house, these are some of the best sounding tubes you can find. They are unique, as tubes go, and they may just change your mind about always using the 6922 because they typically have a blend of clean smoothness and good detail. It sounds oxymoronic, but in my whacked-out G2, they are sweet, sweet, sweet. (Gotta bias... gotta, gotta bias) Even though they have great detail, you can listen to them for hours without treble fatigue. Mine have an excellent soundstage and they all image well. The bass on mine is tight and deep, but there isn't a lot of mid-bass "fog," that bassheads seem to like. This may be more of a function of the big caps I have installed than the tube, though. Yeah, I am a fan of these tubes. When I roll 12Vs, I keep coming back to the black plates and clear tops for lengthy periods (think days, not hours). If you don't want to "season" (break-in) your tubes by listening to music, just leave the amp on, with one in it, overnight. It's a Class A amp, so whether you're playing music or it's just on, it's always juiced the same. YMMV, but I bet there is at least one of your clear tops that will get your attention...
Edited by Judge Buff - 3/1/13 at 7:04am
post #1879 of 2599
Quote:
Originally Posted by Judge Buff View Post

 

Okay, consider this a Public Service Announcement. You truly owe it to yourself to demo at least one of the clear tops (if not all of them) for an extended period. On the 12V side of the house, these are some of the best sounding tubes you can find. They are unique, as tubes go, and they may just change your mind about always using the 6922 because they typically have a blend of clean smoothness and good detail. It sounds oxymoronic, but in my whacked-out G2, they are sweet, sweet, sweet. (Gotta bias... gotta, gotta bias) Even though they have great detail, you can listen to them for hours without treble fatigue. Mine have an excellent soundstage and they all image well. The bass on mine is tight and deep, but there isn't a lot of mid-bass "fog," that bassheads seem to like. This may be more of a function of the big caps I have installed than the tube, though. Yeah, I am a fan of these tubes. When I roll 12Vs, I keep coming back to the black plates and clear tops for lengthy periods (think days, not hours). If you don't want to "season" (break-in) your tubes by listening to music, just leave the amp on, with one in it, overnight. It's a Class A amp, so whether you're playing music or it's just on, it's always juiced the same. YMMV, but I bet there is at least one of your clear tops that will get your attention...

Yea your right... I can buy a Digitial Multimeter... NOW and try those clear tops! Sadly my new 12ua7 Millext Max is NOT as powerful as my indeed G3 [but it does sound better]

 

STILL Buff... my MAN I will TRY IT! [After I get my digital Multi-Meter] 

 

What do I need to set the bias too... I was told 13.5v for 12 and 13.0v for my 6 circuit 

post #1880 of 2599

  I found it to be next to impossible to adjust the bias on the G3. I've been doing it by ear which I know isn't proper, but the one time I tried to probe underneath I hit the wrong spot and the amp shut down. Luckily I didn't fry it beyersmile.png

  I'd planned on installing leads like I saw in a pic in an earlier post but haven't had the time. Heard the project sunrise 2 was easy to bias so shot jeremy an email.Sure enough, easy as you could want. So I couldn't resist and bought one. Suppose to be here tomorrow. Can not wait.

  I love clear tops, very unique sounding tube. But my ken rad 5814s are almost a permanent fixture in my fournier. The sound is so rich and creamy, a delicious tube. RCA 5814 black plate has set up shop in my bravo. Love the bottom end.

  I've read the same on the bias setting. Hopefully I'll get my leads installed this weekend on my G3. Are there trim pots on the bravo V2? I can't find them anywhere. I read they're under the heatsinks but can't confirm.

post #1881 of 2599
Quote:
Originally Posted by stupidmop View Post

  I found it to be next to impossible to adjust the bias on the G3. I've been doing it by ear which I know isn't proper, but the one time I tried to probe underneath I hit the wrong spot and the amp shut down. Luckily I didn't fry it beyersmile.png

  I'd planned on installing leads like I saw in a pic in an earlier post but haven't had the time. Heard the project sunrise 2 was easy to bias so shot jeremy an email.Sure enough, easy as you could want. So I couldn't resist and bought one. Suppose to be here tomorrow. Can not wait.
  I love clear tops, very unique sounding tube. But my ken rad 5814s are almost a permanent fixture in my fournier. The sound is so rich and creamy, a delicious tube. RCA 5814 black plate has set up shop in my bravo. Love the bottom end.
  I've read the same on the bias setting. Hopefully I'll get my leads installed this weekend on my G3. Are there trim pots on the bravo V2? I can't find them anywhere. I read they're under the heatsinks but can't confirm.

come to Jesus talk -.- I'm looking to adjust voltage set a multimeter to read voltage not ownslol
Edited by Mshenay - 3/2/13 at 8:21am
post #1882 of 2599
Quote:
Originally Posted by Mshenay View Post

I adjust the bias on my g3 easily when i got it... Now im using a $20 Walmart n radio shak meter... Both at 200 ohms. Black lead on the RCA out for ground... Red on the r13 spot... N im getiing no reading... Is it me,the cheap meter or my tube cuz i can't adjust the bias this time around...,n it was easy the first time... Still me n radio shak r having a come to Jesus talk -.-
Make sure the meter is set for 20V range. VOLTS not ohms. If this doesn't work, check for an internal fuse blowing. It happens...
I try to set the bias ~11V - 13V on both 6/12 settings. I have never set both sides at the same exact bias because I don't have a perfectly balanced tube. I get the voltages very close to each other, then I listen to get the output levels ~ the same strength per my old fart ears. Typically for me this means the R side gets tweaked up/down after I know the L side is approx loud enough for the volume level the amp is on. When the R output is approx as strong sounding as the L and I like the result, I quit. The better the pots, the easier the tweak. The two sides may be several V different... Let me repeat that. There may be a large difference in each side's voltage level. I've got tubes that may be 4 or 5 volts apart. One side may be 12.4V and the other 16V+.

This is why it's important to buy tubes that are close to balanced in triode emissions. The age and application of these used valves can cause big discrepancies. That's why many folks put a premium on mil-spec tubes as they are designed/made more rugged and why NOS is claimed all the time. If one triode is dying much faster than the other, you don't want the tube.

Sorry for the long post...
Edited by Judge Buff - 3/2/13 at 5:19am
post #1883 of 2599
Psssh, that's not a long post JB. Have you seen some of my posts? http://www.head-fi.org/t/646786/evshrugs-if-i-knew-then-what-i-know-now-discussion-journal/45#post_9210582

Interesting point about voltage biasing, then ear-biasing after that for volume matching. The two tubes I've rolled so far were both equally biased at 13v (6DJ8 variants), and I thought the meter did a far better job than my ears. Maybe I'll have to try it again with my problem-child Amperex, which has a weaker right channel (which of course doesn't help MY head's weaker right "channel"), though I've been addicted to my Sylvania JAN 6DJ8 (mil-spec like Judge Buff mentioned) for like... Months now.
post #1884 of 2599
If you have a song that you really know, and you know how it "should" sound in each channel, it becomes much easier to tweak the volume level. I use "Sirius" by Alan Parsons, usually, just because it is short and I've been listening to it for almost 30 years... Your point about "your head's weaker right channel" is extremely important to old farts like me. I know my right ear is weaker than my left in several ranges of freqs.
post #1885 of 2599
Well buff, i took ur advice. The RCA 12ua7 clear top sounds awesome. N yea volts not ohms silly me

N dang i love how tough tight my 990s r with this tube.

Still have 3 others to try..., might not though... To lazy sadly

I will say my 5963 rca is slightly warmer than my clear top. So i like the tighter crisper sound with this bass head can. Granted i miss the extra sexy mids, but tighter bass wins with my bass can

Still great deal i got on my millet hybrid... The extra tubes it had r loving the g3 n bass cans

Still have to c which tube my mad dog alpha will dig

I will also add i do like the 5963 rca better with my linear 880. Still the mad dog is apparently r warm linear... Man those might b some seriously sexy mids biggrin.gif
Edited by Mshenay - 3/2/13 at 9:20pm
post #1886 of 2599
Judge Buff,
I have a few songs I have analyzed intensely for years across different equipment (posted my "standard quality test playlist" back in 2009 when Head-Fi still had the ability for regular users to blog), and a few special Van Morrison songs that have always been part of my go-to "happy place" songs since my dad played them before I was born. Haven't messed with biasing recently, but from what I remember the difference during tweaking by ear was different types of static buzz if I went too far one way. Using the multimeter revealed the "sweet spot" and saved me a bunch of time, though I think I did go for a bit higher than 13.5 volts.

I also messaged the bugle boy's seller since nobody bid on the tubes, I missed the auction because I realized a little late that I had a job orientation today for the job that will replace Wendy's. The 6N23's also were dropped off at shipping today, no tracking number yet tho.
post #1887 of 2599

@the guy on top biasing by ears......get yo'self a multimeter you fool.biggrin.gif

post #1888 of 2599
Quote:
Originally Posted by DefQon View Post

@the guy on top biasing by ears......get yo'self a multimeter you fool.biggrin.gif

  wink_face.gif  If you're refering to me I got my leads installed today and can't believe the diff. I've got a decent multimeter i picked up from amazon(it says INNOVA 3320 iEquiss), I like it. Been going a year strong now biggrin.gif

    Starting on your mod list for my V2 tomorrow. Thanks again btw. Doing the mosfets first. They are 510s per your suggestion.After hours of research on rockgrotto I determined the V2 had no trim pots. May add that to the list however my tubes are closely matched on the triodes so may not confused_face.gif Got 510N mosfets. I need a few more tools but I've done more with less wink_face.gif.

    My G3 is now running a perfectly biased siemens 6922 gold pin 1955 i think. Holy wow. My first eargasm and it was everything I thought it'd be!beyersmile.png Ordered a project sunrise 2 that was spose to be here today but this happens.

   Believe it or not peter from indeed told me to do the ear thing, after he had told me to use my multimeter blink.gif But I knew better. Just a noob tool move tongue_smile.gif

 Regards,

 Mop

post #1889 of 2599

Just got 2 Sylvania Tubes and one Phillips Mullard.

 

It DEFINITELY makes a huge difference in sound!

I highly recommend you replace the stock tubes immediately with some well regarded tubes, it's a world of difference.

 

Thanks to DefQon for his explanations and tube recommendations!

post #1890 of 2599

 It's the #1 thing you can do to improve sound. Stock tubes leave a lot to be desired IMO. Defqon knows his shizzle biggrin.gif

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