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Bravo Audio - funny looking little tube amps - Page 106

post #1576 of 2599

My work informed me a bit ago I would be traveling extensivly for the next few months "have for the past few as well" so I sold off my v2 12au7 version to a member on here. As soon as I sold it, they said I would be mostly based here in the office for the next few months... DOH. So ordered another in lol. Will probably go the exact same route I did before but with a few tweaks. Decided this time I would gut the board, maybe build a new board to support all of the current mods I had performed.. heck I do not know. Spent a wad at mouser today lol

post #1577 of 2599
Have you considered the Millett hybrid? Or the Bottlehead Crack?
post #1578 of 2599

Did you get a Bravo or Indeed? I would get an Indeed if I need to buy one. Board grounding is really good. Extra layer only for ground.
 

Quote:
Originally Posted by Garage1217 View Post

My work informed me a bit ago I would be traveling extensivly for the next few months "have for the past few as well" so I sold off my v2 12au7 version to a member on here. As soon as I sold it, they said I would be mostly based here in the office for the next few months... DOH. So ordered another in lol. Will probably go the exact same route I did before but with a few tweaks. Decided this time I would gut the board, maybe build a new board to support all of the current mods I had performed.. heck I do not know. Spent a wad at mouser today lol



 

post #1579 of 2599

I have purchased and have been working with the bravo v2. With mods, it is excellent. I have also used the indeed version and it is very good as well. The bravo just stinks out of the box is all. With some minor mods, it is outstanding for the cash.


 

post #1580 of 2599

So designing the new board with all mods included for the bravo v2 12au7 version+... Any other mods you guys have enjoyed that you might want to see built into a new board design? I plan / have started to design a board with all mods built in and very nice parts being used. I feel this amp is quite amazing, especially for the price when modified correctly. Everyone I know that has heard one modified correctly loves it so I wanted to build my own version in a kit form for the DIY crowd to easily build and enjoy. The current mods and changes that will be apart of the design will be as follows...
- 25V 4700uF fake rubycon power supply cap changed to a 4qty of 2200uF 35V Nichicon KT series caps for a total of 8800uF.. May just go to a 3qty for 6600uF which is plenty
- RCA jacks removed / only 1/8 jack input?? just a thought at this stage or maybe just have rca's instead? No need for both IMO as it clutters the board. Also re-route the input to the back of the board for a cleaner look
- Crosstalk mod built in / circuitry re-routed
- Input signal capacitors eliminated rather than removed and jumpered
- Blue LED turned WAY down brightness wise with a 10K resistor + 100uF 10V cap added for soft start
- 25 turn 10K 1/2w bourns bias pots for precision bias adjustment. Along with easy to access points to check and change bias
- Output signal capacitors changed to Nichicon 2200uF KT series caps
- Larger heatsinks for both 530's and 317's / slightly larger more open board design
- IRF630's changed to IRL530's for massive extension of the top end / rather than cutting falling off at 10K
- LT317's changed to Linear technologies LT317A's which are of better quality
- All resistors will be 1% Vishay / dale mil spec units
- Power switch located on the top lid portion of a custom laser cut acrylic chassis (similar to the current design)but with a quality switch
- Improved symmetrical board layout / I would like to add an artistic touch to the look and layout without sacrificing functionality
- Debating on just having solder points for the potentiometer as I am not a fan of the stock alps unit... so one could choose what style they want. Same with the 1/4" jack... The stock unit is not bad and common so could leave it on the board. Still debating with myself on it.
Thoughts? I just really dig this little amp when modded and it deserves to be done right.


 

 

 

 

post #1581 of 2599


Try panasonic low esr for the output caps. I like it better than nichicon.

And you might want to try IRL510 instead of 530 to extend the bandwidth even more.

Quote:
Originally Posted by Garage1217 View Post

So designing the new board with all mods included for the bravo v2 12au7 version+... Any other mods you guys have enjoyed that you might want to see built into a new board design? I plan / have started to design a board with all mods built in and very nice parts being used. I feel this amp is quite amazing, especially for the price when modified correctly. Everyone I know that has heard one modified correctly loves it so I wanted to build my own version in a kit form for the DIY crowd to easily build and enjoy. The current mods and changes that will be apart of the design will be as follows...
- 25V 4700uF fake rubycon power supply cap changed to a 4qty of 2200uF 35V Nichicon KT series caps for a total of 8800uF.. May just go to a 3qty for 6600uF which is plenty
- RCA jacks removed / only 1/8 jack input?? just a thought at this stage or maybe just have rca's instead? No need for both IMO as it clutters the board. Also re-route the input to the back of the board for a cleaner look
- Crosstalk mod built in / circuitry re-routed
- Input signal capacitors eliminated rather than removed and jumpered
- Blue LED turned WAY down brightness wise with a 10K resistor + 100uF 10V cap added for soft start
- 25 turn 10K 1/2w bourns bias pots for precision bias adjustment. Along with easy to access points to check and change bias
- Output signal capacitors changed to Nichicon 2200uF KT series caps
- Larger heatsinks for both 530's and 317's / slightly larger more open board design
- IRF630's changed to IRL530's for massive extension of the top end / rather than cutting falling off at 10K
- LT317's changed to Linear technologies LT317A's which are of better quality
- All resistors will be 1% Vishay / dale mil spec units
- Power switch located on the top lid portion of a custom laser cut acrylic chassis (similar to the current design)but with a quality switch
- Improved symmetrical board layout / I would like to add an artistic touch to the look and layout without sacrificing functionality
- Debating on just having solder points for the potentiometer as I am not a fan of the stock alps unit... so one could choose what style they want. Same with the 1/4" jack... The stock unit is not bad and common so could leave it on the board. Still debating with myself on it.
Thoughts? I just really dig this little amp when modded and it deserves to be done right.


 

 

 

 



 

post #1582 of 2599

Thanks for the input :) However on the Nichicons, those are my personal preference and are considered a low esr cap, that and they are 105C rated and built for audio specifically according to Nichicon. Going for the long haul with these babies :) Do you have a spec sheet on the ESR of a panny say 2200uF at 105C showing lower ESR than an equal KT sereis Nichicon? I do not doubt any claims, Just always like to research. http://products.nichicon.co.jp/en/pdf/XJA043/e-kt.pdf

 

 

On the 510's, yes they are able to extend to 60khz, however I am just fine with the 530's clean extension to 30khz. Either are excellent choices. Sonically however, some have preferred the 530 saying it has a more full and open sound which is TOTALLY subjective to the listener, time of day, barometric pressure... sunspots, fingernail growth and what he ate for breakfast lol.. I doubt anyone could ever tell the difference between the two, but yes a 510 is an equally good choice and extension is technically better so will keep it in mind.

post #1583 of 2599

I liked the way the plexiglass looked but in the end the RF interference was just too horrible, esp. from my phone.

You could dimension the PCB to fit a popular case, e.g. one of the Hammonds.

The tube could go on top of the case protected by valve guard, here's how that looks on my G2-in-a-case:

 

g2.jpg

 

Also, the gain on these amps is way too high resulting in too much background noise, I would certainly lower it.

post #1584 of 2599

Very nice. Basing the board on a standard 4x6" I never had any RF issues but I understand others have so definitely something to consider. Just finished the board layout a few minutes ago. Now have to walk away for a bit and come back and take a close look again and tweak things. Then have to get it to someone that is an expert with board design so I can have them produced rather than what I use for DIY boards.

post #1585 of 2599

Wow... I cannot even count how many hours I have wrapped up with the new design lol. Have been working extensively with one heck of an audio engineer "solderdude" over on the grotto. I have been very impressed, the guy knows his stuff for sure. The new design is light years beyond the indeed and bravo style designs. The design is mainly solderdudes with my board layout. He has re-designed the indeed / bravo / muse amps to the point they cannot even be compared measurement wise. Very impressive specifications now. Cannot wait to show you guys! I will have to talk to admin on here as I plan to setup a group buy but do not know the rules of this forum yet. Plan to offer it in multiple styles from a bare board, main components, cap and tube choices and so forth. Also the new design is quite tweak-able with precision bias setting, supports 6v and 12v tube rolling, dedicated heater power supply section, output grounding / timed relay to eliminate turn on and off pop and more.... All major caps from input, output to PS support 2.5 / 5 and 7.5ish sizes so you can tune how you want. Overall I am SUPER excited about this. Still a ways out but it is coming!

post #1586 of 2599


I'll be really interested. I find my modded Bravo V2 to be more enjoyable than the amp part of my Audio GD FUN. Those little things have great potential with higher quality parts and some design upgrades.

 

Quote:
Originally Posted by Garage1217 View Post

Wow... I cannot even count how many hours I have wrapped up with the new design lol. Have been working extensively with one heck of an audio engineer "solderdude" over on the grotto. I have been very impressed, the guy knows his stuff for sure. The new design is light years beyond the indeed and bravo style designs. The design is mainly solderdudes with my board layout. He has re-designed the indeed / bravo / muse amps to the point they cannot even be compared measurement wise. Very impressive specifications now. Cannot wait to show you guys! I will have to talk to admin on here as I plan to setup a group buy but do not know the rules of this forum yet. Plan to offer it in multiple styles from a bare board, main components, cap and tube choices and so forth. Also the new design is quite tweak-able with precision bias setting, supports 6v and 12v tube rolling, dedicated heater power supply section, output grounding / timed relay to eliminate turn on and off pop and more.... All major caps from input, output to PS support 2.5 / 5 and 7.5ish sizes so you can tune how you want. Overall I am SUPER excited about this. Still a ways out but it is coming!



 

post #1587 of 2599

Make that 2. I have Garage's modded Bravo and it's killer. I'd love to get one of his new creations in a heartbeat.
 

Quote:
Originally Posted by aroldan View Post


I'll be really interested. I find my modded Bravo V2 to be more enjoyable than the amp part of my Audio GD FUN. Those little things have great potential with higher quality parts and some design upgrades.

 



 



 

post #1588 of 2599
Quote:
Originally Posted by Garage1217 View Post

Wow... I cannot even count how many hours I have wrapped up with the new design lol. Have been working extensively with one heck of an audio engineer "solderdude" over on the grotto. I have been very impressed, the guy knows his stuff for sure. The new design is light years beyond the indeed and bravo style designs. The design is mainly solderdudes with my board layout. He has re-designed the indeed / bravo / muse amps to the point they cannot even be compared measurement wise. Very impressive specifications now. Cannot wait to show you guys! I will have to talk to admin on here as I plan to setup a group buy but do not know the rules of this forum yet. Plan to offer it in multiple styles from a bare board, main components, cap and tube choices and so forth. Also the new design is quite tweak-able with precision bias setting, supports 6v and 12v tube rolling, dedicated heater power supply section, output grounding / timed relay to eliminate turn on and off pop and more.... All major caps from input, output to PS support 2.5 / 5 and 7.5ish sizes so you can tune how you want. Overall I am SUPER excited about this. Still a ways out but it is coming!

 

I am definitely interested in this since I just blew up my Bravo V2 again. I have such a hard time soldering the IRF's on that mega crappy pcb. The copper keeps coming loose. Shitty QC right there. 
 

 

post #1589 of 2599

del


Edited by Garage1217 - 7/31/13 at 9:06am
post #1590 of 2599
Quote:
Originally Posted by Garage1217 View Post

Also Kastle, I need to get that amp back. I want to make some more changes to it / no cost to you. You will dig it even more :D



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