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Cavalli EHHA Embedded Hybrid Headphone Amp - Page 119

post #1771 of 1816
Quote:
Originally Posted by capernicus View Post

Bijou is only slightly cheaper for the glass jar kit but I am not a big fan of the electrolytic in the output although from what I have read everyone who builds one seems to love it...

 

Can anyone offer any suggestions or insight?

 

Thanks!

 

 

 

 


Well, I'm listening to my Bijou right now and I'm extremely happy with mine.  I can't really see myself putting the time in to build another desktop tube amp for a while (had this one since April now).  My next desktop build will be a Beta22.  I'm going to spend my Autumn season building some portable stuff first.

 

I think you'll be happy either way, and keep in mind that I haven't had a lot of experience listening to many different desktop tube amps, so my opinion might be tainted.  Nevertheless, I know when my ears are happy.

 

post #1772 of 1816

I've built all three, and will say the the Bijou really does its best work when paired with high-impedence 'phones, like my HD600's.

 

I would recommend the Rev. A over the original EHHA because of the all inclusive design of the board, and that it can be configured

to work with either high or low-impedence 'phones. On my Rev. A build I socketed the output devices so that it could be easily set

up with either BJT's or MOSFET's.

 

To sum up, the one that I kept is the Bijou, although it's anything but stock.

post #1773 of 1816

Thanks for the input... I was all set to place the EHHA Rev A order with numerous comments in this thread suggesting its up there with the B22 but your Bijou praise has me making second thoughts.  Currently I only have a pair of lower end Grados and have been giving some thoughts to maybe buying a pair of some AKG 701s - so I'm definitely on the low Z side of things and have heard the Bijou Grado combo leaves a bit to be desired.   (Although I have been considering some HD600s...)

 

How is the build complexity between the Bijou and the EHHA?  The Bijou circuit seems to be a little more straight forward circuit...

 

Looks like the solution is to build both... unfortunately I only budget for one.

 

Bijou with some HD 600s? or

 

EHHA as with my current Grados and possibly a future procurement of AKG 701s or something else...

 

Any insight?

 

post #1774 of 1816

I prefer the EHHA hands down. Not a big fan of the Bijou. It is a nice amp, don't get me wrong on that front, but I never felt like I wanted to build one. ANd I have built a ton of Cavalli DIy amps in the last 3 years.

post #1775 of 1816

Thanks Sachu, I've been reading a bunch of your posts in the EHHA forums...  Great to know there is a lot of experience bringing these amps to life - I hope my build goes smoothly.

 

From what I have read most seem to really like the EHHA and I've seen a few raving reviews that really caught my attention comparing it to a b22.  Looks like I'll be placing an order this weekend!  Need to start thinking about what I want the case to looks like...

 

 

 

 

post #1776 of 1816

Good choice. You might consider socketing the ouput devices so you can try both MOSFET's and BJT's.

 

BTW, when I sold my first EHHA (original), Sachu thought I was nuts for prefering the Bijou. tongue_smile.gif

post #1777 of 1816

Finished up my EHHA Rev A along with some modifications which yields great results. 

 

1) If you prefer punchier, deeper bass and a more full bodied sound, consider swapping the 2200uF caps in the power supply to 4700uF. I uses a pair of Rifa 4700uF 63V on each power supply to excellent results. Terrific sound on my LCD-2

 

2)I use AMRG(Amtrans) 300ohms resistor for R2(plate loading resistor) as advised by a DIY shop dealing with tubes. More transparent, wider soundstage and silkier highs! 

 

These are the 2 mods i tired and really like the effect, especially the caps mod. Try it folks!

 

I will post up some pictures this weekend.

 

post #1778 of 1816

Had a complete rework, resoldering of my year old EHHA which I had assembled last September with gurubhai. Here are a few pics of the metamorphosis. Need better heatsinks for powering speakers at a later date.EHHA (2).jpgEHHA (4).jpgEHHA (6).jpg

post #1779 of 1816

EHHA Small (23).jpgEHHA Small (19).jpgHad a complete rework, resoldering of my year old EHHA which I had assembled last September with gurubhai. Here are a few pics of the metamorphosis. Need better heatsinks for powering speakers at a later date.EHHA (2).jpgEHHA (4).jpgEHHA (6).jpg

post #1780 of 1816
Quote:
Originally Posted by Audiodoc View Post

EHHA Small (23).jpgEHHA Small (19).jpgHad a complete rework, resoldering of my year old EHHA which I had assembled last September with gurubhai. Here are a few pics of the metamorphosis. Need better heatsinks for powering speakers at a later date.EHHA (2).jpgEHHA (4).jpgEHHA (6).jpg


looks awesome.  no offense, i don't know what you have the EHHA biased at, but the heat sinks on the o22 are skimpy.  the MOSFETs are tough and all, but....

 


Edited by fishski13 - 9/15/11 at 10:02pm
post #1781 of 1816

No offence taken smile.gif.

 

I myself am worried about the adequacy of the heat sinks. Good efficient ones are hard to come by in smaller cities in India. Am searching for them online. Although I have used the amp in an airconditioned room for hours will possibly get better heat sinks in the near future.

 

 

post #1782 of 1816

^ Its nice to hear from you after such a long time. Can't believe its been a year since we built this amp working through the whole night.smile.gif

 

I won't worry about the sigma22 heatsinks. I have measured their temperature & they hardly ever cross 40 degrees. But the heatsinks on output BJTs must be replaced.

I have managed to source some better ones, will pm you the details.

post #1783 of 1816

should have told me guru, would have thrown a bunch of the aavid together when i sent the TP over.

 

 

post #1784 of 1816

^ I surely would have troubled you buddy, if there was any issue.

But I found a source for aavid sinks a while back.

Imagine my surprise though when the delivery guy told that he was delivering these directly from Aavid factory here in New Delhi. :facepalm:

post #1785 of 1816

My EHHA is doing fine but I have few questions:

 

1. One of the heat sinks in the sigma 22 is heating more than the other 3. The one on the right side along the output side length Q15 on silkscreen. Why should it be so. Amps works and sounds flawless.

 

2. Have ordered larger heat sinks for my EHHA boards but their is not enough space to mount them. This is a BJT version. Is it possible to somehow adjust them in the mosfet holes. I know anything wrong and it will fry my transistors. Something I won't try. Rather put the 2 inch thinner heat sinks coz heating is less likely to fry them.

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