or Connect
Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › SOHA II Builders Thread
New Posts  All Forums:Forum Nav:

SOHA II Builders Thread - Page 34

post #496 of 1686
Nice, they are a smart looking case. Is that case tall enough to enclose the valves or will you have to cut holes in the top do you think?

Do they come with all any accessories - like feet? How was modushop to deal with?
post #497 of 1686
Modushop is very easy to deal with, however communications with the Italians from HiFi-2000 in English can be a pain in the “behind”.

They do sell feet but these are overkill for such small enclosures from the Galaxy (Max) line.
I’m using those rubber feet for my β24 and Super Leach power amps, housed in Pesante Dissipante 5U enclosures.
I would say… take a look at Modushop and find out yourself.
post #498 of 1686
Quote:
Originally Posted by Ferrari View Post
Ooh, one of my favourite! I have used that enclosure a while back too.

Hey Ferrary, can I ask you where did you get the jack connector for that soha II???? I've been looking for something similar, but the only thing I could find is the neutrik locking one, and I really don't like how it looks.

Thanks!
post #499 of 1686
I just built the soha II from the glassjar kit. I am a novice at amp building, having only built a couple of cmoys and a pimeta before. Nonetheless, I managed to get the soha up and running on the first try. It sounds great.

I do have one issue though, which has emerged as I am doing the casework. I grounded the iec to a bolt through the case and ran another through the star ground on the board. I now have what sounds like a ground loop if I turn up the volume with no music playing. I experimented by running the power ground to a pair of pliers and the noise went away. Can someone tell me what I am doing wrong?
post #500 of 1686
that's just a ground loop.

The Cavalli-Kan Kumisa III Stereo Headphone Amplifier

last paragraph. That should fix you. Make sure the jacks are of the isolating type. Note the grounding of the pot if you're using a plastic panel.
post #501 of 1686
Quote:
Originally Posted by Alcaudon View Post
Hey Ferrary, can I ask you where did you get the jack connector for that soha II???? I've been looking for something similar, but the only thing I could find is the neutrik locking one, and I really don't like how it looks.

Thanks!
It's a Neutrik NYS221, available at Mouser.
This type is non-isolated. Therefore mounting directly on a metal faceplate is not recommended.
post #502 of 1686
Many thanks for your answers Ferrari. Non isolation is not an issue, since it's for a DIY wooden enclosure.

Btw, someday I might ask you a few questions about your balanced SohaII if you don't mind of course

Thanks!
post #503 of 1686
Quote:
Originally Posted by holland View Post
that's just a ground loop.

The Cavalli-Kan Kumisa III Stereo Headphone Amplifier

last paragraph. That should fix you. Make sure the jacks are of the isolating type. Note the grounding of the pot if you're using a plastic panel.

Thanks for the suggestion. I implimented the ground loop breaker outlined on amb's site. It lowered the noise some, but it is still there. Anything else to try? I suppose I could live with it, as the noise is only audible well past the volume where I would ever foreseeably listen. Is this just the consequence of using a single case?

Update:
The main culprit seems to not be the soha after all, but the Ibasso D3 DAC I am feeding it. I switched to my pmp and the noise is greatly diminished-- not gone but much more faint.
post #504 of 1686
as you know i have finished my build and have liked it so far. I have run into an issue though. After a couple hours of playtime the right channel drops in volume and becomes quite distorted. If I power down then back up it works ok for a little, then back to the problem. If i turn down the B+ it seems to work ok for a while. Does anyone have any suggestions?
post #505 of 1686
swap tubes and see if it follows. Touch the buffer heatsinks. Does one side seem extraordinarily hot?
post #506 of 1686
None of the buffers seem hotter than the other. If I trip the relay by adjusting the B+ it goes away (then comes back later). I will swap tubes tomorrow and see if the problem follows. If I tap either tube I hear the microphonics in the left phone only.
post #507 of 1686
could be cold solder joint. If the tube swap doesn't follow the tube, then check the joints on that one side.

You can also probe the B+, V+, V-, H-, when it happens.

The microphonics could just be a "bad" tube.
post #508 of 1686
Quote:
Originally Posted by tacitapproval View Post
Thanks for the suggestion. I implimented the ground loop breaker outlined on amb's site. It lowered the noise some, but it is still there. Anything else to try? I suppose I could live with it, as the noise is only audible well past the volume where I would ever foreseeably listen. Is this just the consequence of using a single case?

Update:
The main culprit seems to not be the soha after all, but the Ibasso D3 DAC I am feeding it. I switched to my pmp and the noise is greatly diminished-- not gone but much more faint.
Further update: the actual culprit is the laptop power cord coming through the usb of the dac; if I unplug the laptop, no more noise.

My question is if I switched the groundloop breaker from the pcb ground to the rca or iec ground would it be more effective? Does this make sense?
post #509 of 1686
Thread Starter 
tacitapproval, one question on your rca jacks. Are they grounded directly to the case or are they grounded to the input ground point on the board?
Dr. Cavalli gained notoriety with his first DIY amplifier projects. His success has blossomed into Cavalli Audio, a world leader in amplifier design.
Reply
post #510 of 1686
Quote:
Originally Posted by tacitapproval View Post
My question is if I switched the groundloop breaker from the pcb ground to the rca or iec ground would it be more effective? Does this make sense?
I just want to ask but... runeight has beaten me on that.
One remark regarding ground loop breaker: for safety reason, a ground loop breaker should not be connected to the AC input ground (IEC connector).
New Posts  All Forums:Forum Nav:
  Return Home
Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › SOHA II Builders Thread