[headphonejunkie]

 
I am building a jisbos and was wondering if adding elna cerafine 470 uf at c1 and c2 instead of 100 uf caps will be a better thing or worse. The voltage rating is 25 v instead of 35 too,
 
I have some used cerafines from my millet build that are still good.
 
I am thinking they will never see 35 volts and 25 should be suitable. Yes?

 

[FallenAngel]

Double check but I think those go from rail to ground and will see 15v. Will be nice to use.

 

[headphonejunkie]

Yes those do go across V plus and minus. I would think the cerafine would sound better than the silmic. I am just not sure if voltage would exceed 25v on these rails
 
I am worried about a spike or something. I would think the higher capacitance would help bass response too.

 

[FallenAngel]

If they go across V+/V- lines, they'll be probably 30v. If they are from V+/ground and v-/ground, that's 15v.

Looking at the schematics and board, those are between rails and ground. They'll see 15V. Use those caps

 

[headphonejunkie]

Ya. I will give them a try. They are a little tight but should work.

 

[headphonejunkie]

Hey FA
How did you connect up the gnds on these bds. I am curious on my options.
 
Thanks for the info in advance

 

[FallenAngel]

It completely depends on how the rest of your amp is wired... without knowing this, it's impossible to answer.
 
With the "stolen" SOHA board, I just wired it as an opamp.

 

[headphonejunkie]

oh, so you basically just used gnds and such coming off the pins for the op amp. I used a straight setup using bd gnds as required no wires running all over. Of course these little bds are going to be a different matter.

 

[headphonejunkie]

I can see how SOHA II came about though. All these good ideas had to be put on a single bd with less wiring.. Since I had the bds already I had to put them together and give it a try.

 

[FallenAngel]

You'll come up with a nice amp at the end, I know that for sure. I really liked my SOHA + JISBOS. It's a great amp that sounds nice.
 
Yes, the SOHA 2 was an improvement on the design, reworking the tube working voltage points, improved power supply and implementing a great output stage. That's true, but the original SOHA was pretty cool too, working at a low voltage and having some room for improvement as it was a first design.
 
I tried to do a bit in the original discussion and design of it but someone decided to print PCBs early and without permission from Alex Cavalli, that's when things went sour. That's kind of why it isn't discussed any more. Some ass-hat ripped off the design while it was still being developed and people started building them. It's a total bitch move and while I did get a board or two to check out things are going, it wasn't a good way to go about it. I love Alex and his dedication to the work he does. It's just a mess. Now I can only say that the original design was a great start but the PCB had obvious issues. The amp is still good, but it would be nice to add things to it. The JISBOS is an obvious one, an e12 muting circuit is also a good thing to add.
 
Starting fresh, I'd go for the SOHA 2, no questions asked. If you have the original SOHA, it's fun to upgrade and play with.

 

[headphonejunkie]

I recently read about that. That was a bad move. So, the board I have is one of those pirated bds then. Cause cavelli never made any?

 

[FallenAngel]

Yep.
 
Screw it, use it, it's a half-assed layout that should have included space for TO-220 regulators, an easier way to implement the CCS and a way to include diamond buffers, but it still "works".
 
I don't think anyone will hold it against you for using the board.
 
To give credit where it's deserved, it's a cool amp and the JISBOS is a great output stage.
 
Build it, enjoy it, that is all.

 

[headphonejunkie]

WOW. I never knew. It was cavelli's idea to begin with though. So he gets the credit. Its funny how people try to take credit for great ideas sometimes.

 

[headphonejunkie]

Is that why headwize is shut down now?

 

[FallenAngel]

No, HeadWize was shut down for other reasons, that I don't know of. I miss the site though, it was amazing.