[adamus]

I am putting together a soha with jisbos and e12. This is going in a galaxy m 230*230 case from hifi2000.

Can you check this layout and make any suggestions. I will be using silver 4n wire for signal carrying.

 

[Ferrari]

The side profiles of the HiFi-2000 Galaxy enclosure can serve as heatsinking very well.
To make full utilization of it you can re-arrange the PCB's a bit, so that the JISBOS output transistors and the voltage regulators can be mounted on the side profiles of the Galaxy enclosure directly.

And... why don't you use σ24 transformer board and stack the ε24 on top of it? That would be much neater than adding an extra toroid transformer.

 

[adamus]

cheers farrari, good advice, mouing the jisbos like that shoud allow for a bit more bias too.

I would like to use a σ24 but i have a spare small toroid that i may aswell use.

 

[dBel84]

I am not sure what it is that you are trying to achieve by using so many accessory pieces. The E27 is for mounting the RK27 - for which there is an allocated space on the SOHA board. The E24 is to prevent the massive inrush you get with high powered amps (not the case in SOHA) If it is turn on thump that you are trying to avoid - the e12 will do just perfectly.

One question for you.. do you already have all the modules that you intend to build?

Don't get me wrong, I am not being critical , we all build amps the way we want them. I just would hate for you to collect all the pieces and then start to rethink the logic behind it all..dB

 

[synaesthetic]

I'm going to agree with dB... a lot of those parts are unnecessary. I can perfectly understand the Epsilon 12, I would not build a "high-end" SOHA without one. But the other ones, you can probably save a good chunk of money by omitting them.

 

[MisterX]

I would agree that the e24 & it's transformer are unnecessary, but for a different reason.
Latching style illuminated pushbutton switches (like those made by Bulgin) are pretty easy to find and most of them that I have found are rated at 3amps.

BTW this is how I think I would do it in that case---->

 

[adamus]

Thanks for the advice.

My logic is:

Everything is going to be pluggable using molex kk's. This means when i get fed up with the amp i can just unplug and off i go.

I completely agree about the e24 being overkill. However, somewhere down the line i am going to diy my speaker amp, at which point the e24 can be plugged out and moved into the speaker amp. Its my idea of a easy modular based system.

I do completely agree its overkill for a soha based amp .....initially!

 

[adamus]

Mister X, very sensible suggestion switching the soha round. Going along wiht my modular theme using heatsinks instead of the case also makes sense.

I just know 6 months down the line the soha 2, or something equally as good will come out and i wont want to fork out for another case of this quality.

I love twisted logic!

 

[dBel84]

can't fault your modular thinking and if it is for future upgrade possibilities, why not spec your transformer as 15-0-15 A 1A ( ie 30VCT , 30VA )

..dB

 

[adamus]

the main transformer is exactly that. I have taken mister x's advice and gone with a s24 for powering the 24, its only an extra £2.50. The dollar is so low against the pound at the moment.

 

[adamus]

Dbel84, i just re-read your original post. The E24 is not a soft start circuit, from what i can see its just a relay trigger which can be used to bounce, debounce a momentary switch. It can also be used as a thermal breaker for power amps. amb also enabled it to drive LEDs typically found in the anti-vandel switches.

Expensive but quite bling.

 

[dBel84]

yeah , i went over to headwize and read the thread - I was under the impression that it was a soft start but not as you noted..dB

 

[adamus]

update on this.

I have wired up the soha, used 0.22 clarity caps (bit of a job getting those to fit). The jisbos have been fired up and biased to 30ma.

the e12 has been test. It has a delay of about 16 seconds, should be about right for the soha.

The e24 has been assembled, but i am waiting for a pcb mount transformer to arrive.

all looking good so far

 

[adamus]

OMG these sound good. I have a soha with opa2107 next to the soha + jisbos. The jisbos utterly destroy the opamp. I didnt think they would make such an impact.

Steinchen, very impressed!

The soha + Jisbos is pretty formidable. Which headamps get much better than this???

 

[adamus]

Update:

Just got to finish the e24, then case it up. I will also shorten all of the wiring to its minimum.