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SOHA II Builders Thread - Page 54

post #796 of 1688
Quote:
Originally Posted by zkool448 View Post
My soha II is making music



I must've really lucked out because the voltages came up correctly from the start.
Congratulations zkool448 ! I'm not at all surprised that it worked right off the bat. After spending time with Alex's schematics for the SOHAII, Bijou, and now the CTH, I've learned that the designs are rock solid and careful attention during assembly is all that is required...

I'm really looking forward to seeing what your going to do with the casing on this one. Your SSMH is certainly a favorite of mine (and many others based on all of the comments). I think you set the bar pretty high with that one - not to put any pressure on.
post #797 of 1688
excuse the mess, but its almost done...



no hiss, no hum, just clean clean sound. And may i say, with the 5963, quite a solid state sound. very very different to the bijou. but its way off being burnt in, the tubes have barely 10 mins on them.

To get the tubes that high without air wiring them, i used a socket saver in each socket.
post #798 of 1688
hayduke, your build tips and watchouts helped me immensely, many many thanks again!

Btw, I mistakenly soldered the 2x3 header upside down (longer pins to board). When I tried the jumpers they would not stay on I had to desolder the header and ended up melting its plastic in the process (what a pain that was - this was the time sachu's advice came in handy: "Put the iron down and walk away if you're ticked off!"). I replaced it with 6 sip sockets, although a dpdt switch would've been the ideal replacement I didn't have one on hand and I was eager to get it setup.

TimJo, appreciate the kind words In terms of the casework, actually can't wait to get started. I have a change of heart about "matching" cases with my next build (CTH). I'm under the impression that the SOHA II and CHT are fairly close like brothers, but it'll be nice to keep their own distinct 'personalities'.

Here's a quick mock up of what I've envisioned so far, of course it could change depending on how much ventilation is needed... we'll see how close the final product will look



zk
post #799 of 1688
Quote:
Originally Posted by adamus View Post
no hiss, no hum, just clean clean sound. And may i say, with the 5963, quite a solid state sound. very very different to the bijou. but its way off being burnt in, the tubes have barely 10 mins on them.
very nice adamus! that's exactly the locking 1/4" jack I want to use for my case -- do you have a mouser/digikey P/N? thanks.

zk
post #800 of 1688
Zkool448, i dont as i got mine from farnell.

I let the soha play for 5 hour last night, its warming up nicely, and the bass has filled out.

its a hot little beastey, good job i have the vented case.

whats the concensus on setting the B+. I have mine at 60v at the moment.

Going to be sad to see this one go, as i am building it for someone else.
post #801 of 1688
not being able to find a datasheet for the 8416, which heater setting do i want?

EDIT - and here is is finshed, and here is stands with its big brother, the bijou.

post #802 of 1688
Thread Starter 
Very nice.

8416 is 12V.
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 #803 of 1688
Nice, adamus.

Re: the Bijou. Were nameplates actually made? I guess I missed the buy on that.

Re: the SOHA 2. Are you using a zener for R4 and 1mA per triode?
post #804 of 1688
Quote:
Originally Posted by zkool448 View Post
I'm under the impression that the SOHA II and CHT are fairly close like brothers, but it'll be nice to keep their own distinct 'personalities'.
zk, that's a really nice case you're working on. Those with tooling access make those without envious.

CTH and SOHA 2 have their own personalities, particularly in the behavior of tubes. The same tubes sound slightly different in the amps. They have a different tube configuration. It's all on the Alex Cavalli site for reading.

Also, if you're one who does ever push it to that extreme. The CTH is a class AB PP output buffer (diamond) with a healthy bias of 25mA. Though I've never pushed it out of A, there may be possibilities of crossover distortion for the nightly "concert" goers. The SOHA2 is class A SE with a 100mA bias (can push higher if you need with venting/heatsinking).

They are quite different animals. The CTH is one beast of a transportable, and sits at about 1/8th the size of my SOHA 2....with much less heat generation too.
post #805 of 1688
Quote:
Originally Posted by zkool448 View Post
very nice adamus! that's exactly the locking 1/4" jack I want to use for my case -- do you have a mouser/digikey P/N? thanks.

zk
Mouser - 568-NJ3FP6C

This p/n is for the all black version I believe...
post #806 of 1688
Quote:
Originally Posted by zkool448 View Post
In terms of the casework, actually can't wait to get started. I have a change of heart about "matching" cases with my next build (CTH). I'm under the impression that the SOHA II and CHT are fairly close like brothers, but it'll be nice to keep their own distinct 'personalities'.

Here's a quick mock up of what I've envisioned so far, of course it could change depending on how much ventilation is needed... we'll see how close the final product will look



zk
Wow, that's looking sharp. I like the idea of recessing the volume knob like that...
post #807 of 1688
Quote:
Originally Posted by runeight View Post
Very nice.

8416 is 12V.
cheers runeight. I'll give them a go. Given my experience with the 8416 in the soha + jisbos i expect them to really take this on a step
post #808 of 1688
Quote:
Originally Posted by holland View Post
Nice, adamus.

Re: the Bijou. Were nameplates actually made? I guess I missed the buy on that.

Re: the SOHA 2. Are you using a zener for R4 and 1mA per triode?
no, i had it made, only cost me £5 from ebay. and the tail is the resistor at 400mv = 2ma. no zener in sight.... surely too noisey.
post #809 of 1688
Quote:
Originally Posted by holland View Post
zk, that's a really nice case you're working on. Those with tooling access make those without envious.
Thanks holland, I too like this design but it's something I have never attempted before -- It looks like it could be done (fingers crossed)

Quote:
Originally Posted by holland View Post
CTH and SOHA 2 have their own personalities, particularly in the behavior of tubes. The same tubes sound slightly different in the amps. They have a different tube configuration... <snip>
Thanks for breaking down the differences between the SOHA II and CTH. I'm eager to try a variety of tubes and do some A/B comparison... although I realize only the 12.6v variants can be used on my SOHA II as I didn't opt for a high current transformer.

zk
post #810 of 1688
Quote:
Originally Posted by TimJo View Post
Mouser - 568-NJ3FP6C
This p/n is for the all black version I believe...
TimJo, I think you got the right p/n (jack with the metal plate). just placed my mouser order to day for the jack + other misc parts I needed -- thanks!

zk
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