Some G9 questions

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I mean do I have to do some desoldering and resoldering
stuff to do in the transfo ? :shock:
wasn't it easier to do on the pcb ?
( heu, no, sure not ! it wouldn't have the same result ! stupid question ! )

I should get the transfos today !

I will post more questions later :grin:

any advice for reversing the transfo is welcome !

thx
 
depending on what boards your using, everything could already be just fine for you to drop the trannies into place and forget about it. I did.

Tony.
 
OK !
A262A2E should be reversed ! right ?
( that's for the G9 )

do I have to open the transfo ?
how ?

that's the only thing I don't understand about the G9
( sorry guys ! ) :sad:
except that it is almost done !

Help ........ :wink:
 
reversing means putting it in the other way around, not taking it a part and rewiring stuff. It is very easy, you just look at what is noted on the boards you're using and fit the trannie accordingly.
My boards where with a layout already prepared to accept the trannie reversed, really don't worry too much :wink:

Where did you get the boards you're using? This might help us to help you.
 
From Gustav

ah !
OK so it is already done on the PCB !
so there is nothing to do !? just put the trannie in and solder it !

I thought I had to reverse it according to the pcb design !
:?

Sorry , I'm new in DIY !!!
a few more stuff and I'll be OK :grin:

THX Tony
 
welcome anytime... in case it still should go wrong (I doubts this) all it takes is to unsolder the 8 trannielegs and to put it back in 180° turned (as in kompas degrees that is), but as said, Gustav's baords have already a very decent printed explanation on how you should put the OEP into place.

Cheers and have fun doing this!
Tony
 
new to forum!
getting ready for g9 build - has anyone built the HT around CMOS multiplyer - can it supply enough juice - will it have any bearing on the sound as compared to the tx supply.
I'm just thinking of keeping supply simple - 12v (possibly portable!) DC with CMOS phantom and HT!
 
Hi!
i'm new here too,but been reading a lot ,and i can answer this question:
the cmos multiplier configuration is what's called "starved plate",it means powering the tubes with a minimum acceptable tension,and in a short answer,that will not work for the g9 project(which i'm also in the process of building)...i know you saw that in the paia tmp,the multiplier gives around 50 volts,and the g9 needs 245,as clean as posible (which switching suplies like the paia one can not provide)

So my advice is to follow the g9 directions as close as posible,and remember that the power transformers are not a difficult part to obtain...of course,toroidal are preferred,but you can see some pictures of one built with a conventional transformer...

In my case,i asked at a local transformers factory for a custom made trafo ,primary 220v,two 15 v secondaries at 1 ampere and one 220 secondary at 100 ma...they can wind it in a couple of days,for 16 dollars...maybe i go this way,just one power transformer....toroidals are unobtainable here in Montevideo

Good luck!
 
thanks for the info - but have you checked the cmos ETI article on gyrafs site - uses multiple stages ie one cct showing 18V in 433V out! I might be missing an impotant point/theory but could this be a possibility?
Cheers
 
Maybe it could be possible - you'd need to do your own experiments if you feel it's important enough.

Probably it's not a good idea. And after all, a traditional psu is neither complicated, nor expensive.

Jakob E.
 
Thanks for the input - BUT - I do think it's worth pursuing a single 12V supply - I've done a few recordings of brass band/orchestral in some places that have had absolutely shite mains supply.
I think it would be great to use 12dc (lead acid) and HT + 48V derived from this supply - hence the interest in the voltage multiplier.
Could you tell me how much current the G9 draws on the HT.
Another possibility would be to have a sine osc with power output transistors driving into reversed transformer - any thoughts?

Been using a notebook and firewire interface - like the look of the motu traveller (up to 192k/24 bit!) bus powered but apparently cooks the notebook - again - I like the idea of a lead acid 12V (car battery!) supply, could power interface from this also.
 
Hi everyone

It was too good to be truth !!! :sad:

I finished my G9 and plugged it

at first I had a rumble but it disappeared

then It worked but I realized that I had Full volume when vol. pot turned to the left ( I think i can solve that one ! ) :grin:

but when I tried to plug my guitar into the jack connector I heard a kind of Bzzz and have seen a little smoke ( not good I guess )

I tried the other channel and the same Bzzzz

I hope I haven't burnt anything ! :sad:

Anyone knows what this could be ?
 
Hi Jakob !

Do you think it can be the jack's wiring ?



Let's say this is a switching Jack connector ( I know it doesn't look like anything ...... :eek:) )
----
1 l l 2
l l
3 l l 4
\ /

I plugged the "To inst" to 1
"From" inst to 2
"Gnd" to 4

isn't that right ?
 
I'm almost sure my jack wiring is OK

but that's weird ! when I mesure the voltage between the chassis and the
jack's ground or the from inst, I get 240 V !!!!! :shock:

I've gotta have a short circuit somewhere !

I'm gonna test everything !
 
Glad you fixed this.. :thumb:

For high-voltage stuff like this,

1) make sure that you isolate anything carrying HT voltage

2) make sure that every part of the chassis is securely connected to 0V/Gnd. Often there's bad connection to e.g. the frontplate if it's painted or laquered..

Jakob E.
 

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