realy helpful for first time builders so get over there watch these videos very good.
dose any one know if Nik includes the powertransformer brace as shown in gabi's videos in the ceriatone kits?

sorry about the delay couldn't get into this site for about 1 week had to reset my modem when i found out othr people had acess and it was just me who could not get in.
yeh will be ordering one in about 2weeks. i'm thinking of doing a step-bystep instructions for the jcm800 and loading it on this site with lots of pics. like metroamps instructions i found on there forum.

Can any one tell me if this multimeter i brought is any good for testing plate voltage and biasing.
http://www.dse.com.au/cgi-bin/dse.storefront/4873ee4003bdf5c62740c0a87f9c0760/Product/View/Q1467

Have since swap over for the next one up as it has more functions and capacity. here a link for that
http://www.dse.com.au/cgi-bin/dse.storefront/4873ee4003bdf5c62740c0a87f9c0760/Product/View/Q4139


thanks

Yeh, I'm gunna do whatt joe popp did build say 2 then sell them to get money back to buy a new one and also get the experience and then build maybe the 2203 on the third one when i have the exoerience under my belt.

found his site, very helpfull his diagrahm of the jcm2204 was better drawn than nic's (sorry nic) easier to follow for novice. Only thing is he had changed a few thing like main board to what is supplied in nic's kit.
but still very helpfull am going to refer to this for my build.
Still think it would be cool to look at other people builds! not just for my purpose but everyone would get a kick showing off there amp!!!!!!!!!!

I am still making up my on weather to build the 2203 or 2204. the 2204's diagrahm is alot more clearer and better drawn. I feel i easily tackle the 2204. if you could load up a pretty large pic for me to look at that would be good. about same size as nic's diagrahm you loaded up.
it would also make up my mind on what one to build as either amp will be loud enough for gig use (playingat pubs and clubs) As for biasing i will use internal bias method testing resistor that runs on valve sockets across pin 8-1-resistor-ground. This is my first build adding external bias might complicate the build too much.
thanks ryan

On nic's layout the lines that go from cont... to dotted on main circ..board go under the board don't they?
and the lines that are only dotted on board are pre installed by nik when builds your board for the pack 2 kit and also are under board? I have inc.. a pic with these pointed out in green arrows

Yeh thanks i see it on nik's 2203 diagrahm
it gose
Ground --> resistor --> pin 1 --> pin 8

I thought that was the bias pot but wasn't 100% shure.

I'm trying to learn as much as i can before i get the amp so when i do i am well ahead.
I read the metroamp 100watt plexi instructions from start to finish that help heaps in things like you must wire the heater wire tightly together in order to cancel hum ect...

If you have the jcm800 2203 from nik, if it's not too much trouble would you post a large/medium inside pic so that i can see your wiring and compare with mine as i build

THANKS VERY MUCH FOR YOUR HELP VERY GOOD!
found this somewhere on another forum thought i would post here for all to read

Here's how I do it:

1) If not using a bias probe, you need to have a 1 ohm resistor on each power tube socket (one end of resistor to ground; the other end tied to pins 1 & 8 ) Use a 1% tolerance resistor.

2) Turn power on and let tubes warm up. Switch standby to "on".

3) *Be very careful on this step (high voltages)*
Set your meter to the highest DC volts (600 or higher) and put the common (ground) lead in one of the chassis mounting nuts or alligator clip it. With one hand behind your back for safety, touch the positive lead to pin 3 (plate) of one of the power tubes. This is your plate or "B+" voltage. Write it down.

4) EL34's are 25 watts max and you want to set the bias to be between 60% and 70% maximum dissipation watts. (60% = 15 watts; 70% = 17.5 watts) Divide your desired wattage by your plate voltage from step 3. (example: 15/450 = .033 or 33mV) This is your desired bias voltage (probably between 30 and 40 mV).

5) Set your meter to lowest DCV setting (200mV or less) and touch the ground lead to the ground side of the 1 ohm resistor and the positive lead to the pin 1 side. Do this on all power tubes and adjust the tube with the highest value to your desired bias voltage from step 4.

Plate voltage will change a little when adjusting the bias so you may need to take another reading from pin 3 and adjust your equation accordingly and repeat steps 4 & 5.

And here is what nik sent me about biasing his amps

Ryan,
 
  The amp has only 1 bias pot. The tubes should match.
 
  All you need is a multimeter, and read in DC Volts.
 
  There are 4 jacks, 1 for each power tube, and 1 neg jack for the earth.
 
  Just adjust for 1 tube. Since the others match, the readings will be similar.
 
  Preamp tubes are self biasing, just plop em in,
 
Hope this helps, let me know.
 
_________________

I mainly listen to australian rock like:
AC/DC, midnight oil, the angels, rose tattoo, the living end Ect... but i also listen to other band like:
Jimi hendrix, led zeppelin, black sabbath, allman broth..., lynryd skynryd, georgia sattelites, george thorogood, mastodon, alice in chains
mainly rock,bluse but i will listen to anything with a good guitar note,playing and good singing.

If you like AC/DC I STRONGLY suggest you check out the angels and rose tattoo both bands use cranked marshalls with rose tattoo being as loud as AC/DC were back in the day before hugh P.A's were invented.
actualy AC/DC heard both bands and liked them and got them singed to there label.

The angels sound is more pollished and slightly more complexed song structure compared to ac/dc with less yelly singing.

Angels best songs- take a long line, Marseilles, no secrets, am i ever gunna see your face, comin' down

Rose tattoo is a bit heavier than ac/dc with pete wells plays george thorogood style slide on all songs and angry andersons sings in a very similar style to bon scott. wells is considered the australian keith richards.

Rose tattoo's best song- bad boy for love, we can't be beaten, nice boys(no G&R didn't write it)

I don't know why both bands didn't make it world wide but they both had hit after hit in ausralia and are icons here

I thought it would be fun for people to upload pics of the inside of there jcm800 builds.
It would help new builder such as myself we could look at our wiring, what wires to twist together Ect... and compare to ones built by nik and other more pro.. more experienced builders on this forum.
it would help to list what mods you have done if your amp has mods and what model it is the 2203 or 2204.
A large/medium inside pic would help me and others heaps and would be fun experienced builders too, to compare theres with other experienced builders. Could be done in other sections of the forum with other amp types.

thanks

Thanks, i will do that (go ask what Ma they have there el34's at)
Before posting my last question i read heaps and heaps on biasing buy not one information said how to work out plate voltage.
the power in our county is 240volts would that have a differences as to what Ma i set the valves at?

thanks

I'm going to get a jcm800 2203 from nik at ceriatone with PPIMV mod in the pack2+JJ El34 tubes+ head cab package deal. I am fairly confident with the soldering and building of the amp and my father is trained in using a soldering iron as part of his job teaching welding and fitting ect... But the only thing I am unsure of is biasing and setting the new amp up.
If i was retubing say a second hand amp with the exact same tubes or doing a bias check on an old amp i would be probably right. It's just setting up and testing a new amp isn't as easy as retubing.

Could someone explain this in simple idiots form. Lol... I understand how to work out what Ma to set poweramp tubes at you need to divide tube dissipation by the plate voltage and that give you 100% and as tubes run best at about 70% you divide by .7
So say that plate voltage was 470 and the EL34's tube dissipation is 25watts it would be 25 devide by 470 = 53Ma then times by .7 which = 37Ma.
My questions are:

how do you work out/measure plate voltage?

dose nik's ceriatone jcm 800 2203 have a bias trim pot that ajust all vavles and if so were is it located using nik's jcm800 diagrahm?

Are pre-amp tubes self biasing if not how do you bias these?

many thanks in advance!!!!!!!!

P.s. this will be my first build
 

I'm going to get a jcm800 2203 from nik at ceriatone with PPIMV mod in the pack2+JJ El34 tubes+ head cab package deal. I am fairly confident with the soldering and building of the amp and my father is trained in using a soldering iron as part of his job teaching welding and fitting ect... But the only thing I am unsure of is biasing and setting the new amp up.
If i was retubing say a second hand amp with the exact same tubes or doing a bias check on an old amp i would be probably right. It's just setting up and testing a new amp isn't as easy as retubing.

Could someone explain this in simple idiots form. Lol... I understand how to work out what Ma to set poweramp tubes at you need to divide tube dissipation by the plate voltage and that give you 100% and as tubes run best at about 70% you divide by .7
So say that plate voltage was 470 and the EL34's tube dissipation is 25watts it would be 25 devide by 470 = 53Ma then times by .7 which = 37Ma.
My questions are:

how do you work out/measure plate voltage?

dose nik's ceriatone jcm 800 2203 have a bias trim pot that ajust all vavles and if so were is it located using nik's jcm800 diagrahm?

Are pre-amp tubes self biasing if not how do you bias these?

many thanks in advance!!!!!!!!

P.s. this will be my first build