New tubes: tutorial!

[FranciscoArellano]

how do you make the "test tube"? it looks like a windows program in the picture... I bought an emx last week and i would like to change the tubes. I think i'll do it, but i don't want to screw it

[kimchishreds]

EMX-1/ESX-1 Tube Calibration
１．Connect the stereo plug of the cable (see fig.) to PHONES and the monaural plug to
INPUT.
2. While pressing ERACE and STEP EDIT, turn the power on. “Valv Wup” is
indicated as stand-by for pre-heating, and also the waiting time is indicated.
Set up the volume knob and switches as follows:
MASTER VOLUME : MAX
TUBE GAIN : MIN
AUDIO IN LEVEL : MAX
MIC/LINE : MIC
3. “Ajst (L)” and a 4 digits figure are indicated in the LCD. If the value is leas than
0010, the test is O.K.. Press the 16 knob at the right bottom. If the value is over it, it is
required to adjust the valve. Adjust the variable resistors which correspond to the
channels referring to the photo below.

4. As well as　“Ajst(L)”, “Ajst (R)” and a 4 digits figure are indicated in the LCD.
If the value is leas than 0010, the test is O.K.. Press the 16 knob at the right bottom. If
the value is over it, it is required to adjust the valve. Adjust the variable resistors
which correspond to the channels referring to the photo above.
5. Once the balance of L/R is automatically adjusted, “ValvGMax GainMx” is
indicated in the LCD. Turn the TUBE GAIN knob to MAX, and press the 16 knob.
6. Check the L/R balance of TUBE GAIN MAX, and return to the normal mode.[/img]

i Try to follow those instruction for the calibration but the instruction is incomplete.
My “Ajst (L)” value is 0999 so i try to ajust with the variable resistor but value did not change at all.
pussing on button [16] changed nothing. but the bar change buttons [ < ] [ > ] permit to navigate in the different options
“Ajst (L)”“Ajst (R)” “ValvGMax GainMx” etc... there was also a step where all the led's on the ESX where blinkink leaving me in a questionable state! :-/

i just put the cover back on without any further calibration (later, when i get more detailed information)
before: '12AX7 EH' now 'JJ ECC83 S'
BIG difference! less gain/distortion & really more punch & warmth.

If anybody can make a videotutorial on every steps of the calibration or a more complete instructions, i will give him a hug!

UPDATE:
a bad wire (stereo to mono) was maybe the cause of the strange value (0999)
I will retry the calibration this evening.
again, if anyboby have done this before please detail all the steps for a perfect calibration please.

Just strip TS and TRS cable, tie grounds and protect with E-tape, connect a 2.2M resistor to TRS white, connect another 2.2M resistor to TRS red, then twist the ends together with the TS white (funnelling the signal from stereo to mono) with 2.2M ohms resistance from each channel into the white). Make sure grounds don't touch the red, white, or resistors, cover each mend with E-tape (for a quick calibration cable/ solder to mono end later if you want) I don't know how to post a photo on here but I can text it to you. Looks crazy but works. I used E tape because it was cold and I don't solder indoors, nor do I use lead solder. nasty stuff/ illegal in the UK. Look at the EMX service manual, select all, find '2.2M' and the calibration cable pic will be there. ITs not so clear, as the words are close together to ground line and red/ white line...i just did it midstream with the cables without solder. good luck!

[cpkcpk]

Hey, made a separate thread about this but didn't get any replies.

I got new JJ tubes for my ESX a while back, and also had a new trimpot soldered on as one of them came off when I was tweaking them to match the levels. I've never managed to get the levels the same after that, so finally want to make up the calibration cable and match them properly.

Here's the diagram from the service manual: http://imgur.com/a/BI5fg

Could anyone explain how to make this cable like I'm five? Which type of cable should I start off with?

Apocalypso explained how to make it without soldering in the post above, but even that went over my head.

If anyone in the UK has made one and could send it to me, that would also be great

Cheers!

[Brakio]

Hi, I don't know if this video was already referenced in this thread, but in this tutorial it is mentioned how to build the cable:
https://www.youtube.com/watch?v=znPyQGdlP30
It seem to be really simple if you have soldering iron.

[cpkcpk]

Thanks for that video, very helpful!

I have a soldering iron, so is all I need to get a TRS cable, a TS plug and the 2 resistors?

Are these the correct resistors? https://www.switchelectronics.co.uk/2-2 ... resistor-1

So the TRS end is normal, and at the TS end the red and white cables are each soldered to a resistor, and both resistors soldered to the tip?

[Brakio]

That seems ok to me (excepted the photo of the resistor, but the description is). To be sure to have no contact to the shield you may also isolate between them. And you may also isolate at the red and white cable to be sure there is no contact between them before the other side of the resistors.

[cpkcpk]

Yeah the photo is wrong, but they are the correct ones (red, red. black, yellow, brown). Much cheaper than ordering from Digikey for anyone in the UK.

Made the cable and ran the calibration, level is still a tiny bit louder on one channel but much better than before and tube gain sounds good even at max.

I have hardly done any soldering before so the cable was a botch job lol, but the photo at least shows how the resistors are connected a bit clearer than the service manual - http://imgur.com/a/u3k8P

[crossby]

Thanks for mentioning.
gclub