[Jazzavri]

Bonjour à tous . Il y a 1 semaine j ai commander un kit ac18 que j’en vien de finir de monter . Avant tout j ai de bonne base en électricité mais moin en électronique . J ai tout d abord monté mon condensateur d entrée pour tester les tensions de sortie tout était ok . J ai ensuite câblé le reste de l ampli avec la plus grande précaution puis monté mes lampes . J ai branché un baffle en 8 ohm avant le démarrage . Lors de la mise en route toute mes lampes s allume mais aucun son ne sort !! Le baffle ne fait aucun bruit !! J ai essayer avec un autre baffle puis jack et c est pareil !! Après avoir tous débrancher et retourner l ampli je m’en suis rendu compte qu une résistance avait bruler !! Il s agit de r22 . Si vous pourriez m aider à trouver mon problème de câblage ou de composant ? Je vais essayer de mettre des photos en pièces jointes

[sev]

Bonjour Jazzavri,
tho I can understand french, my writing skills will not suffice for technical aspects, hope we can switch over to english.
If R22 has suffered overcurrent, it was most likely caused somewhere around V2 or V1, pls remove the bad component and recheck these areas for shorts or solder bridges.
Some pics would also be helpful.
Remember you´re dealing with lethal voltages, so don´t proceed any further if you are unsure about working with high voltage and stay safe 
regards,
Stefan

[Laurent]

Salut!

Bienvenue dans le forum. Je pense être un des seuls français du forum, donc si tu veux de l'aide efficace, mieux vaut écrire soit en anglais, soit en allemand 

Pour ton problème, des photos aideraient bien. Pour que la résistance brûle, c'est qu'il y a trop de courant. Peut-être as-tu inversé qqchose comme raccorder les EL84 à B3?

Post some pictures, that will help to maybe localize the issue.

Laurent

[Jazzavri]

thank you for your answers i am trying to send pictures. sorry for the language.

[Jazzavri]

<a href='https://www.casimages.com/i/200906103636840069.jpg.html' title='Mon image'>Lien vers mon image</a>

[Jazzavri]

<a href='https://www.casimages.com/i/200906103637613955.jpg.html' title='Mon image'>Lien vers mon image</a>

[Jazzavri]

<a href='https://www.casimages.com/i/200906104830735400.jpg.html' title='Mon image'>Lien vers mon image</a>
<a href='https://www.casimages.com/i/200906104832431028.jpg.html' title='Mon image'>Lien vers mon image</a>
<a href='https://www.casimages.com/i/200906104838564396.png.html' title='Mon image'>Lien vers mon image</a>
<a href='https://www.casimages.com/i/200906104839759251.png.html' title='Mon image'>Lien vers mon image</a>
<a href='https://www.casimages.com/i/200906104845300072.png.html' title='Mon image'>Lien vers mon image</a>

I hope that the link of the photos works, I took the opportunity to put the diagram at the same time. as I specified above I am not an expert in electronics .. I am afraid to turn the amp on again to take tension. is it possible to remove r22 as well as the lamps then turn on the amp again without damaging anything?
 

[Jazzavri]

I just found my mistake and I'm ashamed of it! I have reversed the polarities of c13 c15 and c16! I will redo my wiring !! do you think i may have damaged something other than r22? or the elko themselves?

[Laurent]

As R22 gave up, something happened.

I would strongly suggest to exchange the caps. You cannot really know, how they reacted with the wrong wiring. You're lucky, that R22 burnt and not that a cap exploded !
To be honest, everybody had such an issue once, let it be in the negative bias circuit... 

[Jazzavri]

thank you for your information. from what I tested a priori nothing else to move but I still thought to change the condos. This is my first amp kit after a good ten pedal kit without problem but my mistake is still shameful! i will order all of these and keep you posted thanks 

[Jazzavri]

hi after receiving condos and spare resistors (preventive) I repaired my faults and the amp works wonderfully !! after a good preheating and 45 min of play no parasitic noise the amp is very quiet. I will post pictures of the finished head. Thank you and see you soon

[Laurent]

 

[Jazzavri]

small technical question on the ac18. would it be possible to adapt a 4-switch pedal instead of the tone switch? it will allow to have as an amp has several channels at the foot. the only problem is that with each change of channels, the previous contact opens? I do not see how to schematize the whole? the ac18 is a rather plug and play amp and plays very well at the volume of the guitar but it could be a little more.

[Laurent]

Hi,

Almost everything is possible. In this case you would have to integrate relays to switch the different caps. This would allow to keep the tone switch and also to use a Footswitch.
Whether the complexity in the realisation matches to the need or not, is up to you.

Cheers
Laurent

[Jazzavri]

thank you laurent. I understand the principle of the relay. should be integrated an external 9 v power supply to the pedal with 4 relays and by switch and pulse switches?