Vox AD60VT Valvetronix

[RussU]

Picturevalve, What ended up being your problem? Mine is started doing the same thing. Thanks!

Sorry--I've been busy, on the road, and haven't had time to work on it yet. I'll post what I find when I do. I plan to start with looking at the bridge rectifiers and the power output transistors.

Russ

[RussU]

The problem with the AD60VT blowing fuses turned out to be the BR1 bridge rectifier was shorted. Replaced it, now the amp works fine--no other issues.

[bringsteen]

Hi picturevalve,
where did you get the new output power switch from? Have you got a part-number etc.? Just to be sure, is the output power switch the one to change the output power from 60 to 30...? Thanks!

[TomB]

My AD60VT is blowing its line fuse, too. Hoping for a quick fix, I'm going to replace bridge rectifier BR1 as described above. I would appreciate help with the following two items:

1. How does one disconnect the small white connectors on the boards? For example, two of these go to the small transistors on the large heat sink. The connectors don't seem readily removable.
2. Picturevalve, can I get a copy of that AD60VT schematic? I'll need it if the BR1 replacement doesn't work. My email is nospammer78@yahoo.com

Thanks!

[TomB]

Nevermind on question 2; AD120VT_Service_Manual_Complete.pdf contains AD60VT info as well.

Re/question 1, here is a photo of the wires I wish to disconnect:

[oc disorder]

Think you will find those terminations are soldered in.
Usually if you cut the cable ties the other end unplugs.
Awkward I know , however you have a camera which will help restore the lead dress.
At least some unplug !!

[TomB]

Thanks, oc disorder. I miss the days of 27 different color combinations on wire insulation, but nevertheless I'm diving in to unbundle all those white wires!

[spirou38]

My AD60VT is blowing its line fuse, too. Hoping for a quick fix, I'm going to replace bridge rectifier BR1 as described above. I would appreciate help with the following two items:

1. How does one disconnect the small white connectors on the boards? For example, two of these go to the small transistors on the large heat sink. The connectors don't seem readily removable.
2. Picturevalve, can I get a copy of that AD60VT schematic? I'll need it if the BR1 replacement doesn't work. My email is nospammer78@yahoo.com

Thanks!

Hi fellows,

My son's AD60VT is faulty.
I'm looking for the service manual.
Can you send me a copy of the schematic and boards at pas.voisin38 "at" free.fr ?
Thanks for your help.

Best regards from France,

Pascal

[TomB]

From my perusal, the AD60VT info is contained in the AD120VT service manual at http://www.valvetronix.net/docs/AD12...l_Complete.pdf. On the drawings, I believe X-9861 refers to the one-channel AD60VT main board and X-9862 the two-channel AD120VT board. The document contains other info common to the two.

[spirou38]

From my perusal, the AD60VT info is contained in the AD120VT service manual at http://www.valvetronix.net/docs/AD12...l_Complete.pdf. On the drawings, I believe X-9861 refers to the one-channel AD60VT main board and X-9862 the two-channel AD120VT board. The document contains other info common to the two.

Thanks Tom,

Yes, the X9861 board is the AD60-VT power supply / amplifier board.
After having a quick look on the AD120-VT schematic, I could now investigate
The problem of my son's amp looks like a main power supply problem but there is no blown fuse.
I will first have a look to BR1 ( KBP206G ) Which is a 2A bridge rectifier that seems a little short for a 60W amp ...

Thanks for your help.

Pascal

[spirou38]

Hi Tom,

I have repaired my son's amp .
The little 1.5 A BR02 bridge rectifier was deffect : no led were on, including the power on led ; the 11 V power was varying from 2.7 to 4.9 Volts.

Pascal

[Mark Black]

Thank you for posting your findings/fix.