Hi, take a look at this photos : http://www.voxshowroom.com/uk/amp/ac50cp2_hood.html That shielded cable should go close to the RCA phono reverb connectors. There´s a conenctor there. Maybe it´s related to it ? Send me photos, of all boards. Maybe I can help you. That white cable in the upper left I...

Hi there. So you really have the original 34 Levi's mods? There a bunch of layouts with it, but apparently Frank Levi said they are only close. None is correct. Would you share them?

By the way, I don't know the Sc20h schematic. But I'd live to se it.

Cheers

Yep. It nails the AFD with class!!

Hi, The AC50CPH is originally a dark amp in channel 2. It is voiced that way. I dont think it is the caps, but the amps design. However, without listening it would be hard to tell. If channel 1 is working fine....and 2 is darker, i would say it is the way it is and it will only change the tone with ...

Hi SteveD, OK, now I get the purpose. When you´re using long chains you end up with the signal weakned (tone sucking), so, getting the lost signal back and brigthten it up a bit to compensate is actually a good idea. C68 + R52 seem to affect both at -10db and +4db loop settings. R24+C68 looks like a...

Hi SteveD, I compared both datasheets and at first it seemt to be that TN2404KL and ZVN4424A were "reversed" with each other. My impression is the below datasheet can be wrong. I tried to reverse ZVN4424A and I had no sound in the loop. https://www.mouser.co.uk/datasheet/2/115/ZVN4424A-92441.pdf But...

Steve... ZVN4424A and TN2204 don't have the same pin orientation, do they??? I just looked at both datasheets and they seem reversed from each other : DGS vs SGD. I remember years ago reading that the new part (ZVN) could be inserted with same orientation, but now that I compare both datasheets, it ...

Hi SteveD, Ok, so i´ve taken a bunch of readings. All measured from "pin" to ground. Here it goes : - Pin 39 : 413v - Pin 24 : 416v - Pins 25 and 38 : 156v each (this is the voltage entering the FX board) - Pin 11 : 415v - Pin 9 : 414v - Pin 8 : 8,6v - Pin 7 : 9v - Pin 22 : 1v About R63 : 156v from ...

Hi Steve, You´re right. It doesn´t matter if FET3 is good or bad. All that matter is how much voltage is being sent to it ! OK, I will check the voltage at R63 (from R63 pin that goes to FX board to ground) and at the FET drain pin (from drain pin to ground) again. If this is not how I should do it,...

Hi Steve, I wonder if I have measured correctly the voltage at FET3. One probe to each FET pin and the other probe always to ground. :think I did this process 3 times, one for each pin. If this is the right procedure, then what could eventually cause this drop in voltage ? -A bad resistor in the pow...

Hello SteveD. Can you please comment on the FET3 voltages? Thanks.

Can you compare treble at 4 and then at 0 ? Do you feel a boost in mid frequencies when the treble is at 0 ?
My VM is acting weird. It sounds darker (More true highs but less high-mids) at 4 than at 0.

Well, there´s a chance that my treble pot issue is almost surely not related to my preamp mods. I suspect I have an issue with the FX loop that is influencing tone. I believe I wrote it back in here about an year ago. Either I bypass the loop or not, i always have sound! But accordingly to the manua...

Hi Dana, The 12au7 I've tried in v2 was a JJ. It is a very interesting alternative for HDR instead of a 12ax7. Almost made the amp work as a 2 channel!! It was cheap and I have good experience with JJ in terms of reliability and they work very well with my Ac30. Not so much with the Marshall. I like...

Got it Steve. Sorry, I thought you were going through a specific way of doing it. For sure, that´s what I still wanted to mantain 2 voices that when combined compliment each other. But it´s trickier when you have bright caps in the volume control and a mid-scoop/boost at the body. Well, at least for...