Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: TerryD on July 08, 2014, 07:32:32 am

Title: Vox AC 30C2 Power tubes and diodes
Post by: TerryD on July 08, 2014, 07:32:32 am

First Thanks for all the help I get here.
Just picked up a "like new" Vox AC30C2 from a pawn shop for $500, with a cover and roller palatte.  With the MDF this thing brings about a "near death" experience each and every time you lift it. Sounds great though.
Do the El 84s need to be matched in a Vox Ac 30?   I'm thinking not.
It has a solid state rectifier.  I really like putting FREDS in these type of amps as to my ears they are more musical.  I don't suppose anybody here could give me the diode numbers for the rectifier off the schematic (which not one person seems to be able to find on the net).  Even if I had one, it would be good if I knew the board numbers.  Any easy place to get FREDS?
Also some people change the treble bypass cap on these.  What would that board number be?
 What are good tubes for these?
Thanks again
Terry

Title: Re: Vox AC 30C2 Power tubes and diodes
Post by: Willabe on July 08, 2014, 08:16:45 am

Hi Terry,

It would help if you would post a schemo of this amp.



                      Brad       :icon_biggrin:

Title: Re: Vox AC 30C2 Power tubes and diodes
Post by: kagliostro on July 08, 2014, 10:23:17 am

Give a look to the library of schematics here in the forum

not now, but within today more late or tomorrow  :angel


K

Title: Re: Vox AC 30C2 Power tubes and diodes
Post by: sluckey on July 08, 2014, 05:00:47 pm

Matched tubes are always desirable, but not an absolute necessity.

D7, D8, D9, and D10 are the four diodes you're interested in. They are 1N4007. AES has some freds.

Treble bypass cap??? Are you talking about the bright caps on the volume controls? Those are 120pF, C8 and C15.

Title: Re: Vox AC 30C2 Power tubes and diodes
Post by: TerryD on July 08, 2014, 05:04:38 pm

Thanks for understanding my miscommunication.  AES= Antique Electronic supply I'm assuming.  thanks for the numbers

Title: Re: Vox AC 30C2 Power tubes and diodes
Post by: TerryD on July 09, 2014, 04:19:21 pm

Just getting rid of c15 is an improvement.  Seemed to let a brittle high pitch through all the time.  Very nice amp