NZGuitars.com

Hi All,

I'm currently working on a 15-18w valve amp but I want to build i with a Fender Twin preamp circuit. Does anyone have a diagram of a normal channel of the fender twin? Preferably not a schematic haha..or Can anyone help me translate the schematic preamp circuit of the fender twin to a turret board diagram? If anyone has a drawing..please send it to me! It will help a lot! Cheers!


Regards,
Thomas C

calling pete . . . also, I wouldn't recommend trying to build (apart from a basic kit) ANYTHING just from a diagram, you should understand the schematic, I.E. how it works

bbrunskill wrote:calling pete . . . also, I wouldn't recommend trying to build (apart from a basic kit) ANYTHING just from a diagram, you should understand the schematic, I.E. how it works

Thanks, I understand. I do understand it but It just takes time for me to read them as I'm new to them. I also occasionally get help from a cool old man with the amp build but he lives in wanganui haha.

Also I'm looking to replace the transformer is to use a 230V primary, 330---0---330 bolts secondary @ 120ma, 6.3V C/T @ 3 ams and 5 volts @ 2 amps... On a side note, apparently you can get away with a 5y3 rectifier valve with S/S rectification as well, but what difference does it make? Anyway the replacement transformer is to suit a Japanese Volage. which is why I'm looking for a transformer without changing any circuit at all other than the transformers - would be 100V primary, 250-290v scondary @ 120Ma with 6.3 volt winding @ 3 amps. Do you guys have a recommended place to buy 100v transformers? or are they custom made?

Cheers

Unsure if you meant Twin reverb by "twin"
Twin schematics to follow

with layouts

more twin schematics, I havevn't inspected to note the differences between models so can't comment.

Tube rectifiers gives less well regulated power supply than SS. I.E. more sag.

Similar effect might be obtained by adding a Sag resistor to Power Supply where you might otherwise find, or in series with, the choke.

Don't know of much advantage to hybrid valve and silicon rectification. Somebody else might.

I don;t know what power amp you wish to build but almost certain that 5Y3 (I'm a little bit rusty on the specs) will be inadequate for 4x5881 or 4x6L6.

Fender schematics and layouts on this site - including Twins and Twin Reverbs

http://www.thevintagesound.com/ffg/

With the AB763 amps which I build the tone stack is all on the pots with the use of a tag strip.
I am working 11 hours a day building at the moment but I can post some closeup pics for you when I get a few minutes this weekend.
If you do it this way you will not need a turret board.
You can use an EZ 81 recto valve and run it from the same 6.3 Volt heater supply.
PM me if you like.

Hi All, Thanks for the quick reply.

It seems most of the preamp for "twin" and "deluxe" The v1 preamps are the same? I'm slowly drawing up a schematic and a diagram, will post it here when It's done And alan, I'll PM you as well. The schematic from Steve Luckey and robrobinette is also helpful.

Cheers!

Anyone have a black board lying around? Happy to take them off you! I need it for my amp build. Will take progress shots in the next few weeks.

Thanks!

Have a look at the Rob Rubinette website, he discusses most fender amps from a schematic and layout perspective