Fender Twin Reverb Preamp.

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Marshmallow
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Fender Twin Reverb Preamp.

Post by Marshmallow »

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

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Re: Fender Twin Reverb Preamp.

Post by rickenbackerkid »

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

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Re: Fender Twin Reverb Preamp.

Post by Marshmallow »

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? :lol:

Cheers

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Re: Fender Twin Reverb Preamp.

Post by Ears »

Unsure if you meant Twin reverb by "twin"
Twin schematics to follow
Attachments
twin_reverb_aa769_layout.pdf
(125.5 KiB) Downloaded 165 times
twin_reverb_aa270_schem.pdf
(90.5 KiB) Downloaded 148 times
twin_reverb_aa270_layout.pdf
(126.51 KiB) Downloaded 157 times
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Re: Fender Twin Reverb Preamp.

Post by Ears »

with layouts
Attachments
twin_5e8.pdf
(251.05 KiB) Downloaded 155 times
twin_5d8.pdf
(162.77 KiB) Downloaded 145 times
twin_5c8.pdf
(147.98 KiB) Downloaded 149 times
Last edited by Ears on Tue Dec 12, 2017 6:29 pm, edited 1 time in total.
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Re: Fender Twin Reverb Preamp.

Post by Ears »

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.
Attachments
twin_5f8a.pdf
(104.29 KiB) Downloaded 156 times
twin_5f8.pdf
(149.84 KiB) Downloaded 150 times
twin_5e8a.pdf
(168.14 KiB) Downloaded 149 times
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Re: Fender Twin Reverb Preamp.

Post by tubeswell »

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

http://www.thevintagesound.com/ffg/
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Re: Fender Twin Reverb Preamp.

Post by Anvil Amps Alan »

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.
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Re: Fender Twin Reverb Preamp.

Post by Marshmallow »

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!

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Re: Fender Twin Reverb Preamp.

Post by Marshmallow »

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!

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Re: Fender Twin Reverb Preamp.

Post by Optical »

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

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