Hot wiring a FENDER Twin

simondohertyuk · Post by **simondohertyuk** » Mon Nov 03, 2003 1:36 pm

Has anyone heard of a retro fit for the fender twin which bypasses the roll off filter to give more saturation?

jps · Post by **jps** » Mon Nov 03, 2003 3:33 pm

What roll off filter would you be refering to?

simondohertyuk · Post by **simondohertyuk** » Tue Nov 04, 2003 5:45 am

the preamp gain section. Someone I used to know got a retro fit in San Fran. He had to keep buying Twins because they only lasted 6 months at a time!

doctorwho · Post by **doctorwho** » Tue Nov 04, 2003 10:06 am

Uh, I'm no amp tech, only a player/collector, but I think that a modification that destroys an amp in six months is not a good modification at all.

Andy Ruehl (sp?), the author/owner of a former website, Machine Gun Amps, addressed this issue by stating that he thought it was unwise to try to make a Fender sound like a Marshall, Hiwatt, etc. by modifying the circuit. I play clean through a number of late 1960s Fender Silverface amps and go to pedals if I want to put an edge on the sound. I'm unclear what 'saturation' is in this sense, but I would think that another brand/model of amp, or even an effects pedal, could provide it without the modification and concomitant loss of amp longevity.

I think there was an earlier thread here in The Forum addressing the issue of running an amp on the edge to get a sound, as opposed to using an effects pedal to do the alteration of the sound and let the amp live up to its true purpose and simply amplify it.

This is only my opinion. I firmly believe that the owner of any amp or guitar has the right to modify it to his/her wishes.

simondohertyuk · Post by **simondohertyuk** » Tue Nov 04, 2003 12:00 pm

That's fair enough but if you heard a British band called 'the Stone Roses'(indie), now no more, and listened to tapes of them live you know that you'd'never get that sound from pedals.
anyway......thanks for the input

doctorwho · Post by **doctorwho** » Tue Nov 04, 2003 2:48 pm

Simon, are there any mp3 samples/clips of their stuff available? You've made me curious about this aspect of amps.

rkbsound · Post by **rkbsound** » Sat Nov 08, 2003 5:06 am

Why would you hotwire it? Just get another key made.

philco · Post by **philco** » Sun Nov 09, 2003 8:35 pm

Did you ever think of undersizing the output transformer for a distorted overdriven sound without driving the tubes up to full power? If you ever read the Tone Lizard website, you would learn that it was one of Marshall's old tricks way back in the 60's. A saturated undersized transformer core will hide harsh clipping and smooth out the sound (since the core saturated before the hard clip occurred). It is, in effect, a compressor. Marshall saved money by giving the musician a cheaper smaller transformer, and rock musicians were willing to pay more for the "improved" overdrive sound. Both sides won. I bought a Hammond 125E transformer on sale from Angela Instruments back when I got a Jones for building a small tube amp. It's rated for 15 watts output, so it was meant for something like a Champ, but if you put it in a Deluxe Reverb (22W), it would give you a bit of the Marshall vibe. It only cost me $25, and it has multiple taps for a lot of different impedances on primary and secondary. At that price, you can afford to burn one out every 6 months, but you probably wouldn't if you installed a fan to keep it cool.

The output tranny in my Traynor YCV40 looks about twice the weight of the 125E (and is probably a Hammond as both manufacturers are Canadian), so it is a bit undersized also since it is asked to handle 40W. Don't try this in tube bass amps, unless extreme fuzz tone is your bag. My YCV40 is NOT a good bass amp.

You can also install twin 125E trannies in parallel and have 30W rating which would play a Deluxe Reverb clean, and then switch to just one tranny for overdriven tone. You have to wire and switch the secondary wires (speaker side) correctly to reflect the desired impedance to the primary.

The classic sound of overdriven tube amps is mainly accomplished on the output side, NOT the input side. No amount of preamp twiddling will be the same. Think how an audiophile would design a tube power amp and loudspeaker combo, then do everything possible to screw it up. Now you have a Marshall type amp. And it will only get that sound when the output tranny is saturated. You also need something like Greenback speakers to get the full mojo effect. Preamp distortion is just one more thing to add to the mix, but without a saturated tranny to smooth things out a bit, it is frequently a bit harsh and is NOT the same as overdriven output distortion.

Don't go looking for some overpriced overhyped mojotone tranny. Leo and Jim used the cheapest parts consistent with reliability they could get their hands on. There was NO SUCH THING as a guitar tranny when Leo started making amps. He just bought and tried off-the-shelf audio output trannies until he found some that had the sound he wanted at a low enough price. Hammond trannies may be a bit too "hi-fi" for a real Marshall tone, but they sound good in Traynors. If I ever get a chance at a Deluxe Reverb with a blown output tranny, I may try buying it and installing my Hammond 125E.