Fender Twin 5F8 Amp, Circa 1958

griehund

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Is there a big volume difference between jacks 1 & 2? My tech measured 15dbs difference between them on my 5E8A. It was a Weber build so they may have changed the specs. The low output jacks make it much more versatile.
 

jp

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agree 100% with both statements!
Me too! I don't think it will affect the value of it negatively, since it's already been recovered in tolex. A professional restoration in tweed and a return to its original configuration can only improve its presentation value and most importantly its performance.
 

Quantum Strummer

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Is there a big volume difference between jacks 1 & 2? My tech measured 15dbs difference between them on my 5E8A. It was a Weber build so they may have changed the specs. The low output jacks make it much more versatile.

Agreed re. versatile!

The 5F8 schematic shows two 68K resistors paralleled on the #2 inputs of each channel (Normal & Bright). This oughta reduce the input signal by 6dB (50%), I think, maybe a little more. The #1 inputs each have a 1M cap too. This gives each input a unique voice. For home use I like plugging into the #2 inputs on a Fender amp, even with low-output guitars, and turning up the amp's volume to compensate.

Edit: just had a look at the 5E8A schematic…the inputs are kinda weird! The #1 inputs go through both triodes of the v1 12AY7 tube while the #2s only go through one triode. No grid resistors (stoppers). This explains the bigger dB difference your tech measured. I also had a look at the Weber version of this schematic, and I see it specifies 12AX7s rather than 12AY7s in v1–3. This will make the amp gainier, maybe not a bad thing for lower volume use but—for my taste—over the top when cranked up. If you've got 12AX7s installed you might wanna experiment with 12AY7s instead and see if you like 'em.

-Dave-
 
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Quantum Strummer

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I'd agree, I guess, re. getting the amp re-tweeded so long as you get it done by someone who both does a high quality job and has an established reputation for doing so.

-Dave-
 

griehund

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Agreed re. versatile!

The 5F8 schematic shows two 68K resistors paralleled on the #2 inputs of each channel (Normal & Bright). This oughta reduce the input signal by 6dB (50%), I think, maybe a little more. The #1 inputs each have a 1M cap too. This gives each input a unique voice. For home use I like plugging into the #2 inputs on a Fender amp, even with low-output guitars, and turning up the amp's volume to compensate.

Edit: just had a look at the 5E8A schematic…the inputs are kinda weird! The #1 inputs go through both triodes of the v1 12AY7 tube while the #2s only go through one triode. No grid resistors (stoppers). This explains the bigger dB difference your tech measured. I also had a look at the Weber version of this schematic, and I see it specifies 12AX7s rather than 12AY7s in v1–3. This will make the amp gainier, maybe not a bad thing for lower volume use but—for my taste—over the top when cranked up. If you've got 12AX7s installed you might wanna experiment with 12AY7s instead and see if you like 'em.

-Dave-

When I finished the build my tech noticed the db difference but also the #1 and #2 jacks were juxtapositioned so that #1 was actually #2. I really don't care and I'm not going to bother changing them. I like it the way it is and the low output jack is good for practice.
 
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