1978 Fender Twin Reverb w JBLs - pricing?

JezWynd · April 2019

What kind of mark up do D120F's merit? This is up on Fellowship of Acoustics -

https://www.tfoa.eu/en/fender-twin-reverb-1978-91754839.html

JezWynd · April 2019

Free shipping btw!

ICBM · April 2019

Not sure, but I doubt that much.

The amp normally sells for only about £500-£700 otherwise.

maw4neu · April 2019

With JBL's at least £1000 I'd guess . . . . that said only a body builder or Greek God could physically move, let alone lift a Fender Twin with JBL's due to the MASSIVE weight issue :-) The weight would shear the back of a mere mortal . . .

DJH83004 · April 2019

Interestingly I had one in for service last week with JBLs and the weight difference over the standard Twin Reverb was unbelievable, they do sound wonderful mind such a huge sound, like a TR on steroids!

JezWynd · April 2019

Sorely tempted but it would be an insane purchase for someone who doesn’t gig.
It looks to have had a badge at the top right of speaker cloth, any ideas what that might have been?

DJH83004 · April 2019

I’ve seen them with a JBL badge on the bottom right corner of the grille cloth, but never at the top.

p90fool · April 2019

Free shipping has to be worth a few hundred!

gringopig · April 2019

.

JezWynd · April 2019

gringopig said:

Great amps and bargains too. Perfect for clean pure tone with a nice low end and sparkle on top.

You're really not helping.

ICBM · April 2019

gringopig said:

It's a 135W ultra linear not 100W as stated. These amps sound brilliant. I have a '79 with EVM 12L speakers fitted. I'll bet it's the heaviest Fender Twin Reverb in the world!

The ones with factory-fitted Gauss speakers which replaced the JBLs in the very late 70s are probably even heavier - maybe heavier than a Mesa Trem-o-verb. Still just having one handle on top really doesn't help either...

gringopig · April 2019

.

ICBM · April 2019

gringopig said:

Make sure you also have some sturdy 6L6GC valves. Finding ones that will stand up to 500V plus plate voltage can be tricky. I use Svetlana Winged C but JJ electronic make good 6L6GCs too I am lead to believe.

There's a simple way to fix that - set the voltage selector to 260V. With a 240V supply that will drop the HT voltage to under 500V, the power to around 100W, and everything will run cooler and safer. I always set the Ultra-Linear guitar models like that - the Bassman 70 and 135 I set to 240V if they're being used for bass, but in that case it's better to fit 6550s instead of 6L6s.

gringopig · April 2019

.

JezWynd · April 2019

ICBM said:

gringopig said:

Make sure you also have some sturdy 6L6GC valves. Finding ones that will stand up to 500V plus plate voltage can be tricky. I use Svetlana Winged C but JJ electronic make good 6L6GCs too I am lead to believe.

There's a simple way to fix that - set the voltage selector to 260V. With a 240V supply that will drop the HT voltage to under 500V, the power to around 100W, and everything will run cooler and safer. I always set the Ultra-Linear guitar models like that - the Bassman 70 and 135 I set to 240V if they're being used for bass, but in that case it's better to fit 6550s instead of 6L6s.

Ingenious!

gringopig · April 2019

.

ICBM · April 2019

Well... in theory if Time Travel have serviced the amp properly then it's not easy to adjust the voltage because they will have hardwired the selector inside. You can easily find out - simply very carefully turn the selector from 240 to 260V slowly while watching the front panel light - if the light blinks out between the two, the selector is still operational. Set it to 260V. If it doesn't, then it's been hardwired - but you don't know to which voltage without checking inside or measuring the HT voltage via one of the power valve sockets.

If the amp has been fitted with 1-ohm bias check resistors then you can bias it *fairly* easily yourself, although it's still potentially dangerous. If it hasn't then you will need an external bias 'probe' adaptor, unless you want to measure the voltage drop across the OT... not really a great idea if you need to ask about this sort of thing! 26 and 28 are close enough not to worry about it though, especially if you're running the amp at '260V'.

JJs are good 6L6s, they're about the most robust of the modern ones.

Yes, I have worked on a lot of these amps

. Twins were very common in working bands thirty years ago.

gringopig · April 2019

.

gringopig · April 2019

.

ICBM · April 2019

gringopig said:

I don't need to rebias for a change in supply to the primary? It occurs that I might now I think about it.

Not really. The amp will adjust all the internal voltages in proportion to each other, so it will end up about the same. The bias shouldn't be set so hot that it's that critical anyway. The best way to set the balance is by ear too!

gringopig said:

I'm familiar with electronics and work in engineering but RF Microwave and I got a shock from a valve amp that has left me nervous to say the least as it nearly killed me.

If you get nervous I could probably arrange a site visit

.

JezWynd · April 2019

Is it possible to run this amp at 50% output power by only using two power valves?

Howdy, Stranger!

Categories

In this Discussion

Become a Subscriber!

1978 Fender Twin Reverb w JBLs - pricing?

Comments