Fender 135W Twin Restoration (photos inside)

[Indigo_blues]

Hiya, I haven't been on the forum for a while.. lately my dad and I have been busy with the restoration (more like re-build) of a 70's Fender 135W Twin Reverb which I bought from a softie here. The amp was super dead, super fried up and we took it as a challenge to lovingly restore it back to its original splendour.

We initially did not think the amp was so bad but after a few rounds of checks, my dad discovered that both power and output transformers were dead. So we had to replace both trannies.

I ordered them in from Mercury Magnetics. Over the last few years, I've ordered quite a few trannies from Mercury Magnetics as we've found them to be very very good. They have a wide range of transformers for just about any tube amp out there on the market. So I placed an email to Paul Patronette once again and voila!, the 2 spanking new transformers were at my place within a couple of weeks. The damage was about $640USD to my credit card.

Without further ado, here are some pics...

 

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First up, here's a shot of the front panel.

A point to note that the panel is a blackface. However we know this amp is a 70's model so it must be a silverface... hence we concluded that the previous owners must have done a swop previously...

 

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Here's a shot of the preamp section.. note the turret board and the orange caps.

Nothing much wrong here, except for a couple of resistors which my dad swopped out because of higher values.

 

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Here a shot of the mid-rif section of the amp... the power tube sockets were extremely corroded hence my dad bought new ones and re-wired them in.. painstaking..

 

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Here's a closer shot of the new power tube sockets..

They cost $5 each from Martin Audio and they are gold plated! Anti-corrosion..

Notice how many wires there are connected to each socket? Well each single one was hand-wired by my dad!

 

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These are the old power tube sockets..

Really corroded and can throw away liao..

The reason why they had to be changed was that the corrosion was causing bad contacts with the new power tubes that we put in.. this is a bad situation and hence they had to be changed.

 

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Here is a look at the underside of the amp with the new trannies in place. They proudly say Mercury Magnetics.

What you can't see in this shot are that the filter capacitors in the metal box to the right side of this shot have also been replaced with new ones..

 

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Another shot of the underside..

Close up of the output transformer... 135Watts!! Made in the USA!

 

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The original cab came without the front grill and cloth so we had to re-fabricate a new one.

Its good we have another twin reverb around so we took the front grill board out and re-fabricated a new one to the eact specs...

Here it is.. we are still waiting for the new grill cloth to arrive from the US.. ordered it from Parts is Parts for $15USD.

I chose the silver with blue stripes one.

I'll post new pics once its all done up.

 

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A shot of the old fender logo on the cab..

 

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A shot of the new pilot lamp.. the old filament one had blown and my dad bought a new LED one for replacement. This one will never ever blow but it cost $5.. much more expensive than the filament type which only cost $0.50.

 

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A shot of my dad's workplace..

He's a retiree and former electric engineer. He does this to keep from being bored.

His pride and joy at the moment is a tektronic scope which he bought real cheap recently.. here it is sitting proudly on his table. The unit on top of that is a tone generator which he uses to troubleshoot amps without having to actually plug in a guitar.

If you are sharp you can see a unit to the left of the shot which is the dummy load he connects to the outputs of the amps to simulate the speaker load. You can see the silver heat sink and black fan.

 

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A shot of my dad tweaking the scope...

 

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One more pic of the scope..

My dad says without the scope, it would be impossible to repair the amps..

 

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Here is a wide shot of the work area.. that's my jap strat loaded with fralin single coils.. yummy..

The cab with the silver grill belongs to another twin reverb he's been working on.. next to that is a Vox (AC30 I think)..

Mine is the one with the grill removed in front..

 

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Well I gave it a test run last nite.. the amp is practically a new one now... new tubes, new caps, new trannies... the only problem were the old speakers.

On testing, we realised the old speakers were spoilt too!

Alamak, another $300 to buy new speakers.

We tested the amp on the other twin with the good speakers and my conclusion is the amp rocks!! Super bass response with sparkly chimy highs you would come to expect from a classic Fender tube amp.

Now to get new speakers.....

 

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So for about $1700 factoring in the speakers, we got a spanking new amp with some of the best transformers on the market.

The cost was about double our initial estimate of about $800-$900... but still well worth it I think..

A new Twin Reverb would be probably in the region of $3k but we got a new one for about half the price, and with the mojo of a classic hand-wired amp that's easy to fix.

I'll post up more pics once the grill is all done up..

Hope you enjoyed the read and the photos!

cheers!

 

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Comments are appreciated! Cheers!

 

[gibs]

Don't really understand all that's going on, but it sure is hell of a job to do all of that! Well, it's pretty meaningful to repair amps in old age, knowing that one is madly skilled in a profession that isn't appreciated enough these days (ie. capacitor blown = buy new amp)

COOL STORY BRO!

 

[surreal_gravity]

Lovely work there my friend. Really impressive stuff, especially the rewiring section. Must have taken a while?

So anyway, what speakers are you planning for it?