Requesting info on fender twin

sluushenk_fender

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Hi guys,
Let me start by saying I’m new here.
I recently (1 hour ago) bought a fender twin reverb. I believe it to be a 1975. It has the master volume and the push pull function. The serial number starts with a9****. The guy who I bought it from says it’s original.

Some of the pots have a bit of crackling going but I’m gonna clean them. The amp also crackles sometimes when I’m not turning the knobs.
I’m gonna try adding some pictures

the questions:
1: is there any way to test the tremolo without the pedal?
2: whats the build year( is it ultralinear)
3: why does it crackle?

I hope I provided you with enough information. Thanks in advance!

Btw English isn’t my native language
 

sluushenk_fender

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C0401082-7A59-4A99-87BF-ED3A74A07738.jpeg
9A67B8DE-071E-4525-A8F7-8E4589A0EE24.jpeg
 

sluushenk_fender

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Thanks for the tip, gonna try that tomorrow. Also just gonna buy a new pedal.
yeah gonna look for a tech then.

How is it possible that the capacitors go bad?

what would you guys say it’s worth in its current state? I paid 750 euros.
Thanks again
 

tcadam

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It's been along time since I've looked into it but I have a'76 that I had to date by the pot codes. At the time at least, there wasn't a good way to date the amp by the serial number. Maybe someone's cracked the code by now.

Edit to add: I can't say what it's worth in The Netherlands but if it were in the US, I would say you overpaid a bit. However, I wouldn't lose any sleep over that.
 
Last edited:

JohnFender

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Get some deoxit and spray the tubes pin then put them in and out about 5 times or so, clean the pot with deoxit aswell, check if the board is conductif, if you never opened an amp before make sure you do some research on how to check and discharge the capacitors, there can be about 600v in them
 

Timbresmith1

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Thanks for the tip, gonna try that tomorrow. Also just gonna buy a new pedal.
yeah gonna look for a tech then.

How is it possible that the capacitors go bad?

what would you guys say it’s worth in its current state? I paid 750 euros.
Thanks again
Electrolytic capacitors use an electrolyte (sorta like a car battery). The electrolyte dries out with age/heat, so the capacitance changes/ they fail.
 

Lawdawg

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Thanks for the tip, gonna try that tomorrow. Also just gonna buy a new pedal.
yeah gonna look for a tech then.

How is it possible that the capacitors go bad?

what would you guys say it’s worth in its current state? I paid 750 euros.
Thanks again

It looks ok, but have an amp tech check it out.

If it's in good shape, 750 Euros seems about right based on current US prices. 70s Twin Reverbs used to be a lot cheaper, I paid about $400 (US) for my '73, but I see them selling now for $700 - $1,000. They're great amps, good luck.
 

Milspec

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First off, congrats man, the Twin is always my favorite amp!

It is not what is known as a "ultralinear" which came along in 1977. There are a few things that I would suggest doing:

1. Get it serviced
2. Have them install a bias pot, but also keep the current balance pot. Setting the SF Twin back to blackface era bias makes a big difference.
3. Replace the rectifier diodes. Fender skimped a little on those and they seem to fail too often on Twins. That crackle you hear without touching the knobs could be a bad diode.
4. Upgrade the power cord...even if it has a grounded plug already. It is cheap and eliminates a lot of potential problems.
5. Consider having it "blackfaced"...that is convert it back to the blackface era circuit. It doesn't cost much at all to do it and can be very rewarding.
 

Dacious

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If it's an ultralinear unit it will have '135 watts' on the back panel under the speaker jack. I think with master volume it's later than 74.
 

Blazer

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Probably best to get it checked by a good tech before you do anything else, if it is all original on the inside it will need a few parts replaced as standard. Maybe @Blazer will know of somewhere near you.
Actually no, we live on opposite sides of the Country.

But you could seek out Dolf Koch, who is an authority on restoring tube amps.
 

Jimy

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The serial number probably indicates 1975, but transformer date codes are more reliable. Look for a number that starts with 606. The following three digits indicate year and week. Example: 606725 would mean the transformer was produced in the 25th week of 1977. Fender would assemble the amp some time (relatively soon) after that date.
 

max_twang

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I have the same amp and I love it.

If it has the pull boost, it's not an ultra linear. I disconnected the pull boost but left the master volume.

I second what the posters above said about getting it serviced -- filter caps for sure if they haven't been done.

I know some will not agree, but after I serviced my amp, I gave it a facelift -- new grill cloth, new chassis straps and corners. It looks a lot younger than its actual age. Hmmm, maybe I should do this for myself...
 

sluushenk_fender

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Okay thanks everyone for their responses! If it’s still not working correctly after cleaning the pots and tube sockets I’m gonna seek out a tech. Not trying to be a cheap skate but I always think it’s a good thing to keep stuff original.
If I understand correctly blackfacing the amp is making it breaking up at an earlier point right? If that’s the case I’m definitely not going to do that. Im already in love with those cleans.

It’s a good thing right that it’s not ultralinear right? People don’t like that right?
 




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