# 74 fender twin reverb going for maintenance



## silvertonebetty (Jan 4, 2015)

So as you guys know I just got my 79 Mesa done over.

I was asking him if it was okay to drop my twin off because of the following reasons
1. My tremolo doesn’t work
2. I don’t trust the fella that “supposedly” recapped it but couldn’t bother fixing the tremolo.
3. The person who last worked on my Mesa and let it leave in that mess worked on my fender.
4. It might need tubes ,so I’m not waiting any longer
5. I want to find out what schematic it uses ( there’s four “ for 74 and I want one for myself)
6. I don’t want to need to bother with this stuff again! Or at least for a while

I know maintenance is required for these amps to properly work . I also have no way of knowing when it was last properly inspected, if it’s been modded or if it was modified was it done properly?

All these little questions I don’t have the answers to. So I’m going to be the one to change all that.

If it’s modified like my Mesa was I’ll be getting it put back to stock ! For the most part I don’t like modifications unless I am told how It work and why it would benefit from the mod. But mostly stock!

I’ll post updates when I’m able to drop it off in a f couple weeks


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## Griff (Sep 7, 2016)

Good call.

As my amp tech says when he gives my amps back "now you have a brand new old amp". A well done service is the best thing you can do for older amps.


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## Latole (Aug 11, 2020)

2. I don’t trust the fella that “supposedly” recapped it but couldn’t bother fixing the tremolo

Anybody can recapped ( I do not say job is well done) 
To fix tremolo, you must know electronics or have sone help ; most of the time, you only need to replace the 3 tremolo capacitors


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## Latole (Aug 11, 2020)

5. I want to find out what schematic it uses ( there’s four “ for 74

It is not an issue for a qualified tech to find the right schematic.
it is the easiest part of the job.


Post good pictures of your amp


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## nonreverb (Sep 19, 2006)

Do you have the footswitch for the amp? The reason I ask is that the tremolo won't work without the footswitch or a shorting jack inserted in the tremolo footswitch jack.


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## Latole (Aug 11, 2020)

nonreverb said:


> Do you have the footswitch for the amp? The reason I ask is that the tremolo won't work without the footswitch or a shorting jack inserted in the tremolo footswitch jack.


100% right


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## silvertonebetty (Jan 4, 2015)

nonreverb said:


> Do you have the footswitch for the amp? The reason I ask is that the tremolo won't work without the footswitch or a shorting jack inserted in the tremolo footswitch jack.


Yup and recently the rca end broke off! The tremolo did go click , click ,click


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## silvertonebetty (Jan 4, 2015)

Latole said:


> 5. I want to find out what schematic it uses ( there’s four “ for 74
> 
> It is not an issue for a qualified tech to find the right schematic.
> it is the easiest part of the job.
> ...


I’ll post pictures and progress like I did with the mesa . And I want a schematic for my self 😂


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## nonreverb (Sep 19, 2006)

silvertonebetty said:


> Yup and recently the rca end broke off! The tremolo did go click , click ,click


If you heard the clicking of the neon bulb through the speaker but no tremolo then it could be a problem with the intensity control pot...possibly the LDR


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## silvertonebetty (Jan 4, 2015)

nonreverb said:


> If you heard the clicking of the neon bulb through the speaker but no tremolo then it could be a problem with the intensity control pot...possibly the LDR


Oh . I’m positive it will all be sorted out by the time it’s done


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## silvertonebetty (Jan 4, 2015)

Griff said:


> Good call.
> 
> As my amp tech says when he gives my amps back "now you have a brand new old amp". A well done service is the best thing you can do for older amps.


Yeah like a car the old amps need a tune up now and then


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## Jalexander (Dec 31, 2020)

A good amp tech is a wonderful thing. A quick health check and maybe some quick repairs will be under $100 and give you great peace of mind. If there are bigger issues, it will cost more, but you’ll have a well functioning, safe amp at the end. And like a good mechanic, if there are bigger issues, they will talk you through what they are and your options before you invest in the repair.


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## silvertonebetty (Jan 4, 2015)

Jalexander said:


> A good amp tech is a wonderful thing. A quick health check and maybe some quick repairs will be under $100 and give you great peace of mind. If there are bigger issues, it will cost more, but you’ll have a well functioning, safe amp at the end. And like a good mechanic, if there are bigger issues, they will talk you through what they are and your options before you invest in the repair.


Well my Mesa was big job .

it was far from stock and he replaced every electrolytics in the amp and brought it back to spec.

he also sent me photos and updates while the work was being done and didn’t hide anything


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## silvertonebetty (Jan 4, 2015)

Well I believe the fender just kicked the bucket for now . So in the corner it goes.

I was playing and I hit a cord and then it started squealing.

So I’m thinking from the “serving tube amp” info I was given that I have a tube that kicked the bucket.

Maybe this is why buddy sold it because he knew it needed new tubes and couldn’t afford to drop tubes in it.


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## Frenchy (Mar 23, 2011)

silvertonebetty said:


> Maybe this is why buddy sold it because he knew it needed new tubes and couldn’t afford to drop tubes in it.


New tubes for an old amp is part of the adventure. I always calculate that and a cap job when getting and older tube amp. I got lucky when I got my Fender Twin, came with 3 sets of tubes.


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## silvertonebetty (Jan 4, 2015)

Frenchy said:


> New tubes for an old amp is part of the adventure. I always calculate that and a cap job when getting and older tube amp. I got lucky when I got my Fender Twin, came with 3 sets of tubes.


Yeah . I have no problem getting tubes because the amount and volume I play they will last many and many of years


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## silvertonebetty (Jan 4, 2015)

The fender is going down to Doug’s tomorrow.
I believe I need at least one preamp tube but power tubes should be fine since they are a mixture of newer sovtek and groove tubes . The pre amps if I remember are all old green label Jan Phillips . And some are basically worn off making them really hard to read.


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## Latole (Aug 11, 2020)

Power tubes may be not well matched and/ or need a bias ?


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## silvertonebetty (Jan 4, 2015)

Latole said:


> Power tubes may be not well matched and/ or need a bias ?


I’m not 💯 on that . Generally speaking I’d like to get everything retubed since I have the extra cash .


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## silvertonebetty (Jan 4, 2015)

I like the new lights they installed in the basement, they are bright!

































I’m not sure if the foot switch is original or aftermarket



























and I’m assuming this is the true issue with the vintage 30s. Like really? Why are some people allowed near electronics of any kind !

















at the end of the you must remember this unfortunate fact.

when you buy use especially vintage, you are buying something someone worked on that is 💯 unqualified to stick their fingers into.

oh well it will be in good working order when it gets back .


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## Latole (Aug 11, 2020)

silvertonebetty said:


> I’m not 💯 on that . Generally speaking I’d like to get everything retubed since I have the extra cash .


You don't believe that power tubes should be matched ( between 5 and 8 ma is enough ) nor need a bias ?


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## silvertonebetty (Jan 4, 2015)

Latole said:


> You don't believe that power tubes should be matched ( between 5 and 8 ma is enough ) nor need a bias ?


I meant I’m unsure 😂 not educated enough. I’d think it would be important . See when I got the tubes from Mesa I think I got a matching quad so I didn’t have to worry


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## Latole (Aug 11, 2020)

silvertonebetty said:


> I meant I’m unsure 😂 not educated enough. I’d think it would be important . See when I got the tubes from Mesa I think I got a matching quad so I didn’t have to worry


Matched is one thing 
Bias is another thing.
Do some research with google.

A correctly biased amp will run efficiently and maximizes the life of your tubes.
Under - biased (hot ) amps will lack of punch and tubes will run hotter , shorter tube's life .
Overbiased amps ( cold ) will sound thin and brittle. with tubes running too cool for proper performance .
A correctly biased amps will sound clean and tight a moderate volumes, than at higher volumes breakup and distort musically .


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## MetalTele79 (Jul 20, 2020)

silvertonebetty said:


> when you buy use especially vintage, you are buying something someone worked on that is 💯 unqualified to stick their fingers into.


Or... You get something that hasn't been touched or services ever which will need a once over..... Or, you get something that was worked on by a competent and skilled tech that will last you for many years without issue.

Always ask about the service history on a vintage/used amp and factor that into what you're willing to spend on it. If the seller doesn't know the service history just assume it may need a bit of work.


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## silvertonebetty (Jan 4, 2015)

A


MetalTele79 said:


> Or... You get something that hasn't been touched or services ever which will need a once over..... Or, you get something that was worked on by a competent and skilled tech that will last you for many years without issue.
> 
> Always ask about the service history on a vintage/used amp and factor that into what you're willing to spend on it. If the seller doesn't know the service history just assume it may need a bit of work.


at least I’ll know what has been done after this .


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