Sketchy behavior from amp techs that blew my mind

[tonepoet333]

Nothing's integrated into the board. Boards is boards, parts is parts and there's always solder between 'em.

@Blrfl - I'm talking about the type of integrated circuit board pictured below. Each of those little black rectangles is a capacitor or a resistor. The only visual way to tell the difference is the labeling of Cxx for cap and Rxx for resistor.

Compare that with boards where the components are much easier to identify and swap out.

tonepoet
www.jackshiner.com

 

[corliss1]

It's still not "integrated" - they sit on top and get soldered to it. Just takes a different skillset (and in some cases, tools) to work on.

 

[sds1]

Each of those little black rectangles is a capacitor or a resistor. The only visual way to tell the difference is the labeling of Cxx for cap and Rxx for resistor.

Not entirely accurate. The resistors are black and typically have their value notated on the parts themselves. The capacitors are the brown/tan ones and you'd need a schematic (or a bit of intuition, depending) to know their value.

Surface mount components are actually easier to work with in many ways. I prefer them personally -- so long as they are the larger packages. But like @corliss1 says you'll need to ramp up with tools and some skills to work with them.

 

[Blrfl]

The only visual way to tell the difference is the labeling of Cxx for cap and Rxx for resistor.

JEDEC has standards for the dimensions and markings of surface-mount components, although if something was soldered into the C12 position on a board during manufacturing, it's a fair bet that it's a capacitor.

There are gadgets that will automagically identify and measure parts that are too small to be labeled.

 

[NTC]

I'm talking about the type of integrated circuit board pictured below. Each of those little black rectangles is a capacitor or a resistor. The only visual way to tell the difference is the labeling of Cxx for cap and Rxx for resistor.

Not entirely accurate. The resistors are black and typically have their value notated on the parts themselves. The capacitors are the brown/tan ones and you'd need a schematic (or a bit of intuition, depending) to know their value.

Surface mount components are actually easier to work with in many ways. I prefer them personally -- so long as they are the larger packages. But like @corliss1 says you'll need to ramp up with tools and some skills to work with them.

You beat me to this...

JEDEC has standards for the dimensions and markings of surface-mount components, although if something was soldered into the C12 position on a board during manufacturing, it's a fair bet that it's a capacitor.

There are gadgets that will automagically identify and measure parts that are too small to be labeled.

Don't count on it - I have had to put resistors in spots marked Cx and vice versa.

 

[Blrfl]

Don't count on it - I have had to put resistors in spots marked Cx and vice versa.

Sure, but that's just bad work on the part of whoever laid out the board, not a shortcoming in the technology. The same thing can happen with through-hole boards, too.

 

[NTC]

Sure, but that's just bad work on the part of whoever laid out the board, not a shortcoming in the technology. The same thing can happen with through-hole boards, too.

No, it was a design with unintended features that needed to be corrected and management won't pay for the design change required to fix the silkscreen. Note this wasn't in consumer electronics...

 

[NTC]

For real sketchy behavior: I have Traynor YBA1 that needed a capacitor job and while the hood was up, I asked to have the resistors replaced with metal film (dumb) for lower noise, add a Master volume (pre-pi) and he did a wacky mod where the right input jack selection put the two preamp tubes in series. The sketchy part was that he took out the mustard coupling caps and replaced them with flat Xicons. The amp is now mostly stock, but it lost a lot of the livelyness

 

[GotA24Fretter]

The is the gem I like to trot out for demonstration of sketchy behavior. This is a 3 prong cable install with several burns though the outer jacket and into the jackets of the individual conductors. The chassis joint is trash and they left the death cap connected.

This was a respected, but now defunct, shop in the Austin area. The tech responsible for this work must've landed somewhere after the shop closed.

 

[tele_savales]

I mean, sure, but isn't it a bit depressing?

Everything is depressing.

 

[tele_savales]

For real sketchy behavior: I have Traynor YBA1 that needed a capacitor job and while the hood was up, I asked to have the resistors replaced with metal film (dumb) for lower noise, add a Master volume (pre-pi) and he did a wacky mod where the right input jack selection put the two preamp tubes in series. The sketchy part was that he took out the mustard coupling caps and replaced them with flat Xicons. The amp is now mostly stock, but it lost a lot of the livelyness

That wacky mod is so you don't have to jump the two channels with a patch cord. Try using both channels tone and volume controls to dial in your sound. It's totally reversible.
Now, stealing your mustard caps was a d-bag move and he shouldn't be trusted.

 

[24 track]

I frequently have interactions with customers where there isn't anything actually wrong with their amp, but they've read that X can make something better or Y is a magic component or they've been told Z is designed to fail. Instead of doing any work, these appointments turn into therapy or philosophy sessions where I talk them back from the ledge of assured amp destruction. However, the one I had yesterday was about a Fender Princeton Reverb Reissue and it really kinda blew my mind.

Customer calls semi-local tech A. A tells him he won't work on anything with a circuit board, including the Fender reissue series. That's...a choice...but whatever. (tell me you only want to work on the easiest stuff of all time without telling me...)

Customer calls semi-local tech B. B tells him they wooooould look at it, but these amps have "bad parts" and it "might not be worth it" to fix the unit.

Keep in mind this is for a relatively recent '65 PRRI. A limited version in a knotty pine cab, too.

Customer calls me. I say bring it over. The amp sounds great but the trem is weak and has a tick. I twiddle the bias pot for a few seconds to find the trem sweet spot, the trem gets deeper, the tick goes away, the customer is amazed I never even had to open the amp.

That was it - that was the entire problem. I also explained that with the almost non-existent idle noise and killer tone we were getting that the tubes are in excellent shape, so there's no reason to swap those either. I also explained they've been making the reissue line for 33 years now and there aren't some secret parts that are designed to fail - what could we possibly change in there to improve the tone you've already said you love? He was amazed I didn't try and sell him anything.

Is this really where a lot of "techs" are at now? It seems completely insane to me that a tech wouldn't want to see a Fender reissue. If vintage Fender is "Amp 101" the reissue line has got to be "Amp 102" as they've made more of those than they ever did the originals so any normal repair shop should be seeing them all.the.time. Not because they have issues, but because there are so many of them. I just couldn't understand why a new, clean, non-butchered Princeton Reverb was an automatic "no" from two shops.

<----------discuss---------->

I picked up a fender Deluxe Reverb RI with the same problem, Yesterday I hadn't looked at it yet , you may have diagnosed it for me thank you.
complaint: Vibrato Has a constant click

I have a 65' Fender twin RI had it for years , No issues at all I had one come in for repairs It was a mess inside , cold solder joints the Ribbon connectors were not soldered in properly ( IC caps -I personally don't like, but that's just me) pots & switches were noisy really badly made and this was a relatively new amp, so much so I took mine apart to see if I had the same issues , I did not.

 

[NTC]

That wacky mod is so you don't have to jump the two channels with a patch cord. Try using both channels tone and volume controls to dial in your sound. It's totally reversible.
Now, stealing your mustard caps was a d-bag move and he shouldn't be trusted.

This was about 28 years ago. I do understand the mod, and it did what it was supposed to. It effectively had a pre-volume, post volume, and a master. It DID require a jumper to accomplish. That said, I undid the mod years ago. The only thing left is the master, which is defeatable. (Note to those unfamiliar with a Traynor YBA-1 - they are very similar to a 5F6A).

One other thing - that amp had the same problem for years in that there was noise and popping that seemed to go away whenever the input tube was replaced. That tech did NOT fix that issue. It was due to a bad input section bypass cap. That was the first change I made to that amp...

 

[GotA24Fretter]

I picked up a fender Deluxe Reverb RI with the same problem, Yesterday I hadn't looked at it yet , you may have diagnosed it for me thank you.
complaint: Vibrato Has a constant click

No. The tremolo in the DRRI isn't a bias trem.

Search "Fender Bulletin #9" and do that.

 

[24 track]

No. The tremolo in the DRRI isn't a bias trem.

Search "Fender Bulletin #9" and do that.

where do I find this?

 

[PoorNoodle]

I used to work adjacent to SMT manufacturing. I’ve seen rework stations in China where workers would manually swap out multiple faulty components on tiny PCBs in seconds. It’s easy to do if you have the knowledge and skill.

 

[tewiq]

no:9 Pulled from the net

 

[24 track]

no:9 Pulled from the net

Thank you I did not find this when i looked for it is there a specific site or link where I can look up issues like this I have 2 other Fender amps that are causing me ( different ) issues as well, all I as able to find was a past post from 2022 on TDPRI.

I was able to find this on gear page and an old 2014 TDRI post as well, is there a place to find other service notes for Fender amps?

 

[corliss1]

The is the gem I like to trot out for demonstration of sketchy behavior.

I see your cable and raise you.......a bag of grass seed and tape used as an insulator on this Traynor

Under the ball of tape was a grass seed logo and wires just semi twisted together. Good times.

 

[tewiq]

24 track, it is the only one that I found. After a 10 minutes search for any fender service bulletins ( #1 thru 8, 10-15.......), I gave up.