Is my Fender Pro 185 in serious trouble?

[stratorius]

Hi, this is my first post in this great forum. It's wonderful to see some serious dedication to SS amps, for some are truly great sounding machines.

Such as, imho, the Fender Stage and Pro 185. At Harmony Central the old Stage 185 is one of the highest rated Fender amps which doesn't surprise me. I owned one for 6 years and it suited especially my strat perfectly. The 185 amps produce a lush, roomy and warm sound that is very different from say the smaller Deluxe 112 plus that I play in my study. That one is cardboard in comparison to the 185.

A few months ago I exchanged the Stage 185 for a Pro 185 (same amp, but 212 instead of 112) cause I needed its extra power for the kind of gigs I do. Same sound, even more room in it, very happy with it. Until a few days ago the amp got in big trouble, which gave me the blues.

I have some questions that maybe someone here will be able to answer. While I was playing (clean channel, volume at 5, overdrive from the old Boss OD-1) a loud buzz started to come out of the amp, and the distortion of my sound wasn't part of the OD settings. I switched the amp off, let it rest for a while, switched it on, everything seemed to be OK. But after some playing it all started again. And now when I switch it on the very loud buzz is immediately there, also with the volumes or all knobs at zero; no turning of knobs makes any difference. When I plug in my guitar it produces sound, all knobs work as they should, BUT the sound is nastily distorted and barely audible because of the buzz. The buzz seems to react to certain frequencies, such when I play G's... which puzzles me.

So yes I am a total noob when it comes to amp technics. I wish to have the amp repaired, but not at any cost since it's an already old beast from the early eighties and also since my budget is currently limited. On the other hand I never heard a solid state amp produce the lush and rich sounds that these 185's are capable of. I'd love to keep it as my main amp, even though it is VERY heavy.

To cut a too long story short, these are my questions:
- could it be that it's just filter caps or bad soldering that causes the very loud buzz? Or do the symptoms indicate that the trouble is more serious?
- can filter caps etc be replaced by someone who has no access to genuine Fender parts for this amp?
- is there a danger already that there is DC tension on the speakers? is the distorted sound maybe an indication of that?
- will it be normally be a lot of work (ie expensive) to repair an amp like this, is it worth it?
- is there such a thing as a life span for solid state amps? In the HC reviews people will tell you that the 185's are built for eternity, but can it be that after almost 30 years they simply tend to fall apart?

Many questions, I know, so many thanks in advance for answering some of them. 

(btw I have the amp's manual and schematics for those interested) 

[bry melvin]

Not Familiar with that amp...but if it's got the sound you want go ahead and get it fixed. Most of my amps are as old as yours some older. I use at least one of them daily, usually.

As far as the noise yes capacitors can make a buzz  particularly if it is a 60Hz hum or buzz. I've also had that happen from other components.  I have a Peavey Hybrid that starts buzzing about every 10 years and I replace some transistors.

Fender OEM parts don't really include capacitors. There are several brands of quality that they can be replaced with. Sprague and Illinois for starts.  FWIW NOS (New old stock) for electrolytic capacitors is BS. If you're going to change them you want recently manufactured ones.

They have a shelf life and need to be "reformed" if they are old original types for a particular amp. I have never been fond of that process and not particularly successful at it. The reason I bring it up is often if an older amp is brought into service it's capacitors are not necessarily healthy if it has been sitting unused. This applies to electrolytics only.

Bottom line is an old amplifier can be rejuvenated and if you are fond of it's sound it is  worth the trouble.

It still works ...some...so I would venture that it's not in terminal trouble.

[Jack1962]

First off , if you like this amp , either fix it or have it fixed. Second , with this and any other amp you can use any quality part that cross reference's to the original part. No to the issue with this amp a buzz can have many source's. It is possible that it is a capacitor , weak or bad OPAMP or transistor and oh yea bad solder joints are a common source of noise problems. However , I would start by taking some contact cleaner and giving the thing a good cleaning , then test ya may get lucky. Let me back up a second here , have you  check the amp without the OD pedal ? post the schematic and more people on here can help you , I check on the Fender Website it's not listed there.

                                               Rock On

[stratorius]

First let me post both the manual and the schematic (plus parts list) of the Fender 185 series, for I noticed that owners of these amps search for them on Internet. Hope these links work:

Manual for the Fender Stage 185, Fender Pro 185 and Fender London 185: http://www.mediafire.com/?i31moqzmzyo
Schematics (and parts list) for the 185 series: http://www.mediafire.com/?i2ywmq2dimy

And then thanks guys for responding. In the meantime I already decided, as you both suggest, to have the amp repaired. Replacing it will cost me more, and when the 185 can indeed be rejuvenated as bry melvin states it will be worth the investment because I love the amp.  I'm happy to hear that there's no good reason yet to fear terminal trouble, and that findings parts shouldn't be a problem.

To jack1962, sure I checked the amp without the OD. It's producing the (very) loud buzz (and this 212 150 watts heavyweight is a very loud amp) without any input now, and everything at zero, right after switching it on. Contact cleaner might do the trick today, though I doubt that, but I need to be sure that its effect won't come to a halt during a gig, so I'd want it to have a check up anyway.

Bottom line for me are the costs involved. I'm in France, not anywhere near Paris, but I just tracked down a guy in the region who has some reputation for amp repair. I'll get in contact with him. I have good hope again after your comments. Thanks for that!

[Enzo]

In my experience, your problem is that the two main filter caps have broken their solder - well one of them has anyway.  FLip over the board and resolder the four filter cap pins.  Don;t decide some "look OK" just rsolder them all.

There are a number of Fender solid state models constructed similar to yours, and this is by far the most common failure.

Here is a test:  with the amp running, turn the controls all to zero.  Now ball up your fist and whack the top of the amp hard.  Does that make the amp either start humming or stop humming?  If the amp does anything in response to that blow, then there is a loose connection inside.   You might suggest to your tech person that the amp sounds like a loose filter cap or something that sounds like one.

[phatt]

Hi Enzo,, love your style mate. :tu:

So a DMM and a hammer can fix almost any electrical problem. :lmao:

Seriosly though it's a good simple way to tell if you have suspect joins.
Good one.
cheers Phil.

[stratorius]

Enzo yeah I used both fists in an attempt to fight the buzz, but no change in hum whatsoever and I'm not sure the amp even noticed it for its chassis is built to survive a guerilla attack

Here it is, 66 lbs (not a beauty except for its sound - until recently):

[Jack1962]

I love that testing method Enzo lol lol lol , seriously that is the way I test for that myself it works great . I knew you where a hardcore tech bro lol lol lol


                                            Rock On

[Enzo]

If the fist method seems too hardcore, go to the tool store and get a rubber mallet.   I have several of those too, but geez, sometimes they are ALLLLL the way across the shop, and I don;t want to walk that far.

I call those Fenders "wedge chassis" amps.  The chassis is narrow at front, just the control strip, but in the rear the panel is like 6-8 inches tall, so the bottom of the chassis slopes.  So from the side it would be wedge shaped.  Well, to me anyway.

For some reason, any time I see one of their SS amps built on that style, I expect to find loose filter caps.

[bry melvin]

This is very close to what we Air Force types used to call "brogan maintenance" A boot will work too. :lmao: :lmao:

[J M Fahey]

Hi Enzo.
Now that you mention it, yes, modern SS Fenders very often have a loose filter capacitor, and yes, they love those aluminum wedges; while Valvestates sometimes have similar wedges made out of cheap (in the worst meaning) pre-phosphatised sheet iron.Ugh !!
Yet I had never related both facts.
In fact I often blame false economy, just wave soldering everything instead of hand soldering the very few heavy parts.

[phatt]

The solder issue is only the tip of the iceberg. :trouble

Quite frankly a lot of these amps will become land fill in a few years as the general build quality is just pathetic. (As long as they look pretty they will sell)

Fixed a Marshall JTM 60 a while back and the boards where so badly buckled from heat stress that it had also broken/snapped the plastic efx jacks on the back panel.
The ribbon connectors where breaking just by touching them (the cheapest plastic on the planet next to Valves :duh)

A redneF Performer 1000 SS rig,, again shocking layout/design, really bad heat stress on the board. Laying HOT components flat on a circuitboard might look neat and tidy but just plain stupid if you want to build reliable equipment.
I would never waste time on fender gear now, I've not yet found a new SS model I like.

As to good well built gear,,, I worked on a Teck21 Trademark 60 a while back and although I hate surface mounted double sided boards the general build quality and layout was very good.

I'm only into it for the hobby thing so I don't see that much gear but,,, I've seen enough.

Enough from me,,, end of Rant :grr
Phil

[stratorius]

Guys you call this Fender 185 a modern solid state amp.... I wonder where solid state modernity starts for you... what I do know is that this thing is almost 30 years old, and not nearly as 'modern' as all the hybrid horror these days... or the transtube etc BS before that... yes these Fenders have a reputation for bad soldering, and eh... for great sound as well which is what really matters, and a lot of older Fender amps appear to be great survivors in the end, only hope that mine will be one as well

thanks all for your input btw

[phatt]

LOL, At my age anything after 1980 is modern  :lmao:
If you love the sound it makes then great but if the amp you speak of is the one pictured above it has not had a hard life in it's 30 Years.

Any serious on the road live gigs will soon show up all the design flaws in amps of this era.
I purchased a brand new *Montreau* model,, years back and it broke within a couple of months. IME these things are very flimsy inside.
So any serious on the road work they just stuff up.

Obviously you love the Amp and I Hope you get it sorted out so you can enjoy playing it. :tu:
Phil.

[Enzo]

I rarely think of age.  Guys all the time ask when an amp was made.  I think, how should I know?  I don't care.   I leave that to the fans.   I don't mean it unkindly, but I call the folks who can tell you every model and year amp fans.  The guys who can quote chapter and verse, "Oh the master volume didn't come out until 1974, and then the pull switch was added in 1977, and..." or whatever.  I call them fans, like the guys who like to rattle off baseball stats.  More power to them and bless their hearts.

Jukebox people are the same way.  They want to tell me what year it was made, but I want to know what model it is.

But to me, I think in terms of how things are made.   Old Fender is galvanized heavy steel chassis, Modern Fender is formed sheet steel like these wedgies.  Old Fender is eyelet boards and caps up under a cover.  Modern Fender is large pc board.  I don;t care how old it is within those categories.