Parts to be replaced on ANY wurlitzer 200a amp

[Abraham]

Im plaining a major restoration of my 40 years old 200A amp, so Im here to ask you guys, wich parts are prone to failure due to their age, and which ones are mandatory to get replaced on every amp to be properly serviced?

Thanks in advance!

[Max Brink]

Are you dissatisfied with the tone or is it misbehaving in a particular way that you are trying to address? Because just gutting out a lot of parts and firing from the waist is going to change the tone. In my book Gutting/replacing parts doesn't really count as restoring if it's not done surgically but there are plenty of people that probably disagree with my philosophy... You could spend hours upon hours guessing and checking various capacitors or changing the bias points within the amplifier but in the end it's going to be a lot of work for a minor improvement in the amplifier. In the end there's only so far that you can dial in the 200 and 200A amplifiers...

If you're really looking for good advice on how to get great tone from a Wurlitzer amplifier I would give Tim Warneck a call at Retro Linear and ask him about his EP200 amplifier. His amp is going to give you everything you love about Wurlitzer tone and much more. I'm sure he would be more than happy to help you out!


...And the most direct answer to your question would be that capacitors are often the most prone to changing over decades of use. Transistors second place for being prone to failure but have a larger expected lifespan than capacitors. Specific to the 200A another common problem is the connecting wires between the amplifiers not making a solid connection.

[pianotuner steveo]

Electrolytic capacitors dry out and should be changed in old amplifiers, but if you are not experienced  at this, it may be more trouble than it is worth.

[Abraham]

Thank you guys!

I like the tone, its just some kind of distortion coming out of the amp -I mean its not present on line out, but just headphones & speakers- besides some level of noise I think I should somewhat improve. Such an instrument just deserves the best. I didn't mean to do this myself, I'm taking this to someone experienced in electronics -finding someone experienced in wurlies is just impossible in my area- and he insist those parts meet their tolerances and should not be exchanged just because of age. He will do whatever I ask him anyway... I just want to know what should I ask him to change and where to get those parts from

Sound I get from the PhoneOut/Speakers: https://dl.dropboxusercontent.com/u/5156835/phoneout_chords.mp3

As I'm getting clean output from the line out, I guess the preamp has to be OK, isn't it?

[pianotuner steveo]

That sound is typical for an old Wurlitzer amp. It's not just yours. I'm not saying it's great sound, but it is what a lot of them sound like. I really doubt it has anything to do with your preamp.

Again, IMO, electrolytic caps would be the first thing to replace, I have seen them smoke and nearly catch on fire from amps made in the '50's and '60's

[Abraham]

Do you mean its supossed to sound like this? If I replace the electrolytics may I achieve some improvement?

[pianotuner steveo]

They will possibly improve the sound, but will definitely make it safer. I do not mean to imply that it's supposed to sound like that, but that is what they do sound like after 30+ years. The caps are a very likely source of the noise. Also, I had one once where the board just needed to be resoldered, and that solved noise issues.

There also could be some poor ground connections.

[Abraham]

Ok, so I've checked vv sell those amp refurb kits at $106, it doesn't seem quite cheap but the whole deal breaker is the shipping costs, com'on guys $98 for a little lightweight box of mini-parts!! It wouldn't cost $5 to ship...

So I'll have to locate such parts myself locally... A specific list of required parts to be replaced would help, if anyone already done this before

[timpotent]

What about a Warneck replacement amp ?
Isn't inexpensive,  but it's worth every penny ! 

[Abraham]

...which might be my 2nd choice, though shipping is expensive also... Looks like an easy and definitive replacement and there are many good reviews, if I can't fix this amp this may be the way to go. But my first option is fixing the stock amp, I like to keep vintage gear stock whenever its possible

[retro-mike]

We have posted a few times in regard to wurli amp rebuilds- and I'll re-post again
Rebuilding is virtually pointless.. It's understandable that everybody wants to save some coin. BUT the original amps are problematic in any state, original or rebuilt or even re-issued.  The architecture of the amp is the problem,the hiss, ground loop buzz and all the other associated issues wont be resolved by putting new components into the original boards..

Tim's Board (RetroLinear) is a complete redesign which addresses the issues while maintaining proper vibrato, voicing, and E.Q. curve..
Our boards are built using the best components available, each board is hand stuffed,soldered and assembled in the U.S.A. @ RetroLinear, then individually tested. Our Q.C. process is very thorough.

Timpotent, That board pic is an older rev of our 200a board.
our current production 200a boards are blue.


The 200 amp kit also comes with reed bar shields to address any additional grounding noise.


Here are some demos
https://www.youtube.com/watch?v=o7xGq5KkTHg
https://www.youtube.com/watch?v=u-mo0vHV7io