Dynacord echocord super tube tape delay

[TubeGeek]

Hi guys, it has been a while since I have posted here.  Hope all is well.


I have a Dynacord echocord tape delay on the bench for sorting out.  I have replaced all the electrolytics in the circuit except for two.


One is a multicap can that is going to be impossible to find an exact replacement that will fit, I can figure it out though.  I think I can make a F&T 32/32 cap work here.


My question is on the other cap I found.  It is 48uF 42V...but it is huge.  It connects to the motor through some switches.  Can I simply replace this cap with a F&T 47uF 500V cap?  Is the 50Hz rating anything I need to pay attention to?

[TubeGeek]

Next question...should I be replacing the selenium rectifier?  I am leaning toward leaving it alone but want to make sure I am not missing something important.

[SILVERGUN]

Next question...should I be replacing the selenium rectifier?  I am leaning toward leaving it alone but want to make sure I am not missing something important.

Good to see you around TG.
Here's a little write up about why you should.

[jjasilli]

Ditto.  And I would replace all the components in the PS.  You could replace the cap with a 50v cap. 

[sluckey]

My question is on the other cap I found.  It is 48uF 42V...but it is huge.  It connects to the motor through some switches.  Can I simply replace this cap with a F&T 47uF 500V cap?  Is the 50Hz rating anything I need to pay attention to?

If the motor runs properly, leave it be.

If the rectifier works, leave it be.

[shooter]

leave it be

is that from the Beatles 

+1
there's an old adage from my world that says if it ain't broke DON'T fix it.  especially vintage, looks like well kept

[PRR]

> It is 48uF 42V...but it is huge.

Motor-cap. Typically built better (thus bigger) than radio-caps. As said, if it runs, leave it alone.

If it ever must be replaced you MUST use a cap made for AC motors. Basically air-conditioner supplies, though they are all >>42V (but with modern technology, may be no larger).

[jjasilli]

Here's a film cap that might work:  https://www.mouser.com/ProductDetail/AVX/FFB24D0476K-?qs=n0G5RV3mHfPU6%2fCqThc%2fPw%3d%3d


They're used for el fan motors. 

[TubeGeek]

Thanks for your recommendations.  I took this to the owner and asked him what he would like.  Selenium rectifier is staying in for now.  The motor cap is also staying in.  I think he just wants the machine back so he can play around with it.  It had been to 4 other tech's that declined to work on it.  I guess I was the brave one.


I recommended changing them out but he is the owner so I do what he says. I ave him a print out of the article SG provided just so he knows the concerns.


This thing is pretty cool.  I can get a nice room reverb all the way to a deep hall reverb and all the delay coolness too.


It has six telefunken 12ax7's in it.

[TubeGeek]

Are any of you interested in servicing another one of these? 


I have been contacted by someone in California who wants me to work on theirs but the shipping to Canada is prohibitive.  Just doesn't make sense to pay all the shipping to Canada and back to California.  That'd cost nearly as much as my service work!