Dynaco Crossover Capacitors

[dynaco_dan]

Hi there

This is the two capacitors that I had used in trial mock-ups of, Microstatic tweeter array and AR-LST, using Dynaco 1 1/2" Seas tweeters.

These are, OEM, Original Equipment Manufacturers, capacitors directly from Dynaco and these are the markings as stamped on their bodies.

Dynaco A-25 OEM

TJ Jensen Capacitors

Electrolytic cross-over capacitor

5 uf

50 WDCV

25 WVAC

-25 - +85 'C

Reversible

EAR - 1 - 051405pr

Made in Denmark

Axial leads

Body colour pale metallic yellow

SYE

Dynaco A-35 OEM

TJ Jensen Capacitors

Electrolytic cross-over capacitor

8 uf

50 WVDC

25 WVAC

-25 - +85 'C

Reversible

EAR - 1 - 051608PR

Made in Denmark

Axial leads

Body colour pale metallic yellow

SYE

[Dchristie]

Hi Vern ,

Just looking for some clarification regarding the caps in the A-35 and A-25 models respectively.

I have seen a couple of threads where it was said that both models used a single 5.0 uf cap and also a couple of references which indicared a 5.0 uf cap for the A-25 and 8.0 uf for the A-35.

Your posting above would support the 8.0 uf cap in the A-35.

Does anyone know definitively what is the cap value in the A-35 speaker ?

I am restoring a pair ( they have been modified with a more recent cap and it is a Solen 8.2 uf) so this would also lead me to believe 8.0 uf is correct for the A-35 but I would sure like to get some confirmation from the Dynaco experts.

Thanks

Dean

[JKent]

Never been inside but this thread says 8: http://www.audiokarma.org/forums/showthread.php?t=222826

Although I've seen comments that the 35 xo was the same as the 25, Greg Dunn says the 35 had a "different crossover for a subtly smoother, wider range, and more articulate sound" http://home.indy.net/~gregdunn/dynaco/components/speakers/

Vern is the Dynaco expert (hence "dynaco_dan") and although he said in one post that the 25 and 35 xo's were identical he later retracted that. We all goof

The evidence all seems to point to 8uF. I'd leave the Solens in place.

Kent

[Dchristie]

Thanks Kent.

The crossover in the A-35s is 1200 hz and for the A-25s it is 1500 hz so a larger cap in the A-35s makes sense. I am pretty sure that the 8.0 uf is correct for the A-35 model. Nothing else is changed between the two models - all resistors and combinations for tweeter adjustments are the same.

[dynaco_dan]

Hi there

I posted the actual original A-25 and A-35 capacitor information on May 17th 2011 which was the start of this topic.

I am holding my original crossover board with the 2 different caps and a switch attached to it.

I had tried using a pot instead of a stepped switch with the resistors.

This was my attempt to be able to switch between A-25 and A-35 crossover frequencies.

Also included was an inline open style fuse holder with a 1 amp glass fast blow fuse.

Maybe someone here can check out the cap model number to see what level of cap this was.

Likely it was a lower level but suitable product.

As far as I can see 5uf and 8uf are not made anymore, but a slight value difference above and below these values is not going to be of a significant audible difference.

I bought these from the local Dynaco warrantee depot here in Vancouver.

There is no reason that Dynaco did not have to sub the caps due to a shortage for a brief period.

This is only my guess as I have never seen or heard of this incident happening.

Sadly there is little information here of Dynaco classic products other than positive magazine reviews, no engineering drawings or such.

They seemed to stay with the same resistor and switch suppliers as well.

Thank you Phil for the Dynamax information.