Capacitor log Mundorf Silver in Oil

Hello SNS

In this long thread you would find out I am running in my Lascala's Duelund CAST and VSF in the tweeter and Duelund VSF in the midrange with the not much talked about but should be Duelund inductors in the woofer.

It was the inductor that shocked me!

Hello Everyone

It has been now over 4 years since the last post. 

We have now moved and live in Cape Breton. So the room is not exactly the same room as the past. Actually a very different room! My tests have always been done not from memory though. Always run 3 amps of similar style and brand.

Speaker tests were one cap at a time leaving the other speaker as it was.

I do have updates coming. I had one amp completely redone (Fisher 500C) with Duelund CAST tinned copper. (updates on that coming) 

I have a set of Duelund IC's now to evaluate.

I can say when I had Chris at Parts Connexion install all the CAST caps I wondered what I had done. Very stiff, very mechanical. I was not mad just more disappointed.

All of my past tests were often one cap at a time and test. Not replace the entire amp! It is very disorientating to replace all the caps at once. Going all the way to CAST caps. 

One of the other amps has been rebuilt with all Jupiter Copper Foil caps. Another favourite of mine. During the Pandemic I could only get what was in stock. Limited of everything.

I waited until March of this year to get the amps fixed because we did live fairly close to Parts Connexion but would not be after the move. 

So that being the reason to do it all at one time. (move)

I had issues for sure with Jensen Copper Paper tube caps. At least 3 of them had catastrophic failures. Two of the times damage was done to the amp. The third I caught in time. They would just fail after many years and for no reason. Right out of the blue!

The scary part was not just the cost of the cap! The cost of losing cap but the damage and the hours to repair in shop!

I had posted on this after failure 2 I think. After failure 3 all of the Jensen caps came out. I would never sell them even as used because it is just too risky for anyone.

My repair guy from my home town was very good guy as I have mentioned years ago. To him take out ALL those exotic caps and problems go away. Yes, in a way...

He also suggested maybe that was the cost of having caps like this if I wanted the sound. In reality I wanted the sound but not the risk of fire or expensive damage.

I have had Jupiter leads fall off. Duelund leak oil and Ampohm fail as well. None caused damage though except Jensen. Sadly. Nothing against the caps but one should be concerned. Maybe mine were bad batch but they were from different times.

I was checking the views of this thread. I knew it was a lot years ago but 10,853,109 is more than I think many would expect and for sure more than I expected!

When I started the blog I said well I could not find unbiased non advertising driven info on capacitors. How good were they? Compared to other things what was the value? So I just started posting my tests. I also wanted other people to post later on as well to confirm it. In the beginning I did not know if anyone would see it.

Hi Charles

It is nice to talk to you after all this time! 

Glad to hear your Duelund CAST have worked out long term! My CAST in the speakers or my RS or VSF have never been a problem. 

Only in the amplifier itself which is of course much higher voltage and heat. (being a tube amp) 

Now the caps I used of course were all rated for that voltage. By far the most problems were with Jensen caps and all of the damage was with those caps.

I would have to go count my cap total but it is well over 30. Maybe 40+ :) It adds up!

When I am finished breaking the CAST Tinned Copper in it is going to be about the LONG break in! 

I started to hear some improvement at around 100 hours and that got me thinking and I went online and saw a post on here from Grannyring talking about the 400 hour break in. I knew it with CAST (more than RS or VSF) but never changed a whole amp at once. That was HUGE change. I would often change one or maybe two at a time. Not the whole amp!

How long did you find the break in to be in speakers?

What would it mean to me if I read this thread and owned Jensen Copper paper tube? Well if I had one fail I would likely pull them all. It could be a bad batch? Or maybe they are all bad in time?

roxy54

Did they say why? 

I did not get any "help" with the Jensen either but some were over 10+ years old and Jensen is out of business.

How long should they last? Then what? Fix cap? Pay for damage to amp? Well the 1965 ones in the amp were still "good" in the sense they were not shorted out. The 2008-2012 or whatever the Jensen were, were shot...

A bit of trial and tribulations this whole thing was plus stress. Plus stress on relationship with tech.

My tech guy who I do like as a person, almost wanted to punish me. He does not like the whole industry at all! I get it. From his point of view he could never have a failure rate on his repairs as high as I did or he would be broke. Reputation would be shot. He would say this is not 1935 with old paper in oil caps. Not entirely wrong.

I have had amps repaired with cheap poly caps and could not stand it. :/

Yet most of us do like the "sound" of these modern vintage caps. 

Thank goodness my damage was limited to one brand. That brand was often put into second amp as the caps were not cheap. After 3rd failure they were just all pulled completely. 

A tube amp can be a tough environment.

The only thing was the Jensen was much lighter and maybe drier?

The failed Duelund VSF was 10+ years old and had a lot of hours on it in a tight space. The Jensen Paper Copper made me much more upset as they did not have tons of hours and were in the much roomier 500c. The X101st is very tight quarters and the reason for VSF in this location. 

What is reasonable? Tough question. It is not the cap price it is the damage done and the hours for repair.

Sound evaluation of both amps coming soon. 

That is great to hear SNS!

Was it the wax paper inductors? If it was similar to the wax paper Duelund's I have.

I always have wished I got CAST inductors as I "suspect" a huge improvement in noise reduction and dynamics and the WPIO was already huge.

It is more a function of cost and speaker companies saving money and they all do on the crossovers. (most all anyway)

I was promising an update on the Duelund Tinned Copper. Just before Christmas my wife's mother passed away and then my father just after so my brain was distracted.

Then a pop developed in the 500c when turning on.

So I put the EL84 back in and then heavy distortion in left channel.

Yes frustration was a little high!

On the way back to my dad's celebration of life we brought both amps in to Parts Connexion to find out what was wrong?

The EL84 had a failed Duelund VSF coupling cap. This took out two left channel tubes.

The 500c was suffering from low voltage and whole new power supply was installed. 

CE Manufacturing and Mundorf are the power supply caps. 

The old worn out power supply caps were acting like a resistor. I would have replaced years ago but there really was nothing. 

CE has bought vintage Mallory components and is making caps again.

So my Fisher 500c is not stuffed cans but really a replacement of original power supply.

I know some would say again all new power supply caps better. One of the tests years ago was to see if a Jensen power supply cap was better than vintage. After a month or so the Jensen come out and vintage back in. Jensen sounded dry. I have no idea why but was glad when vintage went back in.