Capacitors...debunking the shame of vintage crossovers

[hifitown]

So let's get back to crossovers. Should I just leave the caps in the N1500as of my 604Es alone or what? I'm concerned that they perform as intended and not interested in tweaking, not yet anyway. Opinions are solicited.

Yes I suspect your crossover is still performing as intended. In any case running it stock is not going to endanger the speaker under normal use that's probably a given. Can a better crossover be made for the 604E? Yeah probably. I wouldn't bother.
The cap inside is the least of your worries (Altec often used gnarly old bipolar 'lytics, that sound, for some reason pretty good). It's more of the (over or under, depending on your perspective) design of the crossover that might be holding it back.
For the 604, I think the cabinet is the bigger concern.

 

[hifitown]

It seems like most of Captain Beefhearts numerous and voluminous posts on this forum can be boiled down to a single sentence: Electrolytic caps are just as good as plastic film caps, because my measurments say so. This puts me in mind of a famous saying by Daniel von Recklingshausen, one of the foremost audio engineers of the 1950s: If it measures good and sounds bad - it is bad. If it sound good and measures bad - you´ve measured the wrong thing. This from a guy who used his ears and kept an open mind. Even Will Shakespeare had this covered 400 years ago. If I may
paraphrase the old bard: There are more things in heaven and earth, Captain Beefheart, than are dreamt of in your EE textbooks. I wish everybody a nice weekend!

Well put, in far fewer words than my blather!

 

[RPMac]

Well put, in far fewer words than my blather!

Could it be as simple as….If it sounds good, it is good?

 

[Boli46]

Could it be as simple as….If it sounds good, it is good?

Exactly!

 

[hifitown]

Could it be as simple as….If it sounds good, it is good?

Absolutely, "If it sounds good, it is good" can be a valid stance, especially for hobbyists. From my dealer/professional perspective— the buying and selling of vintage audio components—it's crucial for me to understand the condition of these components (if possible). This isn't just about ethics; it's also about providing value-added service where possible. I test components (whenever it makes sense, time allowing) to understand their quality and characteristics. If an older version of a component sounds superior, or fits the job better than a newer one, I want to understand why that may be, even if it's based on a mere theory. The older-is-better doctrine, turns out to be a surprisingly safe assumption – – but it's not always true. Plenty of customers find joy with modern components along with the concurrent higher tolerances and improved reliability – – (sometimes). And other times, purchasing modern components from Audio La La Land – – is a very expensive and detrimental pursuit -- the insidiously poor sound of stuff like cheaply made modern tubes or bright caps can eat away at a system. Avoid it, especially if the supply of vintage components is adequate. I for one, feel tubes is invariably one of these categories.

Two decades ago, my father Walt decided to buy our Sencore 103 computerized capacitor tester. I initially questioned the decision since most sellers didn't test old capacitors before listing them on platforms like eBay. But Walt believed in the importance of testing. He felt that certifying the operating condition of an item could enhance its value, assuring buyers of its condition. Over time, I've come to appreciate his wisdom (even if it's free service).
In pursuit of improving the value of occasional vintage tube pairs and quads – – I'm gradually going to be moving to free curve tracing as well.

 

[SONDEKNZ]

My DIY go-to brands...

NON-MAGNETIC RESISTORS:
MILLS Wirewound, 5W-12W for cathodes, GNFB, PSU, etc.
TKD Metal Film, 2W for others

POLYPROPYLENE CAPACITORS:
CORNELL-DUBILIER 940-C series, 600V-3kV, for everything

I like the way all these bits sound and have used them in loads of different applications. Happy camper.

I don't feel the need to spend more on the really esoteric, costly stuff.

YMMV...

 

[EarlK]

I'm quite interested in trying out this 940C series of CDE capacitors mostly because of the dual dielectrics used within the 850V and up examples .



Here in Canada these CDE's are fairly affordable >> though by no means "Solen cheap" ( as one example of the lower end of pricing).

The CDE 940-C, 3.3uF 600V costs around $15.00 ( Cdn ) from Mouser >> dropping to $13.5x with a quantity of 10 ordered.
- Free Shipping kicks in at $100.00 ( Cdn ) on most stuff ( so they say ).

For comparison; a Solen 3.3uF 630V ( from Parts Connexion ) is currently about $5.50 ( Cdn ).

I'd like to hear how the inclusion of that much polyester ( Mylar ) effects the signature HF aggressiveness of a Polypropylene cap.
- I do have experience with how the two dielectrics sound///blend when I combine them as 2 paralleled capacitors .

I usually limit my percentage of Mylar to PP to about 20% of the total capacitance.
- The 940C looks like that content percentage is 33% ( hence the trigger for my curiosity ).

 

[SONDEKNZ]

I'm quite interested in trying out this 940C series of CDE capacitors mostly because of the dual dielectrics used within the 850V and up examples .

View attachment 67081

Here in Canada these CDE's are fairly affordable >> though by no means "Solen cheap" ( as one example of the lower end of pricing).

The CDE 940-C, 3.3uF 600V costs around $15.00 ( Cdn ) from Mouser >> dropping to $13.5x with a quantity of 10 ordered.
- Free Shipping kicks in at $100.00 ( Cdn ) on most stuff ( so they say ).

For comparison; a Solen 3.3uF 630V ( from Parts Connexion ) is currently about $5.50 ( Cdn ).

I'd like to hear how the inclusion of that much polyester ( Mylar ) effects the signature HF aggressiveness of a Polypropylene cap.
- I do have experience with how the two dielectrics sound///blend when I combine them as 2 paralleled capacitors .

I usually limit my percentage of Mylar to PP to about 20% of the total capacitance.
- The 940C looks like that content percentage is 33% ( hence the trigger for my curiosity ).

I have to say that I've never heard any "aggressiveness" in CDE 940-C pp caps.

I have used them extensively in different projects and they always please - and are a big improvement on the ubiquitous SOLENs - without costing moonbeams.

The CDE 940-C .01uF / 3kV caps in particular are a great value IMHO and with their high power handling, can suit a wide range of applications.

What I have heard as "aggressiveness" is highly magnetic resistors. This was particularly true of the sandcast cathode resistors I swapped-out for non-magnetic MILLS MRA12. Big difference!

Just my 10-cents worth.

 

[krca50]

Vishay MKP 1839 axial is my choce for coupling and MKP 1840 in radial package, also.

Wima FKP4 looks good - the datasheet compares them with MKP10 - favourably for FKP4. Got some 1uF/630Vdc and will use them in the next build which will be over by the November. These are film/foil types, Mouser has them. They have lower values also.